FR3143040A1 - Method for prognosis and/or diagnosis of loss of hair density - Google Patents

Abstract

Method for prognosis and/or diagnosis of loss of hair density The present invention relates to a method for prognosis and/or diagnosis of loss of hair density, comprising measuring the expression level of at least one gene chosen from 63 specific genes, in a sample of a subject's scalp. The present invention also relates to a method of cosmetic treatment of the scalp, a method of identifying compounds that prevent hair loss and/or promote hair growth and/or promote an increase in hair thickness. Finally, the present invention relates to a kit and its use for the identification of a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness. Figure for the abstract: none

Description

Method for prognosis and/or diagnosis of loss of hair density

The present invention relates to a method for prognosis and/or diagnosis of loss of hair density. The present invention also relates to a method of cosmetic treatment of the scalp, a method of identifying compounds that prevent hair loss and/or promote hair growth and/or promote an increase in hair thickness. Finally, the present invention relates to a kit and its use for the identification of a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness.

In humans, hair growth is cyclical and has three successive phases: the anagen phase, the catagen phase and the telogen phase. Each hair follicle is therefore constantly renewed, cyclically and independently of adjacent follicles. The anagen phase or growth phase, during which hair lengthens, lasts several years. The catagen phase which follows the anagen phase is very short and lasts only a few weeks. During this phase, the hair undergoes involution, the follicle atrophies and its dermal implantation appears higher and higher. The telogen phase, which lasts a few months, corresponds to a period of rest for the follicle where the hair eventually falls out. After this resting phase, a new follicle is regenerated on site, and a new cycle begins again.

At any given moment, not all hair is in the same phase at the same time. Thus, of the approximately 150,000 hairs in a head of hair, only approximately 10% of them are at rest and will therefore be replaced in a few months according to a biological clock specific to each hair.

Natural hair loss or loss can be estimated, on average, at a few hundred hairs per day for a normal physiological state. However, it happens that the hair cycle can become disrupted and hair loss accelerates and leads to temporary or permanent hair loss called alopecia. Different causes can cause alopecia.

It may be a massive loss or changes in hair called telogen effluvium , during pregnancy, during states of malnutrition or dietary imbalance, or even during states of asthenia, hormonal dysfunction or hormonal changes as may be the case during menopause. It may also involve hair loss or changes in relation to seasonal phenomena. In certain dermatoses of the scalp with inflammatory characteristics, such as psoriasis or seborrheic dermatitis, hair loss can be greatly accentuated or lead to strongly disrupted follicle cycles.

It can also be alopecia which is essentially due to a disruption of hair renewal which initially leads to an acceleration of the frequency of cycles at the expense of the quality of the hair and then its quantity. Successive growth cycles result in increasingly fine and shorter hair, gradually transforming into non-pigmented down. Areas are preferentially affected, notably the temporal or frontal gulfs in men, and in women, there is diffuse alopecia of the vertex. This concerns more particularly androgenic alopecia. In a significant number of cases, premature hair loss occurs in genetically predisposed subjects; this is called androgenetic alopecia; This form of alopecia more preferably affects men. It is also known that certain factors such as hormonal imbalance, physiological stress or malnutrition can accentuate the phenomenon.

There is therefore a need to have new biomarkers allowing the characterization of a loss of hair density, in particular linked to hair loss and/or thinning hair.

There is also a need for a process for screening active ingredients that prevent hair loss and/or promote hair growth and/or promote an increase in hair thickness.

The present invention aims to meet this need.

The present invention results from the unexpected discovery of the inventors that a certain number of specific genes, identified below, are involved in the loss of hair density, in particular linked to hair loss and/or thinning of hair.

1. mesurer le niveau d’expression d’au moins un gène choisi parmi les 63 gènes suivants, dans un échantillon de cuir chevelu dudit sujet :

The present invention thus relates to a method for prognosis and/or diagnosis of a loss of hair density, in particular linked to hair loss and/or thinning of hair, in a subject, said method comprising the following step :

1. measure the level of expression of at least one gene chosen from the following 63 genes, in a scalp sample of said subject:

CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16- 1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72.

The present invention also relates to a method for prognosis and/or diagnosis of loss of hair density, in particular linked to hair loss and/or thinning of hair, in a subject, said method comprising the steps following:

has. measure the level of expression of at least one gene chosen from the following 63 genes, in a scalp sample of said subject:

CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16- 1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72;

b. deduce from step a) whether the scalp of said subject exhibits a loss of hair density or whether the scalp of said subject is likely to develop a loss of hair density; Then

vs. if the scalp is identified as having a loss of hair density or as being likely to develop a loss of hair density in step b), treat said scalp with a cosmetic composition against loss of hair density.

The present invention also relates to a method for identifying a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness, said method comprising the following steps:

has. bringing into contact at least one candidate compound with a sample of the scalp of a subject, then measuring the level of expression of at least one gene chosen from the following genes, in said sample:

CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN and DPT;

b. compare the expression measured in step a) to the expression of the same gene(s) in a scalp sample not exposed to said compound; And

vs. identify said candidate compound as an anti-hair loss or hair growth promoting compound, or promoting an increase in hair thickness, when a decrease in the expression of the gene(s) in the scalp sample which has been exposed to said candidate compound is detected, relative to the expression of the gene(s) in the scalp sample which has not been exposed to the candidate compound.

The present invention also relates to a method for identifying a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness, said method comprising the following steps:

has. bringing into contact at least one candidate compound with a sample of the scalp of a subject, then measuring the level of expression of at least one gene chosen from the following genes, in said sample:

TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2- 4, KRTAP2-2, KRTAP16-1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72;

b. compare the expression measured in step a) to the expression of the same gene(s) in a scalp sample not exposed to said compound; And

vs. identify said candidate compound as an anti-hair loss or hair growth promoting compound, or promoting an increase in hair thickness, when an increase in the expression of the gene(s) in the scalp sample which has been exposed to said candidate compound is detected, relative to the expression of the gene(s) in the scalp sample which has not been exposed to the candidate compound.

The present invention also relates to a kit comprising:

has. means for measuring, in a scalp sample, the level of expression of at least one gene chosen from the following 63 genes, in a scalp sample of said subject:

CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16- 1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72, and

b. an instruction leaflet.

The present invention also relates to the use of a kit according to the invention for the identification of a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness.

The present invention also relates to the use of a kit according to the invention for the prognosis and/or diagnosis of loss of hair density, in particular linked to hair loss and/or thinning of hair, in a subject.

All methods described in the present invention are in vitro methods.

Detailed description of the invention

Met method of prognosis and/or diagnosis

The present invention thus relates to a method for prognosis and/or diagnosis of a loss of hair density, in particular linked to hair loss and/or thinning of hair, in a subject, said method comprising the following step :

has. measure the level of expression of at least one gene chosen from the following 63 genes, in a scalp sample of said subject:

CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16- 1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72.

By “hair density” of a scalp, we mean the number of hairs per square centimeter (cm²) of this scalp. Average hair density is generally greater than 220 hairs/cm². Low hair density is generally less than or equal to 200 hairs/cm², preferably less than or equal to 190 hairs/cm², preferably less than or equal to 185 hairs/cm².

The method for prognosis and/or diagnosis of loss of hair density, in particular linked to hair loss and/or thinning of hair, according to the invention, comprises a step a) of measuring the level of expression of at least one gene chosen from the following 63 genes, in a scalp sample of said subject: CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2 , IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5 -7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12 , KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16-1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10 -10, KRT4, KRT32, KRT39 and KRT72.

Preferably, step a) comprises measuring the expression levels of at least 2 genes, preferably at least 3 genes, preferably at least 5 genes, preferably at least 10 genes, preferably at least 15 genes , preferably at least 20 genes, preferably at least 30 genes, preferably all genes, chosen from the following 63 genes, in a scalp sample of said subject: CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9- 6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16-1, KRTAP10-9, KRTAP10-8, KRTAP10- 7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72.

CCL23 is the gene encoding the chemokine “Chemokine (C-C motif) ligand 23”. The human gene has accession number ID 6368 in the NCBI bank.

CD300C is the gene encoding CMRF35-like molecule 6 (CLM-6). The human gene has accession number ID 10871 in the NCBI bank.

CCL8 is the gene encoding the chemokine “C-C motif chemokine 8”. The human gene has accession number ID 6355 in the NCBI bank.

C7 is the gene encoding the complement component C7. The human gene has accession number ID 730 in the NCBI bank.

FCN1 is the gene coding for ficolin 1 (in English “ficolin-1”). The human gene has accession number ID 2219 in the NCBI bank.

FCER1G is the gene encoding the gamma subunit of the high affinity immunoglobulin epsilon receptor subunit gamma. The human gene has accession number ID 2207 in the NCBI bank.

CCL24 is the gene encoding the chemokine “C-C chemokine motif 24”. The human gene has accession number ID 6369 in the NCBI bank.

FCGR2A is the gene encoding the low affinity immunoglobulin gamma Fc region receptor II-a receptor II-a. The human gene has accession number ID 2212 in the NCBI bank.

VSIG4 is the gene encoding V-set and immunoglobulin domain-containing protein 4. The human gene has accession number ID 11326 in the NCBI bank.

PPBP is the gene encoding platelet basic protein. The human gene has accession number ID 5473 in the NCBI bank.

CD14 is the gene encoding the monocyte differentiation antigen protein CD14. The human gene has accession number ID 929 in the NCBI bank.

C3AR1 is the gene encoding the anaphyllatoxin chemoattractant receptor C3a. The human gene has accession number ID 719 in the NCBI bank.

IFITM1, IFITM2 or IFITM3 are the respective genes encoding interferon-induced transmembrane protein 1, 2 or 3. Human genes have accession IDs 8519 (IFITM1), 10581 (IFITM2), and 10410 (IFITM3) in NCBI.

SPP1 is the gene encoding sphingosine-1-phosphate phosphatase 1. The human gene has accession number ID 81537 in the NCBI bank.

TIMP4 or TIMP1 are the respective genes encoding metalloproteinase inhibitor 4 or 1. The human genes have accession number ID 7079 or 7076 in the NCBI bank.

PCOLCE is the gene encoding “procollagen C-endopeptidase enhancer-1”. The human gene has accession number ID 5118 in the NCBI bank.

POSTN is the gene encoding periostin. The human gene has accession number ID 10631 in the NCBI bank.

DPT is the gene encoding dermatopontin. The human gene has accession number ID 1805 in the NCBI bank.

TDGF1 is the gene encoding teratocarcinoma-derived growth factor 1. The human gene has accession number ID 6997 in the NCBI bank.

POU5F1 is the gene encoding POU domain transcription factor 1, class 5. The human gene has accession number ID 5460 in the NCBI bank.

RUNX2 is the gene encoding Runt-related transcription factor 2. The human gene has accession number ID 860 in the NCBI bank.

LIN28A is the gene encoding the protein lin-28 homolog A. The human gene has accession number ID 79727 in the NCBI bank.

ANGPTL3, ANGPTL4 or ANGPTL7 are the respective genes encoding angiopoietin-related protein 3, 4 or 7. Human genes have accession numbers 27329 (ANGPTL3), 51129 (ANGPTL4) and 10218 (ANGPTL7) in NCBI.

KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4- 9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16-1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, and KRTAP10-10, are all keratin-associated proteins. In NCBI, human genes have accession ID numbers 81870 (KRTAP9-9), 100507608 (KRTAP9-6), 337878 (KRTAP7-1), 387266 (KRTAP5-9), 57830 (KRTAP5-8), 440050 ( KRTAP5-7), 439915 (KRTAP5-5), 387267 (KRTAP5-4), 387266 (KRTAP5-3), 440021 (KRTAP5-2), 440051 (KRTAP5-11), 387273 (KRTAP5-10), 100132386 (KRTAP4 -9), 81871 (KRTAP4-6), 85289 (KRTAP4-5), 84616 (KRTAP4-4), 85291 (KRTAP4-2), 83755 (KRTAP4-12), 653240 (KRTAP4-11), 85285 (KRTAP4- 1), 83897 (KRTAP3-2), 85294 (KRTAP2-4), 728279 (KRTAP2-2), 100505753 (KRTAP16-1), 386676 (KRTAP10-9), 386681 (KRTAP10-8), 386675 (KRTAP10-7 ), 386682 (KRTAP10-3), 386679 (KRTAP10-2), 386678 (KRTAP10-11) and 353333 (KRTAP10-10).

KRT4, KRT32, KRT39 and KRT72 are also keratin proteins. In NCBI, human genes have accession ID numbers 3851 (KRT4), 3882 (KRT32), 390792 (KRT39), and 140807 (KRT72).

The genes according to the invention are typically involved in inflammation and/or immunity, and/or in the differentiation of keratinocytes. In particular, they are involved in inflammation, in the extracellular matrix, in the formation or development of stem cells, and/or in hair keratinization.

By “expression level” of a gene, we mean the quantity of mRNA produced, or the quantity of protein produced, by the expression of this gene. This quantity can for example be expressed as such, in the form of concentration, or ratio.

The expression level of each gene can be measured by any appropriate technique, known from the prior art. To measure mRNA expression, RNAs can be extracted by any RNA extraction method from the skin such as the scalp, for example by the method described in the Materials and Methods paragraph of the example below, then can be processed for specific mRNA quantification by any mRNA quantification method, for example quantitative PCR. To measure protein expression, proteins can be extracted using a buffer suitable for skin protein extraction, for example RIPA buffer or urea buffer, and then processed. by any specific protein evaluation method, for example Western blot or ELISA.

The subject's scalp sample used in the prognosis and/or diagnosis method according to the invention is a sample taken from the subject's scalp, in particular from the vertex.

By “subject” here we mean a human being, preferably aged 20 to 80 years, preferably aged 50 to 75 years, even better aged 65 to 75 years.

In a particular embodiment, the prognosis and/or diagnosis method according to the invention further comprises the steps consisting of:

b. deduce from step a) whether the scalp of said subject exhibits a loss of hair density or whether the scalp of said subject is likely to develop a loss of hair density; And

vs. if the scalp is identified as having a loss of hair density or as being likely to develop a loss of hair density in step b), treat said scalp with a cosmetic composition against loss of hair density.

By “likely to develop a loss of hair density”, we mean a subject who has the beginnings of hair loss; we also mean a subject having a scalp without symptoms such as loss of hair density.

In a particular embodiment, the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the expression level of the gene(s) measured in step (a) in the subject's scalp sample is modulated, in particular significantly modulated, compared to a control.

In a particular embodiment, the control is a reference value.

In a particular embodiment, the reference value is determined by the average value of the expression level of a gene, measured in a determined population, for example a population in a determined age group, and/or having a defined scalp type.

Preferably, the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the level of expression of the gene(s) measured in step (a) in the subject's scalp sample is superior, in particular significantly superior, to a control, said gene(s) being chosen from CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN and DPT. Preferably, for each gene, the control is a reference value determined by the average value of the expression level of the gene, measured in a determined population, for example a population aged 50 to 75 years, and/or having a density average capillary.

Preferably, the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the level of expression of the gene(s) measured in step (a) in the subject's scalp sample is at least 1.2 times, preferably at least 1.25 times, greater than a control, said gene(s) being chosen from CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN and DPT.

Preferably, the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the level of expression of the gene(s) measured in step (a) in the subject's scalp sample is lower, in particular significantly lower, than a control, said gene(s) being chosen from TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16-1, KRTAP10- 9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72. Preferably, for each gene, the control is a reference value determined by the average value of the expression level of the gene, measured in a determined population, for example a population aged 50 to 75 years, and/or having a density average capillary.

Preferably, the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the level of expression of the gene(s) measured in step (a) in the subject's scalp sample is at least 1.2 times, preferably at least 1.25 times, lower than a control, said gene(s) being chosen from TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5- 2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16-1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72.

In a particular embodiment, the reference value is determined by a ROC study (“The ROC curve (receiver operating characteristic) principles and main applications in clinical biology”, H. Delacour et al., Ann Biol Clin 2005; 63 ( 2): 145-54).

By “significantly higher” and “significantly lower” within the meaning of the invention is meant a statistically significant variation in the level of expression of a given gene.

Cosmetic treatment method

The present invention also relates to a method for prognosis and/or diagnosis of loss of hair density, in particular linked to hair loss and/or thinning of hair, in a subject, said method comprising the steps following:

has. measure the level of expression of at least one gene chosen from the following 63 genes, in a scalp sample of said subject:

CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16- 1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72;

b. deduce from step a) whether the scalp of said subject exhibits a loss of hair density or whether the scalp of said subject is likely to develop a loss of hair density; And

vs. if the scalp is identified as having a loss of hair density or as being likely to develop a loss of hair density in step b), treat said scalp with a cosmetic composition against loss of hair density.

The measurement of step a) is preferably carried out as described in the “ Prognostic and/or diagnostic method ” section above.

The scalp sample of said subject and the subject may be as described in the “ Method of Prognosis and/or Diagnosis ” section above.

By “cosmetic composition against loss of hair density”, we mean here any type of cosmetic composition (topical or oral for example) intended to improve hair density and/or reduce hair loss and/or thinning of hair.

The cosmetic composition can be applied by any appropriate route of administration, in particular topically or orally. Preferably, the cosmetic composition is not rinsed. It can be presented for example in the form of lotion, hair mask or treatment or conditioner cream.

Cosmetic compositions allowing the increase in hair density and/or the reduction of hair loss and/or the thinning of hair, may comprise at least one anti-hair loss active ingredient such as minoxidil.

In a particular embodiment, the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the expression level of the gene(s) measured in step (a) in the subject's scalp sample is superior, in particular significantly superior, to a control, said gene(s) being chosen from CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN and DPT.

Preferably, the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the level of expression of the gene(s) measured in step (a) in the subject's scalp sample is lower, in particular significantly lower, than a control, said gene(s) being chosen from TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16-1, KRTAP10- 9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72.

Method for identifying a compound anti-hair loss and/or promoting hair growth and/or promoting increased hair thickness

The present invention also relates to a method for identifying a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness, said method comprising the following steps:

has. bringing into contact at least one candidate compound with a sample of the scalp of a subject, then measuring the level of expression of at least one gene chosen from the following genes, in said sample:

CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN and DPT;

b. compare the expression measured in step a) to the expression of the same gene(s) in a scalp sample not exposed to said compound; And

vs. identify said candidate compound as an anti-hair loss or hair growth promoting compound, or promoting an increase in hair thickness, when a decrease in the expression of the gene(s) in the scalp sample which has been exposed to said candidate compound is detected, relative to the expression of the gene(s) in the scalp sample which has not been exposed to the candidate compound.

The present invention also relates to a method for identifying a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness, said method comprising the following steps:

has. bringing into contact at least one candidate compound with a sample of the scalp of a subject, then measuring the level of expression of at least one gene chosen from the following genes, in said sample:

TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2- 4, KRTAP2-2, KRTAP16-1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72;

b. compare the expression measured in step a) to the expression of the same gene(s) in a scalp sample not exposed to said compound; And

vs. identify said candidate compound as an anti-hair loss or hair growth promoting compound, or promoting an increase in hair thickness, when an increase in the expression of the gene(s) in the scalp sample which has been exposed to said candidate compound is detected, relative to the expression of the gene(s) in the scalp sample which has not been exposed to the candidate compound.

The identification method of the invention is preferably implemented ex vivo .

According to one embodiment, the scalp sample used in the identification method according to the invention is a sample taken, invasively or non-invasively, from the scalp of a subject having low hair density .

The measurement of step a) is preferably carried out as described in the “ Prognostic and/or diagnostic method ” section above.

In a variant, the invention relates to a method for evaluating the effectiveness of a cosmetic treatment against hair loss and/or reduction in hair thickness in a subject, said method comprising, after a step d application of the cosmetic composition, a step (a) of measuring at least one gene, in a scalp sample of said subject.

Preferably this evaluation method further comprises the steps consisting of:

b. comparing said quantity measured in step a) with a control;

vs. determine whether said cosmetic treatment against hair loss and/or promoting hair growth and/or promoting an increase in hair thickness, is effective in said subject.

The method for evaluating effectiveness is preferably implemented in vitro or ex vivo .

The subject is preferably a human being. The subject is preferably 20 to 80 years old, preferably 40 to 75 years old, preferably 60 to 75 years old.

The scalp sample from said subject may be as described in the “ Method of Prognosis and/or Diagnosis ” section above.

The measurement of step a) is preferably carried out as described in the “ Prognostic and/or diagnostic method ” section above.

In a particular embodiment, the control is the level of expression of the gene in a scalp sample of said subject before the application of said cosmetic treatment.

Preferably, said cosmetic treatment is evaluated as being effective in said subject, if the level of expression of the gene(s) measured in step (a) in the subject's scalp sample is lower, in particular significantly lower than the control, the said gene(s) being chosen from CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1 , IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN and DPT.

Preferably, said cosmetic treatment is evaluated as being effective in said subject, if the level of expression of the gene(s) measured in step (a) in the subject's scalp sample is higher, in particular significantly higher, than the control, the said gene(s) being chosen from TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1 , KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4 -4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16-1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3 , KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72.

Kit

The present invention relates to a kit comprising:

has. means for measuring, in a scalp sample, the level of expression of at least one gene chosen from the following 63 genes, in a scalp sample of said subject:

CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16- 1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72, and

b. an instruction leaflet.

By “means for measuring the level of expression of at least one gene in a scalp sample” is meant a means making it possible to quantify the expression of said gene.

In a particular embodiment of the invention, this means is a microfluidic cartridge comprising at least one antibody specific for one of the proteins expressed by one of the genes. This means can also be a means of measuring the expression of the mRNA expressed by one of the genes.

The invention also relates to the use of a kit according to the invention for the identification of an anti-hair loss compound and/or promoting hair growth and/or promoting an increase in hair thickness.

The present invention also relates to the use of a kit according to the invention for the prognosis and/or diagnosis of loss of hair density, in particular linked to hair loss and/or thinning of hair, in a subject.

The present invention will be described in more detail by the examples below.

Example : Method of diagnosis/prognosis of aged scalp, especially scalp with chronological hair loss and thinning hair

Materials and methods

Clinical samples

A single-center case-control clinical study with blinded clinical evaluations was conducted at the Sabouraud Health Center (Paris, France). All volunteers were informed of the objectives of the study and were included after providing written informed consent and granting their rights to the various analyses. The protocol complied with the Declaration of Helsinki and was approved by the local ethics committee (EudraCT#2014-A01704-43 approved by the Comité de Protection des Personnes Ile de France IV).

All study participants were female volunteers, in good health or without any active unstable pathology (no change in treatment in the 3 months preceding participation in the study), aged 65 to 75 years, phototype cutaneous II or III according to the Fitzpatrick classification, agreeing not to dye their hair for the entire duration of the study and to have colored or dyed their hair for the last time more than 10 days before inclusion. Women taking or having taken anti-hair loss treatment in the past were excluded from the study, as were subjects with severe alopecia (type II or type III according to the Ludwig scale).

Subjects were randomized to one of the study groups based on baseline hair density: high hair density (HD) group for subjects with hair density greater than 220/cm² or group Low Hair Density (LD) for subjects with hair density less than 185/cm².

Scalp images (0.651 cm²) were acquired at the vertex using Fotofinder Medicam immediately after hair cutting and 48 h later. Quality controls carried out during the first weeks of the study showed that the quality of the automated image analysis software (Trichoscan v1.1) was not good in this population which presents a lot of white hair, despite several efforts to enhance contrast using hair dye. It was therefore decided that for inclusion purposes, a manual hair count performed on the reference image would be used to confirm total hair density and assign volunteers to the high hair density (HD) or with low hair density (LD). A more detailed analysis was done using the Tiff counting method (phototrichogram reference) to determine the density of anagen and telogen hair (in hair/cm²). Fine hairs (<40µm in diameter) and terminal hairs were counted separately.

The skin of the volunteers was evaluated by a dermatologist who noted the scalp and skin type (oily/dry), various elements of hair quality (density, volume, thickness, diversity of diameter (from Lacharrière, Deloche and al. 2001), percentage of gray hair, length, curl, presence of split ends of damaged hair), scalp assessments (dandruff, atrophic signs such as cupules or halos, presence of telangiectasias) and the presence and severity of signs of photoaging on the face (elastosis, hyperpigmentation, actinic keratosis, seborrheic keratosis, cherry hemangioma).

The sebum level was assessed using a sebum meter (Courage & Khazaka) on the scalp (vertex) and on the forehead. The areas were then degreased with a cotton pad soaked in ethanol (70°) and the rate of sebum excretion was measured 30 min later on the forehead and 48 hours later on the scalp.

Volunteers also completed a self-assessment questionnaire with questions relating to their hair, scalp and skin type and quality, as well as questions regarding their health and lifestyle (medical history, diet, habits). cosmetics, smoking, history of sun exposure).

RNA sequencing

Scalp biopsies, 2.5 mm in diameter, were collected from the vertex area of each volunteer's scalp and used for gene expression profiling (RNA sequencing). Biopsies were placed in Qiagen tubes containing 1 ml of RNA Later buffer (QIAGEN 76106) and transported to the laboratory where the epidermis was isolated within 24 hours of collection.

RNA isolation

Total RNA was isolated from samples with the RNeasy kit (Qiagen, Germantown, MD). RNA purity and integrity were assessed on the Agilent 2100 Bioanalyzer with the RNA 6000 NanoLabChip Reagent Set (Agilent Technologies, Palo Alto, CA) and the Nanodrop Spectrophotometer (ThermoScientific, Wilmington, DE). All samples had RNA integrity number values >7.

Preparation of bank s and RNA sequencing

Library preparation and RNA sequencing were performed as described in the Illumina TruSeq stranded mRNA User Guide (Illumina inc., San Diego, CA, USA). Briefly, the first step was to purify poly-A-containing mRNA molecules from 1 µg of total RNA using magnetic beads attached to poly-T oligos. After purification, the mRNA was fragmented into small pieces using divalent cations at elevated temperature. The cleaved RNA fragments were copied into first-strand cDNA using reverse transcriptase and random primers. The cDNA fragments were then purified with Agencourt AMPure XP beads (Beckman Coulter, Missisauga, Ontario, Canada) and enriched with 13 cycles of PCR to create the final cDNA library. The quality of cDNA was assessed on the TapeStation 2200 (Agilent technologies, Santa Clara, CA, USA) and the library was quantified using the Qbit 3.0 fluorimeter (ThermoFischer Scientific, Canada). Equimolar amounts of each library were sequenced on a HiSeq 2500 instrument (Illumina Inc., San Diego, CA, USA), for paired-end sequencing of 125 nucleotides.

Bioinformatics analyzes

The quality of raw reads was assessed using FastQC (v0.11.2) and MultiQC (v1.3). Quantification of transcript expression was performed from raw read data (raw counts) using Kallisto (v0.43.1). To generate the normalized signals, the raw count values were transformed into TPM (Transcript per Million) using Kallisto, or FPKM (Fragments Per Kilobase per Million reads aligned) using R scripts (v. 3.4.0). Differential expression analyzes were first calculated using the standard DESeq2 (v1.16.1) package (Love et al., 2014: Love, M.I., Huber, W. and Anders, S. 2014. Moderated estimation of fold change and dispersion for RNA-seq data with DESeq2 and not adjusted).

Results

Selected genes which are modulated in the scalp at low hair density (compared to normal (high) hair density) that can be used for diagnosis c of the scalp

Analysis of differential expressions between scalps with LD and with HD identified 63 relevant genes, which are as follows:

Genes (15) involved in inflammation

Embarrassed Fold changes V al eur p adjusted CCL23 1.37 1.36E-02 CD300C 1.36 1.00E-02 CCL8 1.35 2.01E-02 C7 1.35 1.02E-02 FCN1 1.33 2.54E-02 FCER1G 1.33 1.03E-02 CCL24 1.32 2.87E-02 FCGR2A 1.32 1.46E-02 VSIG4 1.3 1.41E-02 PPBP 1.29 4.24E-02 CD14 1.27 2.11E-02 C3AR1 1.27 3.94E-02 IFITM2 1.27 2.57E-02 IFITM1 1.27 9.24E-03 IFITM3 1.26 1.40E-02

Genoa (6) involved in the extracellular matrix

Embarrassed Fold changes Adjusted p-value SPP1 1.46 9.57E-04 TIMP4 1.43 3.10E-03 TIMP1 1.42 1.67E-03 PCOLCE 1.42 1.06E-03 POSTN 1.30 1.96E-02 DPT 1.28 7.34E-03

Genoa (7 ) involved in the the formation or development of stem cells

Embarrassed Fold changes Adjusted p-value TDGF1 -1.31 3.16E-02 POU5F1 -1.40 2.89E-03 RUNX2 -1.38 3.98E-04 LIN28A -1.29 2.59E-02 ANGPTL7 -1.42 3.69E-03 ANGPTL4 -1.26 4.84E-02 ANGPTL3 -1.29 4.96E-02

Genoa (35) involved in the keratinization of hair

Embarrassed Fold changes Adjusted p-value KRTAP9-9 -1.26 4.32E-02 KRTAP9-6 -1.31 4.06E-02 KRTAP7-1 -1.25 2.24E-02 KRTAP5-9 -1.32 2.35E-02 KRTAP5-8 -1.44 4.19E-03 KRTAP5-7 -1.33 2.44E-02 KRTAP5-5 -1.30 3.95E-02 KRTAP5-4 -1.43 4.19E-03 KRTAP5-3 -1.28 4.84E-02 KRTAP5-2 -1.39 1.13E-02 KRTAP5-11 -1.37 9.49E-03 KRTAP5-10 -1.37 1.07E-02 KRTAP4-9 -1.43 4.71E-03 KRTAP4-6 -1.29 3.98E-02 KRTAP4-5 -1.37 3.61E-03 KRTAP4-4 -1.39 4.04E-03 KRTAP4-2 -1.32 1.20E-02 KRTAP4-12 -1.55 5.00E-04 KRTAP4-11 -1.29 1.86E-02 KRTAP4-1 -1.28 3.79E-02 KRTAP3-2 -1.25 3.80E-02 KRTAP2-4 -1.42 2.83E-03 KRTAP2-2 -1.33 1.90E-02 KRTAP16-1 -1.42 3.69E-03 KRTAP10-9 -1.32 1.04E-02 KRTAP10-8 -1.30 2.97E-02 KRTAP10-7 -1.43 2.83E-03 KRTAP10-3 -1.29 4.11E-02 KRTAP10-2 -1.33 2.15E-02 KRTAP10-11 -1.37 6.62E-03 KRTAP10-10 -1.32 2.02E-02 KRT72 -1.29 4.93E-02 KRT4 -1.30 2.65E-02 KRT39 -1.32 2.31E-02 KRT32 -1.35 1.68E-02

These genes represent scalp markers characteristic of the condition of hair thinning and can be used to diagnose the condition of the scalp with respect to hair thinning (and/or hair loss).

Diagnostic methods

A scalp sample is taken from the subject (plucked hair, scalp biopsy). The diagnosis is based on the evaluation of the expression level of specific markers, either at the mRNA level or at the protein level.

For evaluation at the mRNA level, RNAs are extracted by any skin RNA extraction method, e.g. the method described in the Materials and Methods paragraph above, and then are processed for specific quantification of mRNA by any mRNA quantification method, for example by quantitative PCR. The expression level of the marker of interest is then compared to the expression level of the housekeeping genes.

For assessment at the protein level, proteins are extracted using a buffer suitable for skin protein extraction, e.g. RIPA buffer or urea buffer, and then processed by any method. Specific protein assessment, for example Western blot or ELISA. The expression level of the marker is compared to a reference protein (similar to housekeeping genes).

Claims (12)

Method for prognosis and/or diagnosis of a loss of hair density, in particular linked to hair loss and/or thinning hair, in a subject, said method comprising the following steps:
has. measure the level of expression of at least one gene chosen from the following 63 genes, in a scalp sample of said subject:
CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16- 1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72;
b. deduce from step a) whether the scalp of said subject exhibits a loss of hair density or whether the scalp of said subject is likely to develop a loss of hair density; And
vs. if the scalp is identified as having a loss of hair density or as being likely to develop a loss of hair density in step b), treating said scalp with a cosmetic composition against loss of hair density. Method according to claim 1, wherein the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the expression level of the gene(s) measured at step a) in the subject's scalp sample is superior, in particular significantly superior, to a control, said gene(s) being chosen from CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN and DPT. Method according to claim 1, wherein the scalp of said subject is diagnosed as having a loss of hair density or likely to develop a loss of hair density, when the expression level of the gene(s) measured at step (a) in the subject's scalp sample is lower, in particular significantly lower, than a control, said gene(s) being chosen from TDGF1, POU5F1, RUNX2, LIN28A , ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11 , KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16 -1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72. Method according to claim 2 or 3, in which, for each gene, the control is a reference value determined by the average value of the expression level of the gene, measured in a determined population, for example a population aged 50 to 75 years old, and/or having average hair density. Method according to one of claims 1 to 4, in which the cosmetic composition against loss of hair density comprises at least one anti-hair loss active ingredient such as minoxidil. Method for identifying a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness, said method comprising the following steps:
has. bringing into contact at least one candidate compound with a sample of a subject's scalp, then measuring the level of expression of at least one gene chosen from the following genes, in said sample:
CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN and DPT;
b. compare the expression measured in step a) to the expression of the same gene(s) in a scalp sample not exposed to said compound; And
vs. identify said candidate compound as an anti-hair loss or hair growth promoting compound, or promoting an increase in hair thickness, when a decrease in the expression of the gene(s) in the scalp sample which has been exposed to said candidate compound is detected, relative to the expression of the gene(s) in the scalp sample which has not been exposed to the candidate compound. Method for identifying a compound that prevents hair loss and/or promotes hair growth and/or promotes an increase in hair thickness, said method comprising the following steps:
has. bringing into contact at least one candidate compound with a sample of a subject's scalp, then measuring the level of expression of at least one gene chosen from the following genes, in said sample:
TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2- 4, KRTAP2-2, KRTAP16-1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72;
b. compare the expression measured in step a) to the expression of the same gene(s) in a scalp sample not exposed to said compound; And
vs. identify said candidate compound as an anti-hair loss or hair growth promoting compound, or promoting an increase in hair thickness, when an increase in the expression of the gene(s) in the scalp sample which has been exposed to said candidate compound is detected, relative to the expression of the gene(s) in the scalp sample which has not been exposed to the candidate compound. Method according to one of the preceding claims, in which the level of expression of a gene is either the quantity of mRNA produced, or the quantity of protein produced, by the expression of this gene. Method according to one of the preceding claims, in which the expression level of each gene is measured by quantitative PCR, or Western blot or ELISA. Kit including:
has. means for measuring, in a scalp sample, the level of expression of at least one gene chosen from the following 63 genes:
CCL23, CD300C, CCL8, C7, FCN1, FCER1G, CCL24, FCGR2A, VSIG4, PPBP, CD14, C3AR1, IFITM1, IFITM2, IFITM3, SPP1, TIMP4, TIMP1, PCOLCE, POSTN, DPT, TDGF1, POU5F1, RUNX2, LIN28A, ANGPTL3, ANGPTL4, ANGPTL7, KRTAP9-9, KRTAP9-6, KRTAP7-1, KRTAP5-9, KRTAP5-8, KRTAP5-7, KRTAP5-5, KRTAP5-4, KRTAP5-3, KRTAP5-2, KRTAP5-11, KRTAP5-10, KRTAP4-9, KRTAP4-6, KRTAP4-5, KRTAP4-4, KRTAP4-2, KRTAP4-12, KRTAP4-11, KRTAP4-1, KRTAP3-2, KRTAP2-4, KRTAP2-2, KRTAP16- 1, KRTAP10-9, KRTAP10-8, KRTAP10-7, KRTAP10-3, KRTAP10-2, KRTAP10-11, KRTAP10-10, KRT4, KRT32, KRT39 and KRT72, and
b. an instruction leaflet. Use of a kit according to claim 10 for the identification of an anti-hair loss compound and/or promoting hair growth and/or promoting an increase in hair thickness. Use of a kit according to claim 10 for the prognosis and/or diagnosis of loss of hair density, in particular linked to hair loss and/or thinning of hair, in a subject.