JPWO2012137899A1 - Parasites that suppress the onset of type 2 diabetes - Google Patents

Abstract

An object of the present invention is to develop a new therapeutic agent for diabetes that does not cause the symptoms of hypoglycemia as a side effect. As a result of intensive studies, the inventors of the present invention have shown that, when an infectious helminth egg is orally administered to an animal, type 2 diabetes can be prevented or delayed in the administered organism. First revealed. Based on the results, a pharmaceutical composition for preventing or delaying type 2 diabetes containing infectious helminth eggs and obtained by administering infectious helminth eggs to diabetic non-human model animals A non-human model animal for diabetes research can be provided.

Description

  The present invention relates to providing a pharmaceutical composition for treating diabetes using a parasite. The present invention also relates to providing a model animal for analyzing a mechanism of diabetes, in which a parasite is infected in a diabetes model animal.

  Diabetes is roughly classified into the following 4 types, type 1 diabetes, type 2 diabetes, those caused by genetic abnormalities and other diseases, and gestational diabetes, based on the pathogenesis. The total number of diabetic patients is said to be 8.9 million in Japan and 20.8 million in the United States, and it is said that there are 171 million diabetic patients worldwide. The number of patients, including borderline diabetes (pre-diabetes), is said to be 22.1 million in Japan and 61.8 million in the United States.

  In developed countries, the ratio of type 2 diabetes is particularly high in these diabetes categories, and for example, it is known that 95% of diabetic patients in Japan are patients with type 2 diabetes.

  Type 2 diabetes is a diabetes caused by two causes, namely, insulin secretion decline and sensitivity decline, and is a lifestyle-related disease that develops by combining genetic factors and lifestyle habits. In Europe and the United States, reduced sensitivity (high insulin resistance) shows a stronger effect, but in Japan, it is known that reduced insulin secretion in the pancreas is also an important cause.

  The mechanism by which type 2 diabetes develops has not been fully clarified, but people with genetic constitutions that are genetically prone to diabetes (genetic factors) can lead to lifestyle habits that are prone to diabetes (environmental factors). It is thought to become type 2 diabetes. Genetic causes include KCNQ2 (Yasuda K et al., Nat Genet 2008; 40 (9): 1092-1097; Unoki H et al., Nat Genet 2008; 40 (9): 1098-1102), PPARG, KCNJ11, TCF2L7 (The Welcome Trust Case Control Consortium, Nature 2007; 447: 661-678; Sladek R et al., Nature. 2007, 445 (7130): 881-885; Scot L., Science 2007; 316 (5829) : 1341-1345), and KCNJ15 has been pointed out as a causative gene for lean diabetes mainly due to a decrease in insulin secretion (Okamoto, K et al., Am J. Hum. Genet., 2010, 86:54). On the other hand, obesity is an overwhelming risk factor that is likely to cause diabetes, and smoking and lack of exercise are known.

  Treatment of type 2 diabetes is based on diet therapy and exercise therapy. If blood glucose levels cannot be controlled sufficiently, pharmacotherapy is combined with internal medicine and insulin injection. So far, anti-diabetic drugs with various mechanisms of action have been developed, and insulin secretagogues that have an insulin secretion-promoting action (for example, glibenclamide, gliclaside, glimepiride, etc.) or fast-acting insulin secretagogues (phenylalanine derivatives (glinide series) ), For example, nateglinide, mitiglinide calcium hydrate, repaglinide); α-glucosidase inhibitors (αGI drugs such as acarbose, voglibose, miglitol) used as glucose absorption inhibitors; biguanides (BG) having an insulin resistance-improving action (BG Drugs such as metformin hydrochloride, buformin hydrochloride) or thiazolidines (TZD drugs such as pioglitazone hydrochloride); and dipeptidyl peptidase (DPP) IV inhibitors such as sitagliptin, metformin, analogs Liptin); etc. are known.

  Each therapeutic agent has its own side effects, and it is known that symptoms of hypoglycemia occur as a common side effect of pharmacotherapy. However, there is no known method for avoiding this hypoglycemia symptom other than avoiding it in a groping state by adjusting the dosage.

  Parasites refer to parasites classified as animals. In general, those having a harmful effect on the living organism of the parasitic host are closed up, but many do not cause great harm to the parasitic host. Recently, it has also been suggested that parasites are involved in in vivo physiological responses of parasitic hosts. For example, it has been suggested that some parasites such as tapeworms secrete components that suppress allergic reactions. Also in Europe, a specific parasite preparation, the Trichuris elegans preparation "TSO" (OVAMED GmbH) used for the treatment of Crohn's disease and ulcerative colitis has been developed.

Yasuda K et al., Nat Genet 2008; 40 (9): 1092-1097 Unoki H et al., Nat Genet 2008; 40 (9): 1098-1102 The Welcome Trust Case Control Consortium, Nature 2007; 447: 661-678 Sladek R et al., Nature. 2007, 445 (7130): 881-885 Scot L., Science 2007; 316 (5829): 1341-1345 Okamoto, K et al., Am. J. Hum. Genet., 2010, 86:54

  An object of the present invention is to develop a new therapeutic agent for diabetes that does not cause the symptoms of hypoglycemia as a side effect.

  As a result of intensive studies, the inventors of the present invention have confirmed that, when an infectious helminth egg is administered to an animal individual, type 2 diabetes can be prevented or delayed in the administered individual. First revealed. And based on the result, it was clarified that a pharmaceutical composition for preventing or delaying the onset of type 2 diabetes including an infectious helminth egg could be provided.

  Based on the results obtained in the present invention, it is possible to provide a pharmaceutical composition for preventing or delaying the onset of type 2 diabetes, including infectious helminth eggs.

  It is also possible to produce a non-human animal for diabetes research obtained by administering an infectious helminth egg to a non-human model animal of diabetes to infect the worm. By using such non-human animals infected with helminths, we acquired data to delay / suppress the increase in blood glucose levels of non-human model animals with diabetic infection, and infecting worms by administering helminth eggs The non-diabetic non-human animal model can be established as a non-human animal model for studying diabetes. In addition, by elucidating the action target of worms and the mechanism for delaying / suppressing the increase in blood glucose level, a scheme for new drug development can be constructed. Furthermore, a non-human animal model of diabetes in which helminth eggs are infected by administration of helminth eggs can be used not only for elucidating the pathology of diabetes research but also in the development of diabetes preventive / therapeutic drugs.

1, the ^{WBN / Kob-Lepr fa (fa} / fa) rat is a non-human animal models of diabetes, is a diagram showing a change in blood glucose level and blood insulin level caused by the ages. FIG. 2 is a graph showing changes in blood glucose level and body weight with age in WBN / Kob-Lepr ^fa rats infected with rat worms. 3, the WBN / Kob-Lepr ^fa rats rats pinworm eggs were orally administered a diagram showing a change in the blood sugar level due to ages.

The inventors of the present invention revealed for the first time in the art that, when an infectious helminth egg is administered to an animal individual, type 2 diabetes can be prevented or delayed in the administered individual. More specifically, administration of rat helminth Syphacia muris eggs to WBN / Kob-Lepr ^fa rats, which are type 2 diabetes model animals, increases the blood glucose level as a disease state in type 2 diabetes model animals. Revealed that it can be significantly delayed.

  Therefore, in the first aspect, the present invention can provide a pharmaceutical composition for preventing or delaying the onset of type 2 diabetes, comprising an infectious helminth egg.

  Type 2 diabetes is a lifestyle-related disease that develops in a combination of genetic factors and lifestyle habits, which are caused by decreased insulin secretion and decreased sensitivity. As a characteristic feature of type 2 diabetes, it is known that hypersecretion of insulin occurs at the beginning of the onset, but then β-cells of the pancreas are exhausted and insulin secretion decreases. It is generally known that type 2 diabetes with such a condition is treated by taking a drug having an action of promoting insulin secretion or a drug having an action of improving insulin resistance as a pharmacotherapy. Or injecting insulin at the same time as taking these drugs is also combined. In the present invention, as a treatment method for these type 2 diabetes, further options are added, and it is considered that antidiabetic action is exhibited by a mechanism different from that of drugs or insulin injections used so far. And open up new treatment options.

  As the helminth in the present invention, those that have infectivity to the host but show little pathogenicity to the host can be used.For example, Enterobius vermicularis, Enterobius gregorii, Oxyuris equi, Probstmayria vivipara, Skrjabinema ovis, Passalurus ambiguus Syphacia mesocriceti, Syphacia muris, Syphacia obvelata, Syphacia monatna, Syphacia frederici, Syphacia ohtaorum, Syphacia megaloon, Syphacia vandenbrueli, Syphacia emileromani, Syphacia agrarian, Aspiculuris tetraptera

  When the relationship between the administration of helminth eggs to the host and the onset of diabetes was examined, if the helminth eggs were administered before the onset of diabetes, the onset of diabetes can be significantly delayed. On the other hand, when a helminth egg is administered at a stage after the onset of diabetes but has not yet reached the onset of true diabetes, the effect of delaying the progression of the pathology of diabetes is shown. Therefore, in a preferred embodiment of the present invention, the helminth is administered to the host before the onset of diabetes.

  In nature, for example, when a rat worm Syphacia muris is infected to a rat, it is possible that about 500 worm eggs per rat can be taken orally. Infection is established if taken orally. This figure does not change greatly even in the case of other animals known to be infected by helminths, including humans. Also, worms do not have a significant adverse effect on the physiological state of the host. Judging from such circumstances, the pharmaceutical composition of the present invention can contain at least 100, at least 200, at least 300, or at least 400 worm eggs. In consideration of infection efficiency and the like, the pharmaceutical composition of the present invention may contain at most 800 worm eggs, at most 700, or at most 600 eggs. For example, the number of helminth eggs contained in the pharmaceutical composition of the present invention ranges from 100 to 800, 200 to 700, 300 to 600, or 400 to 550, or 450 to 500, etc. Also good. Preferably, the pharmaceutical composition of the present invention contains 500 worm eggs.

  Helminth eggs become larvae in the intestine and become adults in the large intestine over 7 to 50 days when taken orally by the host animal. Adults emerge from the anus and lay eggs. Infection continues in a cycle in which it is reinfected orally. Helminth eggs can survive even in harsh environments such as drying and low temperatures. Therefore, the worm eggs contained in the pharmaceutical composition of the present invention can be stored in a capsule or the like.

In a second aspect, the present invention provides a non-human animal for analysis of the mechanism of diabetes in which 100-800 helminth eggs are administered to a type 2 diabetes model animal to infect helminths can do. Non-human model animals with type 2 diabetes include Wistar Bonn / Kobori-Lepr ^fa (WBN / Kob-Lepr ^fa ) rats (Japan SLC), Zucker Diabetic Fatty (ZDF) rats (Charles River Japan), Goto-Kakizaki (GK) rat (Japan SLC), Spontaneously Diabetic Torii (SDT) rat (Clea Japan), ob / ob mouse (Japan Charles River), AKITA mouse (Japan SLC) db / db mouse (Charles River Japan) KK mice (CLEA Japan), etc. can be used. For example, when a WBN / Kob-Lepr ^fa rat is used as a non-human model animal of type 2 diabetes, an increase in blood glucose level is observed from 7 weeks of age without treatment.

  By using such non-human animals infected with worms by administering such worm eggs, data obtained by helminth infection delaying / suppressing the increase in blood glucose level of diabetic rats were obtained. These non-human model animals can be used as animals for diabetes research. In addition, by elucidating the action target of worms and the mechanism for delaying / suppressing the increase in blood glucose level, a scheme for new drug development can be constructed. Furthermore, a non-human animal model of diabetes in which helminth eggs are infected by administration of helminth eggs can be used not only for elucidating the pathology of diabetes research but also in the development of diabetes preventive / therapeutic drugs.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the following examples are merely illustrative of the present invention and do not limit the scope of the present invention.

Example 1: Pathology of model animal WBN / Kob-Lepr ^fa rat In this example, the pathological transition of diabetes was examined using a diabetic model animal.

In the present embodiment, as the diabetes model animals, using WBN / Kob-Lepr ^fa rats (Japan SLC) (n = 8), and analyzed the pathology characteristic of the diabetic. Specifically, blood glucose level and blood insulin level were measured. Blood glucose levels are measured using ACUU-CHECK AVIVA (Roche Diagnostics Co., Ltd.), and blood insulin levels are measured using an ultrasensitive rat insulin measurement kit (Morinaga Institute of Science, Inc.). And measured by ELISA. As a comparative control, blood glucose levels and blood insulin levels were measured in wild-type WBN / Kob rats (n = 8), which is the origin for the generation of WBN / Kob-Lepr ^fa rats. The obtained results are shown in FIG.

After 7 weeks of age, the body weight and blood glucose levels of WBN / Kob-Lepr ^fa rats were significantly higher than those of WBN / Kob (wild type) with age (see Fig. 1 (a). Body weight data) Is not shown). In addition, a glucose tolerance test (ivGTT) was conducted to examine changes in blood glucose and blood insulin levels. The blood glucose levels and blood insulin levels in WBN / Kob-Lepr ^fa rats were relatively low compared to the wild type. (See Fig. 1 (b)). Of these, insulin levels were significantly higher at 7-8 weeks of age compared to the wild type, but at 10-11 weeks of age no significant difference was observed between the wild type . From this, although it was in the state of excessive insulin secretion in the early stage of disease (7-8 weeks old), it was expected that β-cell exhaustion occurred as the age progressed, and insulin secretion itself decreased. It was.

These results suggested that diabetes in WBN / Kob-Lepr ^fa rats was due to insulin resistance characteristic of type 2 diabetes.

Example 2: Relationship between Helminth Infection and Pathology of Type 2 Diabetes In this example, for the purpose of clarifying the effect of helminth infection on the pathology in diabetic model animals examined in Example 1 went.

The WBN / Kob-Lepr ^fa rats used in Example 1 were infected by being divided into groups 1 to 3 and raised in the vicinity of rats infected with rat worms (Syphacia muris). The blood glucose level and body weight of these three groups of rats were measured weekly. The infection of rat worms was confirmed by detecting the eggs in the anus using cellophane tape. The obtained results are shown in FIG.

  Rats of group 1 (n = 10) were bred in the vicinity of rats infected with rat worms from the age of 5 weeks, but rat worm infection was confirmed at 14 weeks of age. It became clear that the start of the increase was delayed until the age of 14 weeks. This delayed onset effect roughly corresponds to approximately 7 years in terms of human time. On the other hand, in the second group (infection at 12 weeks of age, n = 6) and the third group (infection at 10 weeks of age, n = 6) in which rat worm infection was slow, The increase in blood glucose level as a disease state could not be stopped (see Fig. 2 (a)).

  On the other hand, when the body weights of the rats of each group were compared, there was no difference in the body weights of the rats of the first group to the third group. It became clear (see Figure 2 (b)). Rat worms (Syphacia muris) are known to be parasites that are highly infectious to rats but show little pathogenicity. From these, the delay in the increase in blood glucose level that occurred in Group 1 was not caused by nutritional restriction based on rat helminth infection, but was caused by rat worm infection based on some other physiological mechanism. It was revealed that this was caused by a decrease in blood glucose level.

Example 3: Transition of blood glucose level in diabetic model rats infected with helminths In this example, the influence of the number of infected helminth eggs on the blood glucose level in diabetic model animals examined in Example 1 was clarified. I went for the purpose.

  When rats are naturally infected with the rat helminth Syphacia muris, it is usually possible to ingest about 500 helminth eggs per rat. Thus, in this example, as an experimental group, 500 rat worms Syphacia muris eggs were administered to 4-week-old rats, and the transition of blood glucose level thereafter was examined (FIG. 3 (a)). . As a control, a negative control group in which no parasite eggs were administered, or a group in which 500 non-infectious helminth eggs were administered to 4-week-old rats is shown in FIG. 3 (b). As a comparative example, FIG. 3 (c) shows a group in which 1000 or 10000 rat cecal eggs were administered to 4-week-old rats.

From this result, in WBN / Kob-Lepr ^fa rats, blood glucose level usually increases as a pathological condition of diabetes from around 6 to 7 weeks of age, but at 4 weeks of age, WBN / In Kob-Lepr ^fa rats, it was only after 11 weeks of age that the number of adult worms detected at necropsy was high, and 8 weeks of age even when the number of adults detected at the time of necropsy was small. Showed that the blood glucose level increased. This means that a significant decrease in blood glucose level was shown by the infection of worms by administration of rat worm eggs.

On the other hand, either WBN / Kob in the negative control group in which no parasite eggs were administered, in which 500 non-infectious helminth eggs were administered to 4-week-old rats, or in which cecal eggs were administered -Lepr ^fa rats also showed an increase in blood glucose level characteristic of the pathology of diabetes from 6 to 7 weeks of age.

  Based on the results obtained in the present invention, it is possible to provide a pharmaceutical composition for preventing or delaying the onset of type 2 diabetes, including infectious helminth eggs.

  Moreover, the animal for diabetes research obtained by administering an infectious helminth egg with respect to a diabetes model animal, and infecting a worm can also be produced. By using such animals infected with helminths, data obtained by worm infection delays / suppresses the increase in blood glucose level of diabetic model animals, and diabetic model animals infected with worms become animals for diabetes research. Can be used as In addition, by elucidating the action target of worms and the mechanism for delaying / suppressing the increase in blood glucose level, a scheme for new drug development can be constructed. Furthermore, a model animal for diabetes infected with helminths can be used not only for elucidating the pathology of diabetes research but also for developing a preventive / therapeutic agent for diabetes.

Claims (4)

  A pharmaceutical composition for preventing or delaying onset of type 2 diabetes, comprising an infectious helminth egg.   2. The pharmaceutical composition according to claim 1, wherein the infectious helminth egg is administered before the onset of diabetes.   The pharmaceutical composition according to claim 1 or 2, comprising 100 to 800 infectious helminth eggs.   A non-human model animal for analysis of the mechanism of diabetes, wherein 100 to 800 helminth eggs were administered to a type 2 diabetic non-human model animal to infect the worm.