Medications for intellectual disability or autism

Abstract

summary A novel therapeutic agent effective for treating intellectual disability or autism has been disclosed. The therapeutic agent for intellectual disability or autism contains at least one active ingredient selected from the group consisting of tipifarnib and lonafarnib. Intellectual disability includes memory impairment, and examples of memory impairment include memory impairment caused by abnormalities in the Tsc1 gene and / or Tsc2 gene and epilepsy-induced memory impairment. A method for treating intellectual disability or autism has also been provided, which comprises administering an effective amount of at least one agent selected from the group consisting of tipifarnib and lonafarnib to a patient with intellectual disability or autism.

Description

[Technical Field]

[0001] The present invention relates to a therapeutic agent for intellectual disability or autism. [Background technology]

[0002] Intellectual disability is a condition in which cognitive ability remains at a low level due to intellectual dysfunction that occurred during the developmental period. There are currently no medications available, and treatment, education, and welfare measures are required. Autism appears by around the age of three and is a behavioral disorder characterized by (1) difficulty forming social relationships with others, (2) delayed language development, and (3) a fixation on specific objects, and is thought to be caused by some kind of dysfunction in the central nervous system.

[0003] Patent Document 1 describes specific azaquinoline derivatives, which are effective in treating a number of disorders including autism and epilepsy.

[0004] On the other hand, tipifarnib and lonafarnib are known to be useful as anticancer agents (e.g., Patent Document 2). However, it is not known at all that these drugs are effective in treating intellectual disability or autism. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2002-508768 [Patent Document 2] Special Publication No. 2003-525255 [Non-patent literature]

[0006] [Non-Patent Document 1] Crino, PB, KL Nathanson, and EP Henske, The tuberous sclerosis complex. N Engl J Med, 2006. 355(13): p. 1345-56 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a novel therapeutic agent that is effective in treating intellectual disability or autism. [Means for solving the problem]

[0008] Because intellectual disability and autism often coexist, it is assumed that there are common pathogenic mechanisms for both conditions. Therefore, we searched for diseases that genetically cause these conditions and focused on tuberous sclerosis (TSC). Tuberous sclerosis (TSC) is a nevus syndrome characterized by multiple hamartomas throughout the body, and is accompanied by central nervous system symptoms such as intractable epilepsy, mental retardation, and autism (Non-Patent Document 1). Since the causative genes for TSC are known to be Tsc1m or Tsc2, knockout mice are thought to serve as a pathological model common to both conditions.

[0009] In the present invention, we have produced a mouse model of tuberous sclerosis complex (TSC) and mice exhibiting intellectual disability or autism-like behavioral abnormalities due to other causes, and first confirmed the behavioral abnormalities. We then demonstrated for the first time that tipifarnib and lonafarnib, which have been studied as anticancer drugs, are highly effective against these intellectual disabilities and autism-like behavioral abnormalities, thereby completing the present invention.

[0010] That is, the present invention provides a therapeutic agent for intellectual disability or autism, which comprises at least one active ingredient selected from the group consisting of tipifarnib and lonafarnib. wherein the intellectual disability is a memory disorder. to provide. [Effects of the Invention]

[0011] The present invention provides, for the first time, a therapeutic agent that is effective in treating intellectual disability or autism. [Brief explanation of the drawings]

[0012] [Figure 1] 1 shows the results of a context-dependent fear discrimination test performed in Example 1 below, demonstrating the effect of the therapeutic agent of the present invention. (a) is a schematic diagram of the context-dependent fear discrimination test, (b) is a diagram showing the results of freezing time measurements, indicating abnormalities in context-dependent fear memory in Tsc2+ / - mice and their recovery by administration of the therapeutic agent of the present invention, and (c) is a diagram showing the results of freezing time measurements, indicating abnormalities in context-dependent fear memory in pentylenetetrazole-administered mice and their recovery by administration of the therapeutic agent of the present invention. [Figure 2] 1 shows the results of a three-chamber experiment demonstrating the effect of the therapeutic agent of the present invention on autism, conducted in Example 1 below. (a) is a schematic diagram of the three-chamber experiment. (b) is a diagram showing the results of measuring the time spent in each chamber, indicating autism-like behavioral abnormalities caused by kainic acid administration and recovery by administration of the therapeutic agent of the present invention. [Figure 3] These figures show the morphological abnormalities observed in dendritic spines of primary cultured hippocampal neurons from Tsc2 mutant mice and the effects of the therapeutic agents of the present invention, as performed in Example 1 below. (a) Two types of therapeutic agents of the present invention (lonafarnib and tipifarnib) were administered to primary cultured hippocampal neurons from wild-type (WT) and Tsc2 mutant (Tsc2+ / −) mice for 3 days, followed by staining with antibodies to GFP and vGlut1 (a marker for excitatory synapses). (b) Measurement of dendrite width in Tsc2+ / − neurons. (c) Measurement of dendrite length in the same mice. (d) Measurement of the number of spine synapses. (e) Measurement of the proportion of spine synapses. [Figure 4] FIG. 1 shows the results of a three-chamber experiment conducted in Example 2 below, demonstrating the therapeutic effect of lonafarnib on mice exhibiting social behavioral disorders (autism). DETAILED DESCRIPTION OF THE INVENTION

[0013] As described above, the therapeutic agent of the present invention comprises tipifarnib (6-[(R)-amino(4-chlorophenyl)(1-methyl-1H-imidazol-5-yl)methyl]-4-(3-chlorophenyl)-1-methyl-2(1H)-quinolinone) and lonafarnib ((11R)-5,6-dihydro-3,10-dibromo-8-chloro-11-[1-[1-oxo-2-(1-carbamoyl-4-piperidinyl)ethyl] The active ingredient in the formulation is at least one selected from the group consisting of 4-[2-[4-[(11R)-8-chloro-3,10-dibromo-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridine, 4-[2-[4-[(11R)-8-chloro-3,10-dibromo-6,11-dihydro-5H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-yl]-1-piperidinyl]-2-oxoethyl]-1-piperidinecarboxamide. These drugs are known and commercially available, so commercially available products can be used. These drugs can be used alone or in combination.

[0014] As specifically described in the Examples below, the active ingredient demonstrated excellent therapeutic effects on memory impairment in a tuberous sclerosis model animal created by knocking out the TSC2 gene and on epilepsy-induced memory impairment model animal created by administering the convulsant-inducing drug pentylenetetrazole. The active ingredient also demonstrated excellent therapeutic effects in an autism model animal created by administering the epilepsy-inducing drug kainic acid. These experimental results confirmed that the active ingredient is effective in treating intellectual disability, particularly memory impairment, particularly memory impairment caused by abnormalities in the Tsc1 and / or Tsc2 genes, as well as autism.

[0015] The active ingredient can be administered orally or parenterally, such as subcutaneously, intradermally, intramuscularly, intravenously, enterally, transdermally, intraperitoneally, or intraocularly.

[0016] The dosage of the active ingredient is determined appropriately depending on the patient's symptoms, age, body weight, and other conditions, but the dosage per kg of patient body weight per day (total dosage when both are used in combination) is usually about 75 mg to 200 mg, particularly about 100 mg to 150 mg.

[0017] The above-mentioned active ingredient can be formulated and administered by a conventional formulation method into oral dosage forms such as tablets, powders, pills, granules, capsules, and syrups, or parenteral dosage forms such as injections, liniments, patches, suppositories, and eye drops.

[0018] The present invention will be specifically described below based on examples, although the present invention is not limited to the following examples. [Example]

[0019] Example 1 1. Method (1) Animal Tsc2 + / - Mice were bred and mated as described previously (Kobayashi, T., et al., Renal carcinogenesis, hepatic hemangiomatosis, and embryonic lethality caused by a germ-line Tsc2 mutation in mice. Cancer Res, 1999. 59(6): pp. 1206-11). A mouse model of memory impairment distinct from tuberous sclerosis complex was generated by 10 intraperitoneal injections of pentylenetetrazole (35 mg / kg). Mice exhibiting social behavioral abnormalities were generated by a single intraperitoneal injection of kainic acid (1.5 mg / kg) at 1 week of age.

[0020] (2) Context-dependent fear discrimination test Context-dependent fear discrimination was measured in mice using a context-dependent fear discrimination test (Auerbach, B.D., E.K. Osterweil, and M.F. Bear, Mutations causing syndromic autism define an axis of synaptic pathophysiology. Nature, 2011. 480(7375): pp. 63-8). Specifically, mice were placed in a cage exposed to foot shock (FS). After FS, they were returned to the same cage (familiar condition) the next day, and the freeze time was measured (Fig. 1a). To examine the effects of tipifarnib or lonafarnib (hereinafter simply referred to as "active ingredients"), mice were orally administered the vehicle (carboxymethylcellulose) and the active ingredients, exposed to FS 6 hours later, and returned to the same cage the next day. The freeze time was compared. As a control experiment, the freezing time was measured when the rats were placed in a different cage (novel condition) on the day after FS (Fig. 1a).

[0021] (3) Three-chamber test Social interactions were examined using a three-chamber test. This experimental setup consisted of three compartments, with free movement between them. First, a cage containing a mouse (Stranger 1 mouse) was placed in one compartment, and an empty cage in the other (Fig. 2a). The test mouse was placed in the center compartment, and the time spent in each compartment (time spent in the chamber (s): seconds in the figure) was measured. Next, the mouse in one of the cages was moved to the empty cage (Stranger 1 mouse), and a new mouse (Stranger 2 mouse) was placed in the empty cage (Fig. 2a). The time it took the test mouse to enter the compartment containing the original mouse (Stranger 1 chamber) and the compartment containing the new mouse (Stranger 2 chamber) was measured and compared.

[0022] (4) Primary culture of hippocampal neurons Tsc2 on day 0 or 1 after birth + / -Hippocampi were removed from mice and incubated in 0.25% trypsin-containing Hank's buffer at 37°C for 10 minutes. After washing, the cells were suspended and cultured in Neurobasal medium containing B27 supplement at 37°C under 5% CO2. Two days before fixation, the carrier (DMSO) and active ingredient (2 μM) were added to the culture medium. Lipofectamine 2000 was used for forced gene expression.

[0023] (5) Immune cell staining Cultured neurons were fixed with 4% paraformaldehyde. The fixed neurons were blocked with a buffer containing 10% goat serum and reacted with a primary antibody. Target proteins were then labeled with a fluorescent secondary antibody. The labeled neurons were observed using a Carl Zeiss LSM780 microscope.

[0024] 2. Results (1) Effect on memory impairment caused by Tsc2 gene abnormalities To investigate the effect of the active ingredient on intellectual disability, we first investigated Tsc2, which shows abnormalities in context-dependent fear memory. + / - Experiments were performed using mice. Six hours before FS, lonafarnib (40 mg / kg) or tipifarnib (40 mg / kg) was injected into the Tsc2 + / - Mice were orally administered the drug, and context-dependent fear memory was examined (Fig. 1a). The next day, the mice were returned to the box where they had received FS, and the freezing time was measured. All wild-type (WT) mice remembered the previous day's FS and showed an increased freezing response, but Tsc2 mice showed no significant changes. + / - Mice in the vehicle-treated group did not show an increase in freezing, suggesting that they did not remember the box containing the FS (Fig. 1b). However, mice in the lonafarnib or tipifarnib-treated groups showed an increase in freezing and memory recovery (Fig. 1b). This indicates that a single administration of the active ingredients can improve memory impairment in tuberous sclerosis complex.

[0025] (2) Effect on epilepsy-induced memory impairment To investigate whether the active ingredient is effective against memory impairments other than those induced by tuberous sclerosis complex, we attempted to generate mice with other memory impairments. The convulsant drug pentylenetetrazole was administered 10 times to mice, causing continuous epileptic seizures. Context-dependent fear memory in these mice was examined in the same manner as above, and significant memory impairment was observed. Therefore, we also investigated the effect of the active ingredient on memory impairment in these mice. A single administration of lonafarnib (40 mg / kg, ip) improved pentylenetetrazole-induced memory impairment (Figure 1c). These results demonstrate that the active ingredient is effective in improving not only tuberous sclerosis complex-induced memory impairment, but also epilepsy-induced memory impairment.

[0026] (3) Effects on autism We investigated the effects of drugs using a mouse model exhibiting autism-like behavioral abnormalities (Fig. 2a). To create a model exhibiting social behavior abnormalities, kainic acid (1.5 mg / kg) was injected into 1-week-old mice. After 2 months of age, the mice were subjected to a three-chamber test. When confronted with Stranger 1 and Stranger 2 mice, wild-type mice approached Stranger 2, whereas mice injected with kainic acid neonatally showed no significant difference in the time spent in the Stranger 1 and Stranger 2 chambers (Fig. 2b). These results suggest that the mice exhibited social behavior abnormalities. Therefore, we administered lonafarnib (40 mg / kb, i.p.) once to these mice and performed a three-chamber test. The time spent in the Stranger 2 chamber was significantly increased, indicating normal social behavior (Fig. 2b). These results demonstrate that the active ingredient can improve social behavior abnormalities (autism) other than tuberous sclerosis complex.

[0027] (4) Effect on synapse formation abnormalities The effect of the active ingredient on synaptic abnormalities in a tuberous sclerosis model was investigated. + / - Hippocampal neurons were cultured from mice and the morphology of the neurons after 21 days of culture was compared with wild-type. The wild-type neurons formed typical mushroom-shaped spines, whereas the Tsc2 + / -In mice, dendritic spines did not form, and they showed elongated, immature morphologies called filopodia (Fig. 3a-c). Furthermore, we examined whether excitatory synapses were formed by immunohistochemistry for vGlut1, and found that Tsc2 + / - In mice, no synapses were formed on filopodia (Fig. 3a, d). On the other hand, excitatory synapses were formed directly on dendrites, exhibiting shaft synapse morphology (Fig. 3a, e). + / - The neuronal culture medium was treated with either the carrier or the active ingredient (2 μM). After two days, the neurons were fixed and their morphology was observed. Treatment with the active ingredient resulted in spine morphology comparable to that of wild-type neurons, and spine synapses in which vGlut1 staining was consistent with the spines were formed (Figure 3a-e). These results demonstrate that administration of the active ingredient normalizes synapses in tuberous sclerosis syndrome.

[0028] Example 2 1. Animals To obtain a tuberous sclerosis model exhibiting abnormal social behavior, we developed astrocyte-specific Cre-expressing GFAP-Cr and Tsc1 mice. fl / fl Mice were crossed and GFAP-Cre;Tsc1 fl / fl We first generated a tuberous sclerosis complex (TBSC) model mouse that exhibits abnormal social behavior. fl / fl As a result of crossing mice, GFAP-Cre;Tsc1 mice crossed with GFAP-Cre mice, which express Cre specifically in astrocytes. fl / fl (GFAP-Tsc1 cKO) mice were found to exhibit abnormal social behavior.

[0029] 2. Drug preparation and administration Lonafarnib and tipifarnib were prepared as 4 mg / ml suspensions (solvent: 1 w / v% CMC, 0.9 w / v% NaCl, 5 v / v% DMSO) and administered orally at 40 mg / kg. Pentylenetetrazole (PTZ) was prepared as a 2 mg / ml solution (solvent: 0.9 w / v% NaCl) and administered intraperitoneally.

[0030] 3. Results A three-chamber test was performed in the same manner as in Example 1. In the three-chamber test, when a wild-type mouse was placed between Stranger 1 and Stranger 2, it approached Stranger 2 for a longer period of time, but in GFAP-Tsc1 cKO mice, no significant difference was observed in the time spent in the Stranger 1 and Stranger 2 chambers, indicating abnormalities in social behavior (Figure 4).

[0031] Therefore, we administered lonafarnib (40 mg / kg, ip) once to these mice and performed a three-chamber test. The mice spent significantly more time in the stranger 2 chamber, and their social behavior returned to normal (Figure 4).

Claims

1. A therapeutic agent for intellectual disability or autism, comprising at least one active ingredient selected from the group consisting of tipifarnib and lonafarnib, The therapeutic agent as described above, wherein the intellectual disability is a memory disorder.

2. The therapeutic agent according to claim 1, wherein the memory disorder is caused by an abnormality in the Tsc1 gene and / or the Tsc2 gene.

3. The therapeutic agent according to claim 1, wherein the memory impairment is epilepsy-induced memory impairment.

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