Generation of c-Fos knockout rats, and observation of their phenotype.

c-Fos is a useful marker gene of neuron activation for neuroscience and physiology research. The mechanism and function of neural networks have been elucidated using c-Fos reporter knock-in (KI) mice, but the small size of the mice makes it difficult to perform surgical procedures on specific brain regions. On the other hand, there is a large amount of accumulated data on behavioral studies using rats. Thus, the generation of c-Fos reporter rat is expected, but it is difficult to generate gene-modified rats. Furthermore, c-Fos gene abnormality is expected to be severe in rats, as shown in homozygous of c-Fos knockout (KO) mouse, but such analysis has rarely been performed and is not certain. This study generated c-Fos-deficient rats using CRISPR/Cas, with 1067 bp deletion including exon 1 of the c-Fos gene. Homozygous c-Fos KO rats had growth latency and the same tooth and bone abnormality as homozygous c-Fos KO mice but not heterozygous c-Fos KO rats. Therefore, the c-Fos gene in rats is expected to have the same function as that in mice, and the generation of c-Fos reporter KI rats is further anticipated.

Tracing location by applying Emerald luciferase in an early phase of murine endometriotic lesion formation.

The pathogenesis of endometriosis has not been fully elucidated. We focused on the behavior of the ectopic endometrium, that is, the origin of the endometriotic lesion, before adhering to the peritoneal cavity. To observe lesion formation in the very early phase, we developed a novel endometriosis animal model using bioluminescence technology. We established a new transgenic mouse that expressed Emerald luciferase (ELuc) under the control of the CAG promoter. This transgenic mouse, called the CAG-ELuc mouse, showed strong bioluminescence emission; we succeeded in tracing the lesion location by the emission of ELuc. The accuracy of tracing by ELuc was high (57.7-100% of correspondence) and depended on the dosage of E2 administration. In the very early phase after transplantation, the process of lesion formation can be observed non-invasively and chronologically. We have verified that the preferred location of the uterus (transplanted grafts) was fixed immediately after the transplantation of the grafts.

Role of IL-4 in bone marrow driven dysregulated angiogenesis and age-related macular degeneration.

Age-associated sterile inflammation can cause dysregulated choroidal neovascularization (CNV) as age-related macular degeneration (AMD). Intraocular fluid screening of 234 AMD patients identified high levels of IL-4. The purpose of this study was to determine the functional role of IL-4 in CNV formation using murine CNV model. Our results indicate that the IL-4/IL-4 receptors (IL4Rs) controlled tube formation and global proangiogenic responses of bone marrow cells. CCR2+ bone marrow cells were recruited to form very early CNV lesions. IL-4 rapidly induces CCL2, which enhances recruitment of CCR2+ bone marrow cells. This in vivo communication, like quorum-sensing, was followed by the induction of IL-4 by the bone marrow cells during the formation of mature CNVs. For CNV development, IL-4 in bone marrow cells are critically required, and IL-4 directly promotes CNV formation mainly by IL-4R. The IL-4/IL-4Rα axis contributes to pathological angiogenesis through communications with bone marrow cells leading to retinal degeneration.

Tokishakuyakusan, a Kampo medicine, attenuates endometriosis-like lesions and hyperalgesia in murine with endometriosis-like symptoms.

PROBLEM: How are the effects of Tokishakuyakusan (TSS), a traditional Japanese medicine (Kampo) on murine endometriosis model? METHODS: BALB/c mice were used for making the murine endometriosis model. Homogeneous uterus was surgically implanted with lipopolysaccharide (LPS) in peritoneal cavity. We administered 2 weeks of TSS (1.0 g/kg) orally. Upon treatment completion, we performed the hot plate test for all mice and collected blood samples before sacrifice. Then, the endometriosis-like lesions and uteri in the abdominal cavity were harvested. Concentrations of several cytokines in sera and cyst fluids were measured using Bio-Plex Suspension Array System. IL-33 localization was determined by immunohistochemistry. Gene expression of inflammatory cytokines in the endometriosis-like lesions or the eutopic endometrium was evaluated by real-time RT-PCR. RESULTS: After 14 days of TSS treatment, the numbers of endometriosis-like cysts and cyst weight were significantly decreased. In TSS-treated mice, the latency against heat stimuli was extended. Inflammatory cytokine concentrations in sera were not changed by TSS treatment. TSS intake decreased IL-33 mRNA expression in endometriosis-like lesions and led to the tendency of attenuation of the elevated IL-33 synthesis in the cyst fluids of lesions. CONCLUSION: These results suggest the TSS ameliorated the hyperalgesia and lesion formation on the LPS-accelerated endometriosis-like model. TSS represents a possible ideal target of novel therapeutics for endometriosis patients with dysmenorrhea.

Novel dual-reporter transgenic rodents enable cell tracking in animal models of stem cell transplantation.

In the present study, we have established a novel transgenic mouse and transgenic rats with dual reporters of EGFP and ELuc. In these transgenic (Tg) rodents, both GFP fluorescent and luciferase luminescent signals were ubiquitously detected in the heart, liver, kidney and testis, while only the GFP signal was detected in the brain. This expression system is based on a P2A linked EGFP/ELuc protein allowing both signals to be generated simultaneously. Microscopy experiments, FCM, and luciferase assays showed strong expression in freshly isolated ADSCs from Tg rodents upon transplantation of Tg rat-derived ADSCs into wild-type-mice. The ELuc transgene signal was observed and traced in vivo, and EGFP positive cells could be recovered from ELuc positive tissues in engraftment sites of wild-type mice for multiple analysis. These dual reporter Tg rodents are a useful reconstituted model system of regenerative medicine and are a valuable tool to study stem cells.

New insights into the efficacy of SR-16234, a selective estrogen receptor modulator, on the growth of murine endometriosis-like lesions.

PROBLEM: To evaluate the effects of SR-16234 (SR), a selective estrogen receptor modulator (SERM), on murine endometriosis-like lesions. METHOD OF STUDY: BALB/c mice (n = 53) were used to establish the murine endometriosis model. Ovariectomized, estradiol replaced, 6-week-old murine endometriosis model were injected with lipopolysaccharide (LPS) with or without SR (1 mg/kg/d) or vehicle, over a period of 4 weeks. Upon treatment completion, the endometriosis-like lesions that developed in the abdominal cavity of mice were counted, measured, and collected. Gene expression of inflammatory cytokines and estrogen receptor (ER) in the lesions was assessed by real-time RT-PCR. Immunohistochemical analysis was used to evaluate the effect of SR on cell proliferation, angiogenic activity, inflammation, and NF-κB phosphorylation. RESULTS: Treatment with SR significantly reduced the total number and size of lesions per mouse without inducing endometrial growth. In addition, SR downregulated LPS-enhanced Vegf, Il-6, Ptgs-2, and Ccl-2 and ER mRNA expression in endometriosis-like lesions. Immunohistochemical analysis demonstrated a decrease in percentage of positive cells of Ki67, and intensity and rate of positive cells of ERα, CD3, F4/80, PECAM by SR treatment. SR also decreased the expression of NF-κB p65 and phospho-NF-κB p65. CONCLUSION: SR has a regressive effect on the development of murine endometriosis-like lesions.

Inhibition of IAP (inhibitor of apoptosis) proteins represses inflammatory status via nuclear factor-kappa B pathway in murine endometriosis lesions.

PROBLEM: How is the role of inhibitor of apoptosis proteins (IAPs) in the development of murine endometriosis lesions? METHOD OF STUDY: BALB/c female mice (n = 36) were used for the murine endometriosis model. Endometriotic lesions were surgically induced in mice by transplanting mouse uterine tissue. After 4 weeks of IAP antagonist (BV6) treatment, the expression of inflammatory factors in the implants was evaluated using real-time RT-PCR. Inflammatory state, angiogenic activity, and nuclear factor-kappa B (NF-κB) activation were assessed by immunohistochemical staining. RESULTS: The number, size, and level of inflammatory cytokines (Vegf, Il-6, Ccl-2, Lif) gene expression in the murine endometriosis-like lesions were reduced by BV6 treatment. BV6 repressed the intensity and rate of positive cells of CD3, F4/80, and PECAM immunostaining; in addition, the expression of NF-κB p65 and phospho-NF-κB p65 was also attenuated. CONCLUSION: Inhibitor of apoptosis proteins antagonist represses the inflammation status of murine endometriosis-like lesions viaNF-κB pathway. IAPs may be a novel therapeutic target for endometriosis.

Use of a Human Artificial Chromosome for Delivering Trophic Factors in a Rodent Model of Amyotrophic Lateral Sclerosis.

A human artificial chromosome (HAC) is maintained as an episome within a cell and avoids random integration into the host genome. It can transfer multiple and/or large transgenes along with their regulatory elements thereby resembling native chromosomes. Using this HAC system, we established mesenchymal stem cells (MSCs) that simultaneously expressed hepatocyte growth factor, glial cell line-derived neurotrophic factor, and insulin-like growth factor 1, termed HAC-MSCs. This cell line provides an opportunity for stable transplantation and thorough analyses. We then introduced the cells for the treatment of a neurodegenerative disorder, amyotrophic lateral sclerosis. The HAC-MSCs were transplanted via the fourth cerebral ventricle (CV) or intravenous (i.v.) infusion at various ages of recipient mice. Littermate- and sex-matched mice underwent a sham procedure. Compared to the controls, there was an encouraging trend of increased life span via CV transplantation and delayed onset in i.v. infusion 60 days after transplantation. Further, we confirmed a statistically significant increase in life span via CV transplantation at 100 days. This effect was not seen in mice transplanted with MSCs lacking the HAC. We successfully enhanced the trophic potential of the MSCs using the HAC. This strategy could be a promising direction for the treatment of neurodegenerative disorders.

Inhibitor of apoptosis proteins (IAPs) may be effective therapeutic targets for treating endometriosis.

STUDY QUESTION: What is the role of the inhibitor of apoptosis proteins (IAPs) in human endometriotic tissues and a mouse model of endometriosis? SUMMARY ANSWER: Four IAP proteins were expressed in endometriotic tissue indicating IAPs may be a key factor in the pathogenesis and progression of endometriosis. WHAT IS KNOWN ALREADY: Overexpression of IAPs protects against a number of proapoptotic stimuli. IAPs (c-IAP1, c-IAP2, XIAP and Survivin) are expressed in human ectopic endometrial stromal cells (ESCs) from ovarian endometriomas. STUDY DESIGN, SIZE, DURATION: Forty-eight women with or without ovarian endometrioma are included in this study. BALB/c mice (n = 24) were used for the mouse endometriosis model. Mice with surgically induced endometriosis were treated with an IAP antagonist (BV6) for 4 weeks. PARTICIPANTS/MATERIALS, SETTING, METHODS: Human ectopic endometrial tissues from chocolate cysts and eutopic endometrial tissue were collected. ESCs were enzymatically isolated from these tissues. ESC proliferation was examined by 5-bromo-2'-deoxyuridine-enzyme-linked immunosorbent assay. IAPs expression in tissue derived from eutopic endometria and chocolate cysts was evaluated using real-time RT-PCR and immunohistochemistry. A homologous mouse endometriosis model was established by transplanting donor mouse uterine tissue into the abdominal cavities of recipient mice. After treating the mice with BV6 (i.p. 10 mg/ml), the extent of endometriosis-like lesions in mice was measured and proliferative activity assessed by Ki67 staining. All experiments were repeated a minimum of three times. MAIN RESULTS AND THE ROLE OF CHANCE: IAP (c-IAP1, c-IAP2, XIAP and Survivin) mRNA and protein in human ectopic endometrial tissues were expressed at higher levels than in eutopic endometrial tissues (P < 0.05). All four IAPs proteins were expressed in mouse endometriosis-like implants. BV6 inhibited BrdU incorporation of human ESCs (P < 0.05 versus control). BV6 also decreased the total number, weight, surface area and Ki67 positive cells in the endometriosis-like lesions in the mice (P < 0.05 versus control). LIMITATIONS, REASONS FOR CAUTION: Endometriotic lesions were surgically induced in mice by transplanting mouse uterine tissue only, not human pathological endometriotic tissue. Furthermore, the effects of BV6 on human ESCs and mouse endometriosis-like lesions may differ between the species. WIDER IMPLICATIONS OF THE FINDINGS: Our data support the hypothesis that IAPs are involved in the development of endometriosis, and therefore an inhibitor of IAPs has potential as a novel treatment for endometriosis. STUDY FUNDING/COMPETING INTERESTS: This work was supported by KAKENHI (Japan Society for the Promotion of Science, Grant-in-Aid: to F.T.; 21592098 and to T.H.; 24659731) and Yamaguchi Endocrine Research Foundation. The authors have no conflicts of interest to disclose.

Repression of cyclin D1 expression is necessary for the maintenance of cell cycle exit in adult mammalian cardiomyocytes.

The hearts of neonatal mice and adult zebrafish can regenerate after injury through proliferation of preexisting cardiomyocytes. However, adult mammals are not capable of cardiac regeneration because almost all cardiomyocytes exit their cell cycle. Exactly how the cell cycle exit is maintained and how many adult cardiomyocytes have the potential to reenter the cell cycle are unknown. The expression and activation levels of main cyclin-cyclin-dependent kinase (CDK) complexes are extremely low or undetectable at adult stages. The nuclear DNA content of almost all cardiomyocytes is 2C, indicating the cell cycle exit from G1-phase. Here, we induced expression of cyclin D1, which regulates the progression of G1-phase, only in differentiated cardiomyocytes of adult mice. In these cardiomyocytes, S-phase marker-positive cardiomyocytes and the expression of main cyclins and CDKs increased remarkably, although cyclin B1-CDK1 activation was inhibited in an ATM/ATR-independent manner. The phosphorylation pattern of CDK1 and expression pattern of Cdc25 subtypes suggested that a deficiency in the increase in Cdc25 (a and -b), which is required for M-phase entry, inhibited the cyclin B1-CDK1 activation. Finally, analysis of cell cycle distribution patterns showed that >40% of adult mouse cardiomyocytes reentered the cell cycle by the induction of cyclin D1. The cell cycle of these binucleated cardiomyocytes was arrested before M-phase, and many mononucleated cardiomyocytes entered endoreplication. These data indicate that silencing the cyclin D1 expression is necessary for the maintenance of the cell cycle exit and suggest a mechanism that involves inhibition of M-phase entry.

Parthenolide reduces cell proliferation and prostaglandin E2 [corrected] in human endometriotic stromal cells and inhibits development of endometriosis in the murine model.

OBJECTIVE: To evaluate the effects of parthenolide on human endometriotic cells and murine endometriotic lesions. DESIGN: Experimental study. SETTING: University hospital and laboratory of animal science. PATIENT(S) AND ANIMAL(S): Twenty women with ovarian endometrioma and 30 mice. INTERVENTION(S): Ectopic endometrial tissue from the endometrioma was collected. MAIN OUTCOME MEASURE(S): Human endometriotic stromal cells (ESCs) were pretreated with parthenolide and exposed to tumor necrosis factor (TNF)-α. Interleukin 8 (IL-8) and COX-2 gene expressions were evaluated by real-time reverse transcription-polymerase chain reaction. Interleukin-8 protein, prostaglandin E2 (PGE2) level, and intranuclear p65 protein concentration were determined by ELISA. Cell proliferation was assessed by 5-bromo-2'-deoxyuridine-ELISA. Phosphorylation of signaling pathways in ESCs was evaluated by Western blotting. Gene expression and proliferative activity in murine endometriosis-like lesions were assessed by real-time reverse transcription-polymerase chain reaction and Ki67 staining, respectively. RESULT(S): With parthenolide pretreatment, TNF-α-induced IL-8 gene and protein expression in ESCs were diminished. Tumor necrosis factor α-induced COX-2 expression and PGE2 synthesis were also inhibited. Adding parthenolide repressed TNF-α-induced 5-bromo-2'-deoxyuridine incorporation and IκB phosphorylation in ESCs. As in vivo experiments, administering parthenolide reduced the number, surface area, and weight, the level of Vegf, Il-6, Mcp-1, and Lif gene expression, and the percentage of Ki67-positive cells in murine endometriosis-like lesions. CONCLUSION(S): Parthenolide repressed the development of endometriosis by suppressing the inflammatory peritoneal environment through the nuclear factor κB pathway.