Overexpression of cathepsin S exacerbates lupus pathogenesis through upregulation TLR7 and IFN-α in transgenic mice.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organs. Recent studies suggest relevance between cysteine protease cathepsin S (CTSS) expression and SLE. To investigate the mechanism of CTSS in SLE, CTSS-overexpressing transgenic (TG) mice were generated, and induced lupus-like symptoms. Eight months later, the TG mice spontaneously developed typical SLE symptoms regardless of the inducement. Furthermore, we observed increased toll-like receptor 7 (TLR7) expression with increased monocyte and neutrophil populations in the TG mice. In conclusion, overexpression of CTSS in mice influences TLR7 expression, autoantibodies and IFN-α, which leads to an autoimmune reaction and exacerbates lupus-like symptoms.

Overexpression of hepatic serum amyloid A1 in mice increases IL-17-producing innate immune cells and decreases bone density.

Serum amyloid A (SAA) is an acute-phase protein produced primarily in the liver that plays a key role in both the initiation and maintenance of inflammation. Rapidly secreted SAA induces neutrophilia at inflammatory sites, initiating inflammation and inducing the secretion of various cytokines, including TNF-α, IL-6, and IL-17. IL-17 is expressed in several inflammatory cells, including innate immune cells such as γδT cells, ILC3 cells, and neutrophils. Increased IL-17 levels exacerbate various inflammatory diseases. Among other roles, IL-17 induces bone loss by increasing receptor activator of nuclear factor-κB ligand (RANKL) secretion, which stimulates osteoclast differentiation. Several studies have demonstrated that chronic inflammation induces bone loss, suggesting a role for SAA in bone health. To test this possibility, we observed an increase in IL-17-producing innate immune cells, neutrophils, and γδT cells in these mice. In 6-month-old animals, we detected increased osteoclast-related gene expression and IL-17 expression in bone lysates. We also observed an increase in neutrophils that secreted RANKL in the bone marrow of TG mice. Finally, we demonstrated decreased bone mineral density in these transgenic (TG) mice. Our results revealed that the TG mice have increased populations of IL-17-producing innate immune cells, γδT cells, and neutrophils in TG mice. We additionally detected increased RANKL and IL-17 expression in the bone marrow of 6-month-old TG mice. Furthermore, we confirmed significant increases in RANKL-expressing neutrophils in TG mice and decreased bone mineral density. Our results provide evidence that chronic inflammation induced by SAA1 causes bone loss via IL-17-secreting innate immune cells.

Anti-inflammatory effects of a methanol extract of Dictamnus dasycarpus Turcz. root bark on imiquimod-induced psoriasis.

BACKGROUND: The root bark of Dictamnus dasycarpus Turcz. has been successfully used for the treatment of inflammatory skin conditions such as eczema and pruritus. However, the anti-psoriatic effect of this plant has not until now been investigated. METHODS: The aim of this project was to investigate whether a methanol extract of Dictamnus dasycarpus Turcz. root bark (MEDD) can be used as a therapeutic agent for psoriasis in C57BL/6 mice model of imiquimod (IMQ)-induced psoriasis. IMQ and MEDD was applied to mouse skin continuously for 7 days. The skin phenotype and the levels of inflammatory cytokines, such as interferon (IFN)-γ and interleukin (IL)-17, were analyzed. The immune cell population was determined by flow cytometry, and STAT1 and 3 protein levels were measured. RESULTS: An alleviation of scaly skin phenotype, immune cell infiltration in the dermis, and epidermal hyperplasia was observed after daily MEDD treatment in the lesion-affected area. It was also found that MEDD reduced IL-17 cytokine levels decreased by 44.37% (p < 0.05), the number of IL-17-producing Th17 cells and γδT cells, and the size of the Th1 population secreting IFN-γ decreased by 45.98, 62.21, and 44.42%, respectively (p < 0.05), compared with the vehicle control group. STAT3 signals, associated with IL-17 are also reduced by MEDD. CONCLUSIONS: An anti-psoriatic effect of MEDD was observed, as determined by decreased skin inflammation, reduced number of inflammatory cytokines, and a smaller population of inflammatory cells. These results contribute to the validation of the use of MEDD in the treatment of psoriasis.

Suppression of PRPF4 regulates pluripotency, proliferation, and differentiation in mouse embryonic stem cells.

Mouse embryonic stem cells (mESCs) are characterized by their self-renewal and pluripotency and are capable of differentiating into all three germ layers. For this reason, mESCs are considered a very important model for stem cell research and clinical applications in regenerative medicine. The pre-mRNA processing factor 4 (PRPF4) gene is known to have a major effect on pre-mRNA splicing and is also known to affect tissue differentiation during development. In this study, we investigated the effects of PRPF4 knockdown on mESCs. First, we allowed mESCs to differentiate naturally and observed a significant decrease in PRPF4 expression during the differentiation process. We then artificially induced the knockdown of PRPF4 in mESCs and observed the changes in the phenotype. When PRPF4 was knocked down, various genes involved in mESC pluripotency showed significantly decreased expression. In addition, mESC proliferation increased abnormally, accompanied by a significant increase in mESC colony size. The formation of mESC embryoid bodies and teratomas was delayed following PRPF4 knockdown. Based on these results, the reduced expression of PRPF4 affects mESC phenotypes and is a key factor in mESC. SIGNIFICANCE OF THE STUDY: Our results indicate that PRPF4 affects the properties of mESCs. Suppression of PRPF4 resulted in a decrease in pluripotency of mESC and promoted proliferation. In addition, suppression of PRPF4 also resulted in decreased apoptosis. Moreover, the inhibition of PRPF4 reduced the ability to differentiate and formation of teratoma in mESC. Our results demonstrated that PRPF4 is a key factor of controlling mESC abilities.

PRPF4 is a novel therapeutic target for the treatment of breast cancer by influencing growth, migration, invasion, and apoptosis of breast cancer cells via p38 MAPK signaling pathway.

Pre-mRNA processing factor 4 (PRPF4), a core protein in U4/U6 snRNP, maintains snRNP structures by interacting with PRPF3 and cyclophilin H. Expression of the PRPF4 gene affects cell survival as well as apoptosis and is responsible for retinitis pigmentosa (RP). Proteomics analysis shows that PRPF4 may be a therapeutic target in human cancers. Nevertheless, the exact function and role of the PRPF4 gene are unclear. In this study, we assessed the expression of PRPF4 gene in human breast cancer cells. First, we confirmed that the PRPF4 gene was overexpressed in various breast cancer cell lines. Next, using breast cancer cell lines MCF7 and MDA-MB-468, we established stable cell lines with PRPF4 gene knockdown. We also performed microarray analysis to investigate molecular mechanisms underlying PRPF4 activity. All cell lines with PRPF4 gene knockdown exhibited reduced cell proliferation, remarkable reduction in anchorage-independent colony formation capacity, and reduction of PCNA protein, which is a marker cell of proliferation. Reduced expression of the PRPF4 gene induced apoptosis and changes in the expression of associated apoptotic markers in breast cancer cell lines. Knockdown of the PRPF4 gene reduced cellular capacity for migration and invasion (the key hallmarks of human cancers) and decreased the expression of genes involved in epithelial-mesenchymal transition (EMT). Microarray results showed that the expression of PPIP5K1, PPIPK2, and YWHAE genes was reduced at the transcriptional level, leading to reduced phosphorylation of p38 MAPK. These findings suggest that knockdown of PRPF4 gene slows down breast cancer progression via suppression of p38 MAPK phosphorylation. In conclusion, the PRPF4 gene plays an important role in the growth of breast cancer cells and is therefore a potential therapeutic target.

Serum amyloid A1 is involved in amyloid plaque aggregation and memory decline in amyloid beta abundant condition.

Alzheimer's disease (AD) is a neurodegenerative disorder, characterized by cognitive impairment, progressive neurodegeneration, and amyloid-ß (Aß) lesion. In the neuronal death and disease progression, inflammation is known to play an important role. Our previous study on acute-phase protein serum amyloid A1 (SAA1) overexpressed mice showed that the liver-derived SAA1 accumulated in the brain by crossing the brain blood barrier (BBB) and trigger the depressive-like behavior on mouse. Since SAA1 involved in immune responses in other diseases, we focused on the possibility that SAA1 may exacerbate the neuronal inflammation related to Alzheimer's disease. A APP/SAA overexpressed double transgenic mouse was generated using amyloid precursor protein overexpressed (APP)-c105 mice and SAA1 overexpressed mice to examine the function of SAA1 in Aß abundant condition. Comparisons between APP and APP/SAA1 transgenic mice showed that SAA1 exacerbated amyloid aggregation and glial activation; which lead to the memory decline. Behavior tests also supported this result. Overall, overexpression of SAA1 intensified the neuronal inflammation in amyloid abundant condition and causes the greater memory decline compared to APP mice, which only expresses Aß 1-42.

Hepatic serum amyloid A1 upregulates interleukin-17 (IL-17) in γδ T cells through Toll-like receptor 2 and is associated with psoriatic symptoms in transgenic mice.

Serum amyloid A (SAA) is an acute phase protein with pro-inflammatory cytokine-like properties. Recent studies have revealed that SAA promoted interleukin-17 (IL-17) production by various cells, including γδ T cells. γδ T cells are innate immune cells and express Toll-like receptor 2 (TLR2) on their surface, which is one of the SAA receptors. In this study, we investigated the relationship between γδ T cells and SAA1 through TLR2, by using hepatic SAA1-overexpressing transgenic (TG) mice. By injecting CU-CPT22, which is a TLR2 inhibitor, into the mice, we confirmed that SAA1 induced IL-17 in γδ T cells through TLR2. In vitro studies have confirmed that SAA1 increased IL-17 secretion in γδ T cells in combination with IL-23. We also observed a thickened epidermis layer and granulocyte penetration into the skin similar to the pathology of psoriasis in TG mice. In addition, strongly expressed SAA1 and penetration of γδ T cells in the skin of TG mice were detected. The exacerbation of psoriasis is associated with an increase in IL-17 levels. Therefore, these symptoms were induced by IL-17-producing γδ T cells increased by SAA1. Our study confirmed that SAA1 was a prominent protein that increased IL-17 levels through TLR2 in γδ T cells, confirming the possibility that SAA1 may exacerbate inflammatory diseases through γδ T cells.

Lin28a expression protects against streptozotocin-induced ß-cell destruction and prevents diabetes in mice.

Lin28, which is highly expressed during embryogenesis, has been shown to play an important role in cell growth and embryonic development. Meanwhile, Lin28 represses let-7 miRNA biogenesis and block pre-let-7 processing in the cytoplasm. The let-7 family of miRNAs is known to repress oncogenesis and cell cycle progression by targeting oncogenic genes and signalling pathways. Consequently, Lin28 acts as an oncogene by upregulating let-7 targets through the repression of let-7 biogenesis. A recent genome-wide association study (GWAS) showed that many genes related to Type 2 diabetes (T2D) are also oncogenes or cell cycle regulators. The role of Lin28 in mouse growth and glucose metabolism in metabolic-related tissues has also been studied. In these studies, whole-body Lin28 overexpression was found to promote glucose utilization and prevent weight gain by inhibiting let-7 biogenesis. Furthermore, Lin28 has been found to directly stimulate skeletal myogenesis and cell growth. Therefore, we determined whether similar effects mediated by Lin28a, which is essential for cell growth and proliferation, may also apply to pancreatic ß-cells. We found that overexpression of Lin28a protects pancreatic ß-cells from streptozotocin (STZ)-induced ß-cell destruction in vitro and in vivo. Furthermore, Lin28a-overexpressing transgenic (Tg) mice had higher insulin secretion in the presence of glucose than in control mice. Our findings suggest that the Lin28/let-7 axis is an important regulator of pancreatic ß-cell functions and that precise modulation of this axis may be helpful in treating metabolic diseases such as diabetes. SIGNIFICANCE OF THE STUDY: We demonstrate that Lin28a prevents pancreatic ß-cell death against streptozotocin (STZ)-induced ß-cell destruction in vitro and in vivo. Furthermore, Lin28a promotes cell survival and proliferation by activating the PI3K-Akt signalling pathway, which may be dependent on let-7 regulation. Taken together, our results imply that the Lin28a/let-7 axis is an important regulator of pancreatic ß-cell functions and that precise modulation of this axis may be helpful in treating metabolic diseases such as diabetes.

Placental growth factor (PlGF) is linked to inflammation and metabolic disorders in mice with diet-induced obesity.

Placental growth factor (PlGF), a member of the vascular endothelial growth factor (VEGF) sub-family, plays a major role in angiogenesis and vasculogenesis. Previous study demonstrated that PlGF-overexpressing transgenic (Tg) mice had gestational loss. In addition, PlGF secretion was up-regulated in isolated T lymphocytes (T-cell) upon CD3/CD28 stimulation, suggesting that PlGF could be a regulator of T-cell differentiation and development. T-cells are well known to play a critical role in obesity-induced inflammation. Therefore, to verify the possible link of diet-induced obesity (DIO) with inflammation and related metabolic disorders, such as insulin resistance, we fed high-fat diet (HFD) to Tg mice for 16 weeks. Adiposity and glucose intolerance significantly increase in Tg mice fed a HFD (Tg HFD) compared to wild-type (WT) mice fed HFD (WT HFD). In addition, macrophage infiltrations were significantly higher in the epididymal white adipose tissue (EWAT), liver, and pancreatic islets of Tg HFD mice compared to WT HFD mice. In the in vitro study, we showed that isolated CD4+ T-cells from Tg mice further differentiate into type 1 (Th1) and type 17 (Th17) helper T-cells via CD3/CD28 stimulation. Furthermore, we observed that the pro-inflammatory cytokines IL-6, IL-17, and TNFα, are remarkably increased in Tg mice compared to WT mice. These findings demonstrate that PlGF overexpression in T-cells might lead to inflammatory T-cell differentiation and accumulation in adipose tissue (AT) or metabolism-related tissues, contributing to the development of systemic metabolic disorders. Thus, PlGF may provide an effective therapeutic target in the management of obesity-induced inflammation and related metabolic disorders.

Jazf1 promotes prostate cancer progression by activating JNK/Slug.

Juxtaposed with another zinc finger protein 1 (Jazf1) is a zinc finger protein and is known to affect both prostate cancer and type 2 diabetes. Jazf1 inhibits testicular nuclear receptor 4 (TR4) activation through protein-protein interaction, which results in weight loss and alleviates diabetes. However, the role of Jazf1 in prostate cancer is still poorly understood. Hence, we investigated whether the expression of Jazf1 is associated with prostate cancer progression. We confirmed the upregulation of Jazf1 expression in human prostate tissue samples. In addition, using Jazf1 overexpressing prostate cancer cell lines, DU145 and LNCaP, we found Jazf1 promoted cell proliferation and colony formation ability. We also observed that Jazf1 dramatically enhanced cell migration and invasion in transwell assays. Additionally, we checked the upregulation of vimentin and downregulation of E-cadherin expression in Jazf1-overexpressing DU145 and LNCaP cells. Moreover, we found that Slug, which is known to be regulated by JNK/c-Jun phosphorylation, was upregulated in the microarray analysis of two prostate cancer cell lines. Jazf1 promotes the phosphorylation of JNK/c-Jun, likely promoting cell proliferation and invasion through Slug. In a xenograft model, tumors overexpressing Jazf1 were larger than control tumors, and tumors with decreased Jazf1 were smaller. These data indicated that Jazf1 enhances prostate cancer progression and metastasis via regulating JNK/Slug signaling. Taken together, these results suggest that Jazf1 plays an important role in both androgen dependent and independent prostate cancer.

Tet1 overexpression leads to anxiety-like behavior and enhanced fear memories via the activation of calcium-dependent cascade through Egr1 expression in mice.

Ten-eleven translocation methylcytosine dioxygenase 1 (Tet1) initiates DNA demethylation by converting 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC) at CpG-rich regions of genes, which have key roles in adult neurogenesis and memory. In addition, the overexpression of Tet1 with 5-hmC alteration in patients with psychosis has also been reported, for instance in schizophrenia and bipolar disorders. The mechanism underlying Tet1 overexpression in the brain; however, is still elusive. In the present study, we found that Tet1-transgenic (Tet1-TG) mice displayed abnormal behaviors involving elevated anxiety and enhanced fear memories. We confirmed that Tet1 overexpression affected adult neurogenesis with oligodendrocyte differentiation in the hippocampal dentate gyrus of Tet1-TG mice. In addition, Tet1 overexpression induced the elevated expression of immediate early genes, such as Egr1, c-fos, Arc, and Bdnf, followed by the activation of intracellular calcium signals (i.e., CamKII, ERK, and CREB) in prefrontal and hippocampal neurons. The expression of GABA receptor subunits (Gabra2 and Gabra4) fluctuated in the prefrontal cortex and hippocampus. We evaluated the effects of Tet1 overexpression on intracellular calcium-dependent cascades by activating the Egr1 promoter in vitro Tet1 enhanced Egr1 expression, which may have led to alterations in Gabra2 and Gabra4 expression in neurons. Taken together, we suggest that the Tet1 overexpression in our Tet1-TG mice can be applied as an effective model for studying various stress-related diseases that show hyperactivation of intracellular calcium-dependent cascades in the brain.-Kwon, W., Kim, H.-S., Jeong, J., Sung, Y., Choi, M., Park, S., Lee, J., Jang, S., Kim, S. H., Lee, S., Kim, M. O., Ryoo, Z. Y. Tet1 overexpression leads to anxiety-like behavior and enhanced fear memories via the activation of calcium-dependent cascade through Egr1 expression in mice.

Critical roles of hMAGEA2 in induced pluripotent stem cell pluripotency, proliferation, and differentiation.

Induced pluripotent stem (iPS) cells are important for clinical application and stem cell research. Although human melanoma-associated antigen A2 (hMAGEA2) expression is known to affect differentiation in embryonic stem cells, its specific role in iPS cells remains unclear. To evaluate the function of hMAGEA2 and its characteristics in iPS cells, we produced hMAGEA2-overexpressing iPS cells from hMAGEA2-overexpressing transgenic mice. Although the iPS cells with overexpressed hMAGEA2 did not differ in morphology, their pluripotency, and self-renewal related genes (Nanog, Oct3/4, Sox2, and Stat3), expression level was significantly upregulated. Moreover, hMAGEA2 contributed to the promotion of cell cycle progression, thereby accelerating cell proliferation. Through embryoid body formation in vitro and teratoma formation in vivo, we demonstrated that hMAGEA2 critically decreases the differentiation ability of iPS cells. These data indicate that hMAGEA2 intensifies the self-renewal, pluripotency, and degree of proliferation of iPS cells, while significantly repressing their differentiation efficiency. Therefore, our findings prove that hMAGEA2 plays key roles in iPS cells.

hMAGEA2 promotes progression of breast cancer by regulating Akt and Erk1/2 pathways.

Breast cancer is the most abundant cancer worldwide and a severe problem for women. Notably, breast cancer has a high mortality rate, mainly because of tumor progression and metastasis. Triple-negative breast cancer (TNBC) is highly progressive and lacks the expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Therefore, there are no established therapeutic targets against TNBC. In this study, we investigated whether the expression of human melanoma-associated antigen A2 (MAGEA2) is associated with TNBC. We found that hMAGEA2 is significantly overexpressed in human TNBC tissues; we also observed oncogenic properties using TNBC cell lines (MDA-MB-231 and MDA-MB-468). The overexpression of hMAGEA2 in MDA-MB-231 cell line showed dramatically increased cellular proliferation, colony formation, invasion, and xenograft tumor formation and growth. Conversely, knockdown of hMAEGA2 in MDA-MB-468 cell line suppressed cellular proliferation, colony formation, and xenograft tumor formation. Additionally, we showed that hMAGEA2 regulated the activation of Akt and Erk1/2 signaling pathways. These data indicate that hMAGEA2 is important for progression of TNBC and may serve as a novel molecular therapeutic target.

Overexpression of serum amyloid a 1 induces depressive-like behavior in mice.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by loss of memory and cognitive abilities. In AD, amyloid ß (Aß) protein aggregates in the brain of patients, forming amyloid plaques. Aß plaques are known to be surrounded by activated microglial cells. Serum amyloid A (SAA) is elevated from several hundred to 1000-fold as part of the immune response against various injuries, including trauma, infection, and inflammation. Additionally, continuous elevation of SAA is related to the development of amyloidosis. This study was designed to identify the relationship between SAA1 and AD using liver specific SAA1 overexpressing mice (TG), because SAA1 is expressed in the liver during the acute phase. We detected exogenous SAA1 expression in the brain of TG mice. This result implies that liver-derived SAA1 migrates to the brain tissues. Thus, we confirmed that the blood brain barrier (BBB) functioned normally using Evans-blue staining and CARS. Furthermore, our results show an increase in the accumulation of the 87kDa form of Aß in TG mice compared to wild type mice (WT). Additionally, the number of microglial cells and levels of pro-inflammatory cytokines were increased. Next, we investigated the relationship between SAA1 and depression by performing social interaction tests. The results showed that TG mice have a tendency to avoid stranger mice and an impaired social recognition. In conclusion, the SAA1 TG mouse model is a valuable model to study depression.

Serum amyloid A1 levels and amyloid deposition following a high-fat diet challenge in transgenic mice overexpressing hepatic serum amyloid A1.

Serum amyloid A (SAA) is an acute-phase response protein in the liver, and SAA1 is the major precursor protein involved in amyloid A amyloidosis. This amyloidosis has been reported as a complication in chronic inflammatory conditions such as arthritis, lupus, and Crohn's disease. Obesity is also associated with chronic, low-grade inflammation and sustained, elevated levels of SAA1. However, the contribution of elevated circulating SAA1 to metabolic disturbances and their complications is unclear. Furthermore, in several recent studies of transgenic (TG) mice overexpressing SAA1 that were fed a high-fat diet (HFD) for a relatively short period, no relationship was found between SAA1 up-regulation and metabolic disturbances. Therefore, we generated TG mice overexpressing SAA1 in the liver, challenged these mice with an HFD, and investigated the influence of elevated SAA1 levels. Sustained, elevated levels of SAA1 were correlated with metabolic parameters and local cytokine expression in the liver following 16 weeks on the HFD. Moreover, prolonged consumption (52 weeks) of the HFD was associated with impaired glucose tolerance and elevated SAA1 levels and resulted in systemic SAA1-derived amyloid deposition in the kidney, liver, and spleen of TG mice. Thus, we concluded that elevated SAA1 levels under long-term HFD exposure result in extensive SAA1-derived amyloid deposits, which may contribute to the complications associated with HFD-induced obesity and metabolic disorders.

TET1 contributes to neurogenesis onset time during fetal brain development in mice.

Epigenetic mechanisms are relevant to development and contribute to fetal neurogenesis. DNA methylation and demethylation contribute to neural gene expression during mouse brain development. Ten-eleven translocation 1 (TET1) regulates DNA demethylation by converting 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC). TET1 specifically regulates 5hmC in the central nervous system (CNS), including during neurogenesis in the adult brain. However little is known about its function in fetal neurogenesis. In order to evaluate the role of TET1 in fetal brain development, we generated TET1-overexpressing transgenic (TG) mice. TET1 overexpression was confirmed in the brains of fetal mice, and we detected 5hmC overexpression in the TG brains compared to that in the wild type (WT) brains, using a dot-blot assay. In order to observe the role of TET1 in fetal brain development, we examined fetal brain samples at varied time points by using real-time PCR, Western blotting, and Immunofluorescence (IF). We confirmed that TET1 contributes to neurogenesis by upregulating the protein expressions of neuronal markers in the TG mouse brains, as determined by Western blotting. However the cortex structure or brain mass between WT and TG mice showed no significant difference by IF. In conclusion, TET1 makes the start time of neurogenesis earlier in the TG brains compared to that in the WT brains during fetal brain development.

Critical role of Rgs19 in mouse embryonic stem cell proliferation and differentiation.

Mouse embryonic stem cells (ESCs) are self-renewing, pluripotent, and have the ability to differentiate into the three germ layers required to form all embryonic tissues. These properties are maintained by both intrinsic and extrinsic factors. Many studies have contributed to the understanding of the molecular signal transduction required for pluripotency and controlled differentiation. Such an understanding is important in the potential application of stem cells to cell therapy for disease, and thus there is an interest in understanding the cell cycle regulation, pluripotency, and differentiation of ESCs. The regulator of G protein signaling (RGS) family consists of over 20 members. Rgs19, one such protein, specifically interacts with Gαi to enhance its GTPase activity. Growth factor receptors use Gi proteins for signal transduction, and Rgs19 may thus be involved in the regulation of cell proliferation. In a previous gain-of-function study, Rgs19 overexpression was found to enhance proliferation in various cell types. Our data demonstrate a role for Rgs19 in the regulation of ESC differentiation. Based on the presence of Rgs19 in ESCs, the morphological and molecular properties of wild-type and Rgs19 +/- ESCs during LIF withdrawal, in vitro differentiation, and teratoma formation were compared. Our findings provide insight for the first time into the mechanisms involved in Rgs19 regulation of mouse ESC proliferation and differentiation.

Over-expression of Roquin aggravates T cell mediated hepatitis in transgenic mice using T cell specific promoter.

Chronic hepatitis is a major cause of liver cancer, so earlier treatment of hepatitis might be reducing liver cancer incidence. Hepatitis can be induced in mice by treatment with Concanavalin A (Con A); the resulting liver injury causes significant CD4(+) T cell activation and infiltration. In these T cells, Roquin, a ring-type E3 ubiquitin ligase, is activated. To investigate the role of Roquin, we examined Con A-induced liver injury and T cell infiltration in transgenic (Tg) mice overexpressing Roquin specifically in T cells. In Roquin Tg mice, Con A treatment caused greater increases in both the levels of liver injury enzymes and liver tissue apoptosis, as revealed by TUNEL and H&E staining, than wild type (WT) mice. Further, Roquin Tg mice respond to Con A treatment with greater increases in the T cell population, particularly Th17 cells, though Treg cell counts are lower. Roquin overexpression also enhances increases in pro-inflammatory cytokines, including IFN-γ, TNF-α and IL-6, upon liver injury. Furthermore, Roquin regulates the immune response and apoptosis in Con A induced hepatitis via STATs, Bax and Bcl2. These findings suggest that over-expression of Roquin exacerbates T-cell mediated hepatitis.