Effects and potential mechanisms of IGF1/IGF1R in the liver fibrosis: A review.

Liver fibrosis is a wound-healing response due to persistent liver damage and it may progress to cirrhosis and even liver cancer if no intervention is given. In the current cognition, liver fibrosis is reversible. So, it is of great significance to explore the related gene targets or biomarker for anti-fibrosis of liver. Insulin like growth factor 1 (IGF1) and IGF1 receptor (IGF1R) are mainly expressed in the liver tissues and play critical roles in the liver function. The present review summarized the role of IGF1/IGF1R and its signaling system in liver fibrosis and illustrated the potential mechanisms including DNA damage repair, cell senescence, lipid metabolism and oxidative stress that may be involved in this process according to the studies on the fibrosis of liver or other organs. In particular, the roles of IGF1 and IGF1R in DNA damage repair were elaborated, including membrane-localized and nucleus-localized IGF1R. In addition, for each of the potential mechanism in anti-fibrosis of liver, the signaling pathways of the IGF1/IGF1R mediated and the cell species in liver acted by IGF1 and IGF1R under different conditions were included. The data in this review will support for the study about the effect of IGF1/IGF1R on liver fibrosis induced by various factors, meanwhile, provide a basis for the study of liver fibrosis to focus on the communications between the different kinds of liver cells.

Transcription-replication conflicts in primordial germ cells necessitate the Fanconi anemia pathway to safeguard genome stability.

Preserving a high degree of genome integrity and stability in germ cells is of utmost importance for reproduction and species propagation. However, the regulatory mechanisms of maintaining genome stability in the developing primordial germ cells (PGCs), in which rapid proliferation is coupled with global hypertranscription, remain largely unknown. Here, we find that mouse PGCs encounter a constitutively high frequency of transcription-replication conflicts (TRCs), which lead to R-loop accumulation and impose endogenous replication stress on PGCs. We further demonstrate that the Fanconi anemia (FA) pathway is activated by TRCs and has a central role in the coordination between replication and transcription in the rapidly proliferating PGCs, as disabling the FA pathway leads to TRC and R-loop accumulation, replication fork destabilization, increased DNA damage, dramatic loss of mitotically dividing mouse PGCs, and consequent sterility of both sexes. Overall, our findings uncover the unique source and resolving mechanism of endogenous replication stress during PGC proliferation, provide a biological explanation for reproductive defects in individuals with FA, and improve our understanding of the monitoring strategies for genome stability during germ cell development.

Mesenchymal stem cells combined with autocrosslinked hyaluronic acid improve mouse ovarian function by activating the PI3K-AKT pathway in a paracrine manner.

BACKGROUND: Declining ovarian function in advance-aged women and in premature ovarian insufficiency (POI) patients seriously affects quality of life, and there is currently no effective treatment to rescue ovarian function in clinic. Stem cell transplantation is a promising therapeutic strategy for ovarian aging, but its clinical application is limited due to the low efficiency and unclear mechanism. Here, a novel combination of umbilical cord-mesenchymal stem cells (UC-MSCs) and autocrosslinked hyaluronic acid (HA) gel is explored to rescue ovarian reserve and fecundity in POI and naturally aging mice. METHODS: To investigate HA prolonged the survival after UC-MSCs transplantation, PCR and immunofluorescence were performed to track the cells on day 1, 3, 7 and 14 after transplantation. The effects of HA on UC-MSCs were analyzed by CCK8 assay, RNA-sequencing and 440 cytokine array. In vivo experiments were conducted to evaluate the therapeutic effects of UC-MSCs combined with HA transplantation in 4-vinylcyclohexene diepoxide (VCD)-induced POI mice and naturally aging mice model. Ovarian function was analyzed by ovarian morphology, follicle counts, estrous cycle, hormone levels and fertility ability. To investigate the mechanisms of stem cell therapy, conditioned medium was collected from UC-MSCs and fibroblast. Both in vitro ovarian culture model and 440 cytokine array were applied to assess the paracrine effect and determine the underlying mechanism. Hepatocyte growth factor (HGF) was identified as an effective factor and verified by HGF cytokine/neutralization antibody supplementation into ovarian culture system. RESULTS: HA not only prolongs the retention of UC-MSCs in the ovary, but also boosts their secretory function, and UC-MSCs promote follicular survival by activating the PI3K-AKT pathway through a paracrine mechanism both in vitro and in vivo. More importantly, HGF is identified as the key functional cytokine secreted by MSCs. CONCLUSIONS: The results show that HA is an excellent cell scaffold to improve the treatment efficiency of UC-MSCs for ovarian aging under both physiological and pathological conditions, and the therapeutic mechanism is through activation of the PI3K-AKT pathway via HGF. These findings will facilitate the clinical application of MSCs transplantation for ovarian disorders.

HGF Secreted by Mesenchymal Stromal Cells Promotes Primordial Follicle Activation by Increasing the Activity of the PI3K-AKT Signaling Pathway.

Primordial follicle activation is fundamental for folliculogenesis and for the maintenance of fertility. An effective therapeutic strategy for patients with premature ovarian insufficiency (POI) is to promote the activation of residual primordial follicles. The secretome of human umbilical cord mesenchymal stromal cells (hUC-MSC-sec) contains several components that might promote the activation of primordial follicles. In the present study, we revealed that treatment with the hUC-MSC-sec significantly increased the proportion of activated primordial follicles in mouse ovaries both in vitro and in vivo. The activating effects of hUC-MSC-sec on primordial follicles were attributed to the activation of the PI3K-AKT signaling pathway by hepatocyte growth factor (HGF). While the effect of the hUC-MSC-sec was attenuated by the neutralizing antibodies against HGF, application of exogenous HGF alone also promoted the activation of primordial follicles. Furthermore, we demonstrated that HGF promoted the expression of KITL in granulosa cells by binding with the HGF receptor c-Met, thereby increasing the activity of the PI3K-AKT signaling pathway to activate primordial follicles. Taken together, our findings demonstrate that hUC-MSC-sec promotes primordial follicle activation through the functional component HGF to increase the PI3K-AKT signaling activity, highlighting the application of the hUC-MSC-sec or HGF for the treatment of POI patients.

Stem Cell Transplantation Improves Ovarian Function through Paracrine Mechanisms.

The ovary serves as the source of oocytes for the maintenance of female fertility and is a major supplier of sex hormones for endocrine homeostasis. Various circumstances such as genetic defects, autoimmune disorders, natural aging and environmental toxins can damage the ovaries leading to diminished ovarian function, and there are currently no effective treatment regimens for such loss of function. Stem cells show promise for treating many refractory diseases, and stem cell transplantation has been shown to be effective and safe as a new therapeutic method for ovarian injuries and ovarian aging in both animal models and women with premature ovarian insufficiency. However, the specific mechanisms that underlie the observed positive outcomes of improving ovarian function are not well understood. Evidence is mounting that stem cell-derived conditioned medium, exosomes, and trophic growth factors can also inhibit ovarian damage and alleviate the age-related fertility decline in female mice, indicating that stem cells exert the paracrine effects. Further studies to elucidate the cellular and molecular mechanisms, including signaling pathways, for improving ovarian function and promoting the secretory capacity of stem cells will fill the bench-to-bedside gap of stem cell therapy in the clinic. Furthermore, in-depth analyses of the stem cell secretome and identification of the key effective components will underlie a new paradigm in cell-free therapeutic strategies for ovarian insufficiency and ovarian aging.

CPEB1 deletion is not a common explanation for premature ovarian insufficiency in a Chinese cohort.

PURPOSE: Premature ovarian insufficiency (POI), which is characterized by early menopause before the age of 40 years, affects approximately 1-5% of women. Cytoplasmic polyadenylation element binding protein 1 (CPEB1) is a post-transcriptional regulatory protein that is highly expressed in germ cells and promotes oocytes maturation, and several studies have found microdeletions of chromosome 15q25.2, which contains the CPEB1 gene, in POI patients. However, the deleted region also includes other plausible genes, and thus the contribution of CPEB1 to POI is uncertain. The present study aimed to determine the relationship between CPEB1 deletion and POI in a Chinese cohort. MATERIAL AND METHODS: Quantitative real-time polymerase chain reaction (qPCR) with primers for exon 4 and exon 11 of CPEB1 was performed to detect the CPEB1 deletion in 323 patients with POI and in 300 healthy controls. Subsequent qPCR with primers for each exon of CPEB1 was performed to precisely localize the deletion locus. RESULTS: One patient with primary amenorrhea was found to carry a heterozygous deletion of exons 8-12 of the CPEB1 gene. CONCLUSION: Our study is the first to search for CPEB1 deletions in POI patients using a simple qPCR method, and we show that CPEB1 deletion is not a common cause for POI in a Chinese cohort.

High expression of HMBOX1 contributes to poor prognosis of gastric cancer by promoting cell proliferation and migration.

Homeobox-containing 1 (HMBOX1) has been reported to be associated with biological characteristics of some tumors, but its roles in gastric cancer have never been reported. In the present study, we found that HMBOX1 expression was significantly upregulated in gastric cancer tissues and cell lines and correlated with the TNM stage, lymph-node metastatic and the overall survival (OS) of patients of gastric cancer. The overexpression of HMBOX1 in gastric cancer cells enhanced cell proliferation by accelerating cell cycle, induced cell migration. In contrast, silencing HMBOX1 inhibited these processes. And the expression of HMBOX1 was related with the expression of vascular endothelial growth factor receptor (VEGFR), transforming growth factor-ß (TGF-ß) and CD133. What's more, we found that the expression of CD133 had a significantly positive correlation with HMBOX1 in gastric cancer tissues, and the co-expression of HMBOX1 and CD133 was significantly correlated with poor prognosis of gastric cancer patients, especially for patients at III and IV stage. In conclusion, HMBOX1 was upregulated in gastric cancer and correlated with gastric cancer cell proliferation and migration. Moreover, HMBOX1 combined CD133 might be useful to predict survival of patients with advanced gastric cancer.

Low expression level of HMBOX1 in high-grade serous ovarian cancer accelerates cell proliferation by inhibiting cell apoptosis.

Homeobox-containing 1 (HMBOX1) has been described as a transcription factor involved in the occurrence of some tumors, but its roles in ovarian cancer have never been reported. Here we aimed to investigate the roles of HMBOX1 on high-grade serous ovarian carcinoma (HGSOC). In this present study, HMBOX1 expression was decreased in HGSOC tissues and ovarian cancer cell lines (HO8910 and A2780) compared with ovarian surface epithelial tissues or normal human ovarian surface epithelial cell line (HOSEpiC). The cell proliferation of HOSEpiC was weaker than ovarian cancer cell lines. By altering the expression of HMBOX1 in A2780 and HOSEpiC, we demonstrated that HMBOX1 inhibited the cell proliferation and promoted the cell apoptosis. Furthermore, our study revealed that HMBOX1 downregulated the expression of anti-apoptotic proteins (Bcl-2, Bcl-xL), raised the expression of pro-apoptotic-regulated proteins (Bad, Bax), apoptotic executionior (Caspase3), and P53. In conclusion, HMBOX1 played important roles in occurrence of HGSOC through regulation of proliferation and apoptosis, which implied that HMBOX1 might serve as a new therapeutic target for HGSOC.

Gax suppresses chemerin/CMKLR1-induced preadipocyte biofunctions through the inhibition of Akt/mTOR and ERK signaling pathways.

Adipose tissue is closely associated with angiogenesis and vascular remodeling. Chemerin is involved in inflammatory reaction and vascular dysfunction. However, the mechanisms of chemerin participating in vascular remodeling and whether Growth arrest-specific homeobox (Gax) can effectively intervene it remain obscured. Here, 3T3-F442A preadipocytes were cultured, injected into athymic mice to model fat pads, and treated respectively with Ad-chemerin, Ad-Gax, or specific inhibitors in vitro and in vivo. MTT, flow cytometry, Western blotting, and imunohisto(cyto)-chemistry analyses showed that chemerin enhanced the expression of FABP4 and VEGF, activated Akt/mTOR and ERK pathways, increased the cell percent of S phase, decreased the percent of G0-G1 phase and apoptotic cells, and augmented neovascular density in fat pads. Inversely, Gax suppressed the expression of these adipogenic and vasifactive markers and these signaling proteins, decreased the percent of S phase cells, and increased those of G0-G1 phase and apoptotic cells, and reduced the neovascular density. Our results indicate that chemerin-CMKLR1 activates Akt/mTOR and ERK pathways and facilitates preadipocyte proliferation, adipogenesis, and angiogenesis. Contrarily, Gax weakens the effect of chemerin on preadipocyte biofunctions.

Elevated expression of the centromere protein-A(CENP-A)-encoding gene as a prognostic and predictive biomarker in human cancers.

Centromere protein-A (CENP-A), a histone-H3 variant, plays an essential role in cell division by ensuring proper formation and function of centromeres and kinetochores. Elevated CENP-A expression has been associated with cancer development. This study aimed to establish whether elevated CENP-A expression can be used as a prognostic and predictive cancer biomarker. Molecular profiling of CENP-A in human cancers was investigated using genomic, transcriptomic and patient information from databases, including COSMIC, Oncomine, Kaplan-Meier plotter and cBioPortal. A network of CENP-A co-expressed genes was derived from cBioPortal and analyzed using Ingenuity Pathway Analysis (IPA) and Oncomine protocols to explore the function of CENP-A and its predictive potential. Transcriptional and post-transcriptional regulation of CENP-A expression was analyzed in silico. It was found that CENP-A expression was elevated in 20 types of solid cancer compared with normal counterparts. Elevated CENP-A expression highly correlated with cancer progression and poor patient outcome. Genomic analysis indicated that the elevated CENP-A expression was not due to alterations in the sequence or copy number of the CENP-A gene. Furthermore, CENP-A can be regulated by key oncogenic proteins and tumor-suppressive microRNAs. CENP-A co-expression network analysis indicated that CENP-A function is associated with cell cycle progression. Oncomine analysis showed a strong correlation between elevated CENP-A expression and oncolytic response of breast cancer patients to taxane-based chemotherapy. In conclusion, elevated CENP-A expression is coupled to malignant progression of numerous types of cancer. It may be useful as a biomarker of poor patient prognosis and as a predictive biomarker for taxane-based chemotherapy.