Paracrine effects of human amniotic epithelial cells protect against chemotherapy-induced ovarian damage

Abstract Background Human amniotic epithelial cells (hAECs) are attractive candidates for regenerative medical therapy, with the potential to replace deficient cells and improve functional recovery after injury. Previous studies have demonstrated that transplantation of hAECs effectively alleviate chemotherapy-induced ovarian damage via inhibiting granulose cells apoptosis in animal models of premature ovarian failure/insufficiency (POF/POI). However, the underlying molecular mechanism accounting for hAECs-mediated ovarian function recovery is not fully understood. Methods To investigate whether hAECs-secreting cytokines act as molecular basis to attenuate chemotherapy-induced ovarian injury, hAECs or hAEC-conditioned medium (hAEC-CM) was injected into the unilateral ovary of POF/POI mouse. Follicle development was evaluated by H&E staining at 1, 2 months after hAECs or hAEC-CM treatment. In addition, we performed a cytokine array containing 507 human cytokines on hAECs-derived serum-free conditioned medium. Finally, we further investigated whether hAECs could affect chemotherapy-induced apoptosis in primary human granulosa-lutein (hGL) cells and the tube formation of human umbilical vein endothelial cells (hUVECs) via a co-culture system in vitro. Results We observed the existence of healthy and mature follicles in ovaries treated with hAECs or hAEC-CM, whereas seriously fibrosis and many atretic follicles were found in the contralateral untreated ovaries of the same mouse. To distinguish cytokines involved in the process of hAECs-restored ovarian function, hAEC-CM was analyzed with a human cytokines array. Results revealed that 109 cytokines in hAEC-CM might participate in a variety of biological processes including apoptosis, angiogenesis, cell cycle and immune response. In vitro experiments, hAECs significantly inhibited chemotherapy-induced apoptosis and activated TGF-β/Smad signaling pathway within primary granulosa-lutein cells in paracrine manner. Furthermore, hAEC-CM was shown to promote angiogenesis in the injured ovaries and enhance the tube formation of human umbilical vein endothelial cells (hUVECs) in co-culture system. Conclusions These findings demonstrated that paracrine might be a key pathway in the process of hAECs-mediating ovarian function recovery in animal models of premature ovarian failure/insufficiency (POF/POI)

IRTKS Promotes Insulin Signaling Transduction through Inhibiting SHIP2 Phosphatase Activity

Insulin signaling is mediated by a highly integrated network that controls glucose metabolism, protein synthesis, cell growth, and differentiation. Our previous work indicates that the insulin receptor tyrosine kinase substrate (IRTKS), also known as BAI1-associated protein 2-like 1 (BAIAP2L1), is a novel regulator of insulin network, but the mechanism has not been fully studied. In this work we reveal that IRTKS co-localizes with Src homology (SH2) containing inositol polyphosphate 5-phosphatase-2 (SHIP2), and the SH3 domain of IRTKS directly binds to SHIP2’s catalytic domain INPP5c. IRTKS suppresses SHIP2 phosphatase to convert phosphatidylinositol 3,4,5-triphosphate (PI(3,4,5)P3, PIP3) to phosphatidylinositol (3,4) bisphosphate (PI(3,4)P2). IRTKS-knockout significantly increases PI(3,4)P2 level and decreases cellular PI(3,4,5)P3 content. Interestingly, the interaction between IRTKS and SHIP2 is dynamically regulated by insulin, which feeds back and affects the tyrosine phosphorylation of IRTKS. Furthermore, IRTKS overexpression elevates PIP3, activates the AKT–mTOR signaling pathway, and increases cell proliferation. Thereby, IRTKS not only associates with insulin receptors to activate PI3K but also interacts with SHIP2 to suppress its activity, leading to PIP3 accumulation and the activation of the AKT–mTOR signaling pathway to modulate cell proliferation

Clinical characteristics and prognostic nomograms of 12555 non-severe COVID-19 cases with Omicron infection in Shanghai

Abstract Background Omicron variant of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has rapidly become a global threat to public health. Numerous asymptomatic and mild cases had been admitted in shelter hospitals to quickly win the fight against Omicron pandemic in Shanghai. However, little is known about influencing factors for deterioration and length of stay (LOS) in hospitals among these non-severe cases. Methods This study included 12,555 non-severe cases with COVID-19 in largest shelter hospital of Shanghai, aiming to explore prognostic factors and build effective models for prediction of LOS. Results Data showed that 75.0% of participants were initially asymptomatic. In addition, 94.6% were discharged within 10 days, only 0.3% with deterioration in hospitals. The multivariate analysis indicated that less comorbidities (OR = 1.792, P = 0.012) and booster vaccination (OR = 0.255, P = 0.015) was associated with the decreased risk of deterioration. Moreover, age (HR = 0.991, P < 0.001), number of symptoms (HR = 0.969, P = 0.005), time from diagnosis to admission (HR = 1.013, P = 0.001) and Cycle threshold (CT) values of N gene (HR = 1.081, P < 0.001) were significant factors associated with LOS. Based on these factors, a concise nomogram model for predicting patients discharged within 3 days or more than 10 days was built in the development cohort. In validation cohort, 0.75 and 0.73 of Areas under the curve (AUC) in nomograms, similar with AUC in models of simple machine learning, showed good performance in estimating LOS. Conclusion Collectively, this study not only provides important evidence to deeply understand clinical characteristics and risk factors of short-term prognosis in Shanghai Omicron outbreaks, but also offers a concise and effective nomogram model to predict LOS. Our findings will play critical roles in screening high-risk groups, providing advice on duration of quarantine and helping decision-makers with better preparation in outbreak of COVID-19

Isovalerylspiramycin I inhibits proliferation, migration and invasion of osteosarcoma cells by targeting Topoisomerase 1 and suppressing the ataxia telangiectasia and Rad3‐related/checkpoint kinase 1 pathway

Abstract Purpose Topoisomerase 1 (TOP1) plays a crucial role in various cell cycle processes and its dysregulation can lead to the development of multiple tumours. However, conventional TOP1 inhibitors such as topotecan and irinotecan have poor clinical efficacy in osteosarcoma (OS) patients. This is partly due to the activation of the ataxia telangiectasia and Rad3‐related/checkpoint kinase 1 (ATR/CHEK1) DNA damage repair pathway, which repairs TOP1 poison‐induced DNA lesions, compromises the cytotoxicity of TOP1 inhibitors and contributes to drug resistance. Therefore, there is a need to develop more effective TOP1 inhibitors for OS. Experimental design In this study, we evaluated the antitumor effects of isovalerylspiramycin I (ISP‐I), a novel macrolide antibiotic, using various assays including CCK‐8 proliferation assays, wound healing migration assays, Transwell invasion assays, apoptosis, cell cycle, DNA replication and damage analyses on OS cells. We also performed a surface plasmon resonance‐high‐performance liquid chromatography‐mass spectrometry assay to identify ISP‐I's direct target protein in OS. Molecular docking analysis, thermoshift assays, enzyme activity assays and reverse tests were used to confirm ISP‐1′s target. Finally, we tested the efficacy of ISP‐I in vivo using a tumour xenograft model. Results Our results showed that ISP‐I significantly suppressed the growth of OS cells both in vitro and in vivo. Furthermore, ISP‐I dose‐dependently inhibited cell migration and invasion, and induced apoptosis and cell cycle arrest in OS cells. Mechanistically, ISP‐I directly bound to TOP1 and inhibited DNA replication. Additionally, ISP‐I significantly downregulated the ATR/CHEK1 pathway, which led to the suppression of DNA damage repair, ultimately augmenting DNA damage and triggering cell death. Conclusions In conclusion, our study suggests that ISP‐I could be a novel TOP1 inhibitor that does not activate the ATR/CHEK1 DNA damage repair pathway. This characteristic allows ISP‐I to synergistically inhibit OS cell proliferation, migration and invasion. ISP‐I may represent a promising candidate for the treatment of OS

Identification of a Molecular Activator for Insulin Receptor with Potent Anti-Diabetic Effects

Insulin exerts its actions through the insulin receptor (IR) and plays an essential role in diabetes. The inconvenient daily injection and undesirable side-effects associated with insulin injection demand novel drugs for the diseases. To search for bioactive insulin mimetics, we developed an in vitro screening assay using phospho-IR ELISA. After screening the small molecule chemical libraries, we have obtained a compound (5,8-diacetyloxy-2,3-dichloro-1,4-naphthoquinone) that provokes IR activation by directly binding to the receptor kinase domain to trigger its kinase activity at micromolar concentrations. This compound selectively activates IR but not other receptors and sensitizes insulin's action. Moreover, it elevates glucose uptake in adipocytes and has oral hypoglycemic effect in wild-type C57BL/6J mice and db/db and ob/ob mice without demonstrable toxicity. Hence, this promising compound mimics the biological functions of insulin and is useful for further drug development for diabetes treatment

The association of phosphoinositide 3-kinase enhancer A with hepatic insulin receptor enhances its kinase activity

Dysfunction of hepatic insulin receptor tyrosine kinase (IRTK) causes the development of type 2 diabetes. However, the molecular mechanism regulating IRTK activity in the liver remains poorly understood. Here, we show that phosphoinositide 3-kinase enhancer A (PIKE-A) is a new insulin-dependent enhancer of hepatic IRTK. Liver-specific Pike-knockout (LPKO) mice display glucose intolerance with impaired hepatic insulin sensitivity. Specifically, insulin-provoked phosphoinositide 3-kinase/Akt signalling is diminished in the liver of LPKO mice, leading to the failure of insulin-suppressed gluconeogenesis and hyperglycaemia. Thus, hepatic PIKE-A has a key role in mediating insulin signal transduction and regulating glucose homeostasis in the liver. © 2011 European Molecular Biology Organization.Link_to_subscribed_fulltex

Identification of a molecular activator for insulin receptor with potent anti-diabetic effects (Journal of Biological Chemistry (2011) 286, (37379-37388))

Link_to_subscribed_fulltex