BACKGROUND: and purpose: Ghrelin is the endogenous ligand of the growth hormone secretagogue receptor (GHS-R1). Ghrelin, and GHS-R1, may have a role in placental growth and function, and its unacylated form desacylghrelin (DAG) could be involved in fetal growth. Nevertheless, the effects of DAG on placental function, and the receptor involved in its actions, remain to be determined. We aimed to investigate the effect of DAG in placental BeWo cells viability, proliferation, differentiation, and GSH-R1 expression. METHODS: BeWo cells, a human trophoblast cell line, was cultured with 3 nM DAG during 12, 24, 48, and 72 h. Cell viability, proliferation, differentiation (assessed by human Chorionic Gonadotropin quantification), and GSH-R1 expression were analyzed. To evaluate the mechanism of DAG effect on GSH-R1, 30 nM receptor antagonist ([D-Lys3]-GHRP-6) was added alone or in combination with 3 nM DAG during 12 h and 24 h. RESULTS: DAG has no effect on cell proliferation or viability, but it has an inhibitory effect on cell differentiation. DAG had a stimulatory effect on GSH-R1 expression at 12 and 24 h (p = 0.029 and p = 0.025, respectively). On the contrary, culture with 48 h DAG inhibits GSH-R1 expression compared to the control (p = 0.005), while GSH-R1 antagonist inhibited the effect of DAG on GSH-R1 expression. DAG also reduces intracellular (p = 0.020) and secreted (p = 0.011) hCG concentration in BeWo cells. CONCLUSION: DAG increases GHS-R1 expression, potentially mediated through GHS-R1 itself. DAG may also inhibit placental BeWo cell differentiation, suggesting a possible role of DAG in placental and fetal physiology.

Ovulation is the pinnacle of folliculogenesis, a process that requires an interplay between the oocyte, the granulosa cells, and the theca cells (TCs). TCs are the only source of ovarian androgens, which play a vital role in female fertility. However, abnormally elevated androgen levels reduce fertility. Therefore, uncovering novel mechanisms regulating androgen synthesis in TCs is of great significance. We have shown that salt-inducible kinases (SIKs) regulate granulosa cell steroidogenesis. Here, we investigated whether SIKs regulate androgen production in TCs. SIK2 and SIK3 were detected in the TCs of mouse ovaries and isolated TCs. Next, TCs in culture were treated with luteinizing hormone (LH) in the presence or absence of a highly specific SIK inhibitor. SIK inhibition enhanced the stimulatory effect of LH on steroidogenic gene expression and androgen production in a concentration-dependent manner. SIK inhibition alone stimulated the expression of steroidogenic genes and increased androgen production. Activation of adenylyl cyclase with forskolin or emulation of increased intracellular cyclic AMP levels stimulated steroidogenesis, an effect that was enhanced by the inhibition of SIK activity. The stimulatory effect of downstream targets of cyclic AMP was also significantly augmented by SIK inhibition, suggesting that SIKs control targets downstream cyclic AMP. Finally, it is shown that SIK2 knockout mice have higher circulating testosterone than controls. This evidence shows that TCs express SIKs and reveal novel roles for SIKs in the regulation of TC function and androgen production. This information could contribute to uncovering therapeutic targets to treat hyperandrogenic diseases.

BACKGROUND: Pyroptosis of retinal pigment epithelium (RPE) cells is associated with the etiology of diabetic retinopathy (DR). In this study, we investigated the effect of DNMT1 on RPE cell pyroptosis by regulating miR-20a/TXNIP expression through DNA methylation. METHODS: High glucose (HG)-induced ARPE-19 cells and mice were injected with streptozotocin (STZ) to generate DR cells and animal models. RT‒qPCR was used to detect the expression of miR-20a, and methylation-specific PCR (MS-PCR) was used to determine the occurrence of methylation of miR-20a. The expression of pyroptosis-related proteins (caspase-1 and NLRP3) and DNA methyltransferase (DNMT1) was detected by western blotting, and the expression of inflammatory factors (IL-1β and IL-18) was detected by ELISA. Apoptosis was detected by flow cytometry and TUNEL. HE staining was used to observe the pathological changes in retinal tissue in mice. RESULTS: In HG-induced DR cell models, the expression of miR-20a was significantly downregulated, while the expression of inflammatory factors (IL-1β, IL-18) and pyroptosis-associated proteins (caspase-1, NLRP3) was significantly upregulated. Transfection of miR-20a mimic can effectively reverse HG-induced pyroptosis and release of inflammatory factors. DNMT1 promotes miR-20a methylation and inhibits the expression of miR-20a. DNMT1-mediated methylation is involved in the pyroptosis process of high glucose-induced RPE cells, and silencing DNMT1 can promote the expression of miR-20a, thereby inhibiting the release of IL-1β and IL-18 and reducing the occurrence of cell pyroptosis. miR-20a targets negative regulation of TXNIP expression, and overexpression of TXNIP can effectively reverse the inhibitory effect of miR-20a on pyroptosis. The methylation inhibitor 5-AZ can inhibit the occurrence of pyroptosis and DR processes, while treatment with a miR-20a inhibitor or OE-TXNIP can reverse the effect of 5-AZ. CONCLUSION: DNMT1 promotes DNA methylation, decreases the expression of miR-20a and increases the expression of TXNIP, which ultimately leads to the occurrence of pyroptosis in RPE cells.

The placenta-secreted human chorionic gonadotropin (hCG) is a hormone that plays a critical role in inducing ovarian progesterone production, which is required for maintaining normal pregnancy. The bioavailability of hCG depends on the expression of the beta-subunit of hCG (hCG-β) which is encoded by the chorionic gonadotropin beta (CGB) gene. G protein-coupled estrogen receptor (GPER) is a membrane estrogen receptor involved in non-genomic estrogen signaling. Estradiol (E2) has been shown to stimulate hCG production. However, the role of the GPER in regulating CGB expression remains unknown. In the present study, our results revealed that treatment with G1 upregulated CGB expression in two human choriocarcinoma cell lines, BeWo and JEG-3, and primary human cytotrophoblast cells. In addition, G1 treatment activated the cAMP-response element binding protein (CREB). Using a pharmacological inhibitor and siRNA-mediated knockdown approach, we showed that the stimulatory effect of G1 on CGB expression is mediated by the protein kinase A (PKA)-CREB signaling pathway. This study increases the understanding of the role of GPER in the human placenta. In addition, our results provide important insights into the molecular mechanisms that mediate hCG expression, which may lead to the development of alternative therapeutic approaches for treating placental diseases.

Diabetes mellitus is a metabolic disease that is characterized by elevated blood sugar. Although glucagon-like peptide-1 receptor agonists (GLP-1RA) lower blood glucose in a glucose-dependent manner, most of them are macromolecule polypeptides. Macromolecular peptides are relatively expensive and inconvenient compared with small molecules. Therefore, this study sought to identify the small molecules binding to GLP-1R via cell membrane chromatography (CMC), confirm their agonistic activity, and further study its beneficial effects in a mouse model of type 2 diabetes mellitus (T2DM) induced by a combination of high-fat diet and streptozotocin. We used CMC, calcium imaging and molecular docking techniques to screen and identify the potential small molecule Schisandrin B (Sch B), which exhibits a strong binding effect to GLP-1R, from the small molecule library of traditional Chinese medicine. Through in-vitro experiments, we found that Sch B stimulated insulin secretion in β-TC-6 cells, while GLP-1R antagonist Exendin9-39, adenylate cyclase inhibitor SQ22536, and protein kinase A (PKA) inhibitor H89 could significantly inhibit the insulin secretion induced by Sch B. In vivo, Sch B significantly improved fasting blood glucose levels, intraperitoneal glucose tolerance test damage, and the status of pancreatic tissue damage, and reduced serum insulin levels, total cholesterol, triglyceride and low density lipoprotein in T2DM mice. These results indicate that Sch B alleviates T2DM by promoting insulin release through the GLP-1R/cAMP/PKA signaling pathway, suggesting that Sch B may be a potential GLP-1RA, which is expected to provide a new therapeutic strategy for the prevention and treatment of T2DM.

Patients with type II diabetes are exposed to a high risk of osteoporosis. The present study sought to exploit the detailed mechanisms of the SENP3/HIF-1α/PPAR-γ axis in osteoporosis. A rat model of type II diabetic osteoporosis was established, followed by the isolation of bone marrow mononuclear macrophages (BMMs). Gain- and loss-of-function assays were conducted in rat models and BMMs from rat models, followed by the evaluation of SENP3, HIF-1α, and PPAR-γ expression and detection of osteoclast differentiation-related indexes. Next, the SUMOylated modification of HIF-1α and the regulation of SENP3 on SUMOylated modification level of HIF-1α were assessed using immunoprecipitation, and the binding of HIF-1α to the PPARγ promoter was identified with ChIP and dual-luciferase reporter assays. SENP3 and HIF-1α expression was down-regulated in tissues of type II diabetes-induced osteoporotic rats and BMMs, with high SUMOylated modification levels of HIF-1α. Mechanically, HIF-1α was modified by SUMO2/3. SENP3 suppressed SUMOylated modification of HIF-1α and enhanced HIF-1α stability. HIF-1α bound to the PPAR-γ promoter and facilitated PPAR-γ transcription. SENP3 overexpression restrained osteoblast differentiation in type II diabetes-induced osteoporotic rats and BMMs from rat models. SENP3 knockdown facilitated osteoclast differentiation in type II diabetes-induced osteoporotic rats and BMMs from rat models, which was neutralized by further HIF-1α overexpression. To sum up, SENP3 overexpression restrained osteoclast differentiation in type II diabetic osteoporosis by increasing HIF-1α stability and expression and thus promoting PPAR-γ expression via de-SUMOylation, which might expand the understanding of the mechanisms of type II diabetes combined with osteoporosis.

The progression of diabetic kidney disease (DKD) is associated with increased fibronectin (FN) levels in proximal tubular epithelial cells. Bioinformatics analysis showed that integrin β6 and cell adhesion function were significantly changed in the cortices of db/db mice. Remodelling of cell adhesion is one of the core changes during epithelial-mesenchymal transition (EMT) in DKD. Integrin is a family of transmembrane proteins that regulates cell adhesion and migration, and extracellular FN is the major ligand of integrin β6. We found that the expression of integrin β6 was elevated in the proximal tubules of db/db mice and FN-induced renal proximal tubule cells. The levels of EMT were also significantly increased in vivo and in vitro. In addition, FN treatment activated the Fak/Src pathway, increased the expression of p-YAP, and then upregulated the Notch1 pathway in diabetic proximal tubules. Knockdown of integrin β6 or Notch1 reduced the EMT aggravation induced by FN. Furthermore, urinary integrin β6 was significantly increased in DKD patients. Our findings reveal a critical role of integrin β6 in regulating EMT in proximal tubular epithelial cells and identify a novel direction for the detection and treatment of DKD.

During pregnancy, the maternal body undergoes a considerable transformation regarding the anatomy, metabolism, and immune profile that, after delivery, allows for protection and nourishment of the offspring via lactation. Pregnancy hormones are responsible for the development and functionality of the mammary gland for breast milk production, but little is known about how hormones control its immune properties. Breast milk composition is highly dynamic, adapting to the nutritional and immunological needs that the infant requires in the first months of life and is responsible for the main immune modeling of breastfed newborns. Therefore, alterations in the mechanisms that control the endocrinology of mammary gland adaptation for lactation could disturb the properties of breast milk that prepare the neonatal immune system to respond to the first immunologic challenges. In modern life, humans are chronically exposed to endocrine disruptors (EDs), which alter the endocrine physiology of mammals, affecting the composition of breast milk and hence the neonatal immune response. In this review, we provide a landscape of the possible role of hormones in the control of passive immunity transferred by breast milk and the possible effect of maternal exposure to EDs on lactation, as well as their impacts on the development of neonatal immunity.

Diabetic patients are prone to acute myocardial infarction. Although reperfusion therapy can preserve the viability of the myocardium, it also causes fatal ischemia‒reperfusion injury. Diabetes can exacerbate myocardial ischemia‒reperfusion injury, but the mechanism is unclear. We aimed to characterize the effects of liraglutide on the prevention of ischemia‒reperfusion injury and inadequate autophagy. Liraglutide reduced the myocardial infarction area and improved cardiac function in diabetic mice. We further demonstrated that liraglutide mediated these protective effects by activating AMPK/mTOR-mediated autophagy. Liraglutide markedly increased p-AMPK levels and the LC3 II/LC3 I ratio and reduced p-mTOR levels and p62 expression. Pharmacological inhibition of mTOR increased cell viability and autophagy levels in high glucose and H/R-treated H9C2 cells. Overall, our study reveals that liraglutide acts upstream of the AMPK/mTOR pathway to effectively counteract high glucose- and H/R-induced cell dysfunction by activating AMPK/mTOR-dependent autophagy, providing a basis for the clinical prevention and treatment of ischemia‒reperfusion in diabetes.

Hypoxia in pancreatic islets (islet hypoxia) can occur in type 2 diabetes mellitus. Previously, our in vitro experiments demonstrated that pancreatic stellate cells (PSCs) within the islet are activated in hypoxia, promoting pancreatic β-cell death. Here, we aimed to demonstrate the in vivo activation of intra-islet PSCs and investigate the mechanism of PSC-induced β-cell death in hypoxia. A novel in vivo model of islet hypoxia was established by injecting fluorescent microspheres into a carotid artery of Balb/c mice (Microsphere mice). The intraperitoneal glucose tolerance (IPGTT) was performed, and pancreatic tissues were stained for insulin expression after tissue clearing. Pimonidazole staining was also performed in the pancreas to detect the presence of hypoxia in islets. Next, primary PSCs were isolated and cultured from Balb/c mice. Exosomes were isolated from culture media from PSCs cultured in hypoxia (1% oxygen). MicroRNAs (miRNAs) were prepared from exosomes from PSCs, and miRNA expression profiles were analyzed by miRNA sequencing. Several miRNAs were overexpressed in islets using miRNA mimics. Two weeks after injection of microspheres, the Microsphere mice showed worsening of glucose tolerance in IPGTT. Later, cataracts were developed in the eyes of the mice. The pancreas showed that the areas, perimeters, and diameters of insulin-positive cells decreased in Microsphere mice. Pimonidazole adducts were detected in the islets of these mice, indicating the presence of islet hypoxia. In addition, α-smooth muscle actin-positive cell numbers per islet were higher in Microsphere mice, confirming the in vivo activation of intra-islet PSCs in hypoxia. Mouse islets incubated with exosomes isolated from PSCs cultured in hypoxia showed a decrease in cell viability. The exosomes contained a variety of miRNAs, of which miR-23a-3p was found to notably increase β-cell death through apoptosis. Together, our in vivo and in vitro data provide evidence to support that PSCs within the islets are activated in hypoxia and promote β-cell death through exosomal miRNA transfer, which may contribute to the progression of type 2 diabetes mellitus.

Tubulointerstitial fibrosis (TIF) makes a key role in diabetic kidney disease (DKD). In this study, we revealed that the expressions of Egr1 and protease-activated receptor 1 (PAR1) were increased in renal tissues of DKD rats. In vitro experiments demonstrated that both Egr1 overexpression and high glucose (HG) condition could promote the expressions of PAR1, fibronectin (FN) and collagen I (COL I). Furthermore, HG stimulation enhanced the binding capacity of Egr1 to PAR1 promoter. Both HG condition and Egr1 upregulation could increase, and thrombin inhibitor did not affect activity of TGF-β1/Smad pathway via PAR1. Collectively, Egr1 is involved in TIF of DKD partly through activating TGF-β1/Smad pathway via transcriptional regulation of PAR1 in HG treated HK-2 cells.

Aldosterone regulates blood pressure (BP) through water and sodium balance. In our study, we studied if continuous treatment with a mineralocorticoid receptor antagonist, spironolactone (30 mg/kg/day) for 20 days can: 1) attenuate hypertension development and restore inverted 24-h BP rhythm in hypertensive transgenic (mRen-2)27 rats (TGR) measured by telemetry; 2) improve function of the kidneys and heart; 3) be protective against high salt load (1% in water) by mitigating oxidative injury and improving kidney function. Spironolactone decreased albuminuria and 8-isoprostane in normal and salt load conditions in BP-independent effects. Salt load increased BP, impaired autonomic balance, suppressed plasma aldosterone level and increased natriuresis, albuminuria and oxidative injury in TGR. Spironolactone did not restore the inverted 24-h rhythm of BP in TGR, therefore, mineralocorticoids are not crucial in regulation of BP daily profile. Spironolactone improved kidney function, decreased oxidative stress and was protective against high salt load in the BP-independent manner.

Congenital hypothyroidism (CH) due to thyroglobulin (TG) variants causes very low serum TG levels with normal or enlarged thyroid glands, depending on the severity of the defect, and with autosomal recessive inheritance. The purpose of this study was to functionally characterize p.Cys1281Tyr variant in the TG gene in order to increase our knowledge of the molecular mechanisms associated with CH. In order to find evidence that support the hypothesis that the p.Cys1281Tyr variant would affect the TG folding were performed amino acid prediction, 3D modeling and transient expression analysis in HEK293T cells. 18 of the 21″in silico" algorithms predict a deleterious effect of the p.Cys1281Tyr variant. The full-length 3D model p.Cys1281Tyr TG showed disulfide bond cleavage between the cysteines at positions 1249 and 1281 and rearrangement of the TG structure, while transient expression analysis indicated that p.Cys1281Tyr causes retention of the protein inside the cell. Consequently, these results show that this pathogenic variant makes it impossible for TG to fulfill its function in the biosynthesis process of thyroid hormones, causing CH. In conclusion, our results confirm the pathophysiological importance of misfolding of TG as a consequence of p.Cys1281Tyr variant located in the hinge module/flap region of TG.

Lipid metabolism disorders and mitochondrial dysfunction contribute to the progression of diabetes and chronic liver disease (CLD). Ferroptosis, as a form of cell death centered on reactive oxygen species (ROS) accumulation and lipid peroxidation, is closely related to mitochondrial dysfunction. However, whether there exists mechanistic links between these processes remains unknown. Here, to explore the molecular mechanism of diabetes complicated with CLD, we showed that high glucose could restrain the activity of antioxidant enzymes, promote mitochondrial ROS (mtROS) production, and induce a state of oxidative stress in the mitochondria of human normal liver (LO2) cells. We demonstrated that high glucose induced ferroptosis and promoted the development of CLD, which was reversed by the ferroptosis inhibitor Ferrostatin-1 (Fer-1). In addition, the mitochondria-targeting antioxidant Mito-TEMPO was used to intervene LO2 cells in high-glucose culture, and ferroptosis was found to be inhibited, whereas markers of liver injury and fibrosis improved. Furthermore, high glucose could promote ceramide synthetase 6 (CerS6) synthesis through the TLR4/IKKβ pathway. The knockout of CerS6 in LO2 cells showed that mitochondrial oxidative stress was attenuated, ferroptosis was inhibited, and markers of liver injury and fibrosis were ameliorated. In contrast, the overexpression of CerS6 in LO2 cells showed the opposite changes and these changes were inhibited by Mito-TEMPO. In short, we positioned the study of lipid metabolism to a specific enzyme CerS6, with a high degree of specificity. Our findings revealed the mechanism by which the mitochondria act as a bridge linking CerS6 and ferroptosis, confirming that under high glucose conditions, CerS6 promotes ferroptosis through mitochondrial oxidative stress, eventually leading to CLD.

Molecular iodine (I2) prevents oxidative stress and prostate hyperplasia induced by hyperandrogenism and reduces cell viability in prostate cancer cell lines. Here, we aimed to evaluate the protective effect of I2 and testosterone (T) on hyperestrogenism-induced prostate inflammation. Additionally, the effects of I2 and/or tumor necrosis factor (TNF) on cell viability and interleukin 6 (IL6) secretion were evaluated in a prostate cancer cell line (DU145). We also investigated whether the effects of I2 on viability are peroxisome proliferator-activated receptor gamma (PPARG)-dependent. Castrated (Cx) rats received pellets of either 17β estradiol (E2) or E2 and T and were treated with I2 (0.05%) in the drinking water for four weeks. The experimental groups were sham, Cx, Cx + E2, Cx + E2+I2, Cx + E2+T, and Cx + E2+T + I2. As expected, inflammation was triggered in the Cx + E2 group (high inflammation score; increase in TNF and transcriptional activity of RELA [nuclear factor-kappa B p65 subunit]), and this effect was diminished in the Cx + E2+T group (medium inflammation score and decrease in TNF). The lowest inflammation score (decrease of TNF and RELA and increase of PPARG) was obtained in the Cx + E2+T + I2 group. In DU145 cells, I2 (400 μM) and TNF (10 ng/ml) additively reduced cell viability, and I2 reduced the production of TNF-stimulated IL6. The PPARG antagonist (GW9662) did not inhibit the effects of I2 on the loss of cell viability. In summary, our data suggest that I2 and T exert a synergistic anti-inflammatory action on the normal prostate, and the interrelationship between I2 and TNF leads to anti-proliferative effects in DU145 cells. PPARG does not seem to participate in the I2-induced cell viability loss in the prostate.

The Anti-mullerian hormone (AMH), also known as Mullerian inhibiting substance (MIS), is a glycoprotein that belongs to transforming growth factor β superfamily. The significance of AMH during gonadal differentiation is not clearly deciphered in reptiles. Hence, current study aims to know the onset of AMH secretion and its functional role in Mullerian duct regression gonadal differentiation in tropical lizard, Calotes versicolor which exhibits a novel Female-Male-Female-Male (FMFM) pattern of temperature-dependent sex determination (TSD). The Immunohistochemistry and qRT-PCR techniques were employed to analyze the gonadal expression profile of AMH during different stages of embryonic development. The eggs of the lizard were incubated at both male-producing temperature (MPT: 25.5 ± 0.5 °C) and female-producing temperatures (FPT: 31.5 ± 0.5 °C). The results reveal that the onset of AMH gene expression was observed as early as oviposition prior to the immunolocalization of AMH protein at early-TSP (Temperature-sensitive period). The substantial rise in the intensity of the immunoreaction of AMH protein in the cytoplasm confining to Sertoli cells of seminiferous cords at MPT with low level of expression at FPT during gonadal sex differentiation, specify sexually dimorphic expression of AMH protein. Further, with the onset of sexual differentiation, the developing testis immensely expresses AMH gene which is 7-fold greater than that of transcripts levels in female embryos; signifies its conserved role in Mullerian duct regression thereby promoting testis differentiation. The robust immunnoexpression of AMH protein during post-gonadal differentiation coincides with the onset of the regression of Mullerian duct point out a positive correlation between testis differentiation and Mullerian duct regression, thus facilitating testis differentiation pathway. Based on the immunoexpression pattern of AMH protein and transcript levels of AMH gene, it is inferred that AMH plays a significant role in Mullerian duct regression, favoring testis differentiation.

Four-jointed box kinase 1 (Fjx1) is a planar cell polarity (PCP) protein and a member of the Fat (FAT atypical cadherin 1)/Dchs (Dachsous cadherin-related protein)/Fjx1 PCP complex. Fjx1 is also a non-receptor Ser/Thr protein kinase capable of phosphorylating Fat1 at is extracellular cadherin domains when it is being transported across the Golgi system. As such, Fjx1 is a Golgi-based regulator of Fat1 function by determining its extracellular deposition. Herein, Fjx1 was found to localize across the Sertoli cell cytoplasm, partially co-localized with the microtubules (MTs) across the seminiferous epithelium. It was most notable at the apical ES (ectoplasmic specialization) and basal ES, displaying distinctive stage-specific expression. The apical ES and basal ES are the corresponding testis-specific cell adhesion ultrastructures at the Sertoli-elongated spermatid interface and the Sertoli cell-cell interface, respectively, consistent with the role of Fjx1 as a Golgi-associated Ser/Thr kinase that modulates the Fat (and/or Dchs) integral membrane proteins. Its knockdown (KD) by RNAi using specific Fjx1 siRNA duplexes versus non-targeting negative control siRNA duplexes was found to perturb the Sertoli cell tight junction function, as well as perturbing the function and organization of MT and actin. While Fjx1 KD did not affect the steady-state levels of almost two dozens of BTB-associated Sertoli cell proteins, including structural and regulatory proteins, its KD was found to down-regulate Fat1 (but not Fat2, 3, and 4) and to up-regulate Dchs1 (but not Dchs2) expression. Based on results of biochemical analysis, Fjx1 KD was found to be capable of abolishing phosphorylation of its putative substrate Fat1 at its Ser/Thr sites, but not at its Tyr site, illustrating an intimate functional relationship of Fjx1 and Fat1 in Sertoli cells.

How the growth hormone (GH)/insulin-like growth factor (IGF) system affects osmoregulation in basal vertebrates remains unknown. We examined changes in the expression of components of the GH/IGF axis and gill ion transporters during metamorphosis and following seawater (SW) exposure of sea lamprey. During metamorphosis, increases in gill nka and nkcc1 and salinity tolerance were accompanied by increases in pituitary gh, liver igf1, gill ghr and igf1, but not liver ghr. SW exposure of fully metamorphosed sea lamprey resulted in slight increases in plasma chloride concentrations after SW exposure, indicating a high level of SW tolerance, but no major changes in mRNA levels of gill ion transporters or components of the GH/IGF axis. Our results indicate that metamorphosis is a critical point in the lifecycle of sea lamprey for stimulation of the GH/IGF axis and is temporally associated with and likely promotes metamorphosis and SW tolerance.

cAMP signaling is widely known to be indispensable for decidualization, but the details are not fully understood. Here, we show that cAMP signaling promotes AKT deactivation in endometrial stromal cells, which favors their decidualization. The deactivation of AKT is found to be a consequence of the reduced expression of several inhibitors of PP2A, the major phosphatase of AKT, with CIP2A being the most prominent. CIP2A reduction is obligatory for decidualization, as persistent CIP2A expression impairs chromatin remodeling and the expression of several decidualization markers (IGFBP1, PRL, MAOA, and IL-15). Furthermore, analyses of the responsiveness of the CIP2A promoter to cAMP signaling suggest the ETS family to be a bridge between cAMP signaling and CIP2A reduction. Our results provide novel insights into the role of cAMP signaling in decidualization and might benefit the development of novel therapies for decidualization deficiency, AKT-driven tumors, and the reverse, insulin resistance.

Assisted reproductive technology is widely accepted as an effective treatment to improve female fertility, but the decline of aging oocyte quality remains an important factor in the decrease of female fecundity. However, the effective strategies for improving oocyte aging are still not well understood. In the study, we demonstrated that ROS content and abnormal spindle proportion were increased and mitochondrial membrane potential was decreased in aging oocytes. However, supplementation of α-ketoglutarate (α-KG), an immediate metabolite in the tricarboxylic acid cycle (TCA), for 4 months to aging mice, significantly increased the ovarian reserve showed by more follicle numbers observed. In addition, the oocyte quality was significantly improved, as demonstrated by reduced fragmentation rate and decreased reactive oxygen species (ROS) levels, in addition to a lower rate of abnormal spindle assembly, thereby improving the mitochondrial membrane potential. Consistent with the in vivo data, α-KG administration also improved the post-ovulated aging oocyte quality and early embryonic development by improving mitochondrial functions and reducing ROS accumulation and abnormal spindle assembly. Our data revealed that α-KG supplementation might be an effective strategy to improve the quality of aging oocytes in vivo or in vitro.

Ubiquitination, a common type of post-translational modification, is known to affect various diseases, including cardiac hypertrophy. Ubiquitin-specific peptidase 2 (USP2) plays a crucial role in regulating cell functions, but its role in cardiac functions remains elusive. The present study aims to investigate the mechanism of USP2 in cardiac hypertrophy. Animal and cell models of cardiac hypertrophy were established using Angiotensin II (Ang II) induction. Our experiments revealed that Ang II induced USP2 downregulation in the in vitro and in vivo models. USP2 overexpression suppressed the degree of cardiac hypertrophy (decreased ANP, BNP, and β-MHC mRNA levels, cell surface area, and ratio of protein/DNA), calcium overload (decreased Ca2+ concentration and t-CaMKⅡ and p-CaMKⅡ, and increased SERCA2), and mitochondrial dysfunction (decreased MDA and ROS and increased MFN1, ATP, MMP, and complex Ⅰ and II) both in vitro and in vivo. Mechanically, USP2 interacted with MFN2 and improved the protein level of MFN2 through deubiquitination. Rescue experiments confirmed that MFN2 downregulation neutralized the protective role of USP2 overexpression in cardiac hypertrophy. Overall, our findings suggested that USP2 overexpression mediated deubiquitination to upregulate MFN2, thus alleviating calcium overload-induced mitochondrial dysfunction and cardiac hypertrophy.