Ginsenoside Rd enhances blood-brain barrier integrity after cerebral ischemia/reperfusion by alleviating endothelial cells ferroptosis via activation of NRG1/ErbB4-mediated PI3K/Akt/mTOR signaling pathway.

The incidence of ischemic stroke is increasing year by year and showing a younger trend. Impaired blood-brain barrier (BBB) is one of the pathological manifestations caused by cerebral ischemia, leading to poor prognosis of patients. Accumulating evidence indicates that ferroptosis is involved in cerebral ischemia/reperfusion injury (CIRI). We have previously demonstrated that Ginsenoside Rd (G-Rd) protects against CIRI-induced neuronal injury. However, whether G-Rd can attenuate CIRI-induced disruption of the BBB remains unclear. In this study, we found that G-Rd could upregulate the levels of ZO-1, occludin, and claudin-5 in ipsilateral cerebral microvessels and bEnd.3 cells, reduce endothelial cells (ECs) loss and Evans blue (EB) leakage, and ultimately improve BBB integrity after CIRI. Interestingly, the expressions of ACSL4 and COX2 were upregulated, the expressions of GPX4 and xCT were downregulated, the levels of GSH was decreased, and the levels of MDA and Fe2+ were increased in ischemic tissues and bEnd.3 cells after CIRI, suggesting that ECs ferroptosis occurred after CIRI. However, G-Rd can alleviate CIRI-induced BBB disruption by inhibiting ECs ferroptosis. Mechanistically, G-Rd prevented tight junction loss and BBB leakage by upregulating NRG1, activating its tyrosine kinase ErbB4 receptor, and then activating downstream PI3K/Akt/mTOR signaling, thereby inhibiting CIRI-induced ferroptosis in ECs. Taken together, these data provides data support for G-Rd as a promising therapeutic drug for cerebral ischemia.

Se-(Methyl)-selenocysteine ameliorates blood-brain barrier disruption of focal cerebral ischemia mice via ferroptosis inhibition and tight junction upregulation in an Akt/GSK3ß-dependent manner.

BACKGROUND: Ischemic stroke still ranks as the most fatal disease worldwide. Blood-brain barrier (BBB) is a promising therapeutic target for protection. Brain microvascular endothelial cell is a core component of BBB, the barrier function maintenance of which can ameliorate ischemic injury and improve neurological deficit. Se-methyl L-selenocysteine (SeMC) has been shown to exert cardiovascular protection. However, the protection of SeMC against ischemic stroke remains to be elucidated. This research was designed to explore the protection of SeMC from the perspective of BBB protection. METHODS: To simulate cerebral ischemic injury, C57BL/6J mice were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R), and bEnd.3 was exposed to oxygen-glucose deprivation/reoxygenation (OGD/R). After the intervention of SeMC, the barrier function and the expression of tight junction and ferroptosis-associated proteins were determined. For mechanism exploration, LY294002 (Akt inhibitor) was introduced both in vivo and in vitro. RESULTS: SeMC lessened the brain infarct volume and attenuated the leakage of BBB in mice. In vitro, SeMC improved cell viability and maintained the barrier function of bEnd.3 cells. The protection of SeMC was accompanied with ferroptosis inhibition and tight junction protein upregulation. Mechanism studies revealed that the effect of SeMC was reversed by LY294002, indicating that the protection of SeMC against ischemic stroke was mediated by the Akt signal pathway. CONCLUSION: These results suggested that SeMC exerted protection against ischemic stroke, which might be attributed to activating the Akt/GSK3ß signaling pathway and increasing the nuclear translocation of Nrf2 and ß-catenin, subsequently maintaining the integrity of BBB.

Schizophrenia-Like Behaviors Arising from Dysregulated Proline Metabolism Are Associated with Altered Neuronal Morphology and Function in Mice with Hippocampal PRODH Deficiency.

Despite decades of research being conducted to understand what physiological deficits in the brain are an underlying basis of psychiatric diseases like schizophrenia, it has remained difficult to establish a direct causal relationship between neuronal dysfunction and specific behavioral phenotypes. Moreover, it remains unclear how metabolic processes, including amino acid metabolism, affect neuronal function and consequently modulate animal behaviors. PRODH, which catalyzes the first step of proline degradation, has been reported as a susceptibility gene for schizophrenia. It has consistently been shown that PRODH knockout mice exhibit schizophrenia-like behaviors. However, whether the loss of PRODH directly impacts neuronal function or whether such neuronal deficits are linked to schizophrenia-like behaviors has not yet been examined. Herein, we first ascertained that dysregulated proline metabolism in humans is associated with schizophrenia. We then found that PRODH was highly expressed in the oreins layer of the mouse dorsal hippocampus. By using AAV- mediated shRNA, we depleted PRODH expression in the mouse dorsal hippocampus and subsequently observed hyperactivity and impairments in the social behaviors, learning, and memory of these mice. Furthermore, the loss of PRODH led to altered neuronal morphology and function both in vivo and in vitro. Our study demonstrates that schizophrenia-like behaviors may arise from dysregulated proline metabolism due to the loss of PRODH and are associated with altered neuronal morphology and function in mice.

The role of hyaluronan in renal cell carcinoma.

Renal cell carcinoma (RCC) is associated with high mortality rates worldwide and survival among RCC patients has not improved significantly in the past few years. A better understanding of the pathogenesis of RCC can enable the development of more effective therapeutic strategies against RCC. Hyaluronan (HA) is a glycosaminoglycan located in the extracellular matrix (ECM) that has several roles in biology, medicine, and physiological processes, such as tissue homeostasis and angiogenesis. Dysregulated HA and its receptors play important roles in fundamental cellular and molecular biology processes such as cell signaling, immune modulation, tumor progression and angiogenesis. There is emerging evidence that alterations in the production of HA regulate RCC development, thereby acting as important biomarkers as well as specific therapeutic targets. Therefore, targeting HA or combining it with other therapies are promising therapeutic strategies. In this Review, we summarize the available data on the role of abnormal regulation of HA and speculate on its potential as a therapeutic target against RCC.

Hepatocyte-specific TMEM16A deficiency alleviates hepatic ischemia/reperfusion injury via suppressing GPX4-mediated ferroptosis.

Ischemia/reperfusion (I/R)-induced liver injury with severe cell death is a major complication of liver transplantation. Transmembrane member 16A (TMEM16A), a component of hepatocyte Ca2+-activated chloride channel, has been implicated in a variety of liver diseases. However, its role in hepatic I/R injury remains unknown. Here, mice with hepatocyte-specific TMEM16A knockout or overexpression were generated to examine the effect of TMEM16A on hepatic I/R injury. TMEM16A expression increased in liver samples from patients and mice with I/R injury, which was correlated with liver damage progression. Hepatocyte-specific TMEM16A knockout alleviated I/R-induced liver damage in mice, ameliorating inflammation and ferroptotic cell death. However, mice with hepatic TMEM16A overexpression showed the opposite phenotype. In addition, TMEM16A ablation decreased inflammatory responses and ferroptosis in hepatocytes upon hypoxia/reoxygenation insult in vitro, whereas TMEM16A overexpression promoted the opposite effects. The ameliorating effects of TMEM16A knockout on hepatocyte inflammation and cell death were abolished by chemically induced ferroptosis, whereas chemical inhibition of ferroptosis reversed the potentiated role of TMEM16A in hepatocyte injury. Mechanistically, TMEM16A interacted with glutathione peroxidase 4 (GPX4) to induce its ubiquitination and degradation, thereby enhancing ferroptosis. Disruption of TMEM16A-GPX4 interaction abrogated the effects of TMEM16A on GPX4 ubiquitination, ferroptosis, and hepatic I/R injury. Our results demonstrate that TMEM16A exacerbates hepatic I/R injury by promoting GPX4-dependent ferroptosis. TMEM16A-GPX4 interaction and GPX4 ubiquitination are therefore indispensable for TMEM16A-regulated hepatic I/R injury, suggesting that blockades of TMEM16A-GPX4 interaction or TMEM16A inhibition in hepatocytes may represent promising therapeutic strategies for acute liver injury.

Corticosterone triggers anti-proliferative and apoptotic effects, and downregulates the ACVR1-SMAD1-ID3 cascade in chicken ovarian prehierarchical, but not preovulatory granulosa cells.

The coordinated proliferation and apoptosis of granulosa cells plays a critical role in follicular development. To identify the exact mechanisms of how stress-driven glucocorticoid production suppresses reproduction, granulosa cells were isolated from chicken follicles at different developmental stages and then treated with corticosterone. Using CCK-8, EDU and TUNEL assays, we showed that corticosterone could trigger both anti-proliferative and pro-apoptotic effects in granulosa cells from 6 to 8 mm follicles only, while depicting no influence on granulosa cells from any preovulatory follicles. High-throughput transcriptomic analysis identified 1362 transcripts showing differential expression profiles in granulosa cells from 6 to 8 mm follicles after corticosterone treatment. Interestingly, Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that 17 genes were enriched in the TGF-ß signaling pathway, and 13 showed differential expression patterns consistent with corticosterone-induced effects. The differential expression profiles of these 13 genes were examined by quantitative real-time PCR in cultured chicken ovarian granulosa cells at diverse developmental stages following corticosterone challenge for a short (8 h) or long period (24 h). After 24 h of treatment, INHBB, FST, FMOD, NOG, ACVR1, SMAD1 and ID3 were the genes that responded consistently with corticosterone-induced proliferative and apoptotic events in all granulosa cells detected. However, only ACVR1, SMAD1 and ID3 could initiate coincident expression patterns after being treated for 8 h, suggesting their significance in corticosterone-mediated actions. Collectively, these findings indicate that corticosterone can inhibit proliferation and cause apoptosis in chicken ovarian prehierarchical, but not preovulatory granulosa cells, through impeding ACVR1-SMAD1-ID3 signaling presumptively.

Verification of Bacteroidales 16S rRNA markers as a complementary tool for detecting swine fecal pollution in the Yangtze Delta.

To correctly assess and properly manage the public health risks associated with exposure to contaminated water, it is necessary to identify the source of fecal pollution in a watershed. In this study, we evaluated the efficacy of our two previously developed real time-quantitative PCR (qPCR) assays for the detection of swine-associated Bacteroidales genetic markers (gene 1-38, gene 3-53) in the Yangtze Delta watershed of southeastern China. The results indicated that the gene 1-38 and 3-53 markers exhibited high accuracy (92.5%, 91.7% conditional probability, respectively) in detecting Bacteroidales spp. in water samples. According to binary logistic regression (BLR), these two swine-associated markers were well correlated (P < 0.05) with fecal indicators (Escherichia coli and Enterococci spp.) and zoonotic pathogens (E. coli O157: H7, Salmonella spp. and Campylobacter spp.) in water samples. In contrast, concentrations of conventional fecal indicator bacteria (FIB) were not correlated with zoonotic pathogens, suggesting that they are noneffective at detecting fecal pollution events. Collectively, the results obtained in this study demonstrated that a swine-targeted qPCR assay based on two Bacteroidales genes markers (gene 1-38, gene 3-53) could be a useful tool in determining the swine-associated impacts of fecal contamination in a watershed.

Clcn3 deficiency ameliorates high-fat diet-induced obesity and adipose tissue macrophage inflammation in mice.

Obesity induces accumulation of adipose tissue macrophages (ATMs) and ATM-driven inflammatory responses that promote the development of glucose and lipid metabolism disorders. ClC-3 chloride channel/antiporter, encoded by the Clcn3, is critical for some basic cellular functions. Our previous work has shown significant alleviation of type 2 diabetes in Clcn3 knockout (Clcn3-/-) mice. In the present study we investigated the role of Clcn3 in high-fat diet (HFD)-induced obesity and ATM inflammation. To establish the mouse obesity model, both Clcn3-/- mice and wild-type mice were fed a HFD for 4 or 16 weeks. The metabolic parameters were assessed and the abdominal total adipose tissue was scanned using computed tomography. Their epididymal fat pad tissue and adipose tissue stromal vascular fraction (SVF) cells were isolated for analyses. We found that the HFD-fed Clcn3-/- mice displayed a significant decrease in obesity-induced body weight gain and abdominal visceral fat accumulation as well as an improvement of glucose and lipid metabolism as compared with HFD-fed wild-type mice. Furthermore, the Clcn3 deficiency significantly attenuated HFD-induced ATM accumulation, HFD-increased F4/80+ CD11c+ CD206- SVF cells as well as HFD-activated TLR-4/NF-κB signaling in epididymal fat tissue. In cultured human THP-1 macrophages, adenovirus-mediated transfer of Clcn3 specific shRNA inhibited, whereas adenovirus-mediated cDNA overexpression of Clcn3 enhanced lipopolysaccharide-induced activation of NF-κB and TLR-4. These results demonstrate a novel role for Clcn3 in HFD-induced obesity and ATM inflammation.

Fabrication Technology and Characteristics Research of a Monolithically-Integrated 2D Magnetic Field Sensor Based on Silicon Magnetic Sensitive Transistors.

A monolithically-integrated two-dimensional (2D) magnetic field sensor consisting of two difference structures (DSІ and DSII) is proposed in this paper. The DSІ and DSII are composed of four silicon magnetic sensitive transistors (SMST1, SMST2, SMST3 and SMST4) and four collector load resistors (RL1, RL2, RL3 and RL4). Based on the magnetic sensitive principle of SMST, the integrated difference structure can detect magnetic fields' component (Bx and By) along the x-axis and y-axis, respectively. By adopting micro-electromechanical systems (MEMS) and packaging technology, the chips were fabricated on a p-type <100> orientation silicon wafer with high resistivity and were packaged on printed circuit boards (PCBs). At room temperature, when the VCE = 5.0 V and IB = 8.0 mA, the magnetic sensitivities (Sxx and Syy) along the x-axis and the y-axis were 223 mV/T and 218 mV/T, respectively. The results show that the proposed sensor can not only detect the 2D magnetic field vector (B) in the xy plane, but also that Sxx and Syy exhibit good uniformity.

LNK deficiency aggravates palmitate-induced preadipocyte apoptosis.

LNK (SH2B3) is an intracellular adaptor protein that negatively regulates cellular proliferation or self-renewal of hematopoietic stem cells and some other progenitor cells. LNK is also recognized as a key regulator of insulin resistance and inflammatory responses in several tissues and organs. The function of LNK in adipose tissue is unknown. We previously demonstrated that type 2 diabetes mellitus (T2DM) mouse model had elevated serum free fatty acids (FFAs) levels and increased preadipocyte apoptosis in visceral fat tissue, showing the occurrence of lipotoxicity. Herein, when compared to control mice, the protein expression of LNK decreased in epididymal fat tissue from the high-sucrose/fat diet, low-dose streptozotocin induced T2DM mouse model. We thus investigated whether LNK could regulate palmitate-induced preadipocyte apoptosis in an in vitro apoptotic model in 3T3-L1 preadipocytes. LNK specific siRNA exacerbated palmitate-induced apoptosis and increased pro-apoptotic protein levels of cleaved caspase-3, Bax and cytochrome C; while overexpression of LNK cDNA exhibited significant anti-apoptotic effects. Consistently, LNK specific siRNA further decreased the Akt Ser-473 phosphorylation reduced by palmitate and located on upstream of Bax and cytochrome C. The siRNA-mediated LNK knockdown exacerbated mitochondrial membrane depolarization and mitochondrial-derived reactive oxygen species production induced by palmitate, whereas overexpression of LNK attenuated that. These results indicated that LNK plays a regulatory role in the palmitate-related preadipocyte apoptosis and might be involved in adipose tissue dysfunction.

Immune responsiveness to phytohemagglutinin displays species but not sex differences in three anuran species.

Phytohemagglutinin (PHA)-induced skin swelling response is widely used as a rough surrogate of integrative cell-mediated and innate immunity across multiple vertebrate taxa due to its simplification and feasibility. However, little is known whether there are sex and interspecific differences of immune responsiveness to PHA in ectotherms, especially for anurans. Therefore, we studied sex and species differences of PHA response in three anurans, Asiatic toads (Bufo gargarizans), Dark-spotted frogs (Pelophylax nigromaculatus) and Mongolian toads (Pseudepidalea raddei), captured in northern regions of Anhui Province (China). Footpad thickness was measured prior to (0 h) and after (6, 12, 24, 48 and 72 h) a PHA injection and normalized against saline injection in the opposite footpad. Body mass was recorded at the beginning (0 h) and end of each assay (72 h). Results showed effects of PHA assay, sex and taxa on body mass. Relative maximum swelling response (PHAmax) ranged from 18.58-29.75%, 9.77 to 20.56% and 21.97 to 31.78% and its occurrence over time was apparent 10.6-19.72 h , 7.74-14.01 h and 17.39-23.94 h postinjection for Asiatic toads, Dark-spotted frogs and Mongolian toads, respectively. Finally, the magnitude or timing of PHAmax in Dark-spotted frogs was significantly thinner and faster than in Mongolian toads, and Asiatic toads had an in-between value, not different from the other two species. The magnitude of PHAmax was significantly positively correlated with the timing of PHAmax considering individuals altogether, but not when analyzed within species. Our results indicate that male and female anuran species respond similarly to PHA antigen stimulation, but the magnitude and timing of PHAmax is species-specific. Briefly, we provide new evidence for the suitability of PHA assay in non-model anuran species with different body sizes, and exhort the need to further investigate the nature of PHA assay at the hematological and histological levels in order to extend its application in ecoimmunological studies of amphibians.

Overexpression of Lnk in the Ovaries Is Involved in Insulin Resistance in Women With Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) progression involves abnormal insulin signaling. SH2 domain-containing adaptor protein (Lnk) may be an important regulator of the insulin signaling pathway. We investigated whether Lnk was involved in insulin resistance (IR). Thirty-seven women due to receive laparoscopic surgery from June 2011 to February 2012 were included from the gynecologic department of the Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University. Samples of polycystic and normal ovary tissues were examined by immunohistochemistry. Ovarian cell lines underwent insulin stimulation and Lnk overexpression. Expressed Lnk underwent coimmunoprecipitation tests with green fluorescent protein-labeled insulin receptor and His-tagged insulin receptor substrate 1 (IRS1), and their colocalization in HEK293T cells was examined. Ovarian tissues from PCOS patients with IR exhibited higher expression of Lnk than ovaries from normal control subjects and PCOS patients without IR; mainly in follicular granulosa cells, the follicular fluid and plasma of oocytes in secondary follicles, and atretic follicles. Lnk was coimmunoprecipitated with insulin receptor and IRS1. Lnk and insulin receptor/IRS1 locations overlapped around the nucleus. IR, protein kinase B (Akt), and ERK1/2 activities were inhibited by Lnk overexpression and inhibited further after insulin stimulation, whereas IRS1 serine activity was increased. Insulin receptor (Tyr1150/1151), Akt (Thr308), and ERK1/2 (Thr202/Tyr204) phosphorylation was decreased, whereas IRS1 (Ser307) phosphorylation was increased with Lnk overexpression. In conclusion, Lnk inhibits the phosphatidylinositol 3 kinase-AKT and MAPK-ERK signaling response to insulin. Higher expression of Lnk in PCOS suggests that Lnk probably plays a role in the development of IR.

[Molecular beacon based PNA-FISH method combined with fluorescence scanning for rapid detection of Listeria monocytogenes].

Objective: To simplify the PNA-FISH (Peptide nucleic acid-fluorescence in situ hybridization) test, molecular beacon based PNA probe combined with fluorescence scanning detection technology was applied to replace the original microscope observation to detect Listeria monocytogenes Methods: The 5' end and 3' end of the L. monocytogenes specific PNA probes were labeled with the fluorescent group and the quenching group respectively, to form a molecular beacon based PNA probe. Results: When PNA probe used for fluorescence scanning and N1 treatment as the control, the false positive rate was 11.4%, and the false negative rate was 0; when N2 treatment as the control, the false positive rate decreased to 4.3%, but the false negative rate rose to 18.6%. When beacon based PNA probe used for fluorescence scanning, taken N1 treatment as blank control, the false positive rate was 8.6%, and the false negative rate was 1.4%; taken N2 treatment as blank control, the false positive rate was 5.7%, and the false negative rate was 1.4%. Compared with PNA probe, molecular beacon based PNA probe can effectively reduce false positives and false negatives. The success rates of hybridization of the two PNA probes were 83.3% and 95.2% respectively; and the rates of the two beacon based PNA probes were 91.7% and 90.5% respectively, which indicated that labeling the both ends of the PNA probe dose not decrease the hybridization rate with the target bacteria. Conclusions: The combination of liquid phase PNA-FISH and fluorescence scanning method, can significantly improve the detection efficiency.