The changing of α5-GABAA receptors expression and distribution participate in sevoflurane-induced learning and memory impairment in young mice.

BACKGROUND: Sevoflurane is a superior agent for maintaining anesthesia during surgical procedures. However, the neurotoxic mechanisms of clinical concentration remain poorly understood. Sevoflurane can interfere with the normal function of neurons and synapses and impair cognitive function by acting on α5-GABAAR. METHODS: Using MWM test, we evaluated cognitive abilities in mice following 1 h of anesthesia with 2.7%-3% sevoflurane. Based on hippocampal transcriptome analysis, we analyzed the differential genes and IL-6 24 h post-anesthesia. Western blot and RT-PCR were performed to measure the levels of α5-GABAAR, Radixin, P-ERM, P-Radixin, Gephyrin, IL-6, and ROCK. The spatial distribution and expression of α5-GABAAR on neuronal somata were analyzed using histological and three-dimensional imaging techniques. RESULTS: MWM test indicated that partial long-term learning and memory impairment. Combining molecular biology and histological analysis, our studies have demonstrated that sevoflurane induces immunosuppression, characterized by reduced IL-6 expression levels, and that enhanced Radixin dephosphorylation undermines the microstructural stability of α5-GABAAR, leading to its dissociation from synaptic exterior and resulting in a disordered distribution in α5-GABAAR expression within neuronal cell bodies. On the synaptic cleft, the expression level of α5-GABAAR remained unchanged, the spatial distribution became more compact, with an increased fluorescence intensity per voxel. On the extra-synaptic space, the expression level of α5-GABAAR decreased within unchanged spatial distribution, accompanied by an increased fluorescence intensity per voxel. CONCLUSION: Dysregulated α5-GABAAR expression and distribution contributes to sevoflurane-induced partial long-term learning and memory impairment, which lays the foundation for elucidating the underlying mechanisms in future studies.

Endocannabinoid System Components of the Female Mouse Reproductive Tract Are Modulated during Reproductive Aging.

The endocannabinoid (eCB) system has gained ground as a key modulator of several female fertility-related processes, under physiological/pathological conditions. Nevertheless, its modulation during reproductive aging remains unclear. This study aimed to investigate the expression levels of the main receptors (cannabinoid receptor 1,CB1; cannabinoid receptor 2, CB2; G-protein coupled receptor, GPR55; and transient receptor potential vanilloid type 1 channel, TRPV1) and metabolic enzymes (N-acylphosphatidylethanolamine phospholipase D, NAPE-PLD; fatty acid amide hydrolase, FAAH; monoacylglycerol lipase, MAGL; and diacylglycerol lipase, DAGL-α and -ß) of this system in the ovaries, oviducts, and uteri of mice at prepubertal, adult, late reproductive, and post-reproductive stages through quantitative ELISA and immunohistochemistry. The ELISA showed that among the receptors, TRPV1 had the highest expression and significantly increased during aging. Among the enzymes, NAPE-PLD, FAAH, and DAGL-ß were the most expressed in these organs at all ages, and increased age-dependently. Immunohistochemistry revealed that, regardless of age, NAPE-PLD and FAAH were mainly found in the epithelial cells facing the lumen of the oviduct and uteri. Moreover, in ovaries, NAPE-PLD was predominant in the granulosa cells, while FAAH was sparse in the stromal compartment. Of note, the age-dependent increase in TRPV1 and DAGL-ß could be indicative of increased inflammation, while that of NAPE-PLD and FAAH could suggest the need to tightly control the levels of the eCB anandamide at late reproductive age. These findings offer new insights into the role of the eCB system in female reproduction, with potential for therapeutic exploitation.

Distinct Disease Severity Between Children and Older Adults With Coronavirus Disease 2019 (COVID-19): Impacts of ACE2 Expression, Distribution, and Lung Progenitor Cells.

BACKGROUND: Children and older adults with coronavirus disease 2019 (COVID-19) display a distinct spectrum of disease severity yet the risk factors aren't well understood. We sought to examine the expression pattern of angiotensin-converting enzyme 2 (ACE2), the cell-entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the role of lung progenitor cells in children and older patients. METHODS: We retrospectively analyzed clinical features in a cohort of 299 patients with COVID-19. The expression and distribution of ACE2 and lung progenitor cells were systematically examined using a combination of public single-cell RNA-seq data sets, lung biopsies, and ex vivo infection of lung tissues with SARS-CoV-2 pseudovirus in children and older adults. We also followed up patients who had recovered from COVID-19. RESULTS: Compared with children, older patients (>50 years.) were more likely to develop into serious pneumonia with reduced lymphocytes and aberrant inflammatory response (P = .001). The expression level of ACE2 and lung progenitor cell markers were generally decreased in older patients. Notably, ACE2 positive cells were mainly distributed in the alveolar region, including SFTPC positive cells, but rarely in airway regions in the older adults (P < .01). The follow-up of discharged patients revealed a prolonged recovery from pneumonia in the older (P < .025). CONCLUSIONS: Compared to children, ACE2 positive cells are generally decreased in older adults and mainly presented in the lower pulmonary tract. The lung progenitor cells are also decreased. These risk factors may impact disease severity and recovery from pneumonia caused by SARS-Cov-2 infection in older patients.

Cloning and function analysis of high mobility group box 1(HMGB1)protein of Schistosoma japonicum(Mainland strain) / 中国血吸虫病防治杂志

Objective To clone and express a high mobility group box 1(HMGB1)protein of Schistosoma japonicum(Main-land strain)and analyze its function. Methods The DNA fragment of open reading frame encoding Sj HMGB1 protein was ampli-fied by RT-PCR from the mRNA of S. japonicum worms,then it was subcloned into the expression vector pET28a(+)to form the recombinant expression plasmid SjHMGB1-pET28a. The recombinant expression plasmid was transformed into the component E. coli BL21(DE3),and the tranformant containing recombinant expression plasmid was induced with IPTG to express the recombi-nant protein SjHMGB1. The recombinant SjHMGB1 protein was purified by affinity chromatography with nickel chelating affinity chromatography agarose gel. The Gel retard experiment and animal immunization were performed to analyze the DNA binding ca- pacity and the immunologic property of recombinant SjHMGB1. The expression levels of HMGB1 in different life cycle stages of S. japonicum were analyzed by Western bloting and RT-PCR. Female ICR mice were immunized with the recombinant SjHMGB1 pro-tein and infected with 45±2 cercariae of S. japonicum after three immunizations. Forty-two days post-infection,the worms and eggs of S. japonicum were recovered from the portal vein and liver tissue,respectively. The worm and egg reduction rates were calculat-ed respectively. Results A 530 bp of specific DNA fragment was amplified from mRNA of S. japonicum by RT-PCR,which was the open reading frame(ORF)encoding SjHMGB1protein confirmed by DNA sequencing analysis. The recombinant expression plasmid SjHMGB1-pET28a was constructed by cloning the ORF of SjHMGB1 into a expression vector pET28a(+). The bacterium transformants containing the recombinant plasmid expressed a soluble recombinant protein about 28 kDa after induced by IPTG, and the recombinant SjHMGB1 protein was purified by nickel chelating affinity chromatography. The gel retard experiment showed that the recombinant SjHMGB1 protein could bind to both supercoiled DNA and linear DNA,and the recombinant protein immu-nized mice produced high titers of antiserum IgG. Western bloting indicated that the recombinant SjHMGB1 protein was recognized specifically by the S. japonicum-infected mice serum. Above results showed that the recombinant SjHMGB1 protein possessed both functional activity and immunogenicity as the natural protein. RT-PCR and Western blot results showed that SjHMGB1 was abun-dantly expressed in the adult and egg stages whereas barely detectable in the cercaria stage. The immune protection experiment showed that the recombinant SjHMGB1 induced mice to produce high titers of specific antibody IgG but failed to conduct an effec-tive immune protection against S. japonicum. Conclusion The gene encoding HMGB1 from S. japonicum and the soluble recombi-nant SjHMGB1 protein with natural functional activity are obtained,and the recombinant SjHMGB1 has a high immunogenicity but is not able to induce an effective immune protection against S. japonicum.

TRPC1 expression and distribution in rat hearts.

Transient receptor potential canonical (TRPC) proteins have been identified as a family of plasma membrane calcium-permeable channels. TRPC proteins can be activated by various stimuli and act as cellular sensors in mammals. Stretch-activated ion channels (SACs) have been proposed to underlie cardiac mechano-electric feedback (MEF), although the molecular entity of SAC remains unknown. There is evidence suggesting that transient receptor potential canonical 1 (TRPC1) is a stretch-activated ion channel. As a non-selective cation channel, TRPC1 may cause stretch-induced depolarization and arrhythmia and thus may contribute to the MEF of the heart. In this study, we examined the expression patterns of TRPC1 in detail at both the mRNA and protein levels in rat hearts. We isolated total RNA from the left and right atria, and the left and right ventricles, and detected TRPC1 mRNA in these tissues using reverse-transcriptase polymerase chain reaction (RT-PCR). To study the protein localization and targeting, we performed immunohistochemistry and immunofluorescence labeling with the antibody against TRPC1. TRPC1 was detected in the cardiomyocytes of the ventricle and atrium at both the mRNA and protein levels. The cell membrane and T-tubule showed strong fluorescence labeling in the ventricular myocytes. Purkinje cells, the endothelial cells and smooth muscle cells of the coronary arterioles also displayed TRPC1 labeling. No TRPC1 was detected in fibroblasts. In conclusion, TRPC1 is widely expressed in the rat heart, including in working cells, Purkinje cells and vascular cells, suggesting that it plays an important role in the heart. The specific distribution pattern offered a useful insight into its function in adult rat ventricular cells. Further investigations are needed to clarify the role of TRPC1 in regulating cardiac activity, including cardiac MEF.