Bitter taste TAS2R14 activation by intracellular tastants and cholesterol.

Bitter taste receptors, particularly TAS2R14, play central roles in discerning a wide array of bitter substances, ranging from dietary components to pharmaceutical agents1,2. TAS2R14 is also widely expressed in extra-gustatory tissues, suggesting its additional roles in diverse physiological processes and potential therapeutic applications3. Here, we present cryo-electron microcopy structures of TAS2R14 in complex with aristolochic acid, flufenamic acid and compound 28.1, coupling with different G protein subtypes. Uniquely, a cholesterol molecule is observed occupying what is typically an orthosteric site in class A GPCRs. The three potent agonists bind, individually, to the intracellular pockets, suggesting a distinct activation mechanism for this receptor. Comprehensive structural analysis, combined with mutagenesis, and molecular dynamic simulations studies, illuminate the receptor's broad-spectrum ligand recognition and activation via intricate multiple ligand-binding sites. Additionally, our study uncovers the specific coupling modes of TAS2R14 with gustducin and Gi1 proteins. These findings should be instrumental in advancing our knowledge underlying bitter taste perception and its broader implications in sensory biology and drug discovery.

Study on changing disciplinarian of beak colors in ducks and the regulation network based on transcriptome sequencing.

Beak color in ducks is a primary characteristic of local breeds and genetic resources. Among them, black beaks, a rare packaging trait of high-quality duck products, have attracted much attention. In this study, Runzhou White Created ducks (black beak) and white-feathered Putian black ducks (yellow beak) were used to construct the F2 generation resource population to study the changing discipline of beak color combined with the beak color statistics of gray-beaked ducklings of Runzhou White Created ducks. Subsequently, transcriptome sequencing was performed to identify genetic markers related to beak color. To explore the rules of beak color change and its regulatory network, trends, and trend analysis and weighted gene co-expression network analysis（WGCNA）were performed. The screening results were verified by real-time quantitative polymerase chain reaction. A large difference was observed between the beak colors of birds from the F1 generation at 0 and 42 d of age. The F2 generation results show that nearly half of the black-beaked ducklings become green-beaked; the proportion of black spots for gray- and patterned-beaked ducklings increases with age, with most becoming green-beaked. Moreover, the beak color darkened from the first day, and the gray color value decreased significantly from the second day. Transcriptome sequencing indicated that TYR was differentially expressed between black and yellow beaks at 4 to 6 wk of age, and trend and WGCNA analyses showed that EDNRB signaling pathway genes and MITF were highly expressed in the first week, and TYR, TYRP1, and DCT were highly expressed at 4 to 6 wk of age. Therefore, there is melanin synthesis and deposition after hatching for gray- and patterned-beaked ducklings, while the yellow pigment might be deposited in the epidermis of beaks for black-beaked ducklings. The EDNRB signaling pathway is probably involved in early melanosome maturation and melanin formation in duck beaks, and genes such as TYR can maintain the black-beak phenotype.

Substation of vermicompost mitigates Cd toxicity, improves rice yields and restores bacterial community in a Cd-contaminated soil in Southern China.

Cadmium (Cd) contamination in agricultural soil is a global concern for soil health and food sustainability because it can cause Cd accumulation in cereal grains. An in-situ stabilizing technology (using organic amendments) has been widely used for Cd remediation in arable lands. Therefore, the current study examined the influence of vermicompost (VC) on soil biochemical traits, bacterial community diversity and composition, Cd uptake and accumulation in rice plants and grain yield in a Cd-contaminated soil during the late growing season in 2022. Different doses of VC (i.e., V1 = 0 t ha-1, V2 = 3 t ha-1 and V3 = 6 t ha-1) and two concentrations of Cd (i.e., Cd1 = 0 and Cd2 = 50 mg Cd Kg-1 were used. We performed high-throughput sequencing of 16S ribosomal RNA gene amplicons to characterize soil bacterial communities. The addition of VC considerably affected the diversity and composition of the soil bacterial community; and increased the relative abundance of phyla Chloroflexi, Proteobacteria, Acidobacteriota, Plantomycetota, Gemmatimonadota, Patescibacteria and Firmicute. In addition, VC application, particularly High VC treatment, exhibited the highest bacterial diversity and richness (i.e., Simpson, Shannon, ACE, and Chao 1 indexes) of all treatments. Similarly, the VC application increased the soil chemical traits, including soil pH, soil organic carbon (SOC), available nitrogen (AN), total nitrogen (TN), total potassium (TK), total phosphorous (TP) and enzyme activities (i.e., acid phosphatase, catalase, urease and invertase) compared to non-VC treated soil under Cd stress. The average increase in SOC, TN, AN, TK and TP were 5.75%, 41.15%, 18.51%, 12.31%, 25.45% and 29.67%, respectively, in the High VC treatment (Pos-Cd + VC3) compared with Cd stressed soil. Redundancy analysis revealed that the leading bacterial phyla were associated with SOC, AN, TN, TP and pH, although the relative abundance of Firmicutes, Proteobacteria, Bacteroidata, and Acidobacteria on a phylum basis and Actinobacteria, Gammaproteobacteria and Myxococcia on a class basis, were highly correlated with soil environmental factors. Moreover, the VC application counteracted the adverse effects of Cd on plants and significantly reduced the Cd uptake and accumulation in rice organs, such as roots, stem + leaves and grain under Cd stress conditions. Similarly, applying VC significantly increased the fragrant rice grain yield and yield traits under Cd toxicity. The correlation analysis showed that the increased soil quantities traits were crucial in obtaining high rice grain yield. Generally, the findings of this research demonstrate that the application of VC in paddy fields could be useful for growers in Southern China by sustainably enhancing soil functionality and crop production.

Effect of exogenous hydrogen sulfide on hypoxia/reoxygenation injury in glomerular mesangial cells and its mechanism / 中国药理学通报

Aim To explore the effect of exogenous hydrogen sulfide ( H2 S ) on hypoxia/reoxygenation ( H/R) injury in glomerular mesangial cells and elucidate its relevant mechanism. Methods H/R induced mouse mesangial cell line ( SV40MES13 ) to establish cell damage model. Cell viability was detected by cell proliferation kit ( CCK8 ), the content of H

Evaluation of early effectiveness of local infiltration anesthesia with compound betamethasone in total knee arthroplasty / 中国修复重建外科杂志

OBJECTIVE@#To evaluate the early effectiveness of local infiltration anesthesia (LIA) with compound betamethasone in total knee arthroplasty (TKA).@*METHODS@#The clinical data of 102 patients with knee osteoarthritis who were treated by TKA and met the selection criteria between May 2022 and March 2023 were retrospectively analyzed. They were divided into control group and study group according to whether LIA preparation was added with compound betamethasone, with 51 cases in each group. There was no significant difference of baseline data, such as age, gender, body mass index, operative side, preoperative range of motion (ROM), Knee Society Score (KSS), white blood cell (WBC), and hematocrit between the two groups ( P>0.05). The intraoperative total blood loss and hidden blood loss were recorded, and WBC was recorded on the 1st, 2nd, and 3rd days after operation. Pain was assessed by visual analogue scale (VAS) score on the 1st, 2nd, and 3rd days after operation and morphine intake milligrames equivalent within 48 hours after operation. Passive ROM, maximum extension and flexion angles of knee joint were measured on the 3rd day after operation; the early postoperative complications were recorded.@*RESULTS@#There was no significant difference in total blood loss and hidden blood loss between the two groups ( P>0.05). The postoperative pain levels in both groups were relatively mild, and there was no significant difference in VAS scores in the first 3 days after operation and in morphine intake milligrams equivalent within 48 hours after operation between the two groups ( P>0.05). The WBC in the first 3 days after operation was significantly improved in both groups ( P<0.05). The WBC in the study group was significantly higher than that in the control group on the 1st and 2nd days after operation ( P<0.05), but there was no significant difference between the two groups on the 3rd day after operation ( P>0.05). On the 3rd day after operation, the maximum extension angle of knee joint in the study group was smaller than that in the control group, while the maximum flexion angle and passive ROM of knee joint in the study group were larger than those in the control group, and the differences were significant ( P<0.05). There were 6 cases of fever and 17 cases of deep venous thrombosis in the control group, and 1 case and 14 cases in the study group, respectively. There was no poor wound healing and periprosthetic joint infection in the two groups, and there was no significant difference in the incidence of complications between the two groups ( P>0.05).@*CONCLUSION@#The application of compound betamethasone in LIA during TKA is a safe and optimal strategy to promote the early postoperative rehabilitation of patients.

[Novel CD19-KIRS2/Dap12-BB CAR-T Treatment for 3 Patients with Relapsed and Refractory B-Cell Tumors].

OBJECTIVE: To investigate the safety and efficacy of novel CD19-KIRS2/Dap12-BB chimeric antigen receptor T cells (CAR-T cells) in the treatment of relapsed/refractory B-cell malignancy (R/R BCM). METHODS: Three patients with R/R BCM treated with novel CD19-KIRS2/Dap12-BB CAR-T cells from June 2020 to November 2020 were enrolled, including 1 case of B-cell acute lymphoblastic leukaemia (B-ALL) and 2 cases of non-Hodgkin's lymphoma (NHL), and the efficacy and adverse reactions were observed. RESULTS: After CAR-T cells infusion, patient with B-ALL achieved complete remission (CR) and minimal residual disease (MRD) turned negative, and 2 patients with NHL achieved partial remission (PR). Grade 2 cytokine release syndrome (CRS) occurred in B-ALL patient, grade 1 CRS occurred in 2 NHL patients, and grade II to IV hematologic adverse reactions occurred in 3 patients, all of which were controllable and reversible. The progression-free survival (PFS) of the 3 patients was 143, 199, and 91 days, and overall survival (OS) was 282, 430, and 338 days, respectively. CONCLUSION: The novel CD19-KIRS2/Dap12-BB CAR-T cells in treatment of 3 patients with R/R BCM have significant short-term efficacy and controllable adverse reactions, but the long-term efficacy needs to be further improved.

Prognostic significance of organ failure and infected pancreatic necrosis in acute pancreatitis: An updated systematic review and meta-analysis.

OBJECTIVES: In patients with acute pancreatitis (AP), minimally invasive treatment and the step-up approach have been widely used to deal with infected pancreatic necrosis (IPN) in the last decade. It is unclear whether IPN has become a less important determinant of mortality relative to organ failure (OF). We aimed to statistically aggregate recent evidence from published studies to determine the relative importance of IPN and OF as determinants of mortality in patients with AP (PROSPERO: CRD42020176989). METHODS: Relevant studies were sourced from MEDLINE and EMBASE databases. Relative risk (RR) or weighted mean difference (WMD) was analyzed as outcomes. A two-sided P value of less than 0.05 was regarded as statistical significance. RESULTS: Forty-three studies comprising 11 601 patients with AP were included. The mortality was 28% for OF patients and 24% for those with IPN. Patients with OF without IPN had a significantly higher risk of mortality compared to those with IPN but without OF (RR 3.72, P < 0.0001). However, patients with both OF and IPN faced the highest risk of mortality. Additionally, IPN increased length of stay in hospital for OF patients (WMD 28.75, P = 0.032). CONCLUSION: Though IPN remains a significant concern, which leads to increased morbidity and longer hospital stay, it is a less critical mortality determinant compared to OF in AP.

Long-term analysis of cellular immunity in patients with RRMM treated with CAR-T cell therapy.

Chimeric antigen receptor T (CAR-T) cell therapy exhibits remarkable efficacy against refractory or relapsed multiple myeloma (RRMM); however, the immune deficiency following CAR-Ts infusion has not been well studied. In this study, 126 patients who achieved remission post-CAR-Ts infusion were evaluated for cellular immunity. Following lymphodepletion (LD) chemotherapy, the absolute lymphocyte count (ALC) and absolute counts of lymphocyte subsets were significantly lower than baseline at D0. Grade ≥ 3 lymphopenia occurred in 99% of patients within the first 30 days, with most being resolved by 180 days. The median CD4+ T-cell count was consistently below baseline and the lower limit of normal (LLN) levels at follow-up. Conversely, the median CD8+ T-cell count returned to the baseline and LLN levels by D30. The median B-cell count remained lower than baseline level at D60 and returned to baseline and LLN levels at D180. In the first 30 days, 27 (21.4%) patients had 29 infections, with the majority being mild to moderate in severity (21/29; 72.4%). After day 30, 44 (34.9%) patients had 56 infections, including 20 severe infections. One patient died from bacteremia at 3.8 months post-CAR-Ts infusion. In conclusion, most patients with RRMM experienced cellular immune deficiency caused by LD chemotherapy and CAR-Ts infusion. The ALC and most lymphocyte subsets gradually recovered after day 30 of CAR-Ts infusion, except for CD4+ T cells. Some patients experience prolonged CD4+ T-cell immunosuppression without severe infection.

Design and Synthesis of Novel GPR139 Agonists with Therapeutic Effects in Mouse Models of Social Interaction and Cognitive Impairment.

The GPR139 receptor is an orphan G-protein-coupled receptor (GPCR) mainly found in the central nervous system and is a potential therapeutic target for the treatment of schizophrenia and drug addiction. Guided by the reported structure of GPR139, we conducted medicinal chemistry optimizations of TAK-041, the GPR139 agonist in clinical trials. New compounds with three different core structures were designed and synthesized, and their activity at GPR139 was evaluated. Among them, compounds 15a (EC50 = 31.4 nM) and 20a (EC50 = 24.7 nM) showed potent agonist activity at GPR139 and good pharmacokinetic properties. In murine schizophrenia models, both compounds rescued the social interaction deficits observed in BALB/c mice. Compound 20a also alleviated cognitive deficits in mice with a pharmacologically induced model of schizophrenia. These findings further demonstrated the potential of GPR139 agonists in alleviating the negative symptoms and cognitive deficits of schizophrenia. Compound 20a is worth further evaluation as an antischizophrenia drug candidate.

Identification of SNPs in MITF associated with beak color of duck.

Introduction: Beak color-a pigment-related trait-is an important feature of duck breeds. Recently, little research has addressed genetic mechanism of the beak colors in poultry, whereas the process and the regulation factors of melanin deposition have been well described. Methods: To investigate the genetic mechanism of beak colors, we conducted an integrated analysis of genomic selection signatures to identify a candidate site associated with beak color. For this, we used black-billed (Yiyang I meat duck synthetic line H1, H2, H3&HF) and yellow-billed ducks (Cherry Valley ducks and white feather Putian black duck). Quantitative real-time PCR and genotyping approaches were used to verify the function of the candidate site. Results: We identified 3,895 windows containing 509 genes. After GO and KEGG enrichment analysis, nine genes were selected. Ultimately, MITF was selected by comparing the genomic differentiation (FST). After loci information selection, 41 extreme significantly different loci were selected, which are all located in intron regions of MITF and are in almost complete linkage disequilibrium. Subsequently, the site ASM874695v1:10:g.17814522T > A in MITF was selected as the marker site. Furthermore, we found that MITF expression is significantly higher in black-beaked ducks than in yellow-beaked ducks of the F2 generation (p < 0.01). After genotyping, most yellow-billed individuals are found with homozygous variant; at the same time, there are no birds with homozygous variant in black-billed populations, while the birds with homozygous and heterozygous variant share the same proportion. Conclusion: MITF plays a very critical role in the melanogenesis and melanin deposition of duck beaks, which can effectively affect the beak color. The MITF site, ASM874695v1:10:g.17814522T > A could be selected as a marker site for the duck beak color phenotype.

Exogenous TiO2 Nanoparticles Alleviate Cd Toxicity by Reducing Cd Uptake and Regulating Plant Physiological Activity and Antioxidant Defense Systems in Rice (Oryza sativa L.).

Cadmium (Cd) is a potentially hazardous element with significant biological toxicity, negatively affecting plant growth and physio-biochemical metabolism. Thus, it is necessary to examine practical and eco-friendly approaches to reduce Cd toxicity. Titanium dioxide nanoparticles (TiO2-NPs) are growth regulators that help in nutrient uptake and improve plant defense systems against abiotic and biological stress. A pot experiment was performed in the late rice-growing season (July-November) 2022 to explore the role of TiO2-NPs in relieving Cd toxicity on leaf physiological activity, biochemical attributes, and plant antioxidant defense systems of two different fragrant rice cultivars, i.e., Xiangyaxiangzhan (XGZ) and Meixiangzhan-2 (MXZ-2). Both cultivars were cultivated under normal and Cd-stress conditions. Different doses of TiO2-NPs with and without Cd-stress conditions were studied. The treatment combinations were: Cd-, 0 mg/kg CdCl2·2.5 H2O; Cd+, 50 mg/kg CdCl2·2.5 H2O; Cd + NP1, 50 mg/kg Cd + 50 TiO2-NPs mg/L; Cd + NP2, 50 mg/kg Cd + 100 TiO2-NPs mg/L; Cd + NP3, 50 mg/kg Cd + 200 TiO2-NPs mg/L; Cd + NP4, 50 mg/kg Cd + 400 TiO2-NPs mg/L. Our results showed that the Cd stress significantly (p < 0.05) decreased leaf photosynthetic efficiency, stomatal traits, antioxidant enzyme activities, and the expression of their encoding genes and protein content. Moreover, Cd toxicity destabilized plant metabolism owing to greater accretion of hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels at vegetative and reproductive stages. However, TiO2-NPs application improved leaf photosynthetic efficacy, stomatal traits, and protein and antioxidant enzyme activities under Cd toxicity. Application of TiO2-NPs decreased the uptake and accumulation of Cd in plants and levels of H2O2 and MDA, thereby helping to relieve Cd-induced peroxidation damage of leaf membrane lipids by enhancing the activities of different enzymes like ascorbate peroxidase (APX), catalase (CAT), peroxidase (POS), and superoxide dismutase (SOD). Average increases in SOD, APX, CAT, and POS activities of 120.5 and 110.4%, 116.2 and 123.4%, 41.4 and 43.8%, and 36.6 and 34.2% in MXZ-2 and XGZ, respectively, were noted in Cd + NP3 treatment across the growth stages as compared with Cd-stressed plants without NPs. Moreover, the correlation analysis revealed that the leaf net photosynthetic rate is strongly associated with leaf proline and soluble protein content, suggesting that a higher net photosynthetic rate results in higher leaf proline and soluble protein content. Of the treatments, the Cd + NP3 (50 mg/kg Cd + 200 mg/L TiO2-NPs) performed the best for both fragrant rice cultivars under Cd toxicity. Our results showed that TiO2-NPs strengthened rice metabolism through an enhanced antioxidant defense system across the growth stages, thereby improving plant physiological activity and biochemical characteristics under Cd toxicity.

Goods and Bads of the Endocannabinoid System as a Therapeutic Target: Lessons Learned after 30 Years.

The cannabis derivative marijuana is the most widely used recreational drug in the Western world and is consumed by an estimated 83 million individuals (∼3% of the world population). In recent years, there has been a marked transformation in society regarding the risk perception of cannabis, driven by its legalization and medical use in many states in the United States and worldwide. Compelling research evidence and the Food and Drug Administration cannabis-derived cannabidiol approval for severe childhood epilepsy have confirmed the large therapeutic potential of cannabidiol itself, Δ9-tetrahydrocannabinol and other plant-derived cannabinoids (phytocannabinoids). Of note, our body has a complex endocannabinoid system (ECS)-made of receptors, metabolic enzymes, and transporters-that is also regulated by phytocannabinoids. The first endocannabinoid to be discovered 30 years ago was anandamide (N-arachidonoyl-ethanolamine); since then, distinct elements of the ECS have been the target of drug design programs aimed at curing (or at least slowing down) a number of human diseases, both in the central nervous system and at the periphery. Here a critical review of our knowledge of the goods and bads of the ECS as a therapeutic target is presented to define the benefits of ECS-active phytocannabinoids and ECS-oriented synthetic drugs for human health. SIGNIFICANCE STATEMENT: The endocannabinoid system plays important roles virtually everywhere in our body and is either involved in mediating key processes of central and peripheral diseases or represents a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of the components of this complex system, and in particular of key receptors (like cannabinoid receptors 1 and 2) and metabolic enzymes (like fatty acid amide hydrolase and monoacylglycerol lipase), will advance our understanding of endocannabinoid signaling and activity at molecular, cellular, and system levels, providing new opportunities to treat patients.

A Sensitivity-Optimized Flexible Capacitive Pressure Sensor with Cylindrical Ladder Microstructural Dielectric Layers.

Flexible capacitive pressure sensors have attracted extensive attention due to their dynamic response and good sensing capability for static and small pressures. Using microstructural dielectric layers is an effective method for improving performance. However, the current state of microstructure design is primarily focused on basic shapes and is largely limited by simulation results; there is still a great deal of potential for further innovation and improvement. This paper innovatively proposes to increase the ladder structure based on the basic microstructures, for example, the long micro-ridge ladder, the cuboid ladder, and cylindrical ladder microstructures. By comparing 9 kinds of microstructures including ladder structure through finite element simulation, it is found that the sensor with a cylindrical ladder microstructure dielectric layer has the highest sensitivity. The dielectric layers with various microstructures are obtained by 3D printed molds, and the sensor with cylindrical ladder microstructure dielectric layer has the sensitivity of 0.12 kPa-1, which is about 3.9 times higher than that without microstructure. The flexible pressure sensor developed by us boasts sensitivity-optimized and operational stability, making it an ideal solution for monitoring rainfall frequency in real time.

CD4+ conventional T cells-related genes signature is a prognostic indicator for ovarian cancer.

Introduction: It is believed that ovarian cancer (OC) is the most deadly form of gynecological cancer despite its infrequent occurrence, which makes it one of the most salient public health concerns. Clinical and preclinical studies have revealed that intratumoral CD4+ T cells possess cytotoxic capabilities and were capable of directly killing cancer cells. This study aimed to identify the CD4+ conventional T cells-related genes (CD4TGs) with respect to the prognosis in OC. Methods: We obtained the transcriptome and clinical data from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. CD4TGs were first identified from single-cell datasets, then univariate Cox regression was used to screen prognosis-related genes, LASSO was conducted to remove genes with coefficient zero, and multivariate Cox regression was used to calculate riskscore and to construct the CD4TGs risk signature. Kaplan-Meier analysis, univariate Cox regression, multivariate Cox regression, time-dependent receiver operating characteristics (ROC), decision curve analysis (DCA), nomogram, and calibration were made to verify and evaluate the risk signature. Gene set enrichment analyses (GSEA) in risk groups were conducted to explore the tightly correlated pathways with the risk group. The role of riskscore has been further explored in the tumor microenvironment (TME), immunotherapy, and chemotherapy. A risk signature with 11 CD4TGs in OC was finally established in the TCGA database and furtherly validated in several GEO cohorts. Results: High riskscore was significantly associated with a poorer prognosis and proven to be an independent prognostic biomarker by multivariate Cox regression. The 1-, 3-, and 5-year ROC values, DCA curve, nomogram, and calibration results confirmed the excellent prediction power of this model. Compared with the reported risk models, our model showed better performance. The patients were grouped into high-risk and low-risk subgroups according to the riskscore by the median value. The low-risk group patients tended to exhibit a higher immune infiltration, immune-related gene expression and were more sensitive to immunotherapy and chemotherapy. Discussion: Collectively, our findings of the prognostic value of CD4TGs in prognosis and immune response, provided valuable insights into the molecular mechanisms and clinical management of OC.

hMSH2 coordinated with the expression of E2F1 promotes platinum response in epithelial ovarian cancer.

OBJECTIVE: To explore underlying mechanisms that regulate hMSH2 expression and drug susceptibility in epithelial ovarian cancer (EOC). METHODS: Using data from the Cancer Genome Atlas (TCGA) we used bioinformatical analysis to predict transcription factors (TFs) that potentially regulate hMSH2. RT-qPCR, Western blot, and luciferase assays were undertaken using ovarian cancer cell lines to verify the identified TF. Expressions of the TF were modulated using overexpression or knockdown, and the corresponding cellular responses to cisplatin were examined. RESULTS: The TF, E2F1, was found to regulate the hMSH2 gene. The expression level of E2F1 correlated with cisplatin susceptibility in vitro. Kaplan-Meier analysis of 77 patients with EOC showed that low E2F1 expression was associated with worse survival. CONCLUSIONS: To our knowledge, this is the first report of E2F1 regulated MSH2 expression playing a role in drug resistance of platinum-based treatments for patients with EOC. Further work is need to confirm our results.

Structural basis of selective cannabinoid CB2 receptor activation.

Cannabinoid CB2 receptor (CB2R) agonists are investigated as therapeutic agents in the clinic. However, their molecular mode-of-action is not fully understood. Here, we report the discovery of LEI-102, a CB2R agonist, used in conjunction with three other CBR ligands (APD371, HU308, and CP55,940) to investigate the selective CB2R activation by binding kinetics, site-directed mutagenesis, and cryo-EM studies. We identify key residues for CB2R activation. Highly lipophilic HU308 and the endocannabinoids, but not the more polar LEI-102, APD371, and CP55,940, reach the binding pocket through a membrane channel in TM1-TM7. Favorable physico-chemical properties of LEI-102 enable oral efficacy in a chemotherapy-induced nephropathy model. This study delineates the molecular mechanism of CB2R activation by selective agonists and highlights the role of lipophilicity in CB2R engagement. This may have implications for GPCR drug design and sheds light on their activation by endogenous ligands.

RNA analysis of diet-induced sarcopenic obesity in rats.

Obesity has been suggested as a risk factor for sarcopenia. Sarcopenic obesity (SO), as a new category of obesity, is a high-risk geriatric syndrome in elderly individuals. However, knowledge about the molecular pathomechanisms of SO is still sparse. In the present study, starting at 13 months, male Sprague-Dawley (SD) rats were fed a high-fat diet (HFD) and normal diet (ND) for 28 weeks to establish a rodent animal model of SO with an identical protocol, which was further assessed and verified as a successful SO model. Through RNA-seq analysis of gastrocnemius muscle in SO rats, we found that differentially expressed genes (DEGs) and alternative splicing events (ASEs) focused mainly on inflammatory, immune-response, skeletal muscle cell differentiation, fat cell differentiation and antigen processing and presentation. Furthermore, as the core regulation factor of skeletal muscle, the mef2c (myocyte enhancer Factor 2C) gene also has a significant alternative 3' splice site (A3SS) and down-regulated expression in HFD-induced SO. The alternative genes targeted by mef2c identified by GO analysis were enriched in transcript regulation of RNA polymerase II promoter. In conclusion, these explorative findings in aging high-fat-fed rats might serve as a firm starting point for understanding the pathway and mechanism of sarcopenic obesity.

Structural insight into the constitutive activity of human orphan receptor GPR12.

G protein-coupled receptor 12 (GPR12) is an orphan G protein-coupled receptor that is highly expressed in the thalamus of the brain and plays a vital role in driving thalamocortical functions in short-term memory. GPR12 performs high constitutive activity and couples with Gs, increasing the intracellular cyclic adenosine monophosphate (cAMP) level when it is expressed. However, exploitation for drug development is limited since it is unclear how GPR12 initiates self-activation and signal transduction, and whether it can be modulated by endogenous or synthetic ligands. Here, we report the cryo-electron microscopy structure of the GPR12-Gs complex in the absence of agonists. Our structure reveals the key determinants for the intrinsically high basal activity of GPR12, including extracellular loop 2 partially occupying the orthosteric binding pocket, a tight-packed TM1 and TM7, and unique activation-related residues in TM6 and TM7. Together with mutagenesis data, this study will improve our understanding of the function and self-activation of the orphan receptor GPR12, enable the identification of endogenous ligands, and guide drug discovery efforts that target GPR12.

Diagnosis, prevalence, and outcomes of sarcopenia in kidney transplantation recipients: A systematic review and meta-analysis.

The prevalence of sarcopenia and its clinical predictors and clinical impact vary among kidney transplant recipients (KTRs), in part because of different diagnostic criteria. This study aimed to assess the reported diagnosis criteria of sarcopenia and compare them in terms of prevalence, clinical predictors, and impact of sarcopenia. The Medline, Embase, and Cochrane Library were searched for the full-length reports published until 28 January 2022. The subgroup analysis, meta-regression, and sensitivity analysis were performed and heterogeneity was assessed using the I2 . A total of 681 studies were retrieved, among which only 23 studies (including 2535 subjects, 59.7% men, mean age 49.8 years) were eventually included in the final analysis. The pooled prevalence in these included studies was 26% [95% confidence interval (95% CI): 20-34%, I2  = 93.45%], including 22% (95% CI: 14-32%, I2  = 88.76%) in men and 27% (95% CI: 14-41%, I2  = 90.56%) in women (P = 0.554 between subgroups). The prevalence of sarcopenia diagnosed using low muscle mass was 34% (95% CI: 21-48%, I2  = 95.28%), and the prevalence of using low muscle mass in combination with low muscle strength and/or low physical performance was 21% (95% CI: 15-28%, I2  = 90.37%) (P = 0.08 between subgroups). In meta-regression analyses, the mean age (regression coefficient: 1.001, 95% CI: 0.991-1.011) and percentage male (regression coefficient: 0.846, 95% CI: 0.367-1.950) could not predict the effect size. Lower body mass index (odds ratio (OR): 0.57, 95% CI: 0.39-0.84, I2  = 61.5%), female sex (OR: 0.31, 95% CI: 0.16-0.61, I2  = 0.0%), and higher age (OR: 1.08, 95% CI: 1.05-1.10, I2  = 10.1%) were significantly associated with a higher risk for sarcopenia in KTRs, but phase angle (OR: 0.81, 95% CI: 0.16-4.26, I2  = 84.5%) was not associated with sarcopenia in KTRs. Sarcopenia was not associated with rejections (risk ratio (RR): 0.67, 95% CI: 0.23-1.92, I2  = 12.1%), infections (RR: 1.03, 95% CI: 0.34-3.12, I2  = 87.4%), delayed graft functions (RR: 0.81, 95% CI: 0.46-1.43, I2  = 0.0%), and death (RR: 0.95, 95% CI: 0.32-2.82, I2  = 0.0%) in KRTs. Sarcopenia was found to be very common in KRTs. However, we have not found that sarcopenia had a negative impact on clinical health after kidney transplantation. Large study cohorts and multicentre longitudinal studies in the future are urgently needed to explore the prevalence and prognosis of sarcopenia in kidney transplant patients.