GPR126, also known as ADGRG6, is one of the most deeply studied aGPCRs. Initially, GPR126 was thought to be a receptor associated with muscle development and was primarily expressed in the muscular and skeletal systems. With the deepening of research, it was found that GPR126 is expressed in multiple mammalian tissues and organs, and is involved in many biological processes such as embryonic development, nervous system development, and extracellular matrix interactions. Compared with other aGPCRs proteins, GPR126 has a longer N-terminal domain, which can bind to ligands one-to-one and one-to-many. Its N-terminus contains five domains, a CUB (complement C1r/C1s, Uegf, Bmp1) domain, a PTX (Pentraxin) domain, a SEA (Sperm protein, Enterokinase, and Agrin) domain, a hormone binding (HormR) domain, and a conserved GAIN domain. The GAIN domain has a self-shearing function, which is essential for the maturation, stability, transport and function of aGPCRs. Different SEA domains constitute different GPR126 isomers, which can regulate the activation and closure of downstream signaling pathways through conformational changes. GPR126 has a typical aGPCRs seven-transmembrane helical structure, which can be coupled to Gs and Gi, causing cAMP to up- or down-regulation, mediating transmembrane signaling and participating in the regulation of cell proliferation, differentiation and migration. GPR126 is activated in a tethered-stalk peptide agonism or orthosteric agonism, which is mainly manifested by self-proteolysis or conformational changes in the GAIN domain, which mediates the rapid activation or closure of downstream pathways by tethered agonists. In addition to the tethered short stem peptide activation mode, GPR126 also has another allosteric agonism or tunable agonism mode, which is specifically expressed as the GAIN domain does not have self-shearing function in the physiological state, NTF and CTF always maintain the binding state, and the NTF binds to the ligand to cause conformational changes of the receptor, which somehow transmits signals to the GAIN domain in a spatial structure. The GAIN domain can cause the 7TM domain to produce an activated or inhibited signal for signal transduction, For example, type IV collagen interacts with the CUB and PTX domains of GPR126 to activate GPR126 downstream signal transduction. GPR126 has homology of 51.6%-86.9% among different species, with 10 conserved regions between different species, which can be traced back to the oldest metazoans as well as unicellular animals.In terms of diseases, GPR126 dysfunction involves the pathological process of bone, myelin, embryo and other related diseases, and is also closely related to the occurrence and development of malignant tumors such as breast cancer and colon cancer. However, the biological function of GPR126 in various diseases and its potential as a therapeutic target still needs further research. This paper focuses on the structure, interspecies differences and conservatism, signal transduction and biological functions of GPR126, which provides ideas and references for future research on GPR126.

Membrane proteins are integral components of cellular membranes, accounting for approximately 30% of the mammalian proteome and serving as targets for 60% of FDA-approved drugs. They are critical to both physiological functions and disease mechanisms. Their functional protein-protein interactions form the basis for many physiological processes, such as signal transduction, material transport, and cell communication. Membrane protein interactions are characterized by membrane environment dependence, spatial asymmetry, weak interaction strength, high dynamics, and a variety of interaction sites. Therefore, in situ analysis is essential for revealing the structural basis and kinetics of these proteins. This paper introduces currently available in situ analytical techniques for studying membrane protein interactions and evaluates the characteristics of each. These techniques are divided into two categories: label-based techniques (e.g., co-immunoprecipitation, proximity ligation assay, bimolecular fluorescence complementation, resonance energy transfer, and proximity labeling) and label-free techniques (e.g., cryo-electron tomography, in situ cross-linking mass spectrometry, Raman spectroscopy, electron paramagnetic resonance, nuclear magnetic resonance, and structure prediction tools). Each technique is critically assessed in terms of its historical development, strengths, and limitations. Based on the authors’ relevant research, the paper further discusses the key issues and trends in the application of these techniques, providing valuable references for the field of membrane protein research. Label-based techniques rely on molecular tags or antibodies to detect proximity or interactions, offering high specificity and adaptability for dynamic studies. For instance, proximity ligation assay combines the specificity of antibodies with the sensitivity of PCR amplification, while proximity labeling enables spatial mapping of interactomes. Conversely, label-free techniques, such as cryo-electron tomography, provide near-native structural insights, and Raman spectroscopy directly probes molecular interactions without perturbing the membrane environment. Despite advancements, these methods face several universal challenges: (1) indirect detection, relying on proximity or tagged proxies rather than direct interaction measurement; (2) limited capacity for continuous dynamic monitoring in live cells; and (3) potential artificial influences introduced by labeling or sample preparation, which may alter native conformations. Emerging trends emphasize the multimodal integration of complementary techniques to overcome individual limitations. For example, combining in situ cross-linking mass spectrometry with proximity labeling enhances both spatial resolution and interaction coverage, enabling high-throughput subcellular interactome mapping. Similarly, coupling fluorescence resonance energy transfer with nuclear magnetic resonance and artificial intelligence (AI) simulations integrates dynamic structural data, atomic-level details, and predictive modeling for holistic insights. Advances in AI, exemplified by AlphaFold’s ability to predict interaction interfaces, further augment experimental data, accelerating structure-function analyses. Future developments in cryo-electron microscopy, super-resolution imaging, and machine learning are poised to refine spatiotemporal resolution and scalability. In conclusion, in situ analysis of membrane protein interactions remains indispensable for deciphering their roles in health and disease. While current technologies have significantly advanced our understanding, persistent gaps highlight the need for innovative, integrative approaches. By synergizing experimental and computational tools, researchers can achieve multiscale, real-time, and perturbation-free analyses, ultimately unraveling the dynamic complexity of membrane protein networks and driving therapeutic discovery.

Aim To investigate the role of metabolites of eicosapentaenoic acid (EPA) in promoting the transdifferentiation of pancreatic α cells to β cells. Methods Male C57BL/6J mice were injected intraperitoneally with 60 mg/kg streptozocin (STZ) for five consecutive days to establish a type 1 diabetes (T1DM) mouse model. After two weeks, they were randomly divided into model groups and 97% EPA diet intervention group, 75% fish oil (50% EPA +25% DHA) diet intervention group, and random blood glucose was detected every week; after the model expired, the regeneration of pancreatic β cells in mouse pancreas was observed by immunofluorescence staining. The islets of mice (obtained by crossing GCG

ObjectiveTo explore the clinical efficacy and safety of Fuzheng Huaji Longbi decoction in treating benign prostatic hyperplasia （BPH） in the patients with the syndrome of healthy Qi deficiency and blood stasis. MethodA total of 94 BPH patients were randomized into control and observation groups， with 47 patients in each group. The control group was treated with doxazosin mesylate sustained-release tablets， and the observation group with Fuzheng Huaji Longbi decoction on the basis of the therapy in the control group. After eight weeks， the international prostate symptom score （IPSS）， quality of life （QOL） score， residual urine volume （RUV）， maximum urinary flow rate （Q_max）， TCM syndrome score， TCM symptom score， electrocardiogram， and liver and kidney function were determined to evaluate the clinical efficacy and safety of the two groups. ResultAfter 8 weeks of treatment， the total response rate in the control group was 63.64% （28/44）， which was lower than that （84.44%， 38/45） in the observation group （χ²=5.026， P<0.05）. The clinical efficacy in the observation group was higher than that in the control group （Z=-2.17， P=0.030）. The treatment in both groups decreased the IPSS， QOL score， RUV， and TCM syndrome scores and increased the Q_max （P<0.05）. Moreover， the observation group had lower IPSS， QOL score， RUV， and TCM syndrome score （P<0.05） and higher Q_max than the control group after treatment （P<0.05）. The treatment in the observation group decreased all the TCM symptom scores （P<0.05）， while that in the control group only decreased the frequency of urination at night and the scores of dysuria， weak urine stream， and post-urinary drainage （P<0.05）. After treatment， the observation group had lower frequency of urination at night and lower scores of mental fatigue， cold limbs， lower abdominal discomfort， and loose stool than the control group （P<0.05）. No adverse events associated with the administration of Fuzheng Huaji Longbi decoction were observed during the treatment period. ConclusionFuzheng Huaji Longbi decoction is effective in treating BPH in the patients with the syndrome of healthy qi deficiency and blood stasis. It can relieve the clinical symptoms and improve the quality of life， being a safe and reliable choice for clinical application.

Objective To explore the relationship and internal path between activities of daily living(ADL),sleep quality and mental health of community elderly people in Shanghai.Methods A questionnaire survey was conducted among community residents aged 60 years and older seeing doctors in community health care center of five streets in Shanghai during Sept to Dec,2021 using convenience sampling.Activities of Daily Living(ADL),Pittsburgh Sleep Quality Index(PSQI)and 10-item Kessler Psychological Distress Scale(K10)were adopted in the survey.Single factor analysis,correlation analysis and multiple linear regression were used to analyze the data.The effect relationship between the variables was tested using Bootstrap's mediated effects test.Results A total of 1 864 participants were included in the study.The average score was 15.53±4.47 for ADL,5.60±3.71 for PSQI and 15.50±6.28 for K10.The rate of ADL impairment,poor sleep quality,poor and very poor mental health of the elderly were 23.6%,27.3%,11.9%and 4.9%,respectively.ADL and sleep quality were all positively correlated with mental health(r=0.321,P＜0.001;r=0.466,P＜0.001);ADL was positively correlated with sleep quality(r=0.294,P＜0.001).Multiple linear results of factors influencing mental health showed that ADL(β= 0.457,95%CI:0.341-0.573),sleep quality(β =0.667,95%CI:0.598-0.737)and mental health were positively correlated(P＜0.001).Sleep quality partially mediated the relationship between ADL and mental health(95%CI:0.078-0.124)with an effect size of 33.0%.Conclusion Sleep quality is a mediator between ADL and mental health among community elderly people.Improving ADL and sleep quality may improve mental health in the population.

Objective:To study the current status of longitudinal extrauterine growth restriction (EUGR) in extremely preterm infants (EPIs) and to develop a prediction model based on clinical data from multiple NICUs.Methods:From January 2017 to December 2018, EPIs admitted to 32 NICUs in North China were retrospectively studied. Their general conditions, nutritional support, complications during hospitalization and weight changes were reviewed. Weight loss between birth and discharge > 1SD was defined as longitudinal EUGR. The EPIs were assigned into longitudinal EUGR group and non-EUGR group and their nutritional support and weight changes were compared. The EPIs were randomly assigned into the training dataset and the validation dataset with a ratio of 7∶3. Univariate Cox regression analysis and multiple regression analysis were used in the training dataset to select the independent predictive factors. The best-fitting Nomogram model predicting longitudinal EUGR was established based on Akaike Information Criterion. The model was evaluated for discrimination efficacy, calibration and clinical decision curve analysis.Results:A total of 436 EPIs were included in this study, with a mean gestational age of (26.9±0.9) weeks and a birth weight of (989±171) g. The incidence of longitudinal EUGR was 82.3%(359/436). Seven variables (birth weight Z-score, weight loss, weight growth velocity, the proportion of breast milk ≥75% within 3 d before discharge, invasive mechanical ventilation ≥7 d, maternal antenatal corticosteroids use and bronchopulmonary dysplasia) were selected to establish the prediction model. The area under the receiver operating characteristic curve of the training dataset and the validation dataset were 0.870 (95% CI 0.820-0.920) and 0.879 (95% CI 0.815-0.942), suggesting good discrimination efficacy. The calibration curve indicated a good fit of the model ( P>0.05). The decision curve analysis showed positive net benefits at all thresholds. Conclusions:Currently, EPIs have a high incidence of longitudinal EUGR. The prediction model is helpful for early identification and intervention for EPIs with higher risks of longitudinal EUGR. It is necessary to expand the sample size and conduct prospective studies to optimize and validate the prediction model in the future.

Obiective Alzheimer’s disease (AD) is a degenerative disease of the central nervous system (CNS) caused by a variety of risk factors. There are various pathological changes, but apoptosis of the neurological meridian cells is one of the most important pathological bases. Hyperlipidemia is a high-risk factor for the development of AD, which can lead to increased levels of oxidized low-density lipoprotein (ox-LDL) in brain tissues. PCSK9 is a protease closely related to lipid metabolism, but studies have shown that it may be related to the development of AD. LRP1 is abundantly expressed in neuronal cells, and it is an important transporter for the clearance of Aβ. There is now a large amount of literature confirming that PCSK9 can induce the degradation of LRP1. PI3K/AKT is an important signaling pathway in vivo, which plays an important role in apoptosis, and there is now a large amount of literature confirming that LRP1 activates the PI3K/AKT pathway, which has an anti-apoptotic effect. So can PCSK9 affect the PI3K/AKT pathway through LRP1 and thus regulate neuronal apoptosis? This deserves further investigation.The aim of this study was to explore the role of PCSK9 in mediating ox-LDL pro-apoptotic neuronal cell death and its mechanism, and then further elaborate the mechanism of hyperlipidemia leading to neurodegenerative diseases such as AD. MethodsFirstly, PC12 cells were treated with different concentrations of ox-LDL (0, 25, 50, 75 and 100 mg/L) for 24 h. Oil red O staining was used to detect lipid accumulation in PC12 cells, Hoechst33258 staining and flow cytometry to detect apoptosis in PC12 cells, ELISA to detect the content of Aβ secreted by PC12, Western blot to detect expression of SREBP2, PCSK9 and LRP1. Then PC12 cells were treated with 75 mg/L ox-LDL for different times (0, 6, 12, 24, 48 h), and Western blot were performed to detect the expression of SREBP2, PCSK9 and LRP1. Finally, after transfecting 100 nmol/L PCSK9 siRNA into PC12 cells for 48 h, PC12 cells were treated with 75 mg/L ox-LDL for 24 h, Hoechst33258 staining and flow cytometry to detect apoptosis rate of PC12 cells, and Western blot to detect PCSK9, LRP1, PI3K, AKT, P-PI3K , P-AKT, NF-κB, Bcl-2, Bax, Caspase-9 and Caspase-3 expression, and ELISA detected Aβ content secreted by PC12 cells. Resultsox-LDL increased lipid accumulation and promoted apoptosis and Aβ secretion in PC12 cells, as well as increasing the expression of SREBP2 and PCSK9 and decreasing the expression of LRP1 in PC12 cells. pCsk9 siRNA could be inhibited through the PI3K/AKT pathway and the NF-κB-Bcl-2/Bax-Caspase-9/3 pathway to inhibit ox-LDL-induced apoptosis in PC12 cells while increasing Aβ secretion in PC12 cells. Conclusionox-LDL plays a bidirectional regulatory role in ox-LDL-induced apoptosis of PC12 cells by inducing an increase in PCSK9 expression and a decrease in LRP1 expression in PC12 cells, which in turn affects different signaling pathways downstream.

Objective To study the pharmacokinetics and bioequivalence of two formulations of rasagiline mesylate tablets in healthy subjects under fasting and fed conditions.Methods The two-period,two-sequence,crossover study design was adopted in the fasting study.Thirty-six subjects were enrolled and given either test preparation or reference preparation 1 mg respectively in two periods.After collecting plasma samples,the plasma concentration of rasagiline was determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS)and the bioequivalence was evaluated using the average bioequivalence(ABE)method.The four-period,two-sequence,fully replicate crossover study design was adopted in the fed study.Forty-eight subjects were enrolled and given the test preparation or the reference preparation at a dose of 1 mg twice respectively in four periods.According to the degree of intra-individual variation of Cmax,AUC0-t and AUC0-∞,the equivalence was evaluated using the reference-scaled average bioequivalence and ABE method,respectively.Results In the fasting study,the pharmacokinetic parameters of rasagiline of the test and reference preparation were as follow:Cmax were(9.70±3.14)and(9.62±3.85)ng·mL-1,AUC0-t were(6.03±1.47)and(6.02±1.95)ng·h·mL-1,AUC0-∞ were(6.13±1.51)and(6.12±1.97)ng·h·mL-1.The 90％confidence interval(CI)of the geometric mean ratio(GMR)were 94.11％-118.06％,99.22％-107.74％and 99.16％-107.44％for Cmax,AUC0-t and AUC0-∞,respectively,which were within the acceptance criteria of 80.00％-125.00％.In the fed study,the pharmacokinetic parameters of rasagiline of the test and reference preparation were as follow:Cmax were(3.00±1.92)and(3.52±1.77)ng·mL-1,AUC0_t were(5.02±1.20)and(5.06±1.20)ng·h·mL-1,AUC0-∞ were(5.11±1.23)and(5.14±1.22)ng·h·mL-1.The 90％CI of GMR were 96.99％-101.19％and 97.17％-101.41％for AUC0-t and AUC0-∞,which were within the acceptance criteria of 80.00％-125.00％.The 95％upper confidence bound of Cmax for were less than"0",and the point estimate of GMR were within the acceptance criteria of 80.00％-125.00％.The incidence of adverse events in fasting and fed studies was 22.86％and 22.92％,respectively,and all adverse events were moderate to mild.Conclusion The two rasagiline mesylate tablets were bioequivalent,and both the formulations were well tolerated.

Objective To explore the difference in efficacy of metoprolol versus ivabradine in the treatment of postural orthostatic tachycardia syndrome(POTS)in the elderly after COVID-19 infection.Methods A total of 110 patients diagnosed with POTS at our department from Decem-ber 1,2022 to January 31,2023 were included.According to their drug regimen,they were divided into metoprolol group(62 patients)and ivabradine group(48 patients).On the 28th day of out-patient follow-up,the resting heart rate,heart rate of 10 min of standing,symptom disappearance rate,hospitalization rate,and mortality rate were compared between the two groups.Results On the 28th day of treatment,the resting heart rate and postural heart rate for 10 min were decreased in both groups when compared with the levels at initial diagnosis(P＜0.01).And there were no significant differences in the two types of heart rate between the two groups on the 28th day(71.0±7.0 vs 72.1±7.0,P=0.401;76.5±7.2 vs 77.4±7.6,P=0.573).No obvious differences were observed between the two groups in symptom disappearance rate,hospitalization rate,or mortality rate(88.7％vs 89.6％,3.2％vs2.1％,0％vs 0％,P＞0.05).Conclusion Metoprolol and ivabradine can effectively treat POTS in the elderly patients after COVID-19 infection.

ObjectiveTo observe the effect of Zhengan Xifengtang on blood pressure and fecal microflora of spontaneously hypertensive rats （SHRs）. MethodA total of 75 male SHRs aged nine weeks were randomly divided into SHR group， Benazepril group （1.00 mg·kg^-1·d^-1）， high-dose Zhengan Xifengtang group （34.5 g·kg^-1·d^-1）， medium-dose Zhengan Xifengtang group （17.25 g·kg^-1·d^-1）， and low-dose Zhengan Xifengtang group （8.625 g·kg^-1·d^-1）. A total of 15 male Wistar-Kyoto （WKY） rats aged nine weeks were selected as the normal group. The normal group and SHR group were administrated with an equal volume of distilled water for eight weeks. During the administration， the blood pressure of the rats was measured regularly. After the intervention， fresh feces were collected with a sterile frozen storage tube， and 16S amplicon information was collected and analyzed. Plasma， hippocampus， and ileum of rats were collected for ultra-high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） detection. ResultZhengan Xifengtang decreased the systolic blood pressure and diastolic blood pressure of SHRs. Compared with the SHR group， Zhengan Xifengtang decreased the diversity of fecal microflora of SHRs. At the phylum level， Zhengan Xifengtang increased the relative abundance of SHR Verrucomicrobia and Actinobacteria and decreased the relative abundance of Synergistetes， Tenericutes， and Candidatus Saccharibacteria. Compared with the SHR group， Zhengan Xifengtang increased the relative abundance of Blautia wexlerae， Fusicatenibacter saccharivorans， and Akkermansia muciniphila and decreased the relative abundance of Clostridium lavalense， Intestinimonas butyriciproducens， Acetatifactor muris， Alloprevotella rava， and Oscillibacter valericigenes. Spearman correlation analysis showed that the systolic blood pressure of rats was negatively correlated with the relative abundance of Ethanoligenens， Aerococcus， Butyrivibrio， Olsenella， Bifidobacterium， Clostridium XIVb， Allobaculum， and Fusicatenibacter and positively correlated with the relative abundance of Alloprevotella. Zhengan Xifengtang increased the contents of plasma， hippocampal 5-hydroxy tryptamine（5-HT）， and 5-hydroxyindole acetic acid（5-HIAA） in SHRs and decreased the contents of 5-HT and 5-HIAA in the ileum， and the content of 5-HT in the hippocampus was negatively correlated with that in the ileum. ConclusionZhengan Xifengtang can reduce the blood pressure of SHRs， which may be related to reducing the diversity of SHR microflora， regulating the structure of the microflora， increasing the relative abundance of 5-HT and short-chain fatty acids bacteria， and lowering the relative abundance of pathogenic bacteria related to intestinal inflammation.