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

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.

Objective To observe the therapeutic effect and mechanism of Astragaloside Ⅳ liposomes for influenza A virus infection in mice.Methods Fifty BALB/c mice were randomly divided into normal group(10 mice)and modeling group(40 mice).The modeling group mice were injected with A/PR/8/34(H1N1)influenza virus liquid via nasal drip.The modeling mice were randomly divided into model group,Oseltamivir group,and Astragaloside Ⅳ Liposomes high-and low-dose groups,with 10 mice in each group.The drug was administered by gavage two hours after infection for five days continuously.The appearance of the mice was observed,the body mass,survival condition and lung index as well as viral load in lung were assessed,pathological feature of lung tissue was observed by hematoxylin-eosin(HE)staining method,and mRNA expression levels of monocyte chemoattractant protein 1(MCP-1),macrophage inflammatory protein 1β(MIP-1β),and interferon γ(IFN-γ),CXC chemokine ligand 1(CXCL-1),interleukin(IL)-6,and IL-1β in lung tissues were detected by quantitative polymerase chain reaction(qPCR)method.Enzyme-linked immunosorbent assay(ELISA)was performed to detect the contents of granulocyte-macrophage colony-stimulating factor(GM-CSF)and regulated on activation normal T-cell expressed and secreted(RANTES)in mouse lung tissue.Results Compared with the normal group,mice in the model group showed significant decrease of body mass,shortened survival time(P＜0.001),significantly increased lung index(P＜0.001),significantly increased viral load in lung(P＜0.001),and significantly increased mRNA expression levels of MIP-1β,IFN-γ,CXCL-1,IL-6,IL-1β and MCP-1 in lung tissue(P＜0.05 or P＜0.001),and the structure destruction of lung tissue could be seen in pathology.Compared with the model group,mice in the Astragaloside Ⅳ liposomes high-dose group showed that the decrease in body mass was slowed down,the survival time and survival rate were higher(P＜0.05),and the lung index was significantly decreased(P＜0.05),the viral load in lung was decreased(P＜0.001)and the mRNA expression levels of MIP-1β,IFN-γ,CXCL-1,IL-6,IL-1β and MCP-1 in lung tissue were decreased,and the alveolar structure was relatively intact,and a little connective tissue hyperplasia was seen.Conclusion Astragaloside Ⅳ liposomes can improve the survival time and reduce the viral load of lung tissue in mice with influenza A virus infection,and its mechanism may be related to the inhibition of the expression of inflammatory factors,thus playing an antiviral role.

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective To explore characteristics of co-infection of Chlamydia pneumoniae(Cpn)and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),and identify their effect on SARS-CoV-2-induced inflammatory response.Methods Patients with coronavirus disease 2019(COVID-19)who received treatment in a hospital in Chenzhou City from December 20,2022 to February 20,2023 were selected.According to the severity of COVID-19,severe and critical cases were classified as the severe symptom group,while mild and moderate cases were classified as the mild symptom group.Meanwhile,according to the age of patients(≥18 years old as adults,＜18 years old as juveniles),they were divided into the adult severe symptom group,adult mild symptom group,juvenile severe symptom group,and juvenile mild symptom group.Propensity score was adopted to match age,gender,and under-lying diseases of patients in severe symptom and mild symptom group in a 1∶1 ratio.Bronchoalveolar lavage fluid(BALF),throat swabs,and serum specimens of patients were collected.Cpn IgG/IgM antibody was detected by enzyme-linked immunosorbent assay(ELISA),levels of 12 common cytokines(including interleukin-8[IL-8])in BALF were detected by flow cytometry,differences among groups were compared.Results A total of 102 patients were included,with 61 severe and critical(severe symptom)patients,as well as 41 mild and moderate(mild symp-tom)patients.There were 71 patients aged ≥18 years and 31 juvenile patients aged＜18 years.There were 39 pa-tients in the adult severe symptom group and 32 in the adult mild symptom group,and 30 pairs were successfully matched through propensity score analysis.There were 22 patients in the juvenile severe symptom group and 9 in the juvenile mild symptom group,and 8 pairs were successfully matched through propensity score analysis.Among COVID-19 patients,the positive rates of Cpn IgG and IgM were 36.27％(n=37)and 8.82％(n=9),respective-ly,with 1 case positive for both Cpn IgG and IgM.The level of interferon(IFN)-α in serum specimens from adult patients with severe symptom combined with positive Cpn IgG was higher than that of IgG negative patients(P=0.037).There was no statistically significant difference in the levels of other cytokines in BALF and serum speci-mens between the two groups of patients(all P＞0.05).The levels of IL-8 and IL-17 in serum specimens of patients with positive Cpn IgG in the adult mild symptom group were both higher than those in Cpn IgG negative patients(both P＜0.05).The levels of IL-8 in both BALF and serum specimens from Cpn IgM positivity patients in the ju-venile mild symptom group were higher than those from patients with negative Cpn IgM(both P＜0.05).Logistic regression analysis results showed that Cpn IgG and IgM positivity were not risk factors for the development of se-vere COVID-19.Conclusion Combined Cpn infection is not a risk factor for the development of severe symptom in COVID-19 patients,and Cpn infection has limited impact on the secretion of inflammatory factors caused by SARS-CoV-2.

AP2 transcription factors belong to the AP2/ERF superfamily and are involved in the regula-tion of various biological processes in plant growth and development,as well as in response to biotic and abiotic stresses.However,studies on the AP2 transcription factor family of Perilla frutescens have not been reported.In this study,totally 18 AP2 family members were identified from the Perilla frutescens ge-nome and analyzed for gene structure,conserved motifs,and cis-acting elements using bioinformatics.WRINKLED1(WRI1)is a key regulator of lipid biosynthesis in many plant species and plays an impor-tant role in the regulation of lipid synthesis.Sequence comparison revealed that one member of WRI1 is highly homologous to AtWRI1 and contains two conserved AP2 domains,named PfWRI1.The expression levels of PfAP2 family genes were analyzed in different tissues of Perilla frutescens and at different stages of seed development in conjunction with the transcriptome data,and the results showed that PfWRI1 is highly expressed only in the seeds of Perilla frutescens,suggesting that PfWRI1 may be related to the de-velopmental process of the seeds.The overexpression vector of plant pCAMBIA1303-PfWRI1 was con-structed,and wild-type(Col)and mutant(wri1-1)Arabidopsis thaliana were transformed by Agrobacte-rium tumefaciens to obtain overexpression and complementation lines,respectively.The results showed that the expression of P fWRI1 led to an increase in oil content of Arabidopsis seeds by 8.90％-13.57％compared with Col,and promoted the accumulation of oleic acid(C18:1)and linoleic acid(18:2)and reduced the accumulation of palmitic acid(C16:0),arachidonic acid(C20:0),and cis-11-Eicosenoic acid(C20:1)in transgenic Arabidopsis seeds.In addition,PfWRI1 gene expression increased the ex-pression of glycolysis and fatty acid biosynthesis-related genes AtPKP-α,AtPKP-β1,AtBCCP2,AtSUS2,and AtLIP1.Taken together,PfWRI1 may promote lipid accumulation by increasing unsaturated fatty acid content through interaction with the above genes.

Objective:To investigate the protective effect of endogenous ω-3 polyunsaturated fatty acid(PUFA)against cisplatin-induced myelosuppression and the mechanism of reducing apoptosis in bone marrow nucleated cells using mfat-1 transgenic mice.Methods:The experimental animals were divided into 4 groups:wild-type mice normal control group,mfat-1 transgenic mice normal control group,wild-type mice model group and mfat-1 transgenic mice model group.The mice in the model group were injected intraperitoneally with 7.5 mg/kg cisplatin on day 0 and day 7 to construct a myelosuppression model,while the mice in the normal control group were injected intraperitoneally with an equal amount of saline,and their status was observed and their body weight was measured daily.Peripheral blood was taken after 14 day for routine blood analysis,and the content and proportion of PUFA in peripheral blood were detected using gas chromatography.Bone marrow nucleated cells in the femur of mice were counted.The histopathological changes in bone marrow were observed by histopathological staining.The apoptosis of nucleated cells and the expression level changes of apoptosis-related genes in the bone marrow of mice were detected by flow cytometry and fluorescence quantitative PCR.Results:Compared with wild-type mice,mfat-1 transgenic mice showed significantly increased levels of ω-3 PUFA in peripheral blood and greater tolerance to cisplatin.Peripheral blood analysis showed that endogenous ω-3 PUFA promoted the recovery of leukocytes,erythrocytes,platelets and haemoglobin in peripheral blood of myelosuppressed mice.The results of HE staining showed that endogenous ω-3 PUFA significantly improved the structural damage of bone marrow tissue induced by cisplatin.Flow cytometry and PCR showed that,compared with wild-type mice model group,the apoptosis rate of bone marrow nucleated cells in mfat-1 transgenic mice was significantly reduced(P＜0.001),and the expression of anti-apoptotic genes Bcl-2 mRNA was significantly increased(P＜0.01),while the expressions of pro-apoptotic genes Bax and Bak mRNA were significantly reduced(P＜0.001,P＜0.05).Conclusion:Endogenous ω-3 PUFA can reduce cisplatin-induced apoptosis in bone marrow nucleated cells,increase the number of peripheral blood cells and exert a protective effect against cisplatin-induced myelosuppression by regulating the expression of apoptosis-related genes.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.