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.

Objective:To investigate the effects of different doses of ionizing radiation on the changes in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and reactive oxygen species (ROS) levels in the intestines of mice.Methods:C57BL/6 mice aged 6-8 weeks were randomly assigned to four groups (0 Gy, 0.1 Gy, 0.2 Gy, and 0.5 Gy; n=10/group) and subjected to single whole-body irradiation using a 60Co γ-ray source at a dose rate of 13 mGy/min. At 20 weeks post-irradiation, jejunal, ileal, and colonic tissues were collected. Immunohistochemistry, Western blotting, and reverse transcription-polymerase chain reaction (RT-PCR) were employed to assess mRNA and protein expression of NADPH oxidase components. Hydrogen peroxide (H 2O 2) levels and the expression of Nuclear Factor-kappa B (NF-κB), a transcriptional regulator of Dual Oxidase 2 (DUOX2), were also measured. Results:Compared with the 0 Gy group, mice in the 0.5 Gy group exhibited shortened villus length in the jejunum, villus fusion in the ileum, and increased crypt spacing in the colon, with statistically significant differences ( t=2.48, P < 0.05). No significant differences were observed in other dose groups compared to the 0 Gy group ( P > 0.05).The expression of H 2O 2 in the jejunum, ileum, and colon of the 0.1 Gy group was significantly elevated compared to the 0 Gy group ( t=4.12, 3.12, 3.12; P < 0.05). In the 0.5 Gy group, H 2O 2 expression in the jejunum and colon increased nearly twofold relative to the 0 Gy group ( t=8.67, 8.69; P < 0.05).At 20 weeks post-irradiation, DUOX2 protein expression levels in the jejunum, ileum, and colon were markedly higher in irradiated mice than in the 0 Gy group ( t=3.03, 10.29, 2.74; P < 0.05). DUOX2 mRNA levels in the jejunum, ileum, and colon of the 0.1 Gy group were significantly upregulated compared to the 0 Gy group ( t=12.75, 4.12, 11.14; P < 0.05). Additionally, NOX4 mRNA expression increased in the jejunum of the 0.2 Gy group ( t=4.54, P < 0.05) and in the ileum of the 0.1 Gy group ( t=4.13, P < 0.05).The nuclear factor kappa-B (NF-κB), a transcriptional regulator of DUOX2, showed an upward trend in expression in the jejunum, ileum, and colon of the 0.1 Gy group compared to the 0 Gy group, with statistically significant differences ( t=8.73, 8.18, 7.02; P < 0.05). Conclusion:Low-dose radiation induces long-term effects on the intestinal tract. Specifically, 0.5 Gy irradiation causes mild morphological alterations in the jejunum, ileum, and colon, while 0.1 Gy irradiation promotes the upregulation of DUOX2, a NADPH oxidase, in intestinal tissues.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

This study summarizes the preoperative and intraoperative nursing experience in 5 cases of bridge-to-transplant heart transplantation with left ventricular assist device(LVAD)explant.Key points of nursing include:preoperative care and assessment of LVAD patients,preoperative discussion of the multidisciplinary team,safe transfer of patients to surgical rooms and other preoperative preparation,cardiomyocardial protection and multidisciplinary team cooperation during bridging transplantation,and intra-operative patient safety management.All 5 patients in this group successfully completed the surgery and were discharged.Pressure sores,wound infections,and other postoperative complications have not occurred.Postoperative cardiac function of 5 patients in this group were classified as New York Heart Association class Ⅰ～Ⅱ.The follow-up period for the 5 patients in this group ranged from 6 months to 6 years.The results of the most recent echocardiography follow-up showed that the left ventricular ejection fraction of all patients was all above 65％,with well prognosis.

Objective:To investigate the clinical manifestation, therapy, and prognosis of Susac syndrome and enhance the understanding of this disease.Methods:A case summary was made.The clinical data of two siblings with Susac syndrome treated at Children′s Medical Center, Peking University First Hospital in January 2024 were summarized.Reported cases of pediatric Susac syndrome were reviewed.Results:The onset of the disease in the two siblings was at the age of 3.00 and 6.75 years, with recurrent headaches, tinnitus, hearing loss and encephalopathy symptoms.Cranial magnetic resonance imaging showed multiple cerebral microbleeding and microinfarction lesions, " snowball like" in the corpus callosum and diffuse white matter edema in the brain.Audiometry revealed sensorineural hearing loss.In one case, ophthalmic fluorescein angiography revealed ischemic changes due to branch retinal artery occlusions.No pathogenic variants were detected in gene testing.This child was diagnosed with Susac syndrome, and the symptoms were improved after treatment with Corticosteroids and Rituximab.No relapse was observed during the 9-month follow-up.A total of 20 pediatric cases of Susac syndrome were retrieved, including 18 reported previously and 2 cases from this study.There were 2 boys and 18 girls, with the age of onset ranging from 2.5 to 17.0 years.The common initial symptoms included headache (19 cases), vertigo and tinnitus or hearing loss (9 cases), and vision impairment or visual field defect (4 cases). The symptoms were improved after immunotherapy.Conclusions:With a low incidence, Susac syndrome is rare in children and difficult to diagnose.There may be a genetic predisposition in such disease.Early diagnosis and immunotherapy can low the relapse and improve the prognosis.

Aim To investigate the intervention effect of Rehmannia radix water extract on bleomycin(BLM)-induced pulmonary fibrosis in mice combined with metabolomics and to reveal the potential mechanism,in order to provide new ideas for clinical treatment of pul-monary fibrosis.Methods Male C57BL/6N mice were randomly divided into the control group,model group,pirfenidone group(positive control,PFD,270 mg·kg-1),and low dose(DH-L,4.55 g·kg-1)group,medium dose(DH-M,9.1 g·kg-1)group and high dose(DH-H,18.2 g·kg-1)group of Rehman-nia.Except for the control group,BLM(5 mg·kg-1)was instilled into the trachea to establish the model of pulmonary fibrosis in the other groups.The survival rate,lung index and blood oxygen saturation of mice in each group were evaluated.HE and Masson staining were used to observe the pathological changes of lung tissue.WBP was used to detect lung function.Flow cytometry was used to detect the apoptosis of primary lung cells,ROS and immune cells.ELISA was used to detect the levels of fibrosis markers and inflammatory factors(α-SMA,collagen Ⅰ,collagen Ⅲ,TGF-β1,TNF-α,IL-1 β,and IL-6).Biochemical method was employed to detect the contents of GSH-Px,T-SOD and MDA.Liquid chromatograph mass spectrometer(LC-MS)metabolomics was used to analyze the changes of serum metabolic profile.Results Water extract of Re-hmannia significantly increased the survival rate,oxy-gen saturation and lung function of mice with pulmona-ry fibrosis,reduced the lung coefficient,ameliorated pathological damage and collagen deposition in lung tissue,reduced the levels of apoptosis and oxidative stress,and down-regulated the levels of inflammatory factors in lung tissue.It regulated the levels of metabo-lites such as bile acid metabolism,sphingolipid metabo-lism,and unsaturated fatty acid metabolism.Conclu-sions Water extract of Rehmannia inhibits lung injury and collagen deposition in mice with pulmonary fibrosis by inhibiting inflammatory response,which may be a-chieved by regulating the levels of inflammatory factors through the metabolic pathways of bile acid and sphin-golipid.

″Boundarics in biomedicine″(or″Biomedical boundarics″)is an emerging frontier interdisciplinary subject that focuses on addressing key scientific issues related to the formation,identification,and evolution of biological boundaries within living organisms.In this field,the study of tumor boundaries is of particular importance.Imaging tumor boundaries not only helps to reveal the molecular mechanisms of tumor boundary evolution and interaction with the microenvironment,tumor invasion and metastasis,but is also crucial for clinical tumor diagnosis,treatment decision-making,efficacy monitoring and prognosis evaluation.Molecular probes,as functional substances that enhance imaging signals,play a crucial role in tumor boundary recognition.In this article,the basic concepts and research significance of boundarics in biomedicine and tumor boundarics in biomedicine were summarized firstly.Then a comprehensive review of the research progress in tumor boundary imaging molecular probes was provided,covering areas such as magnetic imaging,optical imaging,acoustic imaging,nuclear imaging,and multimodal imaging.The strategies to regulate the sensitivity,specificity,and safety of molecular probes through chemical structure modifications,conjugation with targeting ligands,and tumor microenvironment-responsive designs were emphasized.Finally,the research trends of molecular probes for tumor boundary imaging were analyzed,and the challenges faced in this field and the future research directions were discussed.

Objective To explore the association between physical activity levels and metabolic dysfunction-associated fatty liver disease(MAFLD)and the modifying effects of different types of obesity.Methods A cross-sectional study was conducted on 19925 participants recruited from the Chengdu sub-cohort of the Southwest China Natural Population Cohort.The participants were recruited between 2018 and 2019.The association between physical activity and MAFLD prevalence was examined using the inverse probability weighting(IPW)method based on the generalized propensity score(GPS).The odds ratios(OR)and the 95％confidence interval(CI)for moderate and vigorous physical activity were calculated using the mild physical activity group as a reference.A restricted cubic spline function was used to model the exposure-response relationship between physical activity and MAFLD risk.The potential modifying effects of obesity types on the association between physical activity and MAFLD were evaluated in male and female populations.Results The prevalence of MAFLD was 17.30％.Compared to those engaging in mild physical activity,individuals participating in vigorous and moderate physical activities had a lower risk of MAFLD,with OR(95％CI)being 0.76(0.67,0.86)and 0.85(0.76,0.94),respectively.The exposure-response relationship showed a nonlinear association between physical activity and MAFLD risks(Pnonlinearity=0.005).The protective effect of physical activity against MAFLD was observed when physical activity reached approximately 20 METs-h/d.However,when physical activity exceeded 70 METs-h/d,no significant effect on MAFLD risk was observed.Among the female population,obesity type significantly modified the association between physical activity and MAFLD(P＜0.05).In females with central obesity,the protective effect of physical activity on MAFLD showed a threshold effect,with the lowest disease risk observed at approximately 25 METs-h/d.However,physical activity exceeding 37.5 METs-h/d showed no statistically significant association with MAFLD risk.In contrast,for females with peripheral obesity,high levels of physical activity had limited effects on reducing MAFLD risks.Conclusion Moderate physical activity can significantly reduce the risk of MAFLD,and the obesity types can modify this association.It is recommended that individuals engage in approximately 20-70 METs-h/d of physical activity.For females with central obesity,physical activity should not exceed 37.5 METs-h/d,while for females with peripheral obesity,it should not exceed 30 METs-h/d.

Objective To investigate the association between 8 insulin resistance(IR)surrogate markers and incident atherosclerotic cardiovascular disease(ASCVD)in population with cardiovascular-kidney-metabolic syndrome(CKM)of stages 0-3,and to identify the surrogate marker with the best predictive performance.Methods A study was conducted on 20121 community residents classified as CKM stages 0-3 from the Chengdu cohort of the China Multi-Ethic Cohort.A Cox proportional hazards model was used to calculate hazard ratios(HRs)between each IR surrogate marker and incident ASCVD.Cubic spline regression was employed to explore the dose-response relationships between these markers and incident ASCVD.The relative relationships between different markers and incident ASCVD were examined through the ratio of HRs(RHRs).Time-dependent area under the receiver operating characteristic curve(TDAUC)and Uno's C-statistic were calculated to compare the predictive performance of each marker for incident ASCVD.Based on the PREVENT equation components and the 8 surrogate markers under analysis,random forest feature selection was used to determine the contribution of each marker to accurate prediction.Results During a follow-up period of82 741.93 person-years,1447 incident cases of ASCVD were recorded,with an incidence density of 17.49 per 1000 person-years.Association analyses indicated that the triglyceride to high-density lipoprotein cholesterol ratio(TG/HDL)and the TyG/(TG/HDL)index were not associated with incident ASCVD(P＞0.05).The TyG index combined with obesity measurement parameters emerged as a reliable predictor of ASCVD incidence.The most promising indicator,TyG index with waist-to-height ratio(TyG_WHtR),exhibited an inverted J-shaped association with incident ASCVD(P for nonlinearity=0.045;TDAUC=0.640;C=0.634),while the TyG index with body mass index(TyG_BMI),waist circumference(TyG_WC),and waist-to-hip ratio(TyG_WHR)showed positive linear associations(all P for trend＜0.05),with relatively lower predictive performance(C=0.564,0.588,and 0.598,respectively).Although both the TyG index and the metabolic score for insulin resistance(METS-IR)were associated with increased ASCVD risk(TyG:Q2 vs.Q1,HR=1.23 and Q4 vs.Q1,HR=1.24;METS-IR:P for non-linearity=0.045),they exhibited poor predictive performance for incident ASCVD.Conclusion The TyG index combined with obesity measurement parameters is an ideal IR surrogate marker for predicting incident ASCVD in populations with stages 0-3 CKM.Monitoring these markers will facilitate the prevention and control of cardiovascular diseases in CKM populations.

Objective To investigate the association between rest-activity rhythm(RAR)and the risks of rheumatoid arthritis(RA),and to evaluate whether genetic susceptibility modifies this relationship.Methods This prospective cohort study utilized data from the UK Biobank,including 88 060 participants who did not have RA at baseline.RAR parameters(e.g.,relative amplitude)were calculated using data obtained through wrist-worn accelerometers.The participants'genetic susceptibility to RA was assessed using a polygenic risk score.Cox proportional hazards models were employed to analyze the association between RAR and RA risk,with interaction terms incorporated to evaluate the effect modification by genetic susceptibility.Results Over a median follow-up period of 7.97 years,660 incident RA cases were identified.After adjusting for age,sex,ethnicity,educational attainment,Townsend deprivation index,drinking status,smoking status,dietary score,body mass index,and polygenic risk score for incident RA,the dose-response analysis revealed a linear relationship between the RAR-related parameters,including the average amplitude during the most active 10 h(M10),interdaily stability(IS),intradaily variability(IV),and the risk of developing RA(P>0.05).In contrast,relative amplitude and the average amplitude during the least active 5 h(L5)showed a nonlinear relationship with the risk of developing RA(P<0.05).Compared to those in the the highest quartile of relative amplitude,participants in the lowest quartile had a 49%increase in the risk of developing RA(hazard ratio[HR]=1.49;95%CI,1.17-1.90).Compared to those in the lowest quartile,participants in the highest quartile of L5 had a 40%increased risk of developing RA(HR=1.40;95%CI,1.12-1.75).Every time M10 increased by one standard deviation,the risk of developing RA decreased by 12%(HR=0.88;95%CI,0.80-0.96).No evidence of effect modification by genetic susceptibility was observed in the RAR-RA association(P>0.05).Conclusion Disrupted rest-activity rhythm is associated with an increased risk of RA,which is independent of genetic susceptibility to RA.Our findings suggest that improving rest-activity rhythm may help reduce RA risks.