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.

Aim To construct CX3CR1GFP transgenic mice based on the Cre/Loxp system,and to analyze the expression efficiency of CX3CR1GFP.Methods Targeted vectors were designed using restriction enzyme-based cloning technology to create a linearized targeted vector for transfecting embryonic stem cells(ES).The ES cells with a deletion of the neomycin resistance gene(neo)were then cloned into blastocysts to generate chimeric CX3CR1+/GFPmice.These mice were subsequently bred with wild-type mice(WT),and repeated backcrossing was performed to obtain CX3CR1GFP/GFP mice.DNA and mRNA from WT and CX3CR1GFP mice were extracted and genotyped using agarose gel electrophoresis.The expression level of CX3CR1 in various tis-sues of the mice was detected by RT-qPCR.Western blot analy-sis was used to analyze the expression of GFP protein in periph-eral blood mononuclear cells(PBMC)and various tissues.The labeling efficiency of immune cells in bone marrow was detected by flow cytometry.The expression of GFP in different mouse tis-sues was observed by immunofluorescence.Results The results of agarose gel electrophoresis showed that the transgenic mouse genotype was CX3CR1GFP/GFP homozygote.RT-qPCR and West-ern blot showed that EGFP were targeted to replace CX3CR1 gene,so CX3CR1 expression was very low in CX3CR1GFP mice,while GFP expression was significantly upregulated.Flow cytom-etry and immunofluorescence showed that GFP effectively marked CX3CR1GFP mice,expressed in various tissues and cells with different expression levels.Conclusion This study con-structs and identifies the CX3CR1GFP genetic reporter mice,and GFP is stably expressed in mice,which provides a foundation for further research into the potential mechanisms of CX3CR1 in im-mune regulation.

The aim of this study was to trace to origin of SARS-CoV-2 originating from imported cold-chain products re-sponsible for an outbreak that occurred on September 6-9,2022 in Mawei District,Fuzhou City,Fujian Province,China.Sam-ples from all positively infected persons and one positive sample from a swab of a cold-chain product during the outbreak were collected for gene sequencing.Epidemiological investigations were conducted on all positively infected persons to analyze the chain of transmission of the virus.Nucleic acids were detected by real-time fluorescence quantitative PCR,and the outbreak was characterized by a total of eight positive infections,which were asymptomatic.Whole-genome sequencing of three infected per-sons and one cold-chain product sample identified 75 nucleotides and 55 amino acid mutation sites of the BA.2.3.7 variant,with four highly homologous whole-genome sequences.These results confirmed that the outbreak was caused by exposure to impor-ted cold-chain products carrying the SARS-CoV-2 Omicron BA.2.3.7 strain.

Objective:To investigate the clinical efficacy and safety of ixazomib-containing regimens in the treatment of patients with multiple myeloma(MM).Methods:A retrospective analysis was performed on the clinical efficacy and adverse reactions of 32 MM patients treated with a combined regimen containing ixazomib in the Hematology Department of the First People's Hospital of Lianyungang from January 2020 to February 2022.Among the 32 patients,15 patients were relapsed and refractory multiple myeloma(R/RMM)(R/RMM group),17 patients who responded to bortezomib induction therapy but converted to ixazomib-containing regimen due to adverse events(AE)or other reasons(conversion treatment group).The treatment included IPD regimen(ixazomib+pomalidomide+dexamethasone),IRD regimen(ixazomib+lenalidomide+dexamethasone),ICD regimen(ixazomib+cyclophosphamide+dexamethasone),ID regimen(ixazomib+dexamethasone).Results:Of 15 R/RMM patients,overall response rate(ORR)was 53.3％(8/15),among them,1 achieved complete response(CR),2 achieved very good partial response(VGPR)and 5 achieved partial response(PR).The ORR of the IPD,IRD,ICD and ID regimen group were 100％(3/3),42.9％(3/7),33.3％(1/3),50％(1/2),respectively,there was no statistically significant difference in ORR between four groups(x2=3.375,P=0.452).The ORR of patients was 50％after first-line therapy,42.9％after second line therapy,60％after third line therapy or more,with no statistically significant difference among them(x2=2.164,P=0.730).In conversion treatment group,ORR was 88.2％(15/17),among them,6 patients achieved CR,5 patients achieved VGPR and 4 patients achieved PR.There was no statistically significant difference in ORR between the IPD(100％,3/3),IRD(100％,6/6),ICD(100％,3/3)and ID(60％,3/5)regimen groups(x2=3.737,P=0.184).The median progression-free survival(PFS)time of R/RMM patients was 9 months(95％CI:6.6-11.4 months),the median overall survival(OS)time was 18 months(95％CI:11.8-24.4 months).The median PFS time of conversion treatment group was 15 months(95％CI:7.3-22.7 months),the median OS time not reached.A total of 10 patients suffered grade 3-4 adverse event(AE).The common hematological toxicities were leukocytopenia,anemia,thrombocytopenia.The common non-hematological toxicities were gastrointestinal symptoms(diarrhea,nausea and vomit),peripheral neuropathy,fatigue and infections.Grade 1-2 peripheral neurotoxicity occurred in 7 patients.Conclusion:The ixazomib-based chemotherapy regimens are safe and effective in R/RMM therapy,particularly for conversion patients who are effective for bortezomib therapy.The AE was manageable and safe.

Objective:To screen interleukin(IL)-1β secretion-related membrane transporters by macrophage experiment in vitro and conventional knockout mice.Methods:THP-1 cell line was differentiated to obtain human THP-1-derived macrophages,and the primary macrophages were obtained from human peripheral blood.FVB wild-type mice with the same sex and age were used as the controls of MRP1 knockout mice.The macrophages in abdominal cavity and bone marrow of mice were cultivated.The cells were treated with ABCC1/MRP1,ABCG2/BCRP,ABCB1/P-gp,OATP1B1,and MATE transporter inhibitors,then stimulated by lipopolysaccharide and adenosine triphosphate.The secretion level of IL-iβ was detected by ELISA,Western blot,and immunofluorescence.Results:After inhibiting ABCC1/MRP1 transporter,the secretion of IL-1β decreased significantly,while inhibition of the other 4 transporters had no effect.In animal experiment,the level of IL-1 β secreted by macrophages in bone marrow of MRP1 knockout mice was significantly lower than control group(P＜0.05).Conclusion:ABCC1/MRP1 transporter is a newly discovered IL-1β secretion pathway,which is expected to become a new target for solving clinical problems such as cytokine release syndrome.

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Butyric acid is a type of short chain fatty acid and an important nutrient in intestinal epithelial cells.In addition to its important role in intestinal health,it has application value in anti-tumor,treatment of neuritis and di-abetes.At the same time,based on the demand for green development in the livestock industry,its anti-inflammato-ry effect can avoid the abuse of antimicrobial agents.As a green,pollution-free,and residue-free new feed,butyric acid ensures the sustainable and healthy development of the livestock industry.This article mainly summarizes the production of butyric acid in the intestine,its effects on the balance of gut microbiota,digestion ability,and inflam-mation in humans and animals,elaborates its application in human health and animal production.

Aim To explore the effects of Lycium berry seed oil on Nrf2/ARE pathway and oxidative damage in testis of subacute aging rats. Methods Fifty out of 60 male SD rats, aged 8 weeks, were subcutaneously injected with 125 mg • kg"D-galactosidase in the neck for 8 weeks to establish a subacute senescent rat model. The presence of senescent cells was observed using P-galactosidase ((3-gal), while testicular morphology was examined using HE staining. Serum levels of testosterone (testosterone, T), follicle-stimulating hormone ( follicle stimulating hormone, FSH ) , luteinizing hormone ( luteinizing hormone, LH ) , superoxide dis-mutase ( superoxide dismutase, SOD ) , glutathione ( glutathione, GSH) and malondialdehyde ( malondial-dehyde, MDA) were measured through ELISA, and the expressions of factors related to aging, oxidative damage, and the Nrf2/ARE pathway were assessed via immunohistochemical analysis and Western blotting. Results After successfully identifying the model, the morphology of the testis was improved and the intervention of Lycium seed oil led to a down-regulation in the expression of [3-gal and -yH2AX. The serum levels of SOD, GSH, T, and FSH increased while MDA and LH decreased (P 0. 05) . Additionally, there was an up-regulated expression of Nrf2, GCLC, NQOl, and SOD2 proteins in testicular tissue ( P 0. 05 ) and nuclear expression of Nrf2 in sertoli cells. Conclusion Lycium barbarum seed oil may reduce oxidative damage in testes of subacute senescent rats by activating the Nrf2/ARE signaling pathway.

This study aims to investigate the effect of salvianolic acid B (Sal B), the active ingredient of Salvia miltiorrhiza, on H9C2 cardiomyocytes injured by oxygen and glucose deprivation/reperfusion (OGD/R) through regulating mitochondrial fission and fusion. The process of myocardial ischemia-reperfusion injury was simulated by establishing OGD/R model. The cell proliferation and cytotoxicity detection kit (cell counting kit-8, CCK-8) was used to detect cell viability; the kit method was used to detect intracellular reactive oxygen species (ROS), total glutathione (t-GSH), nitric oxide (NO) content, protein expression levels of mitochondrial fission and fusion, apoptosis-related detection by Western blot. Mitochondrial permeability transition pore (MPTP) detection kit and Hoechst 33342 fluorescence was used to observe the opening level of MPTP, and molecular docking technology was used to determine the molecular target of Sal B. The results showed that relative to control group, OGD/R injury reduced cell viability, increased the content of ROS, decreased the content of t-GSH and NO. Furthermore, OGD/R injury increased the protein expression levels of dynamin-related protein 1 (Drp1), mitofusions 2 (Mfn2), Bcl-2 associated X protein (Bax) and cysteinyl aspartate specific proteinase 3 (caspase 3), and decreased the protein expression levels of Mfn1, increased MPTP opening level. Compared with the OGD/R group, it was observed that Sal B had a protective effect at concentrations ranging from 6.25 to 100 μmol·L^-1. Sal B decreased the content of ROS, increased the content of t-GSH and NO, and Western blot showed that Sal B decreased the protein expression levels of Drp1, Mfn2, Bax and caspase 3, increased the protein expression level of Mfn1, and decreased the opening level of MPTP. In summary, Sal B may inhibit the opening of MPTP, reduce cell apoptosis and reduce OGD/R damage in H9C2 cells by regulating the balance of oxidation and anti-oxidation, mitochondrial fission and fusion, thereby providing a scientific basis for the use of Sal B in the treatment of myocardial ischemia reperfusion injury.

BACKGROUND:The results of in vivo and in vitro studies showed that catalpol from Rehmannia glutinosa can significantly reduce the level of inflammatory indexes in the synovial tissue of rats with knee osteoarthritis,and meanwhile,it can delay the progression of knee osteoarthritis.But whether catalpol from Rehmannia glutinosa affects chondrocyte senescence and then delay the progression of knee osteoarthritis has not yet been clarified. OBJECTIVE:To investigate investigate whether catalpol from Rehmannia glutinosa could regulate ATDC5 chondrocyte senescence and the possible mechanisms. METHODS:ATDC5 chondrocytes were divided into blank group(0.1%bovine serum albumin),model group(0.1%bovine serum albumin+1 μmol/L adriamycin),low-dose catalpol group(0.1%bovine serum albumin+1 μmol/L adriamycin+20 μmol/L catalpol from Rehmannia glutinosa)and high-dose catalpol group(0.1%bovine serum albumin+1 μmol/L adriamycin+80 μmol/L catalpol from Rehmannia glutinosa).Adriamycin-induced ATDC5 chondrocyte senescence model was constructed,and the corresponding treatments were given according to the above groups.Cell counting kit-8 assay was used to detect the effects of catalpol from Rehmannia glutinosa on ATDC5 chondrocyte viability,and to screen the optimal concentration of catalpol from Rehmannia glutinosa.The senescence of ATDC5 chondrocytes in each group was detected by β-galactosidase staining after the corresponding treatments.Real-time fluorescence quantitative PCR and western blot were used to detect the mRNA and protein expression of P21,P53,type II collagen,matrix metalloproteinase 13,and interleukin-6.Immunofluorescence method was used to detect the expression of P21,P53 and type II collagen.Flow cytometry was used to detect apoptosis in each group. RESULTS AND CONCLUSION:ATDC5 chondrocytes were identified to be successfully induced and senescence model was induced.Catalpol from Rehmannia glutinosa at the concentrations of 0,20,40,and 80 μmol/L showed no significant effects on the cell viability,suggesting that catalpol from Rehmannia glutinosa is non-cytotoxic and can be used safely(P>0.05);when the concentration was≥100 μmol/L,the cell viability was reduced,suggesting that there may be cytotoxic.Therefore,80 μmol/L was chosen as the high dose for subsequent experiments in this study.The percentage of positive cells in the model group was(86.93±2.18)%,which was significantly higher than that in the blank group[(17.32±0.72)%;P<0.05].Compared with the model group,the percentage of positive cells was significantly lower in the low-and high-dose catalpol groups[(57.28±1.73)%and(27.18±0.97)%,respectively;both P<0.05].Compared with the model group,the relative expression of P21,P53,matrix metalloproteinase 13,and interleukin-6 at mRNA and protein levels was significantly downregulated in the low-and high-dose catalpol groups,while the relative expression of type II collagen at mRNA and protein levels was significantly upregulated in both groups(P<0.05),especially in the high-dose catalpol group(P<0.05).Compared with the model group,the fluorescence intensities of P21 and P53 were significantly weakened in the low-and high-dose catalpol groups,while the fluorescence intensity of type II collagen was significantly enhanced in the low-and high-dose catalpol groups(P<0.05),especially in the high-dose catalpol group(P<0.05).The cell apoptosis detected by Annexin V/PI method showed that there was no significant difference between the model group and the blank group(P>0.05);compared with the model group,the apoptotic index was significantly elevated in the low-and high-dose catalpol groups,especially in the high-dose catalpol group(P<0.05).To conclude,catalpol from Rehmannia glutinosa can slow the progression of osteoarthritis by promoting apoptosis of senescent ATDC5 chondrocytes,further removing senescent ATDC5 chondrocytes,and decreasing the senescence-associated phenotypes.