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.

Humans ; Aged ; Lung Diseases ; Pneumonia/drug therapy* ; Adrenal Cortex Hormones/therapeutic use* ; Pulmonary Disease, Chronic Obstructive/drug therapy* ; Administration, Inhalation ; Community-Acquired Infections/drug therapy*

Objective To comapre and analyze the differences and commonalities of expression profiles of serum exosomal microRNA between patients with thyroid nodules and healthy persons at different iodine levels,and then provide evidence for screening early diag-nostic markers of thyroid nodules at different iodine levels.Methods The peripheral blood samples from 10 patients with thyroid nod-ules and healthy volunteers at different iodine levels were collected.Their serum iodine levels were measured by the arsenic cerium cat-alytic spectrophotometry.Serum exosomal microRNA were extracted and the expression levels of microRNA were determined by the high-throughput sequencing technology.The differential target genes were predicted and further performed Gene ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis.Results Compared with healthy volunteers,there were 6 downreg-ulated miRNAs in the patients with thyroid nodules at different iodine levels,namely miR-324-5p,miR-6511b-3p,miR-9903,miR-550a-3p,miR-5001-3p,and miR-3688-3p.Differentially expressed exosomal microRNA could regulate the MAPK signaling path-way,PI3K-AKT signaling pathway,VEGF signaling pathway,and NF-κB signaling pathway.Conclusion Six differentially expressed microRNAs is identified,which may serve as biological markers for the early diagnosis of thyroid nodules at different iodine levels.

Vascular calcification is a highly regulated process of ectopic calcification in cardiovascular system while no effective intervention can be clinically performed up to date.As vascular calcification undergoes a common regulatory mechanism within bone formation,bone morphogenetic protein 7(BMP-7)main-tains contractile phenotype of vascular smooth muscle cells and further inhibits vascular calcification via promoting the process of osteoblast differentiation,reducing ectopic calcification pressure by increasing bone formation and reducing bone resorption.This work systematically reviews the role of BMP-7 in vascular calcifi-cation and the possible mechanism,and their current clinical application as well.The current proceedings may help develope early diagnostic strategy and therapeutic treatment with BMP-7 as a new molecular marker and potential drug target.The expec-tation could achieve early prevention and intervention of vascular calcification and improve poor prognosis on patients.

Rectal cancer is the most common tumor of digestive tract. For female patients, ovarian metastasis ranks the second place in intraperitoneal organ metastasis. Its symptoms are occult, easily missed and insensitive to systemic treatment, so the prognosis is poor. Surgery is the treatment of choice for patients with rectal ovarian metastases, whether R0 resection is possible or not, and reducing tumor load is associated with better prognosis. With the continuous development of hyperthermic intraperitoneal chemotherapy (HIPEC), tumor reduction can reach the cellular level, which can significantly improve survival. Prophylactic ovariectomy remains a controversial issue in patients at high risk of ovarian metastasis. In this review, we summarize the diagnosis, treatment and prevention strategies of rectal cancer ovarian metastases, hoping to provide some reference for clinical practice.
Humans ; Female ; Colorectal Neoplasms/pathology* ; Hyperthermia, Induced ; Peritoneal Neoplasms/secondary* ; Rectal Neoplasms/therapy* ; Ovarian Neoplasms/therapy* ; Combined Modality Therapy ; Cytoreduction Surgical Procedures

OBJECTIVE: To study the protective effect of forsythiaside B (FB) against cerebral oxidative stress injury induced by cerebral ischemia/reperfusion (I/R) in mice and explore the underlying mechanism. METHODS: Ninety C57BL/6 mice were randomized into sham-operated group, middle cerebral artery occlusion (MCAO) model group, and low-, medium and highdose (10, 20, and 40 mg/kg, respectively) FB groups. The expression levels of MDA, ROS, PCO, 8-OHdG, SOD, GSTα4, CAT and GPx in the brain tissue of the mice were detected using commercial kits, and those of AMPK, P-AMPK, DAF-16, FOXO3 and P-FOXO3 were detected with Western blotting. Compound C (CC), an AMPK inhibitor, was used to verify the role of the AMPK pathway in mediating the therapeutic effect of FB. In another 36 C57BL/6 mice randomized into 4 sham-operated group, MCAO model group, FB (40 mg/kg) treatment group, FB+CC (10 mg/kg) treatment group, TTC staining was used to examine the volume of cerebral infarcts, and the levels of ROS and SOD in the brain were detected; the changes in the protein expressions of AMPK, P-AMPK, DAF-16, FOXO3 and P-FOXO3 in the brain tissue were detected using Western blotting. RESULTS: In mice with cerebral IR injury, treatment with FB significantly reduced the levels of ROS, MDA, PCO and 8-OHdG, increased the activities of antioxidant enzymes SOD, GSTα4, CAT and GPx, and enhanced phosphorylation of AMPK and FOXO3 and DAF-16 protein expression in the brain tissue (P < 0.01). Compared with FB treatment alone, the combined treatment with FB and CC significantly reduced phosphorylation of AMPK and FOXO3, lowered expression of DAF-16 and SOD activity, and increased cerebral infarction volume and ROS level in the brain tissue of the mice (P < 0.01). CONCLUSION FB inhibits oxidative stress injury caused by cerebral I/R in mice possibly by enhancing AMPK phosphorylation, promoting the downstream DAF-16 protein expression and FOXO3 phosphorylation, increasing the expression of antioxidant enzymes, and reducing ROS level in the brain tissue.
Mice ; Animals ; AMP-Activated Protein Kinases/metabolism* ; Antioxidants/metabolism* ; Reactive Oxygen Species ; Mice, Inbred C57BL ; Brain Ischemia ; Oxidative Stress ; Infarction, Middle Cerebral Artery ; Reperfusion Injury ; Reperfusion ; Superoxide Dismutase/metabolism*

AIM: To explore the characteristics of astigmatism in preschool children before, during and after the COVID-19 epidemic, so as to provide a reference for further prevention and control of children's vision.METHODS: In the consecutive four years from January 2018 to December 2021, a retrospective analysis of vision data was conducted on 2 273 preschool children(4 546 eyes)younger than 4 years old who participated in children's vision screening test in Baiyun district, Guangzhou. They were divided into 1-year old group(ages<1-year old, 420 cases), 2-year old group(1-year ≤ ages <2-year, 543 cases), 3-year old group(2-year ≤ages <3-year, 614 cases), and 4-year old group(3-year ≤ ages<4-year, 696 cases)according to ages. The analysis included astigmatic degrees of children's eyes as well as their conditions of astigmatism.RESULTS: In 2018, the astigmatic degrees of the both eyes of 1-year-old group were higher than those of other groups(P<0.05). The binocular astigmatic degrees of the preschool children in four groups were obviously higher in 2020 than 2019(P<0.05), while they were significantly decreased in 2021 when compared with 2020(P<0.05). From 2019 to 2020, the increase of astigmatic degrees of the right eye is more considerable than the left eye of preschool children in those four groups(P<0.001). Furthermore, the morbidity of astigmatism basically echoes with the changing tendency of astigmatic degrees from 2018 to 2021.CONCLUSIONS: Preschool children in Baiyun district, Guangzhou, have the highest degree of astigmatism and the fastest progression rate within 1 year old. Before COVID-19 epidemic, the changes in astigmatism and prevalence were relatively stable; during COVID-19 epidemic, the astigmatism and prevalence increased significantly and the astigmatic degrees of right eye increased more than that of the left eye; after the normalization of epidemic prevention and control, the astigmatism and prevalence decreased significantly.

Diabetic peripheral neuropathy (DPN) is one of the most common microvascular complications occurring in both type 1 and type 2 diabetes mellitus patients, which often results in patients suffering from severe hyperalgesia and allodynia. Up to now, the clinical therapeutic effect of DPN is still unsatisfactory. Metformin is an anti-diabetic drug that has been safely and widely used for the treatment of type 2 diabetes for decades. Studies have shown that metformin can improve pain caused by DPN, but its effects on the nerve conduction velocity and morphology of the sciatic nerve of DPN, and the mechanism for improving DPN are not clear. Therefore, the STZ-induced model of type 1 DPN in SD rats was used to study the effects of metformin on DPN, and to preliminarily explore its mechanism in this study. All animal experiments were carried out with approval of the Experimental Animal Welfare Ethics Committee of the Institute of Materia Medica (Chinese Academy of Medical Sciences and Peking Union Medical College). After the model was established successfully, STZ diabetic rats were randomly divided into a model group and a metformin treatment group, and 10 normal SD rats were selected as the normal control group, and the rats were intragastrically administered for 12 weeks. The results showed that metformin significantly reduced blood glucose, glycosylated hemoglobin, food consumption and water consumption in STZ rats. Metformin markedly increased the motor nerve conduction velocity and mechanical stabbing pain threshold, prolonged the hot plate latency threshold, and improved the pathological morphological abnormalities of the sciatic nerve in STZ rats. In addition, metformin increased the content of glutathione (GSH), enhanced the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and reduced the content of malondialdehyde (MDA) in serum and sciatic nerve of STZ diabetic rats, as well as regulating the expression of genes related to oxidative stress in the sciatic nerve. Metformin obviously reduced the levels of pro-inflammatory factors such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β and IL-6 in the serum in STZ rats, and inhibited the gene expression of these inflammatory factors in the sciatic nerve. In summary, metformin significantly increased nerve conduction velocity, improved sciatic nerve morphological abnormalities and pain in DPN rats, which may be related to its effect in improving oxidative stress and reducing inflammation.

Objective:To observe the effect of interleukin-8 (IL-8) on the adhesion and migration of retinal vascular endothelial cells (RCEC).Methods:A cell experiment. Human RCEC (hRCEC) was divided into normal control group (N group), advanced glycation end product (AGE) treatment group (AGE group), and AGE-induced combined IL-8 antagonist SB225002 treatment group (AGE+SB group). The effect of AGE on IL-8 expression in hRCEC was observed by Western blot. The effect of SB225002 on hRCEC migration was observed by cell scratch assay. The effects of SB225002 on leukocyte adhesion and reactive oxygen species (ROS) on hRCEC were detected by flow cytometry. Student- t test was performed between the two groups. Oneway analysis of variance was performed among the three groups. Results:Compared with group N, the expression level of IL-8 in cells of AGE group was significantly increased, with statistical significance ( t=25.661, P<0.001). Compared with N group and AGE+SB group, cell mobility in AGE group was significantly increased ( F=29.776), leukocyte adhesion number was significantly increased ( F=38.159, 38.556), ROS expression level was significantly increased ( F=22.336), and the differences were statistically significant ( P<0.05). Conclusion:IL-8 antagonist SB225002 may down-regulate hRCEC adhesion and migration by inhibiting ROS expression.

The canonical transient receptor potential channel(TRPC)proteins form Ca2+-permeable cation channels that are involved in various heart diseases.However,the roles of specific TRPC proteins in myocardial ischemia/reperfusion(I/R)injury remain poorly understood.We observed that TRPC1 and TRPC6 were highly expressed in the area at risk(AAR)in a coronary artery ligation induced I/R model.Trpc1-/-mice exhibited improved cardiac function,lower serum Troponin T and serum creatine kinase level,smaller infarct volume,less fibrotic scars,and fewer apoptotic cells after myocardial-I/R than wild-type or Trpc6-/-mice.Cardiomyocyte-specific knockdown of Trpc1 using adeno-associated virus 9 mitigated myocardial I/R injury.Furthermore,Trpc1 deficiency protected adult mouse ventricular myocytes(AMVMs)and HL-1 cells from death during hypoxia/reoxygenation(H/R)injury.RNA-sequencing-based transcriptome analysis revealed differential expression of genes related to reactive oxygen species(ROS)generation in Trpc1-/-cardiomyocytes.Among these genes,oxoglutarate dehydrogenase-like(Ogdhl)was markedly downregulated.Moreover,Trpc1 deficiency impaired the calcineurin(CaN)/nuclear factor-kappa B(NF-κB)signaling pathway in AMVMs.Suppression of this pathway inhibited Ogdhl upregulation and ROS generation in HL-1 cells under H/R conditions.Chromatin immunoprecipitation assays confirmed NF-κB binding to the Ogdhl promoter.The cardioprotective effect of Trpc1 deficiency was canceled out by overexpression of NF-κB and Ogdhl in cardiomyocytes.In conclusion,our findings reveal that TRPC1 is upregulated in the AAR following myocardial I/R,leading to increased Ca2+influx into associated cardiomyocytes.Subsequently,this upregulates Ogdhl expression through the CaN/NF-κB signaling pathway,ultimately exacerbating ROS production and aggravating myocardial I/R injury.