1.Structure and Function of GPR126/ADGRG6
Ting-Ting WU ; Si-Qi JIA ; Shu-Zhu CAO ; De-Xin ZHU ; Guo-Chao TANG ; Zhi-Hua SUN ; Xing-Mei DENG ; Hui ZHANG
Progress in Biochemistry and Biophysics 2025;52(2):299-309
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.
2.In situ Analytical Techniques for Membrane Protein Interactions
Zi-Yuan KANG ; Tong YU ; Chao LI ; Xue-Hua ZHANG ; Jun-Hui GUO ; Qi-Chang LI ; Jing-Xing GUO ; Hao XIE
Progress in Biochemistry and Biophysics 2025;52(5):1206-1218
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.
3.Construction of drug utilization evaluation criteria for Dezocine injection based on evidence-based methodology and Delphi method
Yuanyuan GUO ; Chao WANG ; Yinpeng QIN ; Yi ZHANG ; Yishan BU
China Pharmacy 2025;36(15):1841-1845
OBJECTIVE To construct the drug utilization evaluation criteria for Dezocine injection, so as to provide reference for the rational drug use in medical institutions. METHODS On the basis of evidence methodology, relevant guidelines/expert consensus, systematic reviews/meta-analysis were consulted; the evaluation criteria framework for Dezocine injection was established after screening evidence. Delphi method was employed, whereby 28 clinicians and clinical pharmacists from secondary and above-level medical institutions across eight provinces, including Tianjin, Beijing and Shandong, were selected to participate in two rounds of questionnaire surveys. The final indicators were determined based on the experts’ enthusiasm coefficient, authority coefficient, and degree of coordination. RESULTS The effective recovery rate of questionnaire was 100% in the first round and 92.86% in the second round; expert authority coefficient was 0.82 in the first round and 0.81 in the second round; the coordination degree of experts in the first round was 0.29, and in the second round was 0.31 (P<0.001). Drug utilization evaluation standard system for Dezocine injection was formed finally, including three dimensions of medication indications, medication process and medication results, with a total of 11 first-level indicators (such as indications, usage and dosage) and 33 second-level indicators (such as labor analgesia and the management of severe pain following major or moderate surgeries combined with other analgesic drugs). The average importance scores for each indicator ranged from 4.08 to 5.00 points, with an overall average score of 4.61 points and coefficient of variation ranging from 0 to 0.19. CONCLUSIONS The drug utilization evaluation criteria for Dezocine injection established based on evidence-based methodology and Delphi method is authoritative and scientific, which provides a reference for subsequent evaluation of the rationality of clinical medication.
4.Induction of apoptosis in hepatocellular carcinoma cells by polyphyllin 9 through regulating the Fas/FasL sig-naling pathway and the inhibitory effect on the growth of transplanted tumor in nude mice
Minna YAO ; Wei ZHANG ; Kai GAO ; Ruili LI ; Ying YIN ; Chao GUO ; Yunyang LU ; Haifeng TANG ; Jingwen WANG
China Pharmacy 2025;36(18):2238-2243
OBJECTIVE To investigate the induction of apoptosis in hepatocellular carcinoma cells by polyphyllin 9 (PP9) through the regulation of the Fas/Fas ligand (FasL) signaling pathway, and its inhibitory effect on the growth of transplanted tumor in nude mice. METHODS Based on the screening of cell lines and intervention conditions, HepG2 cells were selected as the experimental subject to investigate the effects of 2 μmol/L and 4 μmol/L PP9 treatment on cell colony formation activity, apoptosis rate, as well as the protein expressions of Fas, FasL, cleaved caspase-8 and cleaved caspase-3. Additionally, Fas inhibitor KR- 33493 was introduced to investigate the underlying mechanism of PP9’s anti-hepatocellular carcinoma activity. Using HepG2 cell tumor-bearing nude mice model as the object, and 5-fluorouracil (20 mg/kg) as the positive control, the effects of 10 mg/kg PP9 on tumor volume, tumor mass, and the protein expressions of the nuclear proliferation-associated antigen Ki-67 and cleaved caspase-3 in tumor-bearing nude mice were investigated. RESULTS Compared with the control group, 2, 4 μmol/L PP9 significantly decreased the number of clones and the clone formation rate of cells, but significantly increased the apoptosis rate, the protein expressions of Fas, FasL, cleaved caspase-8 and cleaved caspase-3 (P<0.05 or P<0.01). However, the combination of Fas inhibitor KR-33493 could significantly reverse the effect of PP9 on the up-regulation of proteins related to the Fas/FasL signaling pathway (P<0.01). Compared with the control group, the tumor volume (on day 27), mass and protein expression of Ki- 67 in nude mice of the PP9 group were significantly decreased, while the protein expression of cleaved caspase-3 was significantly increased (P<0.01). CONCLUSIONS PP9 can induce apoptosis of HepG2 cells by activating the Fas/FasL signaling pathway. Meanwhile, PP9 can also effectively inhibit the growth of transplanted tumors in nude mice.
5.Sestrin1 is involved in the regulation of gluconeogenesis in mouse liver cells
Yanfang GUO ; Chao GENG ; Xianghong XIE ; Enhui CHEN ; Zeyu GUO ; Minglong ZHANG ; Xiaojun LIU
Basic & Clinical Medicine 2024;44(2):141-146
Objective To investigate the role and regulatory mechanism of stress-inducing protein 1(SESN1)in liver gluconeogenesis of fasting mice.Methods RT-qPCR was used to detect mRNA expression of SESN1 in liver tissues of C57BL/6J mice and primary mouse hepatocytes treated with forskolin(Fsk)and dexamethasone(Dex).HepG2 cells were transfected with plasmids and the effects of SESN1 overexpression on mRNA expression of gluconeogenesis related genes PGC-1α,PEPCK and G6Pase was detected by RT-qPCR.The effect of SESN1 on the promoter activity of PGC-1α in HepG2 cells was studied using a dual luciferase reporter system.The effect of SESN1 on PGC-1α deacetylation was detected by overexpression of SESN1 and inhibition of SIRT1 expression.By knocking down SIRT1 expression,we detected whether it mediated the changes in mRNA levels of SESN1 in-duced gluconeogenesis related genes.Results The mRNA expression of SESN1 was significantly increased in liver tissues of starved C57BL/6J mice and in primary hepatocytes treated with Fsk and Dex(P<0.001).Over-expression of SESN1 in HepG2 cells promoted mRNA expression of PGC-1α,PEPCK and G6Pase(P<0.001)and promoter activity of PGC-1α(P<0.001).Over-expression of SESN1 decreased the acetylation level of PGC-1α in primary hepatocytes.Sirt family inhibitors NAM and shRNA adenovirus interfered with SIRT1 expression respective-ly,and antagonized the deacetylation effect of SESN1 on PGC-1α.The expression of PGC-1α,PEPCK and G6Pase induced by SIRT1 was also significantly impaired(P<0.000 1).Conclusions SESN1 regulates liver gluconeogene-sis in mice with a SIRT1-dependent mechanism.
6.Correlation of KRAS Gene 3'UTR Polymorphisms with Cervical Cancer and Cervical Intraepithelial Neoplasia in Chinese Han Population in Yunnan Province
Ni GUO ; Cheng ZHANG ; Chao HONG ; Weipeng LIU ; Yufeng YAO ; Zhiling YAN
Journal of Kunming Medical University 2024;45(2):14-22
Objective To investigate the correlation between rs712 and rs7973450 located at the 3'UTR region of the KRAS gene and the risk of cervical cancer(CC)and cervical intraepithelial neoplasia(CIN)in Chinese Han population in Yunnan province.Methods A total of 2405 individuals(461 subjects with CIN,961 subjects with CC and 983 healthy controls)were enrolled.The SNPs were genotyped used TaqMan assay and the correlation of these SNPs with CIN and CC was analyzed.Results The A allele of rs7973450 might be a protective factor for the occurrence of CIN(P = 0.004,OR= 0.651,95%CI 0.487~0.871)and CC(P = 7.00×10-4,OR= 0.667,95%CI 0.529~0.844).There was no significant difference in allelic and genotypic distribution of rs712 among CIN,CC and Control groups(P>0.017).The haplotype assay showed thatrs712A-rs7973450G was associated with increased risk of CIN(P = 4.00×10-4;OR= 1.714,95%CI 1.269~2.314)and CC(P = 3.84×10-5,OR= 1.667,95%CI 1.305~2.131).While haplotype rs712A-rs7973450A was associated with a lower risk of CC(P = 0.012,OR= 0.790,95%CI 0.658~0.950).Conclusion The A allele of rs7973450 in 3'UTR of KRAS gene might be the protective factor for the occurrence of CIN and CC in a Chinese Han population in Yunnan province.
7.The value of high-throughput sequencing data reanalysis in identifying ERBB2 amplification in colorectal cancer patients
Min-Na SHEN ; Li ZHANG ; Xin-Ning CHEN ; Fei HUANG ; Chao-Gang BAI ; Li-Meng CHEN ; Hai-Xiang PENG ; Yan ZHOU ; Bei-Li WANG ; Bai-Shen PAN ; Wei GUO
Fudan University Journal of Medical Sciences 2024;51(2):166-171
Objective To evaluate the value of high-throughput sequencing(HTS)data reanalysis that does not include ERBB2 copy number variation(CNV)analysis,in identifying ERBB2 amplification in patients with colorectal cancer.Methods The HTS data of 252 cases of colorectal cancer diagnosed by pathological biopsy who received peripheral blood cfDNA HTS detection samples were retrospectively analyzed.According to the HTS data of ERBB2 non-amplified samples judged by immunohistochemistry(IHC)and/or fluorescence in situ hybridization(FISH),the number of chromosome 17(Chr17)reads in the total number of reads was calculated the range of the ratio was initially determined as the threshold for prompting ERBB2 amplification.Suspected positive samples were screened according to thresholds and verified by digital PCR,IHC and FISH.Results The proportion of the number of Chr17 reads accounts for the number of total reads in the 89 cases of ERBB2 non-amplified samples determined by IHC and/or FISH ranged from 0.188 to 0.299(0.239±0.192).Using 0.298(1.25 times the mean)as the threshold indicating ERBB2 amplification,the data of 163 samples were analyzed,of which 7 cases were suspected to be positive,and the ratio ranged from 0.302 to 0.853.Among them,5 cases were determined to be positive by IHC and/or FISH,and 6 cases were confirmed to be positive by digital PCR.The ratio of the number of Chr17 reads to the number of total reads was positively correlated with the ratio of ERBB2/EIF2C1,and the correlation was good(r2=0.909).Conclusion The high-throughput sequencing data that does not cover the ERBB2 CNV analysis has a certain hint value for ERBB2 amplification in patients with colorectal cancer.
8.Osteoporotic vertebral compression fracture predicted by functional cross-sectional area of paravertebral muscles
Wensheng ZHANG ; Zhenjie SONG ; Haiwei GUO ; Chunfei WU ; Handi YANG ; Ying LI ; Wenchao LI ; Hongjiang LIU ; Xiaoguang YANG ; Chao YUAN
Chinese Journal of Tissue Engineering Research 2024;33(33):5315-5319
BACKGROUND:Osteoporosis vertebral compression fracture is a common fracture secondary to osteoporosis,and there is currently a lack of effective predictive indicators and methods for osteoporosis vertebral compression fracture. OBJECTIVE:To investigate the predictive effects of paravertebral muscle degeneration,functional cross-sectional area,and percentage of fat infiltration on osteoporotic vertebral compression fractures. METHODS:The 224 patients with osteoporosis diagnosed from January 2018 to June 2022 were included.They were followed up for more than 2 years.They were divided into fracture group and non-fracture group according to the presence and absence of vertebral fracture.The detailed information of demographics,body mass index,bone mineral density and so on were collected.The functional cross-sectional area and percentage of fat infiltration of bilateral Psoas major muscle and extensor dorsi(Erector spinae muscles muscle and multifidus muscle)at the level of lower endplate of L2 vertebral body were measured and calculated. RESULTS AND CONCLUSION:(1)224 patients were ultimately included,of which 126 had fractures as the fracture group and 98 had no fractures as the non-fracture group.There was no statistically significant difference in age,gender,height,body mass,body mass index,and fracture segment between the two groups(P>0.05).(2)The bone mineral density of the fracture group was significantly lower than that of the non-fracture group(P<0.05).Functional cross-sectional areas of Psoas major muscle and extensor dorsi in the fracture group were significantly lower than those in the non-fracture group(P<0.05).The percentage of fat infiltration of the extensor dorsi in the fracture group was significantly higher than that in the non-fracture group(P<0.05).There was no significant difference in percentage of fat infiltration of Psoas major muscle between the two groups(P>0.05).(3)Receiver operating characteristic analysis showed that the vertebral bone mineral density,percentage of fat infiltration of extensor dorsi,functional cross-sectional area of extensor dorsi and percentage of fat infiltration of Psoas major muscle were 0.903 g/cm2,35.426%,418.875 mm2,and 6.375%,respectively.The areas under curve were 0.634,0.755,0.876,and 0.585,respectively.(4)These findings indicate that paravertebral muscle degeneration is strongly associated with the occurrence of osteoporotic vertebral compression fractures.The functional cross-sectional area of extensor dorsi muscle can effectively predict the occurrence of osteoporotic vertebral compression fractures,which is helpful for early prevention and treatment of osteoporotic vertebral compression fractures.
9.Mechanism of Rhei Radix et Rhizoma-Coptidis Rhizoma Improving Liver Insulin Resistance in db/db Mice by Regulating AMPK/ULK1/Beclin1 Pathway
Hongzhang ZHAO ; Min BAI ; Zhandong WANG ; Bing SONG ; Chao GUO ; Xinhong LIU ; Qiong WANG ; Runze YANG ; Yongfeng WANG ; Yanying ZHANG
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(8):9-16
ObjectiveThis study aims to examine the effect of Rhei Radix et Rhizoma-Coptidis Rhizoma on reducing insulin resistance in db/db mice by regulating the adenylate activated protein kinase (AMPK)/UNC-51-like kinase 1 (ULK1)/key molecule of autophagy, benzyl chloride 1 (Beclin1) pathway and elucidate the underlying mechanism. MethodSixty 6-week-old male db/db mice were studied. They were randomly divided into the model group, metformin group (0.26 g·kg-1), and low-, middle-, and high-dose groups (2.25, 4.5, 9 g·kg-1) of Rhei Radix et Rhizoma-Coptidis Rhizoma. A blank group of db/m mice of the same age was set, with 12 mice in each group. After eight weeks of continuous intragastric administration, the blank group and model group received distilled water intragastrically once a day. The survival status of the mice was observed, and fasting blood glucose (FBG) was measured using a Roche blood glucose device. Fasting serum insulin (FINS) was measured using an enzyme-linked immunosorbent assay, and the insulin resistance index (HOMA-IR) was calculated. Hematoxylin-eosin (HE) staining was performed to observe the pathological changes in the liver of the mice. The protein expression levels of AMPK, Beclin1, autophagy associated protein 5 (Atg5), and p62 in liver tissue were determined by using Western blot. The protein expression levels of autophagy associated protein 1 light chain 3B (LC3B) and ULK1 in liver tissue were determined using immunofluorescence. Real-time fluorescence quantitative PCR (Real-time PCR) was used to measure mRNA expression levels of AMPK, Beclin1, Atg5, ULK1, and p62. ResultCompared with the blank group, the model group exhibited a significant increase in body mass (P<0.01). Additionally, the levels of FBG, FINS, and HOMA-IR significantly changed (P<0.01). The structure of liver cells was disordered. The protein expression levels of AMPK, Beclin1, and Atg5 in liver tissue were significantly decreased (P<0.01), while the expression level of p62 protein was significantly increased (P<0.01). The expression levels of mRNA and proteins were consistent. Compared with the model group, the body mass of the metformin group and high and medium-dose groups of Rhei Radix et Rhizoma-Coptidis Rhizoma was significantly decreased (P<0.05). FBG, FINS, and HOMA-IR were significantly decreased (P<0.05,P<0.01). After treatment, the liver structure damage in each group was alleviated to varying degrees. The protein expressions of AMPK, Beclin1, Atg5, LC3B, and ULK1 were increased (P<0.05,P<0.01), while the protein expression of p62 was decreased (P<0.01). The expression levels of mRNA and proteins were generally consistent. ConclusionThe combination of Rhei Radix et Rhizoma-Coptidis Rhizoma can effectively improve liver insulin resistance, regulate the AMPK autophagy signaling pathway, alleviate insulin resistance in db/db mice, and effectively prevent the occurrence and development of type 2 diabetes.
10.Expert Consensus on Clinical Diseases Responding Specifically to Traditional Chinese Medicine:Aural Vertigo
Yingdi GONG ; Zhanfeng YAN ; Wei FENG ; Daxin LIU ; Jiaxi WANG ; Jianhua LIU ; Yu ZHANG ; Shusheng GONG ; Guopeng WANG ; Chunying XU ; Xin MA ; Bo LI ; Shuzhen GUO ; Mingxia ZHANG ; Jinfeng LIU ; Jihua GUO ; Zhengkui CAO ; Xiaoxiao ZHANG ; Zhonghai XIN
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(8):215-222
Aural vertigo frequently encountered in the otolaryngology department of traditional Chinese medicine (TCM) mainly involves peripheral vestibular diseases of Western medicine, such as Meniere's disease, benign paroxysmal positional vertigo, vestibular neuritis, and vestibular migraine, being a hot research topic in both TCM and Western medicine. Western medical therapies alone have unsatisfactory effects on recurrent aural vertigo, aural vertigo affecting the quality of life, aural vertigo not relieved after surgery, aural vertigo with complex causes, and children's aural vertigo. The literature records and clinical practice have proven that TCM demonstrates unique advantages in the treatment of aural vertigo. The China Association of Chinese medicine sponsored the "17th youth salon on the diseases responding specifically to TCM: Aural vertigo" and invited vertigo experts of TCM and Western medicine to discuss the difficulties and advantages of TCM diagnosis and treatment of aural vertigo. The experts deeply discussed the achievements and contributions of TCM and Western medicine in the diagnosis and treatment of aural vertigo, the control and mitigation of the symptoms, and the solutions to disease recurrence. The discussion clarified the positioning and advantages of TCM treatment and provided guidance for clinical and basic research on aural vertigo.

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