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.Effect comparison of flat loop with double C-loop Toric intraocular lenses on astigmatism correction based on standard astigmatism vector analysis
Jintao XIA ; Jia LIU ; Mi HAO ; Ting MA ; Lina CHENG
International Eye Science 2025;25(4):632-637
AIM:To compare the effect of AT TORBI 709M and Tecnis ZMT intraocular lenses on astigmatism correction in patients with corneal astigmatism at 3 mo after operation based on the standard astigmatism vector analysis.METHODS: This was a retrospective case-control study. The clinical data of 69 patients(69 eyes)with corneal astigmatism who underwent phacoemulsification and implantation of toric intraocular lens(IOL)from June 2021 to December 2021 in Day Surgery Center of Xi'an No.1 Hospital was analyzed. The patients were divided into two groups. In group one, 38 cases(38 eyes)were implanted with AT TORBI 709M, and 31 patients(31 eyes)with Tecnis ZMT in group two. The axial length, preoperative astigmatism and axis, and the degree of intraocular lens were recorded. The uncorrected distance visual acuity(UCDVA), best corrected distance visual acuity(BCDVA), diopter, residual astigmatism and axis were recorded preoperatively and at 1 wk, 1 and 3 mo postoperatively. The postoperative surgical indicators, including spherical equivalent(SE), target induced astigmatism vector(TIA), surgically induced astigmatism vector(SIA), magnitude of error(ME), absolute value of angle of error(|AE|), absolute value of difference vector(|DV|), correction index(CI), and index of success(IOS)were evaluated by the standard astigmatism vector analysis.RESULTS:Postoperative UCDVA and BCDVA were significantly improved(all P<0.001), and there were statistically significant differences compared to preoperative UCDVA and BCDVA(all P<0.001). While, there was no significant difference in UCDVA and BCDVA between the two groups(P=0.275, 0.124). The standard astigmatism vector analysis showed that a good astigmatism correction was achieved in both AT TORBI 709M group and Tecnis ZMT group, and both |DV| and IOS were close to 0(P=0.329, 0.288). The CI of the AT TORBI 709M group was closer to 1, indicating a better astigmatism correction, while the CI of the Tecnis ZMT group was higher than 1, suggesting an overcorrection of astigmatism. However, the difference between the two groups was not statistically significant(P=0.193). The mean residual astigmatism at 3 mo postoperatively was -0.11±0.91 D in the AT TORBI 709M group and -0.46±0.76 D in the Tecnis ZMT group, respectively, showing no statistically significance difference(t=1.732, P=0.088).CONCLUSION:Both the flat loop AT TORBI 709M and the double C-loop Tecnis ZMT intraocular lenses can effectively improve postoperative visual acuity in patients with regular corneal astigmatism, showing good rotational stability and comparable correction abilities for both astigmatism with the rule and against-the-rule astigmatism.
3.Study on Kinetic and Static Tasks With Different Resistance Coefficients in Post-stroke Rehabilitation Training Based on Functional Near-infrared Spectroscopy
Ling-Di FU ; Jia-Xuan DOU ; Ting-Ting YING ; Li-Yong YIN ; Min TANG ; Zhen-Hu LIANG
Progress in Biochemistry and Biophysics 2025;52(7):1890-1903
ObjectiveFunctional near-infrared spectroscopy (fNIRS), a novel non-invasive technique for monitoring cerebral activity, can be integrated with upper limb rehabilitation robots to facilitate the real-time assessment of neurological rehabilitation outcomes. The rehabilitation robot is designed with 3 training modes: passive, active, and resistance. Among these, the resistance mode has been demonstrated to yield superior rehabilitative outcomes for patients with a certain level of muscle strength. The control modes in the resistance mode can be categorized into dynamic and static control. However, the effects of different control modes in the resistance mode on the motor function of patients with upper limb hemiplegia in stroke remain unclear. Furthermore, the effects of force, an important parameter of different control modes, on the activation of brain regions have rarely been reported. This study investigates the effects of dynamic and static resistance modes under varying resistance levels on cerebral functional alterations during motor rehabilitation in post-stroke patients. MethodsA cohort of 20 stroke patients with upper limb dysfunction was enrolled in the study, completing preparatory adaptive training followed by 3 intensity-level tasks across 2 motor paradigms. The bilateral prefrontal cortices (PFC), bilateral primary motor cortices (M1), bilateral primary somatosensory cortices (S1), and bilateral premotor and supplementary motor cortices (PM) were examined in both the resting and motor training states. The lateralization index (LI), phase locking value (PLV), network metrics were employed to examine cortical activation patterns and topological properties of brain connectivity. ResultsThe data indicated that both dynamic and static modes resulted in significantly greater activation of the contralateral M1 area and the ipsilateral PM area when compared to the resting state. The static patterns demonstrated a more pronounced activation in the contralateral M1 in comparison to the dynamic patterns. The results of brain network analysis revealed significant differences between the dynamic and resting states in the contralateral PFC area and contralateral M1 area (F=4.709, P=0.038), as well as in the contralateral PM area and ipsilateral M1 area (F=4.218, P=0.049). Moreover, the findings indicated a positive correlation between the activation of the M1 region and the increase in force in the dynamic mode, which was reversed in the static mode. ConclusionBoth dynamic and static resistance training modes have been demonstrated to activate the corresponding brain functional regions. Dynamic resistance modes elicit greater oxygen changes and connectivity to the region of interest (ROI) than static resistance modes. Furthermore, the effects of increasing force differ between the two modes. In patients who have suffered a stroke, dynamic modes may have a more pronounced effect on the activation of exercise-related functional brain regions.
4.Molecular Mechanisms of RNA Modification Interactions and Their Roles in Cancer Diagnosis and Treatment
Jia-Wen FANG ; Chao ZHE ; Ling-Ting XU ; Lin-Hai LI ; Bin XIAO
Progress in Biochemistry and Biophysics 2025;52(9):2252-2266
RNA modifications constitute a crucial class of post-transcriptional chemical alterations that profoundly influence RNA stability and translational efficiency, thereby shaping cellular protein expression profiles. These diverse chemical marks are ubiquitously involved in key biological processes, including cell proliferation, differentiation, apoptosis, and metastatic potential, and they exert precise regulatory control over these functions. A major advance in the field is the recognition that RNA modifications do not act in isolation. Instead, they participate in complex, dynamic interactions—through synergistic enhancement, antagonism, competitive binding, and functional crosstalk—forming what is now termed the “RNA modification interactome” or “RNA modification interaction network.” The formation and functional operation of this interactome rely on a multilayered regulatory framework orchestrated by RNA-modifying enzymes—commonly referred to as “writers,” “erasers,” and “readers.” These enzymes exhibit hierarchical organization within signaling cascades, often functioning in upstream-downstream sequences and converging at critical regulatory nodes. Their integration is further mediated through shared regulatory elements or the assembly into multi-enzyme complexes. This intricate enzymatic network directly governs and shapes the interdependent relationships among various RNA modifications. This review systematically elucidates the molecular mechanisms underlying both direct and indirect interactions between RNA modifications. Building upon this foundation, we introduce novel quantitative assessment frameworks and predictive disease models designed to leverage these interaction patterns. Importantly, studies across multiple disease contexts have identified core downstream signaling axes driven by specific constellations of interacting RNA modifications. These findings not only deepen our understanding of how RNA modification crosstalk contributes to disease initiation and progression, but also highlight its translational potential. This potential is exemplified by the discovery of diagnostic biomarkers based on interaction signatures and the development of therapeutic strategies targeting pathogenic modification networks. Together, these insights provide a conceptual framework for understanding the dynamic and multidimensional regulatory roles of RNA modifications in cellular systems. In conclusion, the emerging concept of RNA modification crosstalk reveals the extraordinary complexity of post-transcriptional regulation and opens new research avenues. It offers critical insights into the central question of how RNA-modifying enzymes achieve substrate specificity—determining which nucleotides within specific RNA transcripts are selectively modified during defined developmental or pathological stages. Decoding these specificity determinants, shaped in large part by the modification interactome, is essential for fully understanding the biological and pathological significance of the epitranscriptome.
5.Structural identification of the related substances in phloroglucinol injection by two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry
Jia-ming LIU ; Yu-ting LU ; Min SONG ; Tai-jun HANG
Acta Pharmaceutica Sinica 2024;59(1):202-213
This study aimed to identify the related substances of phloroglucinol injection by two-dimensional liquid chromatography quadrupole time-of-flight mass spectrometry (2D-LC-Q-TOF/MS). The first-dimensional separation was carried out on an HSS T3 (250 mm × 4.6 mm, 5 μm) column by gradient elution using 1.36 g·L-1 potassium dihydrogen phosphate buffer solution (pH adjusted to 3.0 with diluted phosphoric acid) and acetonitrile as the mobile phases. The separated components were then trapped in switch valve tube lines respectively and delivered to the second-dimensional desalting gradient elution which was performed with a BDS C18 (100 mm × 4.6 mm, 2.4 μm) column using 0.1% formic acid and methanol as the mobile phases. After rapid desalting, electrospray-ionization quadrupole time-of-flight high resolution mass spectrometry was used for determining the accurate masses and elemental compositions of the parents and their product ions for both phloroglucinol and its related substance. Structures of the related substances were then figured out by mass spectrometry elucidation, organic reaction mechanism analysis, and/or comparison with reference substances. Under the established analytical conditions, phloroglucinol and its related substances were adequately separated, 17 main related substances were detected and identified in the injection and its stressed samples for the first time. The identification results can provide reference for the quality control of phloroglucinol injection.
6.Effect of high fat diet intake on pharmacokinetics of metronidazole tablets in healthy Chinese volunteers
Na ZHAO ; Cai-Hui GUO ; Ya-Li LIU ; Hao-Jing SONG ; Ben SHI ; Yi-Ting HU ; Cai-Yun JIA ; Zhan-Jun DONG
The Chinese Journal of Clinical Pharmacology 2024;40(1):102-106
Objective To evaluate the effects of high-fat diet on the pharmacokinetics of metronidazole in Chinese healthy adult subjects.Methods This program is designed according to a single-center,randomized,open,single-dose trial.Forty-seven healthy subjects were assigned to receive single dose of metronidazole tablets 200 mg in either fasting and high-fat diet state,and blood samples were taken at different time points,respectively.The concentrations of metronidazole in plasma were determined by high performance liquid chromatography-mass spectromentry.Results The main pharmacokinetic parameters of metronidazole in fasting state and high-fat diet state were as follows:Cmax were(4 799.13±1 195.32)and(4 044.17±773.98)ng·mL-1;tmax were 1.00 and 2.25 h;t1/2 were(9.11±1.73)and(9.37±1.79)h;AUC0_t were(5.59±1.19)x 104 and(5.51±1.18)x 104 ng·mL-1·h;AUC0_∞ were(5.79±1.33)x 104 and(5.74±1.32)× 104 ng·mL-1·h.Compared to the fasting state,the tmaxof the drug taken after a high fat diet was delayed by 1.25 h(P<0.01),Cmax,AUC0_t,AUC0-∞ were less or decreased in different degrees,but the effects were small(all P>0.05).Conclusion High-fat diet has little effects on the pharmacokinetic parameters of metronidazole,which does not significantly change the degree of drug absorption,but can significantly delay the time to peak.
7.Research status in immunotherapy of colitis-related cancer with MDSCs
Jia CHEN ; Qi XIA ; Yu-Jie HE ; Yue LI ; Ze-Ting YUAN ; Pei-Hao YIN
The Chinese Journal of Clinical Pharmacology 2024;40(2):294-298
Colitis-associated cancer(CAC)is a specific type of colorectal cancer that develops from inflammatory bowel disease(IBD).Myeloid-derived suppressor cells(MDSCs)are a group of myeloid cells with immunosuppressive properties,and MDSCs in the tumor microenvironment proliferate and activate during the development of colitis-associated cancer,inhibiting T-cell production and impairing their function,which impedes the immunotherapeutic effect of colitis-associated cancer.In this paper,we review the immunosuppressive mechanisms of MDSCs in the development of inflammatory bowel disease to colitis-associated cancers and the current drugs targeting MDSCs for immunotherapy of inflammatory colorectal cancers,with a view to providing new strategies for the treatment of colitis-associated cancers.
8.Bioequivalence of amoxicillin clavulanate potassium tablet in healthy volunteers
Yi-Ting HU ; Yu-Fang XU ; Wan-Jun BAI ; Hao-Jing SONG ; Cai-Yun JIA ; Shao-Chun CHEN ; Zhan-Jun DONG
The Chinese Journal of Clinical Pharmacology 2024;40(3):419-424
Objective To evaluate the bioequivalence of test product and reference product in a single dose of amoxicillin clavulanate potassium tablet under fasting and fed conditions in healthy volunteers.Methods An open label,randomized,single dose,four-period,crossover bioequivalence study was designed.Fasting and postprandial tests were randomly divided into 2 administration sequence groups according to 1:1 ratio,amoxicillin clavulanate potassium tablet test product or reference product 375 mg,oral administration separately,liquid chromatography tanden mass spectrometry was applied to determine the concentration of amoxicillin and clavulanate potassium in plasma of healthy subjects after fasting or fed administration,while Phoenix WinNonlin 8.2 software were used for pharmacokinetics(PK)parameters calculation and bioequivalence analysis.Results Healthy subjects took the test product and the reference product under fasting condition,the main PK parameters of amoxicillin are as follows:Cmax were(5 075.57±1 483.37)and(5 119.86±1 466.73)ng·mL-1,AUC0_twere(1.32 × 104±2 163.76)and(1.30 × 104±1 925.11)ng·mL-1,AUC0-∞were(1.32 × 104±2 175.40)and(1.31 ×104±1 935.86)ng·mL-1;the main PK parameters of clavulanic acid are as follows:Cmax were(3 298.27±1 315.23)and(3 264.06±1 492.82)ng·mL-1,AUC0-twere(7 690.06±3 053.40)and(7 538.39±3 155.89)ng·mL-1,AUC0-∞were(7 834.81±3 082.61)and(7 671.67±3 189.31)ng·mL-1;the 90%confidence intervals of Cmax,AUC0-tand AUC0-∞ after logarithmic conversion of amoxicillin and clavulanate potassium of the two products were all within 80.00%-125.00%.Healthy subjects took the test and reference product under fed condition,the main PK parameters of amoxicillin are as follows:Cmax were(4 514.08±1 324.18)and(4 602.82±1 366.48)ng·mL-1,AUC0-twere(1.15 × 104±1 637.95)and(1.15 × 104±1 665.69)ng·mL-1,AUC0-∞ were(1.16 × 104±1 646.26)and(1.15 × 104±1 607.20)ng·mL-1;the main PK parameters of clavulanic acid are as follows:Cmax were(2 654.75±1 358.29)and(2 850.51±1 526.31)ng·mL-1,AUC0-twere(5 882.82±2 930.06)and(6 161.28±3 263.20)ng·mL-1,AUC0-∞ were(6 022.70±2 965.05)and(6 298.31±3 287.63)ng·mL-1;the 90%confidence intervals of Cmax,AUC0-t and AUC0-∞ after logarithmic conversion of amoxicillin and clavulanate potassium of the two products were all within 80.00%-125.00%.Conclusion The two formulations were bioequivalent to healthy adult volunteers under fasting and fed conditions.
9.Protective effect of quercetin mediated ferroptosis pathway on hypertonic stimulation induced dry eye cell model
Jia-Di WANG ; Bai-Ping AN ; Yue LIU ; Cong-Hong CAO ; Bei-Ting ZONG ; Jing YAO
The Chinese Journal of Clinical Pharmacology 2024;40(4):529-533
Objective To investigate the effect of quercetin on HCE-2 injury of human corneal epithelial cells induced by high osmotic pressure and its mechanism.Methods HCE-2 cells were randomly divided into control group(normal osmotic pressure),model group(high osmotic pressure),experimental-L group(high osmotic pressure+31.25 pg·mL-1 quercetin),experimental-M group(high osmotic pressure+62.50 μg·mL-1 quercetin),experimental-H group(high osmotic pressure+125.00 μg·mL-1 quercetin),erastin group(high osmotic pressure+125.00 μg·mL-1 quercetin+30.00 μmol·L-1 iron death inducer erastin).Cell survival rate was detected by cell counting kit 8;reactive oxygen species(ROS)levels was detected by C11-BODIPY 581/591 probe staining;glutathione(GSH)and malondialdehyde(MDA)levels were determined by kit method;the expression levels of glutathione peroxidase 4(GPX4),dihydrolactate dehydrogenase(DHODH)and ferroptosis suppressor protein 1(FSP1)were detected by real-time quantitative polymerase chain reaction and Western blot.Results The cell survival rates of control group,model group,experimental-H group and erastin group were(100.00±3.97)%,(50.05±5.83)%,(86.35±7.35)%and(58.32±4.66)%,respectively;ROS levels were 1.00±0.09,2.45±0.16,1.19±0.05 and 2.09±0.30,respectively;GPX4 protein levels were 1.09±0.11,0.34±0.03,0.91±0.12 and 0.30±0.04,respectively;FSP1 protein levels were 0.92±0.06,0.25±0.03,0.89±0.07 and 0.39±0.07,respectively;DHODH protein levels were 0.89±0.11,0.31±0.04,0.86±0.11,0.41±0.04,respectively.Compared with model group,the above indexes in control group were statistically significant(all P<0.05);the differences between experimental-H group and model group were statistically significant(all P<0.05);the above indexes in erastin group were significantly different from those in experimental-H group(all P<0.05).Conclusion Quercetin can ameliorate HCE-2 cell damage induced by high osmotic pressure by inhibiting iron death pathway.
10.Effects of cinbufagin on proliferation,migration and invasion of human colon cancer cells via JAK2/STAT3 pathway
Jia CHEN ; Qi XIA ; Yi-Nan LI ; Yu-Jie HE ; Ze-Ting YUAN ; Yue LI ; Pei-Hao YIN
The Chinese Journal of Clinical Pharmacology 2024;40(12):1764-1768
Objective To investigate the effects of cinbufagin(CB)on the proliferation,migration and invasion ability as well as epithelial-mesenchymal transition(EMT)of human colon cells HCT116.Methods Logarithmically grown HCT116 cells were randomly divided into blank group and experimental-L,-M,-H groups;the blank group did not receive any treatment(0 nmol·L-1),and experimental-L,-M,-H groups were cultured in 1 640 medium containing 17.5,35 and 70 nmol·L-1 cinbufagin for 48 h.Cell counting kit-8(CCK-8)was used to detect the effect of cinbufagin on the survival rate of HCT116 cells;cloning assay was used to detect the effect of cinbufagin on the proliferation of HCT116 cells;cell scratch assay and Transwell assay were used to detect the effect of cinbufagin on the migration and invasive ability of HCT116 cells;Western blot was used to detect the expression levels of janus kinase 2(JAK2)/signal transducers and activators of transcription 3(STAT3)pathway and EMT-related proteins of HCT116 cells.Results The number of clone formation in blank group and experimental-L,-M,-H groups were 122.67±24.42,73.67±15.82,44.33±4.51 and 21.67±1.53;the rates of migration of scratches were(44.64±9.15)%,(26.91±2.94)%,(19.28±1.52)%and(6.33±2.30)%;the number of invaded cells were 120.33±1.15,58.33±9.07,33.33±1.53 and 18.33±3.21;the relative protein expression of phosphorylated JAK-2(p-JAK-2)/JAK-2 were 1.02±0.06,0.94±0.05,0.75±0.22 and 0.49±0.22;relative protein expression of phosphorylated STAT3(p-STAT3)/STAT3 were 0.89±0.10,0.72±0.04,0.65±0.06 and 0.52±0.18;relative protein expression of E-cadherin were 0.30±0.14,0.41±0.13,0.49±0.14 and 0.69±0.17;relative protein expression of N-cadherin were 0.96±0.11,0.78±0.04,0.69±0.12 and 0.40±0.15;Snail relative protein expression were 0.89±0.08,0.62±0.15,0.44±0.15 and 0.27±0.09;Vimentin relative protein expression were 0.92±0.09,0.76±0.13,0.63±0.01 and 0.43±0.09,respectively.The above indexes in experimental-H group showed statistically significant differences compared to blank group(all P<0.05).Conclusion HCT116 can inhibit the invasion and metastasis of human colorectal cancer cells HCT116 by inhibiting epithelial-mesenchymal transition through JAK2/STAT3 pathway.

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