1.Junctophilin-2 MORN-Helix Domain: Structural Basis for Membrane Binding and Hypertrophic Cardiomyopathy-associated Mutations
Jing-Xin WANG ; Zhi-Wei LI ; Wei LIU ; Wen-Qing ZHANG ; Jian-Chao LI
Progress in Biochemistry and Biophysics 2025;52(8):2103-2116
ObjectiveJunctophilin-2 (JPH2) is an essential structural protein that maintains junctional membrane complexes (JMCs) in cardiomyocytes by tethering the plasma membrane to the sarcoplasmic reticulum, thereby facilitating excitation-contraction (E-C) coupling. Mutations in JPH2 have been associated with hypertrophic cardiomyopathy (HCM), but the molecular mechanisms governing its membrane-binding properties and the functional relevance of its membrane occupation and recognition nexus (MORN) repeat motifs remain incompletely understood. This study aimed to elucidate the structural basis of JPH2 membrane association and its implications for HCM pathogenesis. MethodsA recombinant N-terminal fragment of mouse JPH2 (residues1-440), encompassing the MORN repeats and an adjacent helical region, was purified under near-physiological buffer conditions.X-ray crystallography was employed to determine the structure of the JPH2 MORN-Helix domain. Sequence conservation analysis across species and junctophilin isoforms was performed to assess the evolutionary conservation of key structural features. Functional membrane-binding assays were conducted using liposome co-sedimentation and cell-based localization studies in COS7 and HeLa cells. In addition, site-directed mutagenesis targeting positively charged residues and known HCM-associated mutations, including R347C, was used to evaluate their effects on membrane interaction and subcellular localization. ResultsThe crystal structure of the mouse JPH2 MORN-Helix domain was resolved at 2.6 Å, revealing a compact, elongated architecture consisting of multiple tandem MORN motifs arranged in a curved configuration, forming a continuous hydrophobic core stabilized by alternating aromatic residues. A C-terminal α-helix further reinforced structural integrity. Conservation analysis identified the inner groove of the MORN array as a highly conserved surface, suggesting its role as a protein-binding interface. A flexible linker segment enriched in positively charged residues, located adjacent to the MORN motifs, was found to mediate direct electrostatic interactions with negatively charged phospholipid membranes. Functional assays demonstrated that mutation of these basic residues impaired membrane association, while the HCM-linked R347C mutation completely abolished membrane localization in cellular assays, despite preserving the overall MORN-Helix fold in structural modeling. ConclusionThis study provides structural insight into the membrane-binding mechanism of the cardiomyocyte-specific protein JPH2, highlighting the dual roles of its MORN-Helix domain in membrane anchoring and protein interactions. The findings clarify the structural basis for membrane targeting via a positively charged linker and demonstrate that disruption of this interaction—such as that caused by the R347C mutation—likely contributes to HCM pathogenesis. These results not only enhance current understanding of JPH2 function in cardiac E-C coupling but also offer a structural framework for future investigations into the assembly and regulation of JMCs in both physiological and disease contexts.
2.Proanthocyanin B2 inhibits oxidative stress and alleviates H2O2 induced damage to human oligodendrocytes through NRF2/HO-1/xCT/GPX4 axis
Jian LIU ; Ying CHEN ; Ya-Jie LIANG ; Meng PU ; Zi-Wei ZHANG ; Lu-Lu ZHENG ; Zhi CHAI ; Ying XIAO ; Cun-Gen MA ; Qing WANG
Chinese Pharmacological Bulletin 2024;40(9):1735-1743
Aim To explore the protective effect of an-thocyanin B2(PCB2)on hydrogen peroxide(H2O2)induced oxidative damage and apoptosis in human oli-godendrocytes(MO3.13)and the underlying mecha-nism.Methods The optimal concentration of H2O2 and PCB2 for action was screened,and divided into normal group,PCB2 group(100 mg·L-1 PCB2 treat-ment for 24 hours),H2 O2 model group(500 μmol·L-1 H2O2 treatment for 24 hours),and H2O2+PCB2 group(500 μmol·L-1 H2O2 and 100 mg·L-1 PCB2 co-treated for 24 hours).FRAP method was used to detect the antioxidant capacity of PCB2;CCK-8 meth-od was used to detect the survival rate of cells in each group,while LDH method was used to assess cytotoxic-ity.Microenzyme-linked immunosorbent assay and ELISA were used to examine the levels of LDH,NO,H2O2,as well as the activities of CAT and SOD in each group of cells.Immunofluorescence and Western blot were used to detect the protein expression levels of NRF2,xCT,HO-1,ferritin,and GPX4 in each group of cells.FerroOrange fluorescent probe was used to de-tect the intracellular content of ferrous ions(Fe2+).Results H2O2 could induce MO3.13 oxidative dam-age and lead to cell ferroptosis,while PCB2 could alle-viate MO3.13 oxidative damage and ferroptosis.Com-pared with the H2O2 model group,PCB2 intervention could significantly increase LDH content in MO3.13,reduce NO and H2O2 content,and improve SOD and CAT activity,and up-regulate the protein expression levels of NRF2,xCT,HO-1,ferritin,and GPX4.Conclusion PCB2 can enhance cellular antioxidant capacity and alleviate H2O2 induced MO3.13 oxidative damage through the NRF2/HO-1/xCT/GPX4 axis.
3.Progress in study of multifunctionality of DPP4 and mechanism of action of related drug targets
Lei WANG ; Zhi-Hui YANG ; Yang ZHENG ; Ying ZHANG ; Tie-Jian ZHAO ; Wei-Sheng LUO ; Tian-Jian LIANG ; Jia-Hui WANG
Chinese Pharmacological Bulletin 2024;40(12):2212-2217
DPP4 is a serine exopeptidase that is immobilized on the cell membrane and plays a crucial regulatory role in various physiological and pathological activities within the human body.In addition to acting as a transcription factor to regulate the tran-scription and expression of downstream target genes,DPP4 also functions as a transcription-independent regulator through pro-tein-protein interactions.In recent studies,DPP4 has been strongly linked to various diseases,and several substances with the potential to target DPP4 have been identified.This paper mainly reviews the multifunctionality of DPP4 in regulating vari-ous aspects of energy metabolism,inflammation,tissue repair and carcinogenesis in the body.It also reviews the screening of in vitro inhibitors of DPP4 and its research progress in regulating chronic liver disease,based on the pathological development process of chronic liver disease.
4.Comparison of the efficacy of TiRobot orthopaedic robot assisted F screw technique and inverted triangle parallel nail internal fixation in the treatment of unstable femoral neck fractures
Xing-Long ZHAO ; Jian-Jun SHEN ; Kang-Hu FENG ; Zhi-Wei CHEN ; Yuan-Long SI ; Xuan ZHANG ; Guan-De WANG ; Xiang HAI
China Journal of Orthopaedics and Traumatology 2024;37(2):129-134
Objective To compare the effectiveness of TiRobot assisted F screw technique and inverted triangle parallel nail internal fixation in the treatment of unstable femoral neck fractures.Methods A retrospective analysis was conducted on 72 patients with unstable femoral neck fractures who were treated with percutaneous cannulated screw fixation assisted with TiRobot Orthopaedic robot from December 2019 to April 2021.Among them,37 patients were treated with F screw internal fixa-tion,including 16 males and 21 females,aged47 to 64years old with an average of(53.87±5.28)years old;According to Pauwels classification,there were 1 case of type Ⅰ,19 cases of type Ⅱ,17 cases of type Ⅲ;8 cases of combined medical diseases;17 cases of falling,8 cases of traffic accident and 12 cases of falling from height;The time from injury to operation was 29 to 49 hours with average of(35.00±7.34)hours.Another 35 cases used internal fixation with an inverted triangle parallel nail,including 13 males and 22 females with an average age of 46 to 63 years old(52.36±5.05)years old;According to the Pauwels injury classifi-cation:there were 2 cases of type Ⅰ,21 cases of type Ⅱ,12 cases of type Ⅲ;6 cases of medical diseases,15 cases of falling in-jury,9 cases of traffic accident,11 cases of falling injury;The time from injury to operation was 30 to 45 hours with an average of(33.00±6.83)h.The intraoperative blood loss,operation time,intraoperative fluoroscopy times,follow-up time,fracture healing time,postoperative complications were observed and compared between the two groups.The hip joint function was e-valuated by Harris score at 6 months and 12 months after operation.Results There was no significant difference in operation time,intraoperative blood loss,intraoperative fluoroscopy times and other intraoperative data between two groups(P>0.05).Both groups were followed up regularly,and the follow-up time was 12 to 16 months.The fracture healing time and Harris score of the F screw internal fixation group were better than those of the inverted triangle parallel nail internal fixation group(P<0.05).There was 1 case of femoral neck shortening in the F screw internal fixation group,1 case of nonunion,1 case of nail withdrawal,and 1 case of lower extremity deep vein thrombosis in the inverted triangle internal fixation group.The incidence of complications in the F screw internal fixation group was lower than that in the inverted triangle parallel nail internal fixation group(P<0.05).Conclusion Percutaneous cannulated F screw technique using Tirobot navigation positioning system is a safe and effective treatment for patients with unstable femoral neck fractures.It can significantly shorten the fracture healing time,reduce the incidence of postoperative complications,significantly improve hip joint function,and improve the quality of life.
5.Comparison of the posterior hemipelvectomy of the greater trochanter approach with the standard Kocher-Langen-beck approach in the treatment of posterior acetabulum wall fractures
Jin ZHANG ; Jian-Jun SHEN ; Xiang HAI ; Chuan-Yuan LIU ; Wen-Jie ZHOU ; Zhi-Wei CHEN
China Journal of Orthopaedics and Traumatology 2024;37(8):786-792
Objective To compare the clinical efficacy of the posterior hemipelvectomy of the greater trochanter approach with the standard Kocher-Langenbeck(K-L)approach in the treatment of posterior acetabulum wall fractures and to explore a more optimal approach for the treatment of posterior acetabulum wall fractures.Methods Total of 26 patients with posterior ac-etabulum wall fractures were retrospectively analysed and divided into two groups:the posterior hemipelvectomy of the greater trochanter group(test group)and the standard K-L approach group(control group).In the test group,there were 24 patients including 16 males and 8 females with an average age of(42.00±4.52)years old,the time of injury to surgery was(6.75±1.15)d.In the control group,there were 23 patients including 16 males and 7 females with an average age of(41.00±5.82)years old,the time of injury to surgery was(7.09±1.20)days.The total hospital stay,length of incision,operation time,intraoperative bleeding,postoperative drainage,discharge,fracture reduction quality(Matta criteria),hip abduction muscle strength,hip func-tion(Merle d'Aubigne-Postel score),postoperative complications and the incidence of ectopic ossification were compared.Results All cases were followed up for 6 months.There was no significant difference in incision length,intraoperative bleeding and postoperative drainage between two groups(P>0.05).However,the operation time of the test group was shorter than that of the control group(P<0.05).There was no statistically significant difference in fracture reduction and hip function between two groups(P>0.05).The hip abduction muscle strength of test group was better than that of control group(P<0.05).In addition,there was no significant difference in the incidence of postoperative complications and heterotopic ossification between two groups(P>0.05).Conclusion Compared with the standard K-L approach,the posterior hemipelvectomy of the greater trochanter approach can shorten the operative time,has better recovery of the postoperative hip abduction muscle strength,ex-poses the view of the fracture involving the more comminuted posterior acetabulum wall or the fracture of the roof of the socket,improved the rate of fracture anatomical repositioning,provides a new idea for the clinical treatment of posterior acetabulum wall fractures,and allows patients to perform functional exercises at an early stage.
6.Early gait analysis after total knee arthroplasty based on artificial intelligence dynamic image recognition
Ming ZHANG ; Ya-Nan SUI ; Cheng WANG ; Hao-Chong ZHANG ; Zhi-Wei CAI ; Quan-Lei ZHANG ; Yu ZHANG ; Tian-Tian XIA ; Xiao-Ran ZU ; Yi-Jian HUANG ; Cong-Shu HUANG ; Xiang LI
China Journal of Orthopaedics and Traumatology 2024;37(9):855-861
Objective To explore early postoperative gait characteristics and clinical outcomes after total knee arthroplasty(TKA).Methods From February 2023 to July 2023,26 patients with unilateral knee osteoarthritis(KOA)were treated with TKA,including 4 males and 22 females,aged from 57 to 85 years old with an average of(67.58±6.49)years old;body mass in-dex(BMI)ranged from 18.83 to 38.28 kg·m-2 with an average of(26.43±4.15)kg·m-2;14 patients on the left side,12 pa-tients on the right side;according to Kellgren-Lawrence(K-L)classification,6 patients with grade Ⅲ and 20 patients with grade Ⅳ;the courses of disease ranged from 1 to 14 years with an average of(5.54±3.29)years.Images and videos of standing up and walking,walking side shot,squatting and supine kneeling were taken with smart phones before operation and 6 weeks after operation.The human posture estimation framework OpenPose were used to analyze stride frequency,step length,step length,step speed,active knee knee bending angle,stride length,double support phase time,as well as maximum hip flexion angle and maximum knee bending angle on squatting position.Western Ontario and McMaster Universities(WOMAC)arthritis index and Knee Society Score(KSS)were used to evaluate clinical efficacy of knee joint.Results All patients were followed up for 5 to 7 weeks with an average of(6.00±0.57)weeks.The total score of WOMAC decreased from(64.85±11.54)before op-eration to(45.81±7.91)at 6 weeks after operation(P<0.001).The total KSS was increased from(101.19±9.58)before opera-tion to(125.50±10.32)at 6 weeks after operation(P<0.001).The gait speed,stride frequency and stride length of the affected side before operation were(0.32±0.10)m·s-1,(96.35±24.18)steps·min-1,(0.72±0.14)m,respectively;and increased to(0.48±0.11)m·s 1,(104.20±22.53)steps·min-1,(0.79±0.10)m at 6 weeks after operation(P<0.05).The lower limb support time and active knee bending angle decreased from(0.31±0.38)sand(125.21±11.64)° before operation to(0.11±0.04)s and(120.01±13.35)° at 6 weeks after operation(P<0.05).Eleven patients could able to complete squat before operation,13 patients could able to complete at 6 weeks after operation,and 9 patients could able to complete both before operation and 6 weeks after operation.In 9 patients,the maximum bending angle of crouching position was increased from 76.29° to 124.11° before operation to 91.35° to 134.12° at 6 weeks after operation,and the maximum bending angle of hip was increased from 103.70° to 147.25° before operation to 118.61° to 149.48° at 6 weeks after operation.Conclusion Gait analysis technology based on artificial intelligence image recognition is a safe and effective method to quantitatively identify the changes of pa-tients'gait.Knee pain of KOA was relieved and the function was improved,the supporting ability of the affected limb was im-proved after TKA,and the patient's stride frequency,stride length and stride speed were improved,and the overall movement rhythm of both lower limbs are more coordinated.
7.Effect of ureteral wall thickness at the site of ureteral stones on the clinical efficacy of ureteroscopic lithotripsy
Wei PU ; Jian JI ; Zhi-Da WU ; Ya-Fei WANG ; Tian-Can YANG ; Lyu-Yang CHEN ; Qing-Peng CUI ; Xu XU ; Xiao-Lei SUN ; Yuan-Quan ZHU ; Shi-Cheng FAN
Journal of Regional Anatomy and Operative Surgery 2024;33(12):1077-1081
Objective To investigate the effect of varying ureteral wall thickness(UWT)at the site of ureteral stones on the clinical efficacy of ureteroscopic lithotripsy(URL).Methods The clinical data of 164 patients with ureteral stones in our hospital were retrospectively analyzed.According to different UWT,the patients were divided into the mild thickening group(84 cases,UWT<3.16 mm),the moderate thickening group(31 cases,UWT 3.16 to 3.49 mm),and the severe thickening group(49 cases,UWT>3.49 mm),and the differences of clinical related indicators among the three groups were compared.Results The incidence of postoperative renal colic and leukocyte disorder in the mild thickening group and the moderate thickening group were lower than those in the severe thickening group,and the differences were statistically significant(P<0.05).The postoperative catheterization time in the mild thickening group and the moderate thickening group were shorter than that in the severe thickening group,and the incidences of secondary lithotripsy,residual stones and stone return to kidney in the mild thickening group and the moderate thickening group were lower than those in the severe thickening group,with statistically significant differences(P<0.05).The length of hospital stay and hospitalization cost in the mild thickening group and the moderate thickening group were shorter/less than those in the severe thickening group,with statistically significant differences(P<0.05).Conclusion With the increase of UWT(especially when UWT>3.49 mm),the incidence of postoperative complications and hospitalization cost of URL increase to varying degrees,and the surgical efficacy decreases.In clinical work,UWT measurement holds potential value in predicting the surgical efficacy and complications of URL.
8.The Effect and Safety of Flumatinib in Patients with Chronic Myelogenous Leukemia Failed First-and Second-line Treatment
Li-Ying LIU ; Ji-Feng WEI ; TAO JIA ; Jian-Ping MAO ; Zhi-Mei CAI
Journal of Experimental Hematology 2024;32(2):370-375
Objective:To analyze the efficacy and safety of flumatinib,a second-generation tyrosine kinase inhibitor(TKI)independently developed in China,in patients with chronic myelogenous leukemia in chronic phase(CML-CP)who falied first-line and second-line treatment.Methods:The clinical data of 30 CML-CP patients treated with flumatinib in Lianyungang First People's Hospital from January 2020 to September 2022 were collected retrospectively.Among them,15 patients who received imatinib first-line treatment but failed treatment were included in the second-line group,and the other 15 patients who failed second-line treatment with nilotinib or dasatinib were included in the third-line group.The hematological and molecular responses of the patients in the two groups at 3,6 and 12 months of treatment,and the event-free survival(EFS)and adverse reactions of patients at the end of follow-up were statistical analyzed.Results:At 3,6,and 12 months of treatment,10,11,and 12 patients in the second line group achieved major molecular response(MMR),which was higher than that of 3,4,and 5 patients in the third line group(P=0.010,P=0.011,P=0.010).At 3 months of treatment,12 and 13 patients achieved complete hematological response(CHR)and early molecular response(EMR)in the second-line group,which was higher than that of 9 and 13 patients in the third-line group,but the difference between the two groups was not statistically significant(P=0.232,P=1.000);At 6 and 12 months of treatment,6 and 7 patients in the second-line group achieved MR4.5,which were higher than of 3 and 2 cases in the third-line group,but the difference was not statistically significant(P=0.427,P=0.713).The hematological adverse reactions of patients in the second-line group during treatment the period were mainly grade 1-2 thrombocytopenia and anemia,and no grade 3-4 of adverse reactions occurred.In the third-line group,there were 2 cases of grade 1-2 thrombocytopenia,grade 1-2 anemia and white blood cell 3 cases were reduced each,1 case of grade 3-4 anemia,2 cases of grade 3-4 neutropenia.The non-hematological adverse reactions in the second-line group were rash(2 cases),headache(1 case),diarrhea(1 case),fatigue(1 case),limb pain(1 case).There were 1 cases of diarrhea,1 cases of nausea,and 1 cases of edema in the third-line group.There was no statistical significance in hematological and non-hematological adverse reactions between the two groups of patients(P>0.05).At the end of follow-up,the EFS rate of patients in the second-line group was higher than that in the third-line group(100%vs 93.3%),but the difference was not statistically significant(P=0.317).Conclusion:The second-generation TKI flumatinib independently developed in China,has good curative effect and safety for CML-CP patients who failed first-line and second-line treatment.
9.Clinical Efficacy and Safety of Ixazomib-Containing Regimens in the Treatment of Patients with Multiple Myeloma
Ran CHEN ; Lian-Guo XUE ; Hang ZHOU ; Tao JIA ; Zhi-Mei CAI ; Yuan-Xin ZHU ; Lei MIAO ; Ji-Feng WEI ; Li-Dong ZHAO ; Jian-Ping MAO
Journal of Experimental Hematology 2024;32(2):483-492
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.
10.Thalassemia Genotypes and HbA2 levels of Children in Wuzhou,Guangxi
Song-Xiao WEI ; Feng-Yuan LI ; Ying-Ying MAI ; Jian-Zhi LIANG
Journal of Experimental Hematology 2024;32(3):831-835
Objective:To analyze thalassemia genotypes and distribution of children in Wuzhou Guangxi,and evaluate the diagnostic value of HbA2 in children's thalassemia screening,so as to provide scientific evidence for the prevention and control strategies of thalassemia.Methods:Four hundred and fifty-eight children suspected with thalassemia in Wuzhou were enrolled from March 2017 to June 2022.The level of HbA2 was detected using Bio-Rad VARIANT Ⅱ Hb analysis system.The deletion of α-thalassemia was measured with gap-PCR assay,and the point mutation of α-and β-thalassemia was tested with DNA reverse dot blot hybridization assay.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic value of HbA2 for children's thalassemia.Results:A total of 304 thalassemia carriers were detected in 458 children,accounting for 66.38%.One hundred and seventy-five cases were defined to be α-thalassemia,with the main type of--SEA/αα(54.86%).Thirty-six cases were defined to be intermediate α-thalassemia,with the main type of-α3.7/--SEA(9.72%).In 108 cases with β-thalassemia,βCD41-42/βN was the main type,accounting for 49.07%,followed by βIVS-Ⅱ-654/βN(14.81%).Seven cases were moderate/severe β-thalassemia(predominantly β-28/β-28 and βCD41-42/βCD17)Twenty-one genotypes of α-and β-thalassemia were found in the children.There was significant difference of HbA2 level between the children with different types of thalassemia and healthy controls(all P<0.001).ROC curve analysis showed that the sensitivities of HbA2 for α-thalassemia,β-thalassemia and αβ-thalassemia were 74.3%,82.4%and 85.7%,with the optimal cut-off values of 2.60%,3.60%and 3.70%,respectively,the specificities were 64.3%,96.1%and 96.8%,and the area under the curve were 0.690,0.887 and 0.916,respectively.Conclusion:The thalassemia genotypes of children in Wuzhou are diverse.It is necessary to further strengthen the prevention and control measure of thalassemia to reduce birth defects and improve birth quality.

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