1.Comparison of bioelectrical impedance analysis and dual energy X ray absorptiometry in measuring body composition among Tibetan children and adolescents
Chinese Journal of School Health 2026;47(4):569-573
Objective:
To compare the consistency between bioelectrical impedance analysis (BIA) and dual energy X ray absorptiometry (DXA) in measuring body composition among Tibetan children and adolescents and to explore the applicability of BIA in plateau region, so as to provide scientific and convenient body composition measurement support among children and adolescents.
Methods:
From May to June, 2022, a total of 344 Tibetan children and adolescents aged 6-17 years were selected from Golmud Municipal National Middle School and Changjiangyuan Nationality Primary School in Qinghai Province by cluster sampling method, and their fat mass, fat mass percentage and lean mass were measured by DXA and BIA. The consistency and correlation between the two methods were assessed by using the Wilcoxon rank-sum test, Spearman correlation analysis, intraclass correlation coefficient (ICC), and Bland-Altman analysis.
Results:
DXA measured fat mass and fat mass percentage were significantly higher than those obtained by BIA (6-12 years old: Z =9.91, 11.28; 13-17 years old: Z =9.02, 10.21), while lean mass and lean mass percentage were significantly lower than BIA results (6-12 years old: Z =-11.60, -11.30; 13-17 years old: Z =-10.77, -10.36) (all P < 0.05 ). The two methods showed strong correlations in fat mass and lean mass (all r >0.80, all ICC >0.90), but exhibited poor agreement in fat mass percentage and lean mass percentage (6-12 years old: Lin s CCC =0.64, 0.41; 13-17 years old: Lin s CCC = 0.79 , 0.35). Bland-Altman analysis showed that the difference between the two methods was negatively correlated with the average value in FM%(6-12 years old: r =-0.75, 13-17 years old: r =-0.79, both P <0.01).
Conclusion
BIA and DXA show high consistency in measuring body fat mass and lean body mass in Tibetan children and adolescents, although some bias is still present in certain individuals.
2.Clinical features and multimodal quantitative radiological features of primary liver cancer patients with different traditional Chinese medicine syndrome types
Feng WU ; Muqing LUO ; Wantingting WEN ; Ziwei CAI ; Yinqi LIU ; Jian XIANG ; Xiaona ZHOU ; Qian GUO ; Kun ZHANG
Journal of Clinical Hepatology 2026;42(5):1093-1100
ObjectiveTo investigate the association of the traditional Chinese medicine (TCM) syndrome types of primary liver cancer (PLC) with clinical features and multimodal quantitative radiological features on computed tomography (CT) and magnetic resonance imaging (MRI), and to provide a reference for the objectification of TCM syndrome differentiation and precise diagnosis and treatment. MethodsA retrospective analysis was performed for the clinical data of 312 patients who were diagnosed with PLC in The First Affiliated Hospital of Hunan University of Chinese Medicine from March 2020 to June 2025, and according to the TCM syndrome type, they were divided into stagnation of liver Qi group with 40 patients, stagnation of liver Qi and spleen deficiency group with 109 patients, Qi stagnation and blood stasis group with 62 patients, dampness-heat toxin amassment group with 81 patients, and liver-kidney Yin deficiency group with 20 patients. Clinical features and multimodal quantitative radiological features were compared between the patients with different TCM syndrome types. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups; the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple groups, and the Dunn’s multiple test was used for further comparison between two groups; the chi-square test was used for comparison of categorical data between groups, and the Bonferroni method was used for further comparison between two groups. ResultsThere were significant differences between the patients with different TCM syndrome types in China liver cancer staging (CNLC), Child-Pugh class, alanine aminotransferase, aspartate aminotransferase, albumin, direct bilirubin, total bilirubin, prothrombin time, neutrophil, and albumin-bilirubin score (all P<0.05). In the stagnation of liver Qi group, the patients with Child-Pugh class A accounted for 75.00%; among the patients with CNLC stage I PLC, the patients with stagnation of liver Qi accounted for 60.00%, and those with Qi stagnation and blood stasis syndrome accounted for 59.68%, while among the patients with CNLC stage IV PLC, the distribution proportion of dampness-heat toxin amassment (27.16%) and liver-kidney Yin deficiency (30.00%) was significantly higher than that of stagnation of liver Qi (2.50%) (all P<0.05). Radiological examination showed that there were significant differences between the patients with different TCM syndrome types in the number of tumors, ascites, venous tumor thrombus, maximum tumor diameter, intrahepatic metastasis, and lymph node metastasis in the hepatic hilar and retroperitoneal regions (all P<0.05). Compared with the patients with stagnation of liver Qi, the patients with liver depression and spleen deficiency or liver-kidney Yin deficiency were more likely to develop intrahepatic metastasis; the patients with liver depression and spleen deficiency, dampness-heat toxin amassment, or liver-kidney Yin deficiency were more likely to develop lymph node metastasis in the hepatic hilar and retroperitoneal regions; the patients with liver-kidney Yin deficiency were more likely to experience multiple tumors; the patients with liver depression and spleen deficiency or dampness-heat toxin amassment were more likely to develop ascites (all P<0.05). Compared with the patients with Qi stagnation and blood stasis syndrome, the patients with liver depression and spleen deficiency had a significantly longer maximum tumor diameter and a significantly higher proportion of patients with venous tumor thrombus (both P<0.05). Furthermore, among the 184 patients with MRI diffusion-weighted imaging sequences, the patients with dampness-heat toxin amassment or Qi stagnation and blood stasis syndrome had significantly higher ADC values and relative ADC values than those with stagnation of liver Qi (all P<0.05). ConclusionThere are significant differences in CT/MRI radiological features and clinical features between PLC patients with different TCM syndrome types, among whom the patients with liver depression and spleen deficiency, dampness-heat toxin amassment, and liver-kidney Yin deficiency tend to exhibit progressive radiological features, and those with dampness-heat toxin amassment or Qi stagnation and blood stasis syndrome tend to have higher ADC values. These findings provide an objective basis for TCM syndrome differentiation in PLC.
3.Application of Recombinant Collagen in Biomedicine
Huan HU ; Hong ZHANG ; Jian WANG ; Li-Wen WANG ; Qian LIU ; Ning-Wen CHENG ; Xin-Yue ZHANG ; Yun-Lan LI
Progress in Biochemistry and Biophysics 2025;52(2):395-416
Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.
4.Clinical practice guidelines for intraoperative cell salvage in patients with malignant tumors
Changtai ZHU ; Ling LI ; Zhiqiang LI ; Xinjian WAN ; Shiyao CHEN ; Jian PAN ; Yi ZHANG ; Xiang REN ; Kun HAN ; Feng ZOU ; Aiqing WEN ; Ruiming RONG ; Rong XIA ; Baohua QIAN ; Xin MA
Chinese Journal of Blood Transfusion 2025;38(2):149-167
Intraoperative cell salvage (IOCS) has been widely applied as an important blood conservation measure in surgical operations. However, there is currently a lack of clinical practice guidelines for the implementation of IOCS in patients with malignant tumors. This report aims to provide clinicians with recommendations on the use of IOCS in patients with malignant tumors based on the review and assessment of the existed evidence. Data were derived from databases such as PubMed, Embase, the Cochrane Library and Wanfang. The guideline development team formulated recommendations based on the quality of evidence, balance of benefits and harms, patient preferences, and health economic assessments. This study constructed seven major clinical questions. The main conclusions of this guideline are as follows: 1) Compared with no perioperative allogeneic blood transfusion (NPABT), perioperative allogeneic blood transfusion (PABT) leads to a more unfavorable prognosis in cancer patients (Recommended); 2) Compared with the transfusion of allogeneic blood or no transfusion, IOCS does not lead to a more unfavorable prognosis in cancer patients (Recommended); 3) The implementation of IOCS in cancer patients is economically feasible (Recommended); 4) Leukocyte depletion filters (LDF) should be used when implementing IOCS in cancer patients (Strongly Recommended); 5) Irradiation treatment of autologous blood to be reinfused can be used when implementing IOCS in cancer patients (Recommended); 6) A careful assessment of the condition of cancer patients (meeting indications and excluding contraindications) should be conducted before implementing IOCS (Strongly Recommended); 7) Informed consent from cancer patients should be obtained when implementing IOCS, with a thorough pre-assessment of the patient's condition and the likelihood of blood loss, adherence to standardized internally audited management procedures, meeting corresponding conditions, and obtaining corresponding qualifications (Recommended). In brief, current evidence indicates that IOCS can be implemented for some malignant tumor patients who need allogeneic blood transfusion after physician full evaluation, and LDF or irradiation should be used during the implementation process.
5.Discriminating Tumor Deposits From Metastatic Lymph Nodes in Rectal Cancer: A Pilot Study Utilizing Dynamic Contrast-Enhanced MRI
Xue-han WU ; Yu-tao QUE ; Xin-yue YANG ; Zi-qiang WEN ; Yu-ru MA ; Zhi-wen ZHANG ; Quan-meng LIU ; Wen-jie FAN ; Li DING ; Yue-jiao LANG ; Yun-zhu WU ; Jian-peng YUAN ; Shen-ping YU ; Yi-yan LIU ; Yan CHEN
Korean Journal of Radiology 2025;26(5):400-410
Objective:
To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer.
Materials and Methods:
A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs.
Results:
All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027).
Conclusion
The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.
6.Discriminating Tumor Deposits From Metastatic Lymph Nodes in Rectal Cancer: A Pilot Study Utilizing Dynamic Contrast-Enhanced MRI
Xue-han WU ; Yu-tao QUE ; Xin-yue YANG ; Zi-qiang WEN ; Yu-ru MA ; Zhi-wen ZHANG ; Quan-meng LIU ; Wen-jie FAN ; Li DING ; Yue-jiao LANG ; Yun-zhu WU ; Jian-peng YUAN ; Shen-ping YU ; Yi-yan LIU ; Yan CHEN
Korean Journal of Radiology 2025;26(5):400-410
Objective:
To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer.
Materials and Methods:
A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs.
Results:
All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027).
Conclusion
The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.
7.Discriminating Tumor Deposits From Metastatic Lymph Nodes in Rectal Cancer: A Pilot Study Utilizing Dynamic Contrast-Enhanced MRI
Xue-han WU ; Yu-tao QUE ; Xin-yue YANG ; Zi-qiang WEN ; Yu-ru MA ; Zhi-wen ZHANG ; Quan-meng LIU ; Wen-jie FAN ; Li DING ; Yue-jiao LANG ; Yun-zhu WU ; Jian-peng YUAN ; Shen-ping YU ; Yi-yan LIU ; Yan CHEN
Korean Journal of Radiology 2025;26(5):400-410
Objective:
To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer.
Materials and Methods:
A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs.
Results:
All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027).
Conclusion
The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.
8.Effect of annexin A1 mimetic peptide Ac2-26 on the inflammatory response in severe heatstroke mice and its protective mechanisms
Ya-Wen WANG ; Jing-Jing JI ; Jia-Li CUN ; Zhi-Feng LIU ; Xin-Jian ZHANG
Medical Journal of Chinese People's Liberation Army 2025;50(11):1444-1450
Objective To investigate the protective effects of the ANXA1(Annexin A1)mimetic peptide Ac2-26 on mice with severe heatstroke(HS)and its underlying mechanisms.Methods Twenty-four adult healthy male C57BL/6J mice weighing 20-25 g were randomly divided into four groups using a simple random sampling method:control group(Con group),Con+Ac2-26 group,severe heatstroke group(HS group),and severe heatstroke+Ac2-26 group(HS+Ac2-26 group),with 6 mice in each group.Mice in Con+Ac2-26 group and HS+Ac2-26 group were injected intraperitoneally with Ac2-26(6 mg/kg),and the remaining mice of two groups were injected intraperitoneally with normal saline of equivalent volume.One hour after drug administration,mice in HS group and HS+Ac2-26 group were placed in a high-temperature and high-humidity simulated environment[(37.0±0.5)℃,75%±5%humidity],while mice in Con group and Con+Ac2-26 were kept in a room temperature and humidity environment[(24±0.5)℃and 40±5%humidity]throughout the experiment.The anal temperature of the mice was recorded every 5 minutes;when the anal temperature of mice in HS group and HS+Ac2-26 group reached 42℃,they were removed from the high-temperature environment and placed in a room temperature environment for 6 hours of rewarming,after which blood samples of mice in each group were collected.Flow cytometry was used to detect the proportion of neutrophils and the expression levels of Cd11b and Cd62L(molecules related to neutrophil activation).Enzyme-linked immunosorbent assay(ELISA)was used to measure the plasma levels of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6),IL-10,and IL-4.Hematoxylin-eosin staining(HE staining)was performed to observe the pathological changes in lung,kidney and liver tissues.Furthermore,RNA sequencing(RNA-seq)was conducted to detect changes in neutrophil gene expression.Results Compared with Con group,Con+Ac2-26 group showed no significant increase in neutrophil proportion,decreased expression of CD62L and CD11b,no significant changes in cytokine levels,and no obvious pathological changes in lung,kidney,or liver tissues.Compared with HS group,the time for mice in HS+Ac2-26 group to reach an anal temperature of 42℃and the time to develop hypothermia after model establishment were both prolonged(P<0.05);the proportion of neutrophils was reduced(P<0.05);the plasma levels of pro-inflammatory cytokines TNF-α and IL-6 were decreased(P<0.05);and the plasma level of anti-inflammatory cytokine IL-10 was increased(P<0.05).HE staining results showed that compared with HS group,HS+Ac2-26 group had a reduced range of inflammatory cell infiltration in lung,kidney,and liver tissues.RNA-seq results revealed that compared with HS group,HS+Ac2-26 group had decreased expression levels of molecules related to the oxidative phosphorylation signaling pathways and neutrophil extracellular trap(NETs).Conclusion Annexin A1 mimetic peptide Ac2-26 may reduce the pro-inflammatory response and alleviate the heatstroke-induced organ histopathologic damage in heatstroke mice by inhibiting oxidative phosphorylation in heat-stressed cells and NETs formation.
9.Feixin Decoction Treats Hypoxic Pulmonary Hypertension by Regulating Pyroptosis in PASMCs via PPARγ/NF-κB/NLRP3 Signaling Pathway
Junlan TAN ; Xianya CAO ; Runxiu ZHENG ; Wen ZHANG ; Chao ZHANG ; Jian YI ; Feiying WANG ; Xia LI ; Jianmin FAN ; Hui LIU ; Lan SONG ; Aiguo DAI
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(18):1-9
ObjectiveTo investigate the mechanism by which Feixin decoction treats hypoxic pulmonary hypertension (HPH) by regulating the peroxisome proliferator-activated receptor gamma (PPARγ)/nuclear factor-kappa B (NF-κB)/NOD-like receptor pyrin domain containing 3 (NLRP3) signaling pathway. MethodsForty-eight male SD rats were randomly allocated into normal, hypoxia, and low-, medium- and high-dose (5.85, 11.7, 23.4 g·kg-1, respectively) Feixin decoction groups, with 8 rats in each group. Except the normal group, the remaining five groups were placed in a hypoxia chamber with an oxygen concentration of (10.0±0.5)% for 8 h per day, 28 days, and administrated with corresponding drugs during the modeling process. After 4 weeks of treatment, echocardiographic parameters [pulmonary artery acceleration time (PAT), pulmonary artery ejection time (PET), right ventricular anterior wall thickness (RVAWd), and tricuspid annular plane systolic excursion (TAPSE)] were measured for each group. The right ventricular systolic pressure (RVSP) was measured by the right heart catheterization method, and the right ventricular hypertrophy index (RVHI) was calculated by weighing the heart. The pathological changes in pulmonary arterioles were observed by hematoxylin-eosin staining. The co-localization of α-smooth muscle actin (α-SMA) with NLRP3, N-terminal gasdermin D (N-GSDMD), and cysteinyl aspartate-specific proteinase-1 (Caspase-1) in pulmonary arteries was detected by immunofluorescence. The protein levels of PPARγ, NF-κB, NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), N-GSDMD, interleukin-1β (IL-1β), interleukin-18(IL-18), and cleaved Caspase-1 in the lung tissue was determined by Western blot. The ultrastructural changes in pulmonary artery smooth muscle cells (PASMCs) were observed by transmission electron microscopy. ResultsCompared with the normal group, the hypoxia group showed increased RVSP and RVHI (P<0.01), decreased right heart function (P<0.01), increased pulmonary vascular remodeling (P<0.01), increased co-localization of α-SMA with NLRP3, N-GSDMD, and Caspase-1 in pulmonary arterioles (P<0.01), up-regulated protein levels of NF-κB, NLRP3, ASC, N-GSDMD, IL-1β, IL-18, and cleaved Caspase-1 in the lung tissue (P<0.05, P<0.01), a down-regulated protein level of PPARγ (P<0.05, P<0.01), and pyroptosis in PASMCs. Compared with the hypoxia group, Feixin decoction reduced RVSP and RVHI, improved the right heart function and ameliorated pulmonary vascular remodeling (P<0.05, P<0.01), decreased the co-localization of α-SMA with NLRP3, N-GSDMD, and Caspase-1 (P<0.05, P<0.01), down-regulated the protein levels of NF-κB, NLRP3, ASC, N-GSDMD, IL-1β, IL-18, and cleaved Caspase-1 in the lung tissue (P<0.05, P<0.01), up-regulated the protein level of PPARγ (P<0.05, P<0.01), and alleviated pyroptosis in PASMCs. ConclusionFeixin decoction can ameliorate pulmonary vascular remodeling and right heart dysfunction in chronically induced HPH rats by regulating pyroptosis in PASMCs through the PPARγ/NF-κB/NLRP3 pathway.
10.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.


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