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. Exploring mechanism of hypolipidemic effect of total Ligustrum robustum (Roxb. ) Blume on hyperlipidemic golden hamsters based on intestinal flora
Chen-Xi XU ; Rui-Le PAN ; Meng-Chen DONG ; Zhi-Hong YANG ; Xiao-Ya LI ; Wen JIN ; Run-Mei YANG
Chinese Pharmacological Bulletin 2024;40(3):476-483
Aim To evaluate the hypolipidemic effect of the total phenylpropanoid glycosides extracted from Ligustrum robustum (Roxb.) Blume (LRTPG) on hyperlipidemic golden hamsters and explore its regulatory effect on intestinal flora. Methods Sixty hamsters were randomly divided into a control group, a model group, a positive drug group, LRTPG-L group, LRTPG-M group, and LRTPG-H group. After the successful induction of the model by high-fat diet, the animals were continuously administered for four weeks, and their blood lipids and liver lipids were detected. The formed feces from the colorectal region of the hamsters in the control group, model group and LRTPG-H group were collected for 16S rDNA sequencing. Results LRTPG reduced serum TG, TC, LDL-C and liver TG, TC concentrations significantly in hyperlipidemic hamsters. The results of the intestinal microbiota sequencing showed that compared to the control group, LRTPG significantly decreased the relative abundance of the phylum Firmicutes and increased the relative abundance of the phylum Bacteroidetes and Verrucomicrobia (P < 0.01) at the phylum level. At the family level, LRTPG significantly increased the relative abundance of Christensenellaceae, Peptococcaceae, and Verrucomicrobiaceae (P < 0.05 or P < 0.01). At the genus level, LRTPG significantly increased the relative abundance of Oscillospira, Oscillibacter, Flavonifractor and Akkermansiaceae (P < 0.05 or P < 0.01). These changes in the flora were beneficial to the hypolipidemic effect of LRTPG. Conclusion LRTPG may exert its hypolipidemic effect by improving the intestinal flora disorder caused by a high-fat diet in golden hamsters.
3.Systematic characterization and identification of the chemical constituents of the Schisandra chinensis decoction based on a hybrid scanning technique of UHPLC/IM-QTOF-MS
Li-li HONG ; Hong-da WANG ; Xiao-yan XU ; Wan-di HU ; Jing-yuan LIU ; Xiao-ying WANG ; Xiu-mei GAO ; Wen-zhi YANG
Acta Pharmaceutica Sinica 2024;59(3):678-692
italic>Schisandra chinensis is a traditional Chinese medicine with the functions of reinforcing deficiency, strengthening, and inducing astringency, appliable to treat the chronic cough and deficiency in breath, palpitation, and insomnia,
4.A Rapid Non-invasive Method for Skin Tumor Tissue Early Detection Based on Bioimpedance Spectroscopy
Jun-Wen PENG ; Song-Pei HU ; Zhi-Yang HONG ; Li-Li WANG ; Kai LIU ; Jia-Feng YAO
Progress in Biochemistry and Biophysics 2024;51(5):1161-1173
ObjectiveIn recent years, with the intensification of environmental issues and the depletion of ozone layer, incidence of skin tumors has also significantly increased, becoming one of the major threats to people’s lives and health. However, due to factors such as high concealment in the early stage of skin tumors, unclear symptoms, and large human skin area, most cases are detected in the middle to late stage. Early detection plays a crucial role in postoperative survival of skin tumors, which can significantly improve the treatment and survival rates of patients. We proposed a rapid non-invasive electrical impedance detection method for early screening of skin tumors based on bioimpedance spectroscopy (BIS) technology. MethodsFirstly, we have established a complete skin stratification model, including stratum corneum, epidermis, dermis, and subcutaneous tissue. And the numerical analysis method was used to investigate the effect of dehydrated and dry skin stratum corneum on contact impedance in BIS measurement. Secondly, differentiation effect of different diameter skin tumor tissues was studied using a skin model after removing the stratum corneum. Then, in order to demonstrate that BIS technology can be used for detecting the microinvasion stage of skin tumors, we conducted a simulation study on the differentiation effect of skin tumors under different infiltration depths. Finally, in order to verify that the designed BIS detection system can distinguish between tumor microinvasion periods, we conducted tumor invasion experiments using hydrogel treated pig skin tissue. ResultsThe simulation results show that a dry and high impedance stratum corneum will bring about huge contact impedance, which will lead to larger measurement errors and affect the accuracy of measurement results. We extracted the core evaluation parameter of relaxed imaginary impedance (Zimag-relax) from the simulation results of the skin tumor model. When the tumor radius (Rtumor) and invasion depth (h)>1.5 mm, the designed BIS detection system can distinguish between tumor tissue and normal tissue. At the same time, in order to evaluate the degree of canceration in skin tissue, the degree of tissue lesion (εworse) is defined by the relaxed imaginary impedance (Zimag-relax) of normal and tumor tissue (εworse is the percentage change in virtual impedance of tumor tissue relative to that of normal tissue), and we fitted a Depth-Zimag-relax curve using relaxation imaginary impedance data at different infiltration depths, which can be applied to quickly determine the infiltration depth of skin tumors after being supplemented with a large amount of clinical data in the future. The experimental results proved that when εworse=0.492 0, BIS could identify microinvasive tumor tissue, and the fitting curve correction coefficient of determination was 0.946 8, with good fitting effect. The simulation using pig skin tissue correlated the results of real human skin simulation with the experimental results of pig skin tissue, proving the reliability of this study, and laying the foundation for further clinical research in the future. ConclusionOur proposed BIS method has the advantages of fast, real-time, and non-invasive detection, as well as high sensitivity to skin tumors, which can be identified during the stage of tumor microinvasion.
5.Application of the OmniLogTM microbial identification system in the detection of the host spectrum for wild-type plague phage in Qinghai Plateau
Cun-Xiang LI ; Zhi-Zhen QI ; Qing-Wen ZHANG ; Hai-Hong ZHAO ; Long MA ; Pei-Song YOU ; Jian-Guo YANG ; Hai-Sheng WU ; Jian-Ping FENG
Chinese Journal of Zoonoses 2024;40(1):21-25
The growth of three plague phages from Qinghai Plateau in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,PTB5,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were detected through a micromethod based on the OmniLogTM microbial identification system and by the drop method,to provide a scientific basis for future ecological studies and classification based on the host range.For plague vaccine strains EV76 and 614F,successful phage infection and subsequent phage growth were observed in the host bacte-rium.Diminished bacterial growth and respiration and a concomitant decrease in color were observed with the OmniLogTM mi-crobial identification system at 33 ℃ for 48 h.Yersinia pseudotuberculosis PTB5 was sensitive to Yersinia pestis phage 476,but Yersinia pseudotuberculosis PST5 was insensitive to phage 087 and 072204.Three strains of non-Yersinia pestis(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were insensitive to Yersinia pestis pha-ges 087,072204,and 476 showed similar growth curves.The growth of phages 476 and 087,as determined with the drop method,in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersin-ia enterocolitica 52302-2)showed the same results at 37 ℃,on the basis of comparisons with the OmniLogTM microbial i-dentification system;in contrast,phages 072204 did not show plaques on solid medium at 37 ℃ with plague vaccine strains EV76 and 614F.Determination based on the OmniLogTM detection system can be used as an alternative to the traditional determination of the host range,thus providing favorable application val-ue for determining the interaction between the phage and host bacteria.
6.Advances in crystal nucleation for amorphous drugs
Jie ZHANG ; Kang LI ; Zi-qing YANG ; Zi-han DING ; Sai-jun XIAO ; Zhi-ming YUE ; Li-mei CAI ; Jia-wen LI ; Ding KUANG ; Min-zhuo LIU ; Zhi-hong ZENG
Acta Pharmaceutica Sinica 2024;59(7):1962-1969
Amorphous solid dispersion (ASD) is one of the most effective formulation approaches to enhance the water solubility and oral bioavailability of poorly water-soluble drugs. However, maintenance of physical stability of amorphous drug is one of the main challenges in the development of ASD. Crystallization is a process of nucleation and crystal growth. The nucleation is the key factor that influences the physical stability of the ASD. However, a theoretical framework to describe the way to inhibit the nucleation of amorphous drug is not yet available. We reviewed the methods and theories of nucleation for amorphous drug. Meanwhile, we also summarized the research progress on the mechanism of additives influence on nucleation and environmental factors on nucleation. This review aims to enhance the better understanding mechanism of nucleation of amorphous drug and controlling over the crystal nucleation during the ASD formulation development.
7.Inhibitory effects of toosendanin on in vitro and in vivo growth of lung adenocarcinoma cells by regulating CDCA5 expression
Zhi-Cheng ZHANG ; Li-Xia SU ; Rui-Ling MENG ; Wen-Juan GUAN ; Hong-Qian LI
The Chinese Journal of Clinical Pharmacology 2024;40(7):994-998
Objective To investigate the inhibitory effect of toosendanin on the growth of lung adenocarcinoma cells in vitro and in vivo by regulating the expression of cell division cycle associated protein 5(CDCA5).Methods The expression of CDCA5 in different lung tissues was analyzed in TCGA database.The expression level of CDCA5 in BEAS-2B cells and A549 cells was detected by Western blot.The effect of different concentrations of toosendanin on the viability of A549 cells was determined by cell counting kit-8(CCK-8)assay.The A549 cells were randomly divided into 4 groups:control group(normal cells cultured normally),toosendanin group(normal cells cultured with 40 μmol·L-1 toosendanin),toosendanin+pcDNA group(cells transfected with pcDNA empty vector and cultured with 40 μmol·L-1 toosendanin),and toosendanin+CDCA5 group(cells transfected with CDCA5 overexpression vector and cultured with 40 μmol·L-1 toosendanin).After 48 h of cultivation,the proliferation and apoptosis of each group of cells were detected by CCK-8 and flow cytometry,and the expression of proliferation and apoptosis related proteins in each group of cells was detected by Western blot.The BALB/c nude mice were randomly divided into sh-NC and sh-CDCA5 stable transfected cell lines with nude mouse xenograft models.Daily intraperitoneal injection of 0.9%NaCl and 40μmol·L-1 toosendanin solution was given to observe and record the changes in tumor tissue volume and body mass.Results The results of CCK-8 showed that after 48 hours,the survival rates of A549 cells treated with 10,20,30,40,50,60 and 70 μmol·L-1 toosendanin were(80.74±8.71)%,(72.96±6.53)%,(61.01±4.86)%,(51.20±3.13)%,(42.10±5.94)%,(38.93±3.18)%and(33.48±2.94)%,respectively.Toosendanin significantly inhibited the proliferation of A549 cells.The proliferation rates of cells in the control group,toosendanin group,toosendanin+pcDNA group,and toosendanin+CDCA5 group were(100.00±4.19)%,(49.18±6.70)%,(55.75±5.74)%,and(77.66±7.48)%,respectively;the expression levels of CDCA5 protein were 1.08±0.11,0.44±0.04,0.43±0.05 and 0.99±0.10,respectively.The expression levels of CDCA5 protein in tumor tissues of nude mice in the sh-NC group,sh-CDCA5 group,toosendanin+sh-NC group,and toosendanin+sh-CDCA5 group were 1.04±0.14,0.42±0.04,0.56±0.08 and 0.32±0.04,respectively.Compared with the sh-NC group,the tumor blocks formed by nude mice in other groups were significantly smaller,and the tumor volume and weight were significantly lower(all P<0.05).Compared with the toosendanin+sh-NC group,the toosendanin+sh-CDCA5 group had more significant inhibitory effect on tumor formation,and the difference was statistically significant(P<0.05).Conclusion Toosendanin can inhibit the growth of lung adenocarcinoma cells in vitro and in vivo,which is mainly related to the inhibition of CDCA5 expression.
8.Quantitative Evaluation of Latent Fingerprints Developed by Fluorescent Methods Based on Python
Zhuo-Hong YU ; Zhi-Ze XU ; Meng WANG ; Wen-Zhuo FAN ; Jie LI ; Ming LI ; Chuan-Jun YUAN
Chinese Journal of Analytical Chemistry 2024;52(7):964-974,中插1-中插12
A serious of rare earth luminescent micro/nano-materials with various properties were synthesized via chemical method for fluorescent development of latent fingerprints(LFPs).Three evaluation indexes namely contrast,sensitivity and selectivity were introduced to evaluate the effects of LFP development.Quantitative formulas for calculating the contrast,sensitivity and selectivity were further put forward,and a quality evaluation system based on Python was thus established.In addition,the objective evaluation value was finally confirmed to be consistent with the subjective visual judgment.The reproducibility of this evaluation method was finally confirmed.The effects of luminescence intensity and color of developing materials on the contrast,particle size of developing materials on the sensitivity,and micromorphology and surface property of developing materials on the selectivity were discussed in detail.Five effective ways were also proposed to promote the quality of LFP development,such as increasing the luminescence intensity,tuning the luminescence color,decreasing the particle size,adjusting the micromorphology,and modifying the surface property.This quality evaluation system based on Python could evaluate the effects of LFP development objectively,accurately and comprehensively,exhibiting easy operability,high efficiency,sensitive response,accurate and reliable results,and wide applicability,which would provide beneficial references for the reasonable selection of LFP development methods as well as objective evaluation of evidence value.
9.Biomarkers Screening and Mechanisms Analysis of the Restraint Stress-Induced Myocardial Injury in Hyperlipidemia ApoE-/-Mice
Shang-Heng CHEN ; Sheng-Zhong DONG ; Zhi-Min WANG ; Guang-Hui HONG ; Xing YE ; Zi-Jie LIN ; Jun-Yi LIN ; Jie-Qing JIANG ; Shou-Yu WANG ; Han-Cheng LIN ; Yi-Wen SHEN
Journal of Forensic Medicine 2024;40(2):172-178
Objective To explore the biomarkers and potential mechanisms of chronic restraint stress-induced myocardial injury in hyperlipidemia ApoE-/-mice.Methods The hyperlipidemia combined with the chronic stress model was established by restraining the ApoE-/-mice.Proteomics and bioinformatics techniques were used to describe the characteristic molecular changes and related regulatory mechanisms of chronic stress-induced myocardial injury in hyperlipidemia mice and to explore potential diagnostic biomarkers.Results Proteomic analysis showed that there were 43 significantly up-regulated and 58 sig-nificantly down-regulated differentially expressed proteins in hyperlipidemia combined with the restraint stress group compared with the hyperlipidemia group.Among them,GBP2,TAOK3,TFR1 and UCP1 were biomarkers with great diagnostic potential.KEGG pathway enrichment analysis indicated that fer-roptosis was a significant pathway that accelerated the myocardial injury in hyperlipidemia combined with restraint stress-induced model.The mmu_circ_0001567/miR-7a/Tfr-1 and mmu_circ_0001042/miR-7a/Tfr-1 might be important circRNA-miRNA-mRNA regulatory networks related to ferroptosis in this model.Conclusion Chronic restraint stress may aggravate myocardial injury in hyperlipidemia mice via ferrop-tosis.Four potential biomarkers are selected for myocardial injury diagnosis,providing a new direction for sudden cardiac death(SCD)caused by hyperlipidemia combined with the restraint stress.
10.Exploration of the Effect of Guhuaisi Kangfu Pills on Neovascularisation of Steroid-Induced Osteonecrosis of the Femoral Head in Rats Based on Gene Expression of VEGF/PI3K/Akt Pathway
Wen-Xi LI ; Liang-Yu TIAN ; Jin ZHANG ; Cai-Hong SHEN ; Zhi-Min YANG ; Xiao-Yan FENG ; Jia-Qiao GUO ; Yu-Ju CAO
Journal of Guangzhou University of Traditional Chinese Medicine 2024;41(8):2127-2135
Objective To observe the therapeutic effect and mechanism of Guhuaisi Kangfu Pills on rats with steroid-induced osteonecrosis of the femoral head(SONFH).Methods Sixty rats were randomly divided into blank group,model group,Xianling Gubao Capsules group and Guhuaisi Kangfu Pills low-,medium-and high-dose groups,10 rats in each group.Except for the blank group,the SONFH model was established by lipopolysaccharide combined with Glucocorticoid induction method in all other groups of rats.At the end of the intervention,for the femoral head,blood vessel radiography was performed to observe the microvascular changes in the bone marrow,and hematoxylin-eosin(HE)staining and calculation of the empty bone trap rate,Micro-CT scanning analysis,and compression experiments were carried out,and the real-time quantitative polymerase chain reaction(RT-qPCR)was used to detect the gene expressions of phosphatidylinositol 3-kinase(PI3K),protein kinase B(Akt)1,vascular endothelial growth factor(VEGF)and platelet endothelial cell adhesion molecule 1(CD31)in whole blood.Results Compared with the blank group,the blood supply in the femoral head medullary cavity of the model group was poor,the empty bone lacuna rate was increased(P<0.05),the bone mineral density and bone volume fraction were significantly decreased(P<0.05),the maximum load and elastic modulus of the femoral head were decreased(P<0.05),and the mRNA expression levels of Akt1,PI3K,VEGF and CD31 in whole blood were decreased(P<0.05).Compared with the model group,the blood supply in the femoral head medullary cavity was relatively good,the empty bone lacuna rate was decreased(P<0.05),the bone mineral density,bone volume fraction,trabecular number and trabecular thickness were significantly increased(P<0.05),the trabecular separation was significantly decreased(P<0.05),the maximum load and elastic modulus of the femoral head were increased(P<0.05),and the mRNA expression levels of Akt1,PI3K,VEGF and CD31 in the whole blood were increased(P<0.05)in the high-dose group of Guhuaisi Kangfu Pills and Xianling Gubao Capsules group.There was no significant difference in the above indexes between the high-dose group of Guhuaisi Kangfu Pills and the Xianling Gubao Capsules group(P>0.05).Conclusion Guhuaisi Kangfu Pills improves SONFH in rats,and its mechanism is related to the promotion of VEGF/PI3K/Akt pathway gene expression,thereby promoting angiogenesis.

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