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.Gut dysbiosis aggravates cognitive deficits,amyloid pathology and lipid metabolism dysregulation in a transgenic mouse model of Alzheimer's disease
Chang QU ; Qing-Qing XU ; Wen YANG ; Mei ZHONG ; Qiuju YUAN ; Yan-Fang XIAN ; Zhi-Xiu LIN
Journal of Pharmaceutical Analysis 2023;13(12):1526-1547
Gut dysbiosis,a well-known risk factor to triggers the progression of Alzheimer's disease(AD),is strongly associated with metabolic disturbance.Trimethylamine N-oxide(TMAO),produced in the dietary choline metabolism,has been found to accelerate neurodegeneration in AD pathology.In this study,the cognitive function and gut microbiota of TgCRND8(Tg)mice of different ages were evaluated by Morris water maze task(MWMT)and 16S rRNA sequencing,respectively.Young pseudo germ-free(PGF)Tg mice that received faecal microbiota transplants from aged Tg mice and wild-type(WT)mice were selected to determine the role of the gut microbiota in the process of neuropathology.Excessive choline treatment for Tg mice was used to investigate the role of abnormal choline metabolism on the cognitive functions.Our results showed that gut dysbiosis,neuroinflammation response,Aβ deposition,tau hyper-phosphorylation,TMAO overproduction and cyclin-dependent kinase 5(CDK5)/transcription 3(STAT3)activation occurred in Tg mice age-dependently.Disordered microbiota of aged Tg mice accelerated AD pathology in young Tg mice,with the activation of CDK5/STAT3 signaling in the brains.On the contrary,faecal microbiota transplantation from WT mice alleviated the cognitive deficits,attenuated neuro-inflammation,Aβ deposition,tau hyperphosphorylation,TMAO overproduction and suppressed CDK5/STAT3 pathway activation in Tg mice.Moreover,excessive choline treatment was also shown to aggravate the cognitive deficits,Aβ deposition,neuroinflammation and CDK5/STAT3 pathway activation.These findings provide a novel insight into the interaction between gut dysbiosis and AD progression,clarifying the important roles of gut microbiota-derived substances such as TMAO in AD neuropathology.
3.Epidemiological characteristics of a 2019-nCoV outbreak caused by Omicron variant BF.7 in Shenzhen.
Yan Peng CHENG ; Dong Feng KONG ; Jia ZHANG ; Zi Quan LYU ; Zhi Gao CHEN ; Hua Wei XIONG ; Yan LU ; Qing Shan LUO ; Qiu Ying LYU ; Jin ZHAO ; Ying WEN ; Jia WAN ; Fang Fang LU ; Jian Hua LU ; Xuan ZOU ; Zhen ZHANG
Chinese Journal of Epidemiology 2023;44(3):379-385
Objective: To explore the epidemiological characteristic of a COVID-19 outbreak caused by 2019-nCoV Omicron variant BF.7 and other provinces imported in Shenzhen and analyze transmission chains and characteristics. Methods: Field epidemiological survey was conducted to identify the transmission chain, analyze the generation relationship among the cases. The 2019-nCoV nucleic acid positive samples were used for gene sequencing. Results: From 8 to 23 October, 2022, a total of 196 cases of COVID-19 were reported in Shenzhen, all the cases had epidemiological links. In the cases, 100 were men and 96 were women, with a median of age, M (Q1, Q3) was 33(25, 46) years. The outbreak was caused by traverlers initial cases infected with 2019-nCoV who returned to Shenzhen after traveling outside of Guangdong Province.There were four transmission chains, including the transmission in place of residence and neighbourhood, affecting 8 persons, transmission in social activity in the evening on 7 October, affecting 65 persons, transmission in work place on 8 October, affecting 48 persons, and transmission in a building near the work place, affecting 74 persons. The median of the incubation period of the infection, M (Q1, Q3) was 1.44 (1.11, 2.17) days. The incubation period of indoor exposure less than that of the outdoor exposure, M (Q1, Q3) was 1.38 (1.06, 1.84) and 1.95 (1.22, 2.99) days, respcetively (Wald χ2=10.27, P=0.001). With the increase of case generation, the number and probability of gene mutation increased. In the same transmission chain, the proportion of having 1-3 mutation sites was high in the cases in the first generation. Conclusions: The transmission chains were clear in this epidemic. The incubation period of Omicron variant BF.7 infection was shorter, the transmission speed was faster, and the gene mutation rate was higher. It is necessary to conduct prompt response and strict disease control when epidemic occurs.
Male
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Humans
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Female
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SARS-CoV-2
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COVID-19/epidemiology*
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Disease Outbreaks
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Epidemics
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China/epidemiology*
5.Naringenin inhibits thoracic aortic aneurysm formation in mice with Marfan syndrome.
Zhi Qing LI ; Bing YU ; Ze Yu CAI ; Ying Bao WANG ; Xu ZHANG ; Biao ZHOU ; Xiao Hong FANG ; Fang YU ; Yi FU ; Jin Peng SUN ; Wei LI ; Wei KONG
Journal of Peking University(Health Sciences) 2022;54(5):896-906
OBJECTIVE:
To identify whether naringenin plays a protective role during thoracic aneurysm formation in Marfan syndrome.
METHODS:
To validate the effect of naringenin, Fbn1C1039G/+ mice, the mouse model of Marfan syndrome, were fed with naringenin, and the disease progress was evaluated. The molecular mechanism of naringenin was further investigated via in vitro studies, such as bioluminescence resonance energy transfer (BRET), atomic force microscope and radioligand receptor binding assay.
RESULTS:
Six-week-old Fbn1C1039G/+ mice were fed with naringenin for 20 weeks. Compared with the control group, naringenin significantly suppressed the aortic expansion [Fbn1C1039G/+ vs. Fbn1C1039G/++naringenin: (2.49±0.47) mm, n=18 vs. (1.87±0.19) mm, n=22, P < 0.05], the degradation of elastin, and the expression and activity of matrix metalloproteinase 2 (MMP2) and MMP9 in the ascending aorta of Fbn1C1039G/+ mice. Besides, treatment with naringenin for 6 weeks also attenuated the disease progress among the 20-week-old Fbn1C1039G/+ mice with established thoracic aortic aneurysms [Fbn1C1039G/+ vs. Fbn1C1039G/++naringenin: (2.24±0.23) mm, n=8 vs. (1.90±0.17) mm, n=8, P < 0.05]. To understand the underlying molecular mechanisms, we examined the effects of naringenin on angiotensin Ⅱ type 1 receptor (AT1) signaling and transforming growth factor-β (TGF-β) signaling respectively, which were the dominant signaling pathways contributing to aortopathy in Marfan syndrome as previously reported. The results showed that naringenin decreased angiotensin Ⅱ (Ang Ⅱ)-induced phosphorylation of protein kinase C (PKC) and extracellular regulating kinase 1/2 (ERK1/2) in HEK293A cell overexpressing AT1 receptor. Moreover, naringenin inhibited Ang Ⅱ-induced calcium mobilization and uclear factor of activated T-cells (NFAT) signaling. The internalization of AT1 receptor and its binding to β-arrestin-2 with Ang Ⅱ induction were also suppressed by naringenin. As evidenced by atomic force microscope and radioligand receptor binding assay, naringenin inhibited Ang Ⅱ binding to AT1 receptor. In terms of TGF-β signaling, we found that feeding the mice with naringenin decreased the phosphorylation of Smad2 and ERK1/2 as well as the expression of TGF-β downstream genes. Besides, the serum level of TGF-β was also decreased by naringenin in the Fbn1C1039G/+ mice. Furthermore, we detected the effect of naringenin on platelet, a rich source of TGF-β, both in vivo and in vitro. And we found that naringenin markedly decreased the TGF-β level by inhibiting the activation of platelet.
CONCLUSION
Our study showed that naringenin has a protective effect on thoracic aortic aneurysm formation in Marfan syndrome by suppressing both AT1 and TGF-β signaling.
Angiotensin II/metabolism*
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Animals
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Aortic Aneurysm, Thoracic/prevention & control*
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Calcium/metabolism*
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Disease Models, Animal
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Elastin/metabolism*
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Fibrillin-1/metabolism*
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Flavanones
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Marfan Syndrome/metabolism*
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Matrix Metalloproteinase 2
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Matrix Metalloproteinase 9
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Mice
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Mice, Inbred C57BL
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Protein Kinase C/metabolism*
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Receptor, Angiotensin, Type 1/metabolism*
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Transforming Growth Factor beta/metabolism*
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Transforming Growth Factors/metabolism*
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beta-Arrestins/metabolism*
6. Schisandrae Fructus oil-induced elevation in serum triglyceride and lipoprotein concentrations associated with physiologic hepatomegaly in mice
Si-Yuan PAN ; Xue-Lan SONG ; Zhao-Heng LIN ; Hai-Chuan TAI ; Si-Yuan PAN ; Qing YU ; Yi ZHANG ; Gan LUO ; Xiao-Yan WANG ; Nan SUN ; Zhu-Sheng CHU ; Yi ZHANG ; Pei-Li ZHU ; Zhi-Ling YU ; Kam-Ming KO
Asian Pacific Journal of Tropical Biomedicine 2022;12(2):59-68
Objective: To investigate hypertriglyceridemia and hepatomegaly caused by Schisandrae Sphenantherae Fructus (FSS) and Schisandra chinensis Fructus (FSC) oils in mice. Methods: Mice were orally administered a single dose of Schisandrae Fructus oils. Serum and hepatic triglyceride (TG), triglyceride transfer protein (TTP), apolipoprotein B48 (Apo B48), very-low-density lipoprotein (VLDL), hepatocyte growth factor (HGF), alanine aminotransfease (ALT) and liver index were measured at 6-120 h post-dosing. Results: FSS and FSC oil caused time and dose-dependent increases in serum and hepatic TG levels, with maximum increases in the liver (by 297% and 340%) at 12 h post-dosing and serum (244% and 439%) at 24-h post-dosing, respectively. Schisandrae Fructus oil treatments also elevated the levels of serum TTP by 51% and 63%, Apo B48 by 152% and 425%, and VLDL by 67% and 38% in mice, respectively. FSS and FSC oil treatments also increased liver mass by 53% and 55% and HGF by 106% and 174%, but lowered serum ALT activity by 38% and 22%, respectively. Fenofibrate pre/ co-treatment attenuated the FSS and FSC oil-induced elevation in serum TG levels by 41% and 49% at 48 h post-dosing, respectively, but increased hepatic TG contents (by 38% and 33%, respectively) at 12 h post-dosing. Conclusions: Our findings provide evidence to support the establishment of a novel mouse model of hypertriglyceridemia by oral administration of FSS oil (mainly increasing endogenous TG) and FSC oil (mainly elevating exogenous TG).
7.Effects of manual loading on calcitonin gene-related peptide and nerve growth factor in rats with chronic low back pain.
Zhi-Zhen LYU ; Qing-Guang ZHU ; Ling-Jun KONG ; Yan-Bin CHENG ; Guang-Xin GUO ; Xin ZHOU ; Shuai-Pan ZHANG ; Min FANG
China Journal of Orthopaedics and Traumatology 2021;34(3):282-287
OBJECTIVE:
To observe the analgesic effect of manipulation loading on chronic low back pain (CLBP) model rats and the expression of inflammatory factors in psoas major muscle tissue, and to explore the improvement of manipulation on local inflammatory microenvironment.
METHODS:
Thirty two SPF male SD rats weighing 340-360g were randomly divided into blank group, sham operation group, chronic low back pain model group and treatment group, with 8 rats in each group. In the model group, L
RESULTS:
There was no significant difference in PWT and PWL between the blank group and the sham operation group after modeling (
CONCLUSION
Local massage loading has analgesic effect on CLBP rats, at the same time, it can inhibit the content of CGRP and NGF in psoas muscle tissue of CLBP rats, and improve the local inflammatory microenvironment.
Animals
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Calcitonin
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Calcitonin Gene-Related Peptide
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Low Back Pain/therapy*
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Male
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Nerve Growth Factor/genetics*
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Rats
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Rats, Sprague-Dawley
8.Study on chemical constituents from fruiting bodies of Ganoderma calidophilum.
Ting-Ting ZHANG ; Jiao-Cen GUO ; Qing-Yun MA ; Fan-Dong KONG ; Li-Man ZHOU ; Qing-Yi XIE ; Hao-Fu DAI ; Zhi-Fang YU ; You-Xing ZHAO
China Journal of Chinese Materia Medica 2021;46(7):1783-1789
Chemical constituents were isolated and purified from fruiting bodies of Ganoderma calidophilum by various column chromatographic techniques, and their chemical structures were identified through combined analysis of physicochemical properties and spectral data. As a result, 11 compounds were isolated and identified as(24E)-lanosta-8,24-dien-3,11-dione-26-al(1), ganoderone A(2), 3-oxo-15α-acetoxy-lanosta-7,9(11), 24-trien-26-oleic acid(3),(23E)-27-nor-lanosta-8,23-diene-3,7,25-trione(4), ganodecanone B(5), ganoderic aldehyde A(6), 11β-hydroxy-lucidadiol(7), 3,4-dihydroxyacetophenone(8), methyl gentiate(9), ganoleucin C(10), ganotheaecolumol H(11). Among them, compound 1 is a new triterpenoid. The cytotoxic activities of all of the compounds against tumor cell lines were evaluated. The results showed that compounds 1, 3, 4 and 6 showed cytotoxic activity against BEL-7402, with IC_(50) values of 26.55, 11.35, 23.23, 18.66 μmol·L~(-1); compounds 1 and 3-6 showed cytotoxic activity against K562, with IC_(50) values of 5.79, 22.16, 12.16, 35.32, and 5.59 μmol·L~(-1), and compound 4 showed cytotoxic activity against A549, with IC_(50) value of 42.50 μmol·L~(-1).
Cell Line, Tumor
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Fruiting Bodies, Fungal
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Ganoderma
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Molecular Structure
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Triterpenes/pharmacology*
9.Incidence and risk factors of anastomotic leak after transanal total mesorectal excision in China: a retrospective analysis based on national database.
Lei GU ; Yong Bo AN ; Ming Yang REN ; Quan WANG ; Hong Yu ZHANG ; Gang YU ; Jian Zhi CHEN ; Miao WU ; Yi XIAO ; Zhi Cong FU ; Hong ZHANG ; Wei Dong TONG ; Dan MA ; Qing XU ; Hong Wei YAO ; Zhong Tao ZHANG
Chinese Journal of Gastrointestinal Surgery 2021;24(6):505-512
Objective: Transanal total mesorectal excision (taTME) was a very hot topic in the first few years since its appearance, but now more introspections and controversies on this procedure have emerged. One of the reasons why the Norwegian Ministry of Health stopped taTME was the high incidence of postoperative anastomotic leak. In current study, the incidence and risk factors of anastomotic leak after taTME were analyzed based on the data registered in the Chinese taTME Registry Collaborative (CTRC). Methods: A case-control study was carried out. Between November 15, 2017 and December 31, 2020, clinical data of 1668 patients undergoing taTME procedure registered in the CTRC database from 43 domestic centers were collected retrospectively. After excluding 98 cases without anastomosis and 109 cases without complete postoperative complication data, 1461 patients were finally enrolled for analysis. There were 1036 males (70.9%) and 425 females (29.1%) with mean age of (58.2±15.6) years and mean body mass index of (23.6±3.8) kg/m(2). Anastomotic leak was diagnosed and classified according to the International Study Group of Rectal Cancer (ISREC) criteria. The risk factors associated with postoperative anastomotic leak cases were analyzed. The impact of the cumulative number of taTME surgeries in a single center on the incidence of anastomotic leak was evaluated. As for those centers with the number of taTME surgery ≥ 40 cases, incidence of anastomic leak between 20 cases of taTME surgery in the early and later phases was compared. Results: Of 1461 patients undergoing taTME, 103(7.0%) developed anastomotic leak, including 71 (68.9%) males and 32 (31.1%) females with mean age of (59.0±13.9) years and mean body mass index of (24.5±5.7) kg/m(2). The mean distance between anastomosis site and anal verge was (2.6±1.4) cm. Thirty-nine cases (37.9%) were classified as ISREC grade A, 30 cases (29.1%) as grade B and 34 cases (33.0%) as grade C. Anastomotic leak occurred in 89 cases (7.0%,89/1263) in the laparoscopic taTME group and 14 cases (7.1%, 14/198) in the pure taTME group. Multivariate analysis showed that hand-sewn anastomosis (P=0.004) and the absence of defunctioning stoma (P=0.013) were independently associated with anastomotic leak after taTME. In the 16 centers (37.2%) which performed ≥ 30 taTME surgeries with cumulative number of 1317 taTME surgeries, 86 cases developed anastomotic leak (6.5%, 86/1317). And in the 27 centers which performed less than 30 taTME surgeries with cumulative number of 144 taTME surgeries, 17 cases developed anastomotic leak (11.8%, 17/144). There was significant difference between two kinds of center (χ(2)=5.513, P=0.019). Thirteen centers performed ≥ 40 taTME surgeries. In the early phase (the first 20 cases in each center), 29 cases (11.2%, 29/260) developed anastomotic leak, and in the later phase, 12 cases (4.6%, 12/260) developed anastomotic leak. The difference between the early phase and the later phase was statistically significant (χ(2)=7.652, P=0.006). Conclusion: The incidence of anastomotic leak after taTME may be reduced by using stapler and defunctioning stoma, or by accumulating experience.
Adult
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Aged
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Anastomotic Leak/etiology*
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Case-Control Studies
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China/epidemiology*
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Female
;
Humans
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Incidence
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Laparoscopy
;
Male
;
Middle Aged
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Postoperative Complications/epidemiology*
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Rectal Neoplasms/surgery*
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Rectum/surgery*
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Retrospective Studies
;
Risk Factors
10.Prevalence of CYP2C19 gene mutations in patients with coronary heart disease and its biological activation effect in clopidogrel antiplatelet response.
Lin Juan GUO ; Xing Hua JIANG ; Wen Feng HE ; Peng YU ; Rong WAN ; Qi Ling KONG ; Chuan LIU ; Jian Hua YU ; Zhi Gang YOU ; Qi CHEN ; Bo ZHU ; Yan Qing WU ; Jin Song XU ; Kui HONG
Chinese Journal of Cardiology 2021;49(1):43-48
Objective: The purpose of this study was to investigate the effects of CYP2C19 gene mutations on clopidogrel antiplatelet activity in the patients with coronary heart disease treated by percutaneous coronary intervention. Methods: Patients with coronary heart disease, who hospitalized in the Second Affiliated Hospital of Nanchang University from March 2011 to June 2019, and healthy individuals with matching genetic background, gender, and age as controls were included in this study. Basic clinical data were analyzed and blood samples of all research subjects were obtained for extraction of DNA, and Sanger first-generation sequencing method was used to detect CYP2C19 gene mutation from full exon and exon and intron junction. CYP2C19 gene variations in patients with coronary heart disease were compared with the 1000 Genomes Browse database and the sequencing results of healthy controls to determine whether the gene variation was a genetic mutation or a genetic polymorphism. After that, PolyPhen-2 prediction software was used to analyze the harmfulness of gene mutations to predict the effect of mutations on protein function. The same dose of CYP2C19 wild-type plasmid and the CYP2C19 gene mutant plasmids were transfected into human normal liver cells HL-7702. After transfection of 24 h, the expression of CYP2C19 protease in each group was detected. The liver S9 protein was incubated with clopidogrel, acted on platelets to detect the platelet aggregation rate and the activity of human vasodilator-activated phosphoprotein (VASP). Results: A total of 1 493 patients with coronary heart disease (59.36%) were enrolled, the average age was (64.5±10.4) years old, of which 1 129 were male (75.62%). Meanwhile, 1 022 healthy physical examination volunteers (40.64%) were enrolled, and the average age was (64.1±11.0) years old, of which 778 were male (76.13%). A total of 5 gene mutations of CYP2C19 gene were identified in 12 patients (0.80%), namely, 4 known mutations T130K (1 case), M136K (6 cases), N277K (3 cases), V472I (1 case) and one new mutation G27V (1 case), no corresponding gene mutation was found in healthy controls. It was found that T130K and M136K were probably damaging, G27V was possibly damaging, and N277K and V472I were benign mutations. In vitro, we demonstrated that the platelet aggregation rate of the M136K gene mutation group was 24.83% lower than that of the wild type (59.58% vs. 34.75%; P<0.05), and the phosphorylated VASP level was 23.0% higher than that of the wild type (1.0 vs. 1.23; P<0.05). However, the platelet aggregation rate and phosphorylated VASP level were similar between of G27V, T130K, N277K, V472I gene mutation groups and wild type group (P>0.05). Conclusions: In this study, 5 gene mutations are defined in patients with coronary heart disease, namely G27V, T130K, M136K, N277K, V472I. In vitro functional studies show that CYP2C19 gene mutation M136K, as a gain-of-function gene mutation, can enhance the activation of CYP2C19 enzyme on clopidogrel, thereby inhibiting the platelet aggregation rate.

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