In a healthy human, the airway mucus forms a thin, protective liquid layer covering the surface of the respiratory tract. It comprises a complex blend of mucin, multiple antibacterial proteins, metabolic substances, water, and electrolytes. This mucus plays a pivotal role in the lungs' innate immune system by maintaining airway hydration and capturing airborne particles and pathogens. However, heightened mucus secretion in the airway can compromise ciliary clearance, obstruct the respiratory tract, and increase the risk of pathogen colonization and recurrent infections. Consequently, a thorough exploration of the mechanisms driving excessive airway mucus secretion is crucial for establishing a theoretical foundation for the eventual development of targeted drugs designed to reduce mucus production. Across a range of lung diseases, excessive airway mucus secretion manifests with unique characteristics and regulatory mechanisms, all intricately linked to mucin. This article provides a comprehensive overview of the characteristics and regulatory mechanisms associated with excessive airway mucus secretion in several prevalent lung diseases.
Humans ; Mucus/metabolism* ; Mucins/physiology* ; Lung Diseases/metabolism* ; Respiratory Mucosa/metabolism* ; Pulmonary Disease, Chronic Obstructive/physiopathology* ; Asthma/physiopathology* ; Cystic Fibrosis/physiopathology* ; Mucociliary Clearance/physiology*

OBJECTIVE: To explore the neuroprotective effect and underlying mechanism of Xingnao Kaiqiao acupuncture (acupuncture for regaining consciousness and opening orifices) in the rat models of cerebral ischemia-reperfusion injury (CIRI) based on the p53 protein (p53)/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling pathway. METHODS: Of 102 male Wistar rats, 20 rats were randomly collected as a sham-operation group. Using a modified external carotid artery filament insertion method, CIRI models were prepared by occluding the middle cerebral artery in the rest rats. After modeling and excluding 1 non-successfully modeled rat and 1 dead one, the other modeled rats were randomized into a model group, an agonist group, an acupuncture group, and an acupuncture + agonist group, 20 rats in each one. Xingnao Kaiqiao acupuncture therapy was delivered in the rats of the acupuncture group and the acupuncture + agonist group. The acupoints included "Shuigou" (GV26), bilateral "Neiguan" (PC6), and "Sanyinjiao" (SP6) on the affected side. Electroacupuncture was attached to "Neiguan" (PC6) and "Sanyinjiao" (SP6) on the affected side, with dense-disperse wave, a frequency of 2 Hz/15 Hz and intensity of 1 mA. The intervention was delivered twice daily, 20 min each time and for 7 consecutive days. In the agonist group and acupuncture+agonist group, p53 agonist, COTI-2 was intraperitoneally injected (15 mg/kg), once daily for 7 consecutive days. Neurological deficit was evaluated using Zausinger's six-point scale. Cerebral infarction volume was quantified by triphenyl tetrazolium chloride (TTC) staining. Histopathological changes were observed using hematoxylin-eosin (HE) staining. Iron deposition was assessed by Prussian blue staining. Mitochondrial ultrastructure in the ischemic cortex was examined under transmission electron microscopy (TEM). Serum iron (Fe²⁺) was measured with chromometry. Malondialdehyde (MDA) and glutathione (GSH) levels in the ischemic hippocampus were determined using thiobarbituric acid and microplate assays, respectively. The mean fluorescence intensity of reactive oxygen species (ROS) in the ischemic cortex was analyzed by flow cytometry. The mRNA and protein expression of GPX4, SLC7A11, and p53 in the ischemic hippocampus were evaluated using quantitative real-time PCR (qRT-PCR) and Western blotting, respectively. RESULTS: Compared with the sham-operated group, the model group exhibited the decrease in neurological deficit score (P<0.01), and the increase in cerebral infarction volume percentage (P<0.01). The changes of brain tissue were presented in extensive cellular necrosis, pyknotic and deeply-stained nuclei, and vacuolar degeneration. The iron deposition was elevated in cortex and hippocampus (P<0.01), mitochondrial membrane density increased, the cristae was broken or reduced, and the outer membrane ruptured. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were elevated (P<0.01) and the level of GSH was reduced (P<0.01). The mRNA and protein expression of GPX4 and SLC7A11 was reduced (P<0.01), while that of p53 rose (P<0.01). When compared with the model group, in the agonist group, the neurological deficit score was reduced (P<0.05), the percentage of infarction volume was higher (P<0.01), the histopathological damage was further exacerbated, and the percentage of iron deposition increased in the cortex and hippocampus (P<0.01). The mitochondrial quantity decreased, the membrane density increased, the mitochondrial cristae were broken or reduced, and the outer membrane was ruptured. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were higher (P<0.01, P<0.05) and the level of GSH was reduced (P<0.05). The mRNA and protein expression of GPX4 and SLC7A11 decreased (P<0.01, P<0.05), while that of p53 was elevated (P<0.01). Besides, in comparison with the model group, the neurological deficit score was higher in the acupuncture group and the acupuncture + agonist group (P<0.01, P<0.05), the percentage of cerebral infarction volume was lower in the acupuncture group (P<0.01), the pathological damage of brain tissue was alleviated in the acupuncture group and the acupuncture + agonist group, and the percentage of iron depositiondecreased in the cortex and hippocampus (P<0.01). The mitochondrial structure was relatively clear, the mitochondrial cristae were fractured or reduced mildly in the acupuncture group and the acupuncture + agonist group. The levels of Fe²⁺ and MDA, as well as the mean flourscence intensity of ROS were lower (P<0.01) and the level of GSH was higher (P<0.01) in the acupuncture group. The mean fluorescence intensity of ROS were dropped (P<0.01) in the acupuncture + agonist group. The mRNA expression of GPX4 and SLC7A11 was elevated (P<0.01) and that of p53 was reduced (P<0.01, P<0.05) in either the acupuncture group or the acupuncture + agonist group; the protein expression of GPX4 and SLC7A11 rose (P<0.05, P<0.01) and that of p53 was dropped (P<0.01) in the acupuncture group; and the protein expression of p53 was also lower in the acupuncture + agonist group (P<0.05). When compared with the agonist group, in the acupuncture + agonist group, neurological deficit score increased (P<0.01), the percentage of cerebral infarction volume decreased (P<0.01), the pathological brain tissue damage was reduced, the percentage of iron deposition in cortex and hippocampus decreased (P<0.01), the mitochondrial structure was relatively clear and the cristae broken or reduced slightly; the levels of Fe²⁺ and MDA, as well as the mean fluorescence intensity of ROS were dropped (P<0.01), while the level of GSH increased (P<0.05); the mRNA and protein expression of GPX4 and SLC7411 was elevated (P<0.01, P<0.05), and that of p53 reduced (P<0.01). In comparison with the acupuncture + agonist group, in the acupuncture group, the neurological deficit score increased (P<0.05), the percentage of cerebral infarction volume decreased (P<0.05), the pathological brain tissue damage was alleviated, the percentage of iron deposition in cortex and hippocampus decreased (P<0.01), the mitochondrial structure was normal in tendency; the levels of Fe²⁺ and MDA, as well as the mean fluorescence intensity of ROS were reduced (P<0.05), while the level of GSH rose (P<0.01); the mRNA and protein expression of GPX4 and SLC7411 was elevated (P<0.01, P<0.05), and that of p53 reduced (P<0.01, P<0.05). CONCLUSION Xingnao Kaiqiao acupuncture can alleviate neurological damage in CIRI rats, which is obtained probably by inhibiting ferroptosis through p53/SLC7A11/GPX4 pathway.
Animals ; Reperfusion Injury/metabolism* ; Male ; Acupuncture Therapy ; Rats ; Tumor Suppressor Protein p53/genetics* ; Brain Ischemia/metabolism* ; Rats, Wistar ; Signal Transduction ; Humans ; Phospholipid Hydroperoxide Glutathione Peroxidase/genetics* ; Disease Models, Animal ; Acupuncture Points ; Amino Acid Transport System y+/genetics*

This study investigated the effect of Wuling San on transforming growth factor-β1(TGF-β1)-induced fibrosis, inflammation, and oxidative stress in human renal tubular epithelial cells(HK-2) and its mechanism of antioxidant stress injury. HK-2 cells were cultured in vitro and divided into a control group, a TGF-β1 model group, and three treatment groups receiving Wuling San-containing serum at low(2.5%), medium(5.0%), and high(10.0%) doses. TGF-β1 was used to establish the model in all groups except the control group. CCK-8 was used to analyze the effect of different concentrations of Wuling San on the activity of HK-2 cells with or without TGF-β1 stimulation. The expression of key fibrosis molecules, including actin alpha 2(Acta2), collagen type Ⅰ alpha 1 chain(Col1α1), collagen type Ⅲ alpha 1 chain(Col3α1), TIMP metallopeptidase inhibitor 1(Timp1), and fibronectin 1(Fn1), was detected using qPCR. The expression levels of inflammatory cytokines, including tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6), interleukin-8(IL-8), and interleukin-4(IL-4), were measured using ELISA kits. Glutathione peroxidase(GSH-Px), malondialdehyde(MDA), catalase(CAT), and superoxide dismutase(SOD) biochemical kits were used to analyze the effect of Wuling San on TGF-β1-induced oxidative stress injury in HK-2 cells, and the expression of nuclear factor E2-related factor 2(Nrf2), heme oxygenase 1(HO-1), and NAD(P)H quinone oxidoreductase 1(NQO1) was analyzed by qPCR and immunofluorescence. The CCK-8 results indicated that the optimal administration concentrations of Wuling San were 2.5%, 5.0%, and 10.0%. Compared with the control group, the TGF-β1 model group showed significantly increased levels of key fibrosis molecules(Acta2, Col1α1, Col3α1, Timp1, and Fn1) and inflammatory cytokines(TNF-α, IL-1β, IL-6, IL-8, and IL-4). In contrast, the Wuling San administration groups were able to dose-dependently inhibit the expression levels of key fibrosis molecules and inflammatory cytokines compared with the TGF-β1 model group. Wuling San significantly increased the activities of GSH-Px, CAT, and SOD enzymes in TGF-β1-stimulated HK-2 cells and significantly inhibited the level of MDA. Furthermore, compared with the control group, the TGF-β1 model group exhibited a significant reduction in the expression of Nrf2, HO-1, and NQO1 genes and proteins. After Wuling San intervention, the expression of Nrf2, HO-1, and NQO1 genes and proteins was significantly increased. Correlation analysis showed that antioxidant stress enzymes(GSH-Px, CAT, and SOD) and Nrf2 signaling were significantly negatively correlated with key fibrosis molecules and inflammatory cytokines in the TGF-β1-stimulated HK-2 cell model. In conclusion, Wuling San can inhibit TGF-β1-induced fibrosis in HK-2 cells by activating the Nrf2 signaling pathway, improving oxidative stress injury, and reducing inflammation.
Humans ; Oxidative Stress/drug effects* ; Transforming Growth Factor beta1/metabolism* ; Fibrosis/genetics* ; Cell Line ; Drugs, Chinese Herbal/pharmacology* ; Epithelial Cells/immunology* ; Inflammation/metabolism*

OBJECTIVE: To evaluate the dynamic changes of glucocorticoid (GC) dose and the feasibility of GC discontinuation in rheumatoid arthritis (RA) patients under the background of Chinese medicine (CM). METHODS: This multicenter retrospective cohort study included 1,196 RA patients enrolled in the China Rheumatoid Arthritis Registry of Patients with Chinese Medicine (CERTAIN) from September 1, 2019 to December 4, 2023, who initiated GC therapy. Participants were divided into the Western medicine (WM) and integrative medicine (IM, combination of CM and WM) groups based on medication regimen. Follow-up was performed at least every 3 months to assess dynamic changes in GC dose. Changes in GC dose were analyzed by generalized estimator equation, the probability of GC discontinuation was assessed using Kaplan-Meier curve, and predictors of GC discontinuation were analyzed by Cox regression. Patients with <12 months of follow-up were excluded for the sensitivity analysis. RESULTS: Among 1,196 patients (85.4% female; median age 56.4 years), 880 (73.6%) received IM. Over a median 12-month follow-up, 34.3% (410 cases) discontinued GC, with significantly higher rates in the IM group (40.8% vs. 16.1% in WM; P<0.05). GC dose declined progressively, with IM patients demonstrating faster reductions (median 3.75 mg vs. 5.00 mg in WM at 12 months; P<0.05). Multivariate Cox analysis identified age <60 years [P<0.001, hazard ratios (HR)=2.142, 95% confidence interval (CI): 1.523-3.012], IM therapy (P=0.001, HR=2.175, 95% CI: 1.369-3.456), baseline GC dose ⩽7.5 mg (P=0.003, HR=1.637, 95% CI: 1.177-2.275), and absence of non-steroidal anti-inflammatory drugs use (P=0.001, HR=2.546, 95% CI: 1.432-4.527) as significant predictors of GC discontinuation. Sensitivity analysis (545 cases) confirmed these findings. CONCLUSIONS RA patients receiving CM face difficulties in following guideline-recommended GC discontinuation protocols. IM can promote GC discontinuation and is a promising strategy to reduce GC dependency in RA management. (Trial registration: ClinicalTrials.gov, No. NCT05219214).
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Arthritis, Rheumatoid/drug therapy* ; Glucocorticoids/therapeutic use* ; Medicine, Chinese Traditional ; Retrospective Studies

Objective:To investigate the arsenic metabolism pattern and possible influencing factors in the population in drinking-water-borne endemic arsenic poisoning (drinking-water-borne arsenic poisoning for short) areas.Methods:In December 2004, a cluster sampling method was used to select arsenic poisoning population (arsenic poisoning group) and healthy population (control group) in drinking-water-borne arsenic poisoning area of Bayannur City, Inner Mongolia Autonomous Region as the survey subjects. A questionnaire survey was conducted. Arsenic content in drinking water at home of survey subjects, the levels of urinary arsenic and its metabolites, including [trivalent arsenic (As Ⅲ), inorganic arsenic (iAs), monomethylarsenic acid (pentavalent, MMA V), dimethylarsenic acid (pentavalent, DMA V), total arsenic (tAs), percentage of inorganic arsenic (iAs%), percentage of monomethylarsenic acid (MMA%), percentage of dimethylarsenic acid (DMA%), primary methylation index (PMI), secondary methylation index (SMI)] were tested using high performance liquid chromatography-inductively coupled plasma mass spectrometry; nail arsenic and nail selenium levels were tested using atomic fluorescence spectrometer. The influencing factors of arsenic metabolism pattern were analyzed by multiple linear regression. Results:A total of 536 survey subjects were included, including 155 individuals in the arsenic poisoning group and 381 in the control group. The water arsenic level ranged from 0.0 to 825.7 μg/L. Compared with the control group, there was no significant difference in the distribution of gender, education level and dental fluorosis in the arsenic poisoning group ( P > 0.05), but there were significant differences in the distribution of age, marital status, smoking, drinking and water arsenic ( P < 0.05). Compared with the control group, the levels of urinary As Ⅲ, iAs, MMA V, DMA V, tAs, MMA%, MMA/DMA and nail arsenic in the arsenic poisoning group were higher ( P < 0.05), while the levels of urinary DMA%, SMI and nail selenium were lower ( P < 0.05); but there was no statistically significant difference in the levels of urinary iAs% and PMI ( P > 0.05). Gender, education level, depth of wells, water arsenic, total number of wells and nail arsenic were the influencing factors of urinary As Ⅲ (β = - 19.82, - 23.83, 0.61, 0.21, 7.26, 2.98, P < 0.05). Age, depth of wells, water arsenic and nail arsenic were the influencing factors of urinary tAs (β = 3.18, 3.25, 1.31, 15.59, P < 0.05). Gender, education level, depth of wells, water arsenic, total number of wells and nail arsenic were the influencing factors of urinary iAs (β = - 20.47, - 25.90, 0.64, 0.25, 7.87, 3.11, P < 0.05). Age, gender, education level, water arsenic and nail arsenic were the influencing factors of urinary MMA V (β = 0.52, - 17.07, - 21.84, 0.22, 2.77, P < 0.05). Age, depth of wells, water arsenic and nail arsenic were the influencing factors of urinary DMA V (β = 2.35, 2.47, 0.85, 9.22, P < 0.05). Conclusions:Compared with healthy individuals, there are differences in arsenic metabolism pattern among individuals with drinking-water-borne arsenic poisoning. Age, gender, education level, depth of wells, water arsenic, total number of wells and nail arsenic may be influencing factors of different arsenic metabolism patterns.

Objective In this study,inbred BALB/c mice infected with the pneumonia virus of mice(PVM)were used to establish an animal model of viral pneumonia,and the changes in the pro-inflammatory alarmin molecule,high mobility group box 1 protein(HMGB1),during PVM infection were observed,as well as the in vivo intervention effects of the HMGB1 inhibitor,glycyrrhizic acid(GA),on PVM-induced lung injury.Methods Three-week-old female BALB/c mice were randomly divided into three groups,each consisting of 6 mice.One group,uninfected by PVM,served as the control group(Control).The other two groups were inoculated intranasally with PVM at a dose of 1×104 50％tissue culture infective dose(TCID50)/25 μL,and subsequently treated with GA saline solution(GA group)or plain saline solution(normal saline,NS group)via gavage for 15 consecutive days.During this period,changes in body weight and appearance were monitored in each group.At the end of the experiment,lung tissue samples were collected from all groups.The distribution of PVM and HMGB1 proteins in the lung tissues was analyzed using hematoxylin-eosin staining and immunohistochemistry.The expression levels of HMGB1 and its Toll-like receptor 4(TLR-4),advanced glycosylation end-product-specific receptor(AGER),and inflammatory cytokines such as interleukin(IL)-1β,IL-2,and tumor necrosis factor-α(TNF-α)in lung tissues of mice were measured using real time fluorescence quantitative PCR.Results Compared with the Control group,the NS group showed a significant weight loss after 6 days(P＜0.05).Histopathological tests revealed pronounced inflammatory lesions in their lungs.Immunohistochemistry results showed that HMGB1 was released from the nucleus to the cytoplasm,and real time fluorescence quantitative PCR results indicated that the expression levels of HMGB1,IL-1β,and IL-2 were significantly upregulated(P＜0.05).In the GA group,there was no significant change in the clinical symptoms or body weight.However,compared with the NS group,the pathological damages of lung tissues in the GA group were significantly reduced,and the expression levels of HMGB1,IL-1 β,IL-2,and interferon-γ(IFN-γ)in lung tissues were also significantly decreased(P＜0.05),although the expression level of AGER was significantly increased(P＜0.05).Conclusion PVM infection can cause significant inflammatory pathological lung damages in mice,and GA can effectively alleviate the damages.Its therapeutic effect may be related to the activation of HMGB1 signaling pathway.

The rare-earth-elements-doped upconversion nanoparticles NaYF4:Yb3+,Er3+were synthesized by solvothermal method,and NaYF4:Yb3+,Er3+@SiO2 were prepared by coating SiO2 on the surface of NaYF4:Yb3+,Er3+by inverse microemulsion method in this work.Based on the fluorescence quenching principle between NaYF4∶Yb3+,Er3+@SiO2 and SQA-Fe3+,a NaYF4∶Yb3+,Er3+@SiO2-SQA-Fe3+fluorescence nanosensor was constructed for detection of trace hydrogen peroxide(H2O2).Under optimal conditions,the linear range of this method for detecting H2O2 was 1.8?84.0 μmol/L,with detection limit(3σ)of 0.47 μmol/L.The recoveries of H2O2 spiked in milk were 98.4%?99.7%.This method could be used for detection of H2O2 residue in milk samples,with advantages such as low detection limit,good stability and strong anti-interference ability.

Objective:To investigate the relationship between the outcome of skin injury and urinary arsenic methylation metabolism levels in people exposed to arsenic through drinking water.Methods:Using cluster sampling method, permanent residents from drinking-water-borne endemic arsenic poisoning areas in Bayannur City, Inner Mongolia Autonomous Region were selected as survey subjects in 2004 (before water improvement). In 2017 (after water improvement), 74 survey subjects from 2004 were tracked and followed up. Urine samples were collected from survey subjects and high-performance liquid chromatography inductively coupled plasma mass spectrometry was used to detect the levels of arsenic methylation metabolites in urine. According to the "Diagnosis of Endemic Arsenic Poisoning" (WS/T 211-2015), the clinical grading (normal, suspicious, mild, moderate and severe) of skin injury of the survey subjects and the outcome of 2017 (improved, unchanged, aggravated) were assessed. A database was established and SPSS 25.0 software was used for statistical analysis.Results:The clinical grading ratios of skin injuries among survey subjects in 2004 and 2017 were compared, the differences were statistically significant (normal, suspicious, mild, moderate and severe: 38, 18, 4, 14 cases in 2004 and 27, 31, 3, 13 cases in 2017, χ 2 = 53.02, P < 0.001). Compared with 2004, in 2017, the levels of total arsenic (tAs), inorganic arsenic (iAs), monomethylarsenic (MMA), dimethylarsenic (DMA), percentage of inorganic arsenic (iAs%), and ratio of monomethylarsenic to dimethylarsenic (MMA/DMA) in the urine of survey subjects were low, and the differences were statistically significant ( Z = - 8.24, - 9.07, - 7.81, - 8.04, - 8.24, - 3.56, P < 0.001). The levels of dimethylarsenic percentage (DMA%), monomethylation rate (PMI) and dimethylation rate (SMI) were higher, and the differences were statistically significant ( Z = - 6.39, - 8.24, - 3.52, P < 0.001). In 2004, patients with different clinical grading of skin injuries had different outcomes in 2017 (χ 2 = 30.80, P < 0.001). There were statistically significant differences in tAs, iAs, MMA and DMA variation in urine among skin injury patients with different outcomes ( H = 10.62, 9.35, 8.80, 9.13, P < 0.05). Conclusions:Improving water can significantly reduce the levels of tAs, iAs, MMA, and DMA in the urine of arsenic exposed individuals. The outcome of skin injury in individuals exposed to arsenic through drinking water is related to the variation of urinary arsenic methylation metabolites tAs, iAs, MMA, and DMA.

Abstract: Objective　To analyze the influencing factors of mother-to-child transmission of hepatitis B virus after combined immunological blockade, and to evaluate the effect of mother-to-child blockade, and to provide a basis for health policies and health interventions for preventing mother-to-child blockade of hepatitis B virus. Methods A total of 11 363 pairs of HBsAg positive pregnant women and their infants aged 7-12 months in Hainan Province from 2015 to 2020 were included in the study. The general situation, the situation of health care and delivery in this pregnancy and perinatal period, the detection of hepatitis B markers, the situation of antiviral therapy, the general situation of mother and infant during delivery and the implementation of blockade measures for mother-to-child transmission of hepatitis B were collected and analyzed. Results Among the 11 363 pairs of HBsAg positive pregnant women and their infants delivered in hospitals in Hainan province from 2015 to 2020, the positive rate of HBsAg in children at 7-12 months after birth was 1.47 %, and the difference in HBsAg positive rate of infants born in different years was not statistically significant (P>0.05). There were no significant differences in the positive rate of HBsAg among children born to pregnant women with different nationalities, educational levels, occupations, delivery modes, delivery places, obstetric operations and perineal laceration, abnormal perinatal period, children with different genders and premature delivery and perinatal (all P<0.05). There was significant difference in HBsAg positive rate among infants born to pregnant women of different ages, the positive rate of HBsAg of infants born to young pregnant women was higher than that of older pregnant women (P<0.05). The rate of antiviral therapy was low in HBeAg positive pregnant women, and the positive rate of HBsAg in their infants was 2.54%, which was higher than 0.83% in HBeAg negative pregnant women (P<0.05). Conclusions Combined immunological blockade with hepatitis B vaccine and hepatitis B immunoglobulin can effectively prevent the mother-to-child transmission of HBV. HBsAg-positive women can give birth at the right age, and HBeAg-positive pregnant women can be treated with antiviral therapy to block mother-to-child transmission, providing the important basis for the formulation of hepatitis B prevention and control strategies and measures.

BACKGROUND: Dysfunction of the gap junction channel protein connexin 43 (Cx43) contributes to myocardial ischemia/reperfusion (I/R)-induced ventricular arrhythmias. Cx43 can be regulated by small ubiquitin-like modifier (SUMO) modification. Protein inhibitor of activated STAT Y (PIASy) is an E3 SUMO ligase for its target proteins. However, whether Cx43 is a target protein of PIASy and whether Cx43 SUMOylation plays a role in I/R-induced arrhythmias are largely unknown. METHODS: Male Sprague-Dawley rats were infected with PIASy short hairpin ribonucleic acid (shRNA) using recombinant adeno-associated virus subtype 9 (rAAV9). Two weeks later, the rats were subjected to 45 min of left coronary artery occlusion followed by 2 h reperfusion. Electrocardiogram was recorded to assess arrhythmias. Rat ventricular tissues were collected for molecular biological measurements. RESULTS: Following 45 min of ischemia, QRS duration and QTc intervals statistically significantly increased, but these values decreased after transfecting PIASy shRNA. PIASy downregulation ameliorated ventricular arrhythmias induced by myocardial I/R, as evidenced by the decreased incidence of ventricular tachycardia and ventricular fibrillation, and reduced arrythmia score. In addition, myocardial I/R statistically significantly induced PIASy expression and Cx43 SUMOylation, accompanied by reduced Cx43 phosphorylation and plakophilin 2 (PKP2) expression. Moreover, PIASy downregulation remarkably reduced Cx43 SUMOylation, accompanied by increased Cx43 phosphorylation and PKP2 expression after I/R. CONCLUSION PIASy downregulation inhibited Cx43 SUMOylation and increased PKP2 expression, thereby improving ventricular arrhythmias in ischemic/reperfused rats heart.
Rats ; Male ; Animals ; Myocardial Reperfusion Injury/metabolism* ; Connexin 43/genetics* ; Sumoylation ; Down-Regulation ; Rats, Sprague-Dawley ; Arrhythmias, Cardiac/drug therapy* ; Myocardial Ischemia/metabolism* ; RNA, Small Interfering/metabolism*