Objective To investigate the role of homocysteine(Hcy)in the pathogenesis of irritable bowel syn-drome(IBS)and its effects on intestinal motility,visceral hypersensitivity,and barrier function.Methods Clinical cohorts and animal models were combined for this study.Clinically,fifteen IBS patients meeting Rome Ⅲcriteria and 15 control individuals were enrolled to detect fecal Hcy levels and their correlation with symptoms.As for animal experiments,water avoidance stress(WAS)and 2,4,6-trinitrobenzene sulfonic acid(TNBS)chemical induction were utilized to establish IBS rat and mouse models,combined with a high-methionine diet(HMD)to simulate hyperhomocysteinemia.IBS symptoms were evaluated through fecal water content,carmine red intestinal transit time,and visceral hypersensitivity scores.Immune-fluorescence and Western blot were used to detect intes-tinal epithelial tight junction proteins.Serum and fecal Hcy concentrations were measured to assess Hcy levels.Statistical analyses included t-tests and One-way Anova.Results Fecal Hcy level in IBS patients were signifi-cantly higher than those in the healthy control group which demonstrated a positive correlation with defecation fre-quency(P＜0.01).In animal models,the combination of TNBS administration and a high-methionine diet markedly elevated serum and fecal Hcy levels in mice,while synergistically exacerbated intestinal motility disor-ders and visceral hypersensitivity.In vitro experiments showed that Hcy treatment down-regulates the expression of tight junction proteins in human colon cancer cell line(Caco-2).Conclusions Hcy plays an important role in the pathogenesis of IBS by impairing intestinal barrier function and enhancing visceral hypersensitivity,and it may serve as a potential new target for the treatment of IBS.

Objective:To investigate the effect and underlying mechanism of sonodynamic therapy (SDT) on inflammation-related atrial fibrillation (AF) susceptibility.Methods:Lipopolysaccharide (LPS)-stimulated mouse and HL-1 mouse atrial myocyte models were used. (1) In vivo study: experimental groups included control, LPS, LPS+SDT, and SDT groups, with 20 mice in each group. Atrial fibrillation inducibility and duration were assessed by electrical stimulation. Western blot was used to analyze atrial expression of NOD-like receptor family pyrin domain-containing protein 3 (NLRP3), interleukin (IL)-1β, and IL-18. Immunohistochemistry was used to detect calcium voltage-gated channel subunit alpha1 C (CACNA1C) expression. (2) In vitro study: cell counting kit-8 (CCK-8) and Western blot were used to determine the optimal and safe LPS concentration. The safe incubation condition for the sonosensitizer sinoporphyrin sodium was determined by CCK-8 and fluorometry. An LPS-induced inflammatory model in HL-1 atrial myocytes was used, with experimental groups including control, LPS, LPS+SDT, LPS+sinoporphyrin sodium, and LPS+ultrasound groups. NLRP3 was overexpressed using plasmid transfection, with experimental groups including control, NLRP3 plasmid, negative control plasmid, and NLRP3 plasmid+SDT groups. SDT was applied to LPS-stimulated or NLRP3-overexpressing HL-1 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to measure mRNA and protein levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Cleaved Caspase-1, IL-1β, IL-18, and CACNA1C. The NLRP3 inhibitor MCC950 was used to validate the relationship of NLRP3 and CACNA1C. The experimental groups included control, LPS, LPS+MCC950, and MCC950 groups. Intracellular reactive oxygen species (ROS) levels were detected using the probe DCFH-DA, and the ROS scavenger N-acetyl-L-cysteine (NAC) was used to test if the effects of SDT was ROS-dependent.Results:(1) In vivo: The LPS+SDT group exhibited a lower incidence of atrial fibrillation induction and a shorter duration of atrial fibrillation compared to the LPS group(both P<0.05). Protein expression levels of NLRP3 and IL-1β were lower than those in the LPS group (all P<0.05), while the expression of CACNA1C subunit tended to increase relative to the LPS group ( P>0.05). (2) In vitro: The safe concentration of LPS for administration was ≤20 μg/ml, with an optimal pro-inflammatory concentration of 4 μg/ml. The safe concentration of sinoporphyrin sodium for administration was 0.4 μmol/L, with an optimal incubation time of 4 hours. Compared to the LPS group or NLRP3 plasmid group, the LPS+SDT group or NLRP3 plasmid+SDT group exhibited lower expression levels of NLRP3, ASC, Cleaved Caspase-1, IL-1β, and IL-18, and higher mRNA and protein levels of CACNA1C (all P<0.05). The LPS+MCC950 group had higher CACNA1C protein expression than the LPS group ( P<0.05). SDT increased intracellular ROS levels, and NAC blocked the regulatory effects of SDT on NLRP3 and CACNA1C. Conclusion:SDT reduces atrial fibrillation susceptibility in mice by inhibiting NLRP3 inflammasome activation in atrial cardiomyocytes, thereby upregulating the L-type calcium channel subunit CACNA1C.

Objective:To investigate the effect and underlying mechanism of sonodynamic therapy (SDT) on inflammation-related atrial fibrillation (AF) susceptibility.Methods:Lipopolysaccharide (LPS)-stimulated mouse and HL-1 mouse atrial myocyte models were used. (1) In vivo study: experimental groups included control, LPS, LPS+SDT, and SDT groups, with 20 mice in each group. Atrial fibrillation inducibility and duration were assessed by electrical stimulation. Western blot was used to analyze atrial expression of NOD-like receptor family pyrin domain-containing protein 3 (NLRP3), interleukin (IL)-1β, and IL-18. Immunohistochemistry was used to detect calcium voltage-gated channel subunit alpha1 C (CACNA1C) expression. (2) In vitro study: cell counting kit-8 (CCK-8) and Western blot were used to determine the optimal and safe LPS concentration. The safe incubation condition for the sonosensitizer sinoporphyrin sodium was determined by CCK-8 and fluorometry. An LPS-induced inflammatory model in HL-1 atrial myocytes was used, with experimental groups including control, LPS, LPS+SDT, LPS+sinoporphyrin sodium, and LPS+ultrasound groups. NLRP3 was overexpressed using plasmid transfection, with experimental groups including control, NLRP3 plasmid, negative control plasmid, and NLRP3 plasmid+SDT groups. SDT was applied to LPS-stimulated or NLRP3-overexpressing HL-1 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to measure mRNA and protein levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Cleaved Caspase-1, IL-1β, IL-18, and CACNA1C. The NLRP3 inhibitor MCC950 was used to validate the relationship of NLRP3 and CACNA1C. The experimental groups included control, LPS, LPS+MCC950, and MCC950 groups. Intracellular reactive oxygen species (ROS) levels were detected using the probe DCFH-DA, and the ROS scavenger N-acetyl-L-cysteine (NAC) was used to test if the effects of SDT was ROS-dependent.Results:(1) In vivo: The LPS+SDT group exhibited a lower incidence of atrial fibrillation induction and a shorter duration of atrial fibrillation compared to the LPS group(both P<0.05). Protein expression levels of NLRP3 and IL-1β were lower than those in the LPS group (all P<0.05), while the expression of CACNA1C subunit tended to increase relative to the LPS group ( P>0.05). (2) In vitro: The safe concentration of LPS for administration was ≤20 μg/ml, with an optimal pro-inflammatory concentration of 4 μg/ml. The safe concentration of sinoporphyrin sodium for administration was 0.4 μmol/L, with an optimal incubation time of 4 hours. Compared to the LPS group or NLRP3 plasmid group, the LPS+SDT group or NLRP3 plasmid+SDT group exhibited lower expression levels of NLRP3, ASC, Cleaved Caspase-1, IL-1β, and IL-18, and higher mRNA and protein levels of CACNA1C (all P<0.05). The LPS+MCC950 group had higher CACNA1C protein expression than the LPS group ( P<0.05). SDT increased intracellular ROS levels, and NAC blocked the regulatory effects of SDT on NLRP3 and CACNA1C. Conclusion:SDT reduces atrial fibrillation susceptibility in mice by inhibiting NLRP3 inflammasome activation in atrial cardiomyocytes, thereby upregulating the L-type calcium channel subunit CACNA1C.

Objective To study the mutation of FLCN gene in Chinese patients with sporadic and familial primary spontaneous pneumothorax. Methods A complete genetic analysis of FLCN by use of SSCP-PCR was performed in 102 unrelated Chinese patients with isolated PSP. Results Three novel mutations (c. 924_926del, c. 1611_1631del and c. 1740C.T) and a previously reported mutation (c. 1733insC) were identified in five familial and five sporadic PSP patients. Of the 21 family members of patients with PSP including 3 previous considered as sporadic, 4 ( 19% ) had history of at least one episode of PSP and 9 (43% ) were FLCN mutant carriers without PSP. Seven of the nine (78% ) mutant carriers had pulmonary cysts detected by high-resolution computed tomography ( HRCT) . Although c. 924_926del and c. 1611 _1631 del were found in eight patients from the same geographic district, haplotype analysis demonstrated that they did not share the same affected haplotype,thus excluding common ancestry. Conclusion This study first demonstrates that FLCN mutation contributes to not only familial but also apparently sporadic' patients with isolated PSP. It suggests that mutation analysis and HRCT scan may be recommended for first-degree family members of PSP patients with FLCN mutations, irrespective of their family history status of PSP.