Objective:To evaluate the effect of tropisetron on pyroptosis in cardiomyocytes subjected to hypoxia-reoxygenation (H/R) and the relationship with α7 nicotinic acetylcholine receptor (α7nAChR).Methods:Routinely cultured H9C2 cardiomyocytes were divided into 4 groups ( n=6 each) using a random number table method: control group (C group), H/R group, tropisetron plus H/R group (Tro+ H/R group), and α7nAchR antagonist MLA plus tropisetron plus H/R group (MLA+ Tro+ H/R group). H/R was produced by 12 h exposure of cells to hypoxia followed by 6 h reoxygenation in the other three groups except group C. Tropisetron at the final concentration of 10 nmol/L was added at 1 h before hypoxia in group Tro+ H/R.In group MLA+ Tro+ H/R, MLA was added at 2 h before hypoxia, and then 1 h later tropisetron at the final concentration of 10 nmol/L was given.At 6 h of reoxygenation, the pyroptosis rate of cardiomyocytes was determined by fluorescence immunostaining of caspase-1-AlexaFluor 488/DAPI, the concentrations of interleukin-1beta (IL-1β) and IL-18 in the supernatant were determined by enzyme-linked immunosorbent assay, the activity of LDH in the supernatant was measured by 2, 4 dinitrophenylhydra-zine colorimetric method, and the expression of α7nAchR, NLRP3 and caspase-1 in cardiomyocytes was detected by Western blot. Results:Compared with group C, the pyroptosis rate, activity of LDH and concentrations of IL-1β and IL-18 in the supernatant were significantly increased, the expression of NLRP3 and caspase-1 was up-regulated, and the expression of α7nAchR was down-regulated in group H/R ( P<0.05). Compared with group H/R, the pyroptosis rate, activity of LDH and concentrations of IL-1β and IL-18 in the supernatant were significantly decreased, the expression of NLRP3 and caspase-1 was down-regulated, and the expression of α7nAchR was up-regulated in group Tro+ H/R ( P<0.05). Compared with group Tro+ H/R, the pyroptosis rate, activity of LDH and concentrations of IL-1β and IL-18 in the supernatant were significantly increased, the expression of NLRP3 and caspase-1 was up-regulated, and the expression of α7nAchR was down-regulated in group MLA+ Tro+ H/R ( P<0.05). Conclusion:α7nAchR is involved in the process of tropisetron inhibiting pyroptosis in cardiomyocytes subjected to H/R.

Objective:To investigate the preventive and therapeutic effects of compound wild chrysanthemum eye pad on blue light-induced alteration of meibomian gland function in mice and its mechanism.Methods:Sixty-four 15-week-old male C57BL/6J mice were divided into two groups of 32 mice each according to random numbers for the prevention test and the treatment test.The respective 32 mice in the prevention and treatment experiments were randomly divided into normal group, blue light group, solvent group and eye pad group according to random numbers, with eight mice in each group, respectively.In the prevention experiments, mice in each group were exposed to blue light at a wavelength of 460 nm and a light intensity of 2 000 lx for 6 hours per day for 15 consecutive days to establish a mouse model of meibomian gland function changes except for the normal group.The solvent group and the eye pad group were treated with the corresponding eye pad before and after the blue light exposure for 25 minutes daily for the 15 consecutive days.The blue light group was treated with blue light exposure only for 15 days, and the mice were photographed at the edge of the meibomian gland on day 15 to observe the function of the meibomian gland except for the normal group.In the treatment test, all groups of mice except the normal group were induced the altered function of the mouse meibomian gland by the above method.The solvent and eye pad groups were treated with corresponding eye pads for 25 minutes in the morning and afternoon of each day for 15 consecutive days after blue light exposure.The blue light group was kept in a standard environment for 15 days and the changes in meibomian gland function of mice were detected by meibomian gland photographs on day 15.Photography of the eyelid margin in vitro, oil red O staining, and hematoxylin-eosin staining were performed to observe the histologic changes in the meibomian glands of mice after the preventive and experimental treatment.The relative expression of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) mRNA in mouse meibomian gland tissues was detected by real-time fluorescence quantitative PCR.The expression of nuclear factor-κB (NF-κB) and phosphorylation of NF-κB (p-NF-κB) proteins in mice meibomian gland tissues was detected by Western blot to assess the degree of amelioration of blue light-induced inflammation in mouse meibomian glands by the compound wild chrysanthemum eye pad.This study was conducted in accordance with the Statement of the Association for Research in Vision and Ophthalmology on the Use of Animals in Ophthalmology and Vision Research, and was approved by the Animal Ethics Committee of Xiamen University (No.XMULAC20220258). Results:Compared with the normal group, a gradually increased number of blocked meibomian gland openings, and a gradually decreased remaining area of lower meibomian gland, were observed in the mice after 15 days of blue light group, and all the differences were statistically different (all at P<0.05). In the prevention test, the number of obstructed opening in the eye pad group was 1.833±0.753, which was significantly less than 3.667±1.033 in the solvent group ( P<0.05). The relative remaining area of the lower lid meibomian gland in the eye pad group was 0.718±0.091, which was significantly greater than 0.624±0.130 in the solvent group ( P<0.05). Hematoxylin-eosin staining showed inflammatory cell infiltration in mouse meibomian gland in the blue light and solvent groups.There was no inflammatory cell infiltration in eye pad group, and the morphology of the acini was similar to that of the normal group.Oil red O staining showed that there was no significant lipid deposition in the groups.The relative expressions of IL-1β, IL-6, TNF-α, and IFN-γ mRNA were significantly lower, and the relative expressions of NF-κB and p-NF-κB proteins were significantly lower in the eye pad group than in the solvent group, showing statistically significant differences (all at P<0.05). In the treatment test, the number of obstructed openings in the eye pad group and solvent group was 4.333±1.211 and 4.833±1.722, respectively, and the relative remaining area of the lower meibomian gland was 0.572±0.151 and 0.588±0.154, respectively, showing no statistically significant differences (both at P>0.05). Hematoxylin-eosin staining showed inflammatory cell infiltration in mouse meibomian glands in the blue light and solvent groups, with a similar morphology of acini as in the normal group.There was no inflammatory cell infiltration in eye pad group.Oil red O staining showed that there was no significant lipid deposition in the groups.The relative expressions of IL-1β, IL-6, and IFN-γ mRNA were significantly lower and the relative expressions of NF-κB and p-NF-κB proteins were significantly lower in the eye pad group than in the solvent group (all at P<0.05). Conclusions:Compound wild chrysanthemum eye pad may have preventive and therapeutic effects on blue light-induced changes in meibomian gland function by reducing the inflammatory response of meibomian gland tissue through the inhibition of the NF-κB signaling pathway.

Objective: To study the role of corticotropin-releasing hormone (CRH) system in locus ceruleus (LC) in irritable bowel syndrome (IBS) and to explore its molecular mechanism. Methods: The IBS rat was established by maternal separation following with postnatal stress. The tissues sample of LC was obtained by micropunched nuclei. The expression of c-Fos, CRH and its receptors including corticotropin-releasing hormone receptor (CRHR) 1 and CRHR2 of rats’ LC tissues of control group and IBS group was detected by quantitative polymerase chain reaction(PCR). The expression of DNA methyltransferase (DNTM) 1, DNMT3a and DNMT3b at the mRNA level were also measured. In addition, the expression of histone methyltransferase ASH2-like protein (ASH2L) and SET and MYND domain containing 2 (SMYD2) was determined by Western blotting. T test was used for statistical analysis. Results: The rectal pneumatic pressure of IBS group was lower than that of control group ((69.82±5.47) mmHg vs. (86.86±5.98) mmHg; 1 mmHg=0.133 kPa), however compared with that of control group, the expression of c-Fos at the mRNA level increased (2.11±0.44 vs.1.00±0.19), and the differences were statistically significant (t=6.215 and 2.321, P<0.01 and 0.05). In addition, compared with that of control group, the expression of CRH at the mRNA level increased (1.99±0.35 vs.1.00±0.13), and the difference was statistically significant (t= 2.797, P<0.05). Compared with that of control group, the expression of SMYD2 at the protein level up-regulated (1.04±0.21 vs. 0.61±0.12), and the difference was statistically significant (t=4.451, P<0.01). However, there were no statistically significant differences in the expression of CRHR-1, CRHR2, DNMT1, DNMT3a, DNMT3b at the mRNA level, and the expression of ASH2L between IBS group and control group (0.96±0.13 vs. 1.00±0.26, 1.35±0.63 vs. 1.00±0.43, 1.40±0.61 vs.1.00±0.19, 1.39±0.58 vs. 1.00±0.21, 1.45±0.71vs.1.00±0.39 and 0.80±0.19 vs. 1.05±0.26, respectively; all P>0.05). Conclusions Maternal separation combined with postnatal stress affect the transcription of Crh gene in LC and cause the activation of the stress regulation network CRH and norepinephrine system, resulting in the increase of the visceral sensitivity of rats. The abnormal transcription of Crh gene may be related with SMYD2-mediated histone H3K36 methylation, but not related with the modification of DNA methylation.