Effect of fluoxetine on depression-induced changes in the expression of vasoactive intestinal polypeptide and corticotrophin releasing factor in rat duodenum

AIM: To investigate changes in vasoactive intestinal polypeptide (VIP) and corticotrophin releasing factor (CRF) in the plasma and duodenum of chronic stress- induced depressed rats and the effects of fluoxetine hydrochloride (fluoxetine) treatment on depression- induced changes in VIP and CRF. METHODS: A Sprague-Dawley rat model of chronic stress-induced depression was produced. Thirty experimental rats were randomly divided into the following groups: control group, saline-treated depressed group, and fluoxetine-treated depressed group. Open- f ield testing was performed to assess the rats’ behavior. VIP and CRF levels in plasma were measured by ELISA. Immunofluorescence techniques combined with laser scanning confocal microscopy (LSCM) were used to investigate VIP and CRF expression in the duodenum. RESULTS: The open-field behavior, both crossing and rearing, of depression model rats, decreased signif icantly compared with those of normal control rats over 5 min. Defecation times increased significantly. Compared to the control group, FITC fluorescence of duodenal CRF expression and plasma CRF levels in the depressed rats increased significantly (fluorescence intensity of duodenal CRF: 11.82 ± 2.54 vs 25.17 ± 4.63; plasma CRF: 11.82 ± 2.54 ng/L vs 25.17 ± 4.63 ng/L, P < 0.01), whereas duodenal VIP expression and plasma VIP levels decreased signif icantly (fluorescence intensity of duodenal VIP: 67.37 ± 18.90 vs 44.51 ± 16.37; plasmaVIP: 67.37 ± 18.90 ng/L vs 44.51 ± 16.37 ng/L, P < 0.01). Fluoxetine improved depressed behavior, increased VIP expression and decreased CRF expression in plasma and the duodenal tissue of depressed rats. CONCLUSION: Chronic stress can induce injury to the duodenum, accompanied by increasing CRF and decreasing VIP in the plasma and duodenum. Treatment with fluoxetine can ameliorate pathological changes in the duodenum of depressed rats, which suggests that antidepressants are an effective therapeutic agent for some duodenal diseases caused by chronic stress. VIP is a potential therapeutic strategy.

Effects of fluoxetine on mast cell morphology and protease-1 expression in gastric antrum in a rat model of depression

AIM: To investigate the effects of fluoxetine on depression-induced changes of mast cell morphology and protease-1 (rMCP-1) expression in rats. METHODS: A Sprague-Dawley rat model of chronic stress-induced depression was established. Fifty experimental rats were randomly divided into the following groups: normal control group, fluoxetine + normal control group, depressed model group, saline + depressed model group, and fluoxetine + depressed model group. Laser scanning confocal microscopy (LSCM) immunofluorecence and RT-PCR techniques were used to investigate rMCP-1 expression in gastric antrum. Mast cell morphology was observed under transmission electron microscopy. ANOVA was used for statistical analysis among groups.RESULTS: Morphologic observation indicated that depression induced mast cell proliferation, activation, and granule hyperplasia. Compared with the normal control group, the average immunofluorescence intensity of gastric antrum rMCP-1 significantly increased in depressed model group (37.4 ± 7.7 vs 24.5 ± 5.6, P < 0.01) or saline + depressed model group (39.9 ± 5.0 vs 24.5 ± 5.6, P < 0.01), while there was no significant difference between fluoxetine + normal control group (23.1 ± 3.4) or fluoxetine + depressed model group (26.1 ± 3.6) and normal control group.The average level of rMCP-1mRNA of gastric antrum significantly increased in depressed model group (0.759 ± 0.357 vs 0.476 ± 0.029, P < 0.01) or saline + depressed model group (0.781 ± 0.451 vs 0.476 ± 0.029, P < 0.01 ), while no significant difference was found between fluoxetine + normal control group (0.460 ± 0.027) or fluoxetine + depressed model group (0.488 ± 0.030) and normal control group. Fluoxetine showed partial inhibitive effects on mast cell ultrastructural alterations and de-regulated rMCP-1 expression in gastric antrum of the depressed rat model.CONCLUSION: Chronic stress can induce mast cell proliferation, activation, and granule hyperplasia in gastric antrum. Fluoxetine counteracts such changes in the depressed rat model.

Application of next generation sequencing in the screening of monogenic diseases in China,2021:a consensus among Chinese newborn screening experts

Newborn screening(NBS)refers to a maternal and newborn healthcare technology,in which special examinations of congenital and genetic diseases that could seriously impact the health of newborns,are implemented during the neonatal period to provide early diagnosis and treatment[1].With a history of more than 60 years,NBS has advanced greatly due to technological progress resulting in significant improvement in the number of diseases covered by NBS and in screening efficiency[2-7].