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Objective:To investigate the counteractive effect of mouse dermal fibroblasts (MdFBs) during their adipogenic differentiation against Staphylococcus aureus infection, and to explore its mechanisms. Methods:MdFBs were obtained from newborn C57BL/6 mice, and their adipogenic differentiation was induced by culture in an adipogenic medium for 48 hours. Real-time fluorescence-based quantitative PCR (RT-PCR) was performed to determine the mRNA expression of cathelicidin antimicrobial peptide (CAMP) on days 0-6 during the adipogenic differentiation of MdFBs, and Western blot analysis to determine the protein expression of CAMP in the culture supernatant of MdFBs during their adipogenic differentiation. MdFBs were divided into 4 groups: co-stimulation group stimulated by S. aureus suspensions and cultured in an adipogenic medium, adipogenic control group cultured in an adipogenic medium, S. aureus-stimulation group stimulated by S. aureus suspensions and cultured in a common medium, and control group stimulated by phosphate-buffered saline and cultured in a common medium; Western blot analysis and RT-PCR were conducted to determine the protein and mRNA expression of CAMP. S. aureus (5 × 10 4 CFU/ml) was cultured with the culture supernatant of MdFBs after 5-day adipogenic differentiation (adipogenic group), and the growth activity was evaluated every 2 hours during 10 - 24 hours after the start of co-culture; S. aureus cultured with the culture supernatant of MdFBs in a common medium served as the normal control group, and that cultured with cell-free culture supernatant served as the negative control group. Differences between groups were assessed using unpaired t-test or analysis of variance. Results:Significant differences were observed in the relative mRNA expression of CAMP among different time points (days 0, 1, 2, 4, and 6) during the adipogenic differentiation of MdFBs (1.14 ± 0.74, 68.04 ± 12.72, 683.12 ± 38.06, 1 390.68 ± 226.21, 454.57 ± 204.12, F = 50.08, P < 0.001) ; the CAMP mRNA expression was significantly higher on days 1, 2, 4, and 6 than on day 0 ( t = 9.09, 31.03, 10.63, 3.85, respectively, all P < 0.05), and showed an initial rise and subsequent fall during days 0 - 6. The CAMP protein expression in the culture supernatant of MdFBs peaked on days 2-5 and subsequently decreased. Significant differences were observed in the mRNA and protein expression of CAMP among the control group, S. aureus-stimulation group, adipogenic control group and co-stimulation group (mRNA: 0.08 ± 0.02, 0.38 ± 0.10, 0.49 ± 0.11, 0.80 ± 0.03, respectively, F = 43.25, P < 0.05; protein: 0.433 ± 0.176, 0.574 ± 0.176, 1.007 ± 0.176, 1.217 ± 0.176, respectively, F = 46.79, P < 0.05), and the relative mRNA and protein expression of CAMP was significantly higher in the co-stimulation group than in the adipogenic control group, S. aureus-stimulation group and control group (all P < 0.05). At 10 hours during culture, the growth activity of S. aureus was significantly lower in the adipogenic group (0.053 ± 0.015) than in the normal control group and negative control group (0.109 ± 0.015, 0.106 ± 0.015, t = 11.30, 13.26, respectively, both P < 0.05) ; during 10 - 24 hours, the growth activity of S. aureus also showed a significant decrease in the adipogenic group compared with the normal control group and negative control group (all P < 0.05) . Conclusion:MdFBs secreted CAMP during the adipogenic differentiation, and could inhibit the proliferation of S. aureus.
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ObjectiveTo investigate the effect and mechanism of Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex in regulating the intestinal function in the rat model of slow transit constipation (STC) due to yang deficiency via the vasoactive intestinal peptide (VIP)/cathelicidin antimicrobial peptide (cAMP)/protein kinase A (PKA)/aquaporin (AQP) pathway. MethodSD rats were randomized into 6 groups (n=6), including a control group, a model group, high-, medium-, and low-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex groups, and a prucalopride group. Other groups except the control group were treated with loperamide hydrochloride combined with ice water by gavage for the modeling of STC due to yang deficiency. The number of fecal pellets, time to the first black stool defecation, fecal water content, intestinal propulsion rate, and score of fecal properties were recorded in each group. At the end of the treatment, the colon was stained with hematoxylin-eosin (HE) to reveal the histopathological changes and Alcian blue/periodic acid-Schiff (AB-PAS) to reveal the secretion of colonic mucus. The enzyme-linked immunosorbent assay (ELISA) was employed to measure the level of VIP in the serum. The mRNA level of AQP in the colon was measured by polymerase chain reaction (Real-time PCR). Immunohistochemical staining was performed to observe the expression of AQPs in the colon and kidney tissues. Western blot was performed to determine the protein levels of cAMP, PKA, and VIP in the colon tissue. ResultCompared with the control group, the model group had longer time to the first black stool defecation, reduced fecal pellets and water content, reduced Bristol Stool Form Scale score and intestinal propulsion rate, and constipation aggravated(P<0.01). Moreover, increased the intestinal lesions, reduced the mucus secretion, reduce the serum VIP level, up-regulated the expression levels of AQP1 in the colon and kidney tissues, inhibited the expression of AQP3 and AQP9(P<0.01)., and down-regulated the protein levels of cAMP, PKA, and VIP in the colon tissue. Compared with the model group, the high-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex group had shortened time to the first black stool defecation, increased fecal pellets and water content, increased Bristol Stool Form Scale score and intestinal propulsion rate, and alleviated constipation symptoms. Moreover, high-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex reduced the intestinal lesions, increased the mucus secretion, elevated the serum VIP level(P<0.01)., down-regulated the expression levels of AQP1 in the colon and kidney tissues, promoted the expression of AQP3 and AQP9(P<0.05,P<0.01), and up-regulated the protein levels of cAMP, PKA, and VIP in the colon tissue. The medium- and low-dose groups had weaker effect than the high-dose group(P<0.01). ConclusionHigh-dose Aconiti Lateralis Radix Praeparata-Cinnamomi Cortex can improve the intestinal motility and balance the intestinal water and fluid metabolism by up-regulating the VIP/cAMP/PKA/AQP pathway, thereby mitigating the constipation symptoms in the rat model of slow transit constipation due to yang deficiency.
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Objective: To explore the effects of maternal vitamin D deficiency before and during pregnancy on the intestinal flora and cathelicidin antimicrobial peptide (CAMP) in offspring rats. Methods: Twenty-four female Sprague-Dawley rats (8-week-old) were randomly assigned to three groups (n=8 per group), i.e. control group (C group), vitamin D deficiency group (VDD group), and vitamin D supplement group (VDS group). Special diets were used to build the rat models of vitamin D deficiency before and during pregnancy. Maternal 25(OH)D level was detected by liquid chromatography tandem mass spectrometry (LC-MS/MS) at gestational day 14. At the age of 4 weeks in offsprings, the level of 25(OH)D was measured; the faeces were collected for the detection of intestinal flora; the mRNA and protein expression of CAMP were evaluated by real-time quantitative RTPCR and Western blotting, respectively. Results: The rat models of vitamin D deficiency before and during pregnancy were successfully established. The relative abundance of intestinal Lactobacillus in the offspring rats in C group, VDD group and VDS group was 0.050±0.016, 0.028±0.013 and 0.033±0.021, respectively. Compared with C group, the relative abundance of intestinal Lactobacillus in VDD group significantly decreased (P<0.05),and the mRNA and protein expression of colonic CAMP significantly decreased as well (P<0.05). Compared with VDD group, VDS group showed a trend of increase in the abundance of intestinal Lactobacillus; the mRNA expression of colonic CAMP didn't change significantly, but the protein expression of colonic CAMP significantly increased (P<0.05). Conclusion: Vitamin D deficiency during pregnancy results in decreased abundance of intestinal Lactobacilli as well as reduced mRNA and protein expression of colonic CAMP in offspring rats. Vitamin D supplementation significantly improves the protein expression of colonic CAMP and induces a trend of increase in the abundance of intestinal Lactobacilli in offspring rats.
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Inflammatory skin diseases such as atopic dermatitis (AD) and rosacea were complicated by barrier abrogation and deficiency in innate immunity. The first defender of epidermal innate immune response is the antimicrobial peptides (AMPs) that exhibit a broad-spectrum antimicrobial activity against multiple pathogens, including Gram-positive and Gram-negative bacteria, viruses, and fungi. The deficiency of these AMPs in the skin of AD fails to protect our body against virulent pathogen infections. In contrast to AD where there is a suppression of AMPs, rosacea is characterized by overexpression of cathelicidin antimicrobial peptide (CAMP), the products of which result in chronic epidermal inflammation. In this regard, AMP generation that is controlled by a key ceramide metabolite S1P-dependent mechanism could be considered as alternate therapeutic approaches to treat these skin disorders, i.e., Increased S1P levels strongly stimulated the CAMP expression which elevated the antimicrobial activity against multiple pathogens resulting the improved AD patient skin.