Co-cultures of human coronary smooth muscle cells and dimethyl sulfoxide-differentiated HL60 cells upregulate ProMMP9 activity and promote mobility-modulation by reactive oxygen species

FTY720 ameliorates experimental MPO-ANCA-associated vasculitis by regulating fatty acid oxidation via the neutrophil PPARα-CPT1a pathway

OBJECTIVES

Increasing studies demonstrated the importance of C5a and anti-neutrophil cytoplasmic antibody (ANCA)-induced neutrophil activation in the pathogenesis of ANCA-associated vasculitis (AAV). Sphingosine-1-phosphate (S1P) acts as a downstream effector molecule of C5a and enhances neutrophil activation induced by C5a and ANCA. The current study investigated the role of a S1P receptor modulator, FTY720, in experimental autoimmune vasculitis (EAV) and explored the immunometabolism-related mechanisms of FTY720 in modulating ANCA-induced neutrophil activation.

METHODS

The effects of FTY720 in EAV were evaluated by quantifying haematuria, proteinuria, crescent formation, tubulointerstitial injury and pulmonary haemorrhage. RNA sequencing of renal cortex and gene enrichment analysis were performed. The proteins of key identified pathways were analysed in neutrophils isolated from peripheral blood of patients with active AAV and normal controls. We assessed the effects of FTY720 on ANCA-induced neutrophil respiratory burst and neutrophil extracellular traps formation (NETosis).

RESULTS

FTY720 treatment significantly attenuated renal injury and pulmonary haemorrhage in EAV. RNA sequencing analyses of renal cortex demonstrated enhanced fatty acid oxidation (FAO) and peroxisome proliferator-activated receptor (PPAR) signalling in FTY720-treated rats. Compared with normal controls, patients with active AAV showed decreased FAO in neutrophils. FTY720-treated differentiated HL-60 cells showed increased expression of carnitine palmitoyltransferase 1a (CPT1a) and PPARα. Blocking or knockdown of CPT1a or PPARα in isolated human neutrophils and HL-60 cells reversed the inhibitory effects of FTY720 on ANCA-induced neutrophil respiratory burst and NETosis.

CONCLUSION

FTY720 attenuated renal injury in EAV through upregulating FAO via the PPARα-CPT1a pathway in neutrophils, offering potential immunometabolic targets in AAV treatment.

Effects of IL-1β on MMP-9 Expression in Cementoblast-Derived Cell Line and MMP-Mediated Degradation of Type I Collagen

It has been reported that matrix metalloproteinases (MMPs) are induced by many cytokines, and they are involved in various inflammatory processes, including periodontitis. However, the effects of interleukin-1β (IL-1β) on MMP-9 expression in cementoblasts, the cells responsible for cementum production, remain largely unknown. In this study, we used qPCR and gelatin zymogram analysis to show that IL-1β upregulated MMP-9 expression in cementoblast-derived cell line. Several signaling pathways, such as ERK1/2, JNK, p38, and AP-1 (c-Fos and ATF-2), were activated in response to IL-1β stimulation. Furthermore, enhancement of AP-1 activity by IL-1β was further confirmed by the AP-1 reporter assay and the electrophoretic mobility shift assay (EMSA). Pretreatment with specific inhibitors of ERK1/2 (U0126), JNK (SP600125), and AP-1 (tanshinone IIA) attenuated IL-1β-induced MMP-9 expression. In addition, inhibitors of ERK1/2 (U0126) and JNK (SP600125) attenuated IL-1β-enhanced AP-1 activity. This suggested that IL-1β stimulated AP-1 activation, at least partially, through ERK1/2 and JNK signaling pathways. Moreover, we found that IL-1β also upregulated the expression of MMP-13 and enhanced MMP-mediated degradation of type I collagen. Collectively, these results suggested that IL-1β induced MMP-9 expression by activation of AP-1 through the ERK1/2 and JNK signaling pathways in cementoblast-derived cell line and enhanced MMP-mediated collagen degradation possibly by MMP-13 and MMP-9.

Prophylactic efficacy of enteral miconazole administration for neonatal intestinal perforation and its potential mechanism

PURPOSE

Intestinal perforation (IP) is a fatal complication in extremely low birth weight infants (ELBWI). We started administrating enteral miconazole (MCZ) to ELBWI in 2002. Since then, the incidence of IP has significantly decreased. The aim of this study was to elucidate the prophylactic effect of MCZ for the treatment of neonatal IP, and to establish a new prophylactic concept for this disease.

METHODS

In in vivo experiments, the effects of MCZ were examined histopathologically using a mouse model of intestinal ischemia. In in vitro experiments, the cytoprotective effect of MCZ against hypoxia was evaluated using Caco-2 intestinal cells, and its anti-inflammatory potential using a co-culture model of Caco-2 and HL60 cells.

RESULTS

MCZ showed a tissue protective effect against intestinal ischemia. MCZ reduced high mobility group-box 1 (HMGB1) release in Caco-2 cells under hypoxic stress and attenuated the potential to activate co-cultured HL60 leukocytes with Caco-2 cells by suppressing interleukin-8 (IL-8).

CONCLUSION

MCZ may have preventive roles in the clinical management of IP in ELBWI by the suppression of IL-8 and HMGB-1.