2-Aminoethyl diphenylborinate inhibits bleomycin-induced skin and pulmonary fibrosis via interrupting intracellular Ca2+ regulation

Essential oil extract p‑cresol effect on Ca2+ signaling and its underlying mechanism in DBTRG‑05MG human glioblastoma cells

The effect of para (p)-cresol, an essential oil component, on calcium ion (Ca2+) signaling in human glioblastoma is unknown. The present study aimed to investigate how p-cresol influences intracellular Ca2+ levels ([Ca2+]i) and viability in DBTRG-05MG human glioblastoma cells. Cells were treated with p-cresol to assess its impact on cell viability and [Ca2+]i. Cell viability was evaluated using a WST-1 assay. [Ca2+]i was measured using a fluorescence-based Ca2+ indicator. Cells were loaded with the Ca2+-sensitive dye (fura-2), and fluorescence intensity was recorded before and after p-cresol treatment to determine changes in [Ca2+]i. p-Cresol induced concentration-dependent increases in [Ca2+]i between 50 and 150 µM. At 50-250 µM, p-cresol triggered cell death; this effect was reversed by pretreating the cells with the Ca2+ chelator BAPTA-AM. The removal of extracellular Ca2+ inhibited Ca2+ entry. p-Cresol-induced Ca2+ influx was confirmed by Mn2+-induced quenching of fura-2 fluorescence. Store-operated Ca2+ channel modulators SKF96365 and 2-aminoethoxydiphenyl borate and the protein kinase C inhibitor GF109203X inhibited p-cresol-induced Ca2+ entry, but voltage-gated Ca2+ channel blocker nifedipine did not. Treatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin in Ca2+-free medium inhibited p-cresol-induced [Ca2+]i rises; conversely, treatment with p-cresol decreased thapsigargin-induced [Ca2+]i rises. Furthermore, phospholipase C (PLC) inhibition with U73122 abolished p-cresol-induced [Ca2+]i rises. In DBTRG-05MG cells, p-cresol triggered Ca2+-associated cell death. The process involved the entry of Ca2+ through PKC-regulated store-operated Ca2+ channels and release of Ca2+ from the endoplasmic reticulum, which depends on PLC. Additionally, BAPTA-AM, which has Ca2+-chelating properties, may be a promising compound in preventing p-cresol-induced cytotoxicity, a potential breakthrough in neurotoxic research in glioblastoma cell model.

Regulation of myofibroblast dedifferentiation in pulmonary fibrosis

Idiopathic pulmonary fibrosis is a lethal, progressive, and irreversible condition that has become a significant focus of medical research due to its increasing incidence. This rising trend presents substantial challenges for patients, healthcare providers, and researchers. Despite the escalating burden of pulmonary fibrosis, the available therapeutic options remain limited. Currently, the United States Food and Drug Administration has approved two drugs for the treatment of pulmonary fibrosis-nintedanib and pirfenidone. However, their therapeutic effectiveness is limited, and they cannot reverse the fibrosis process. Additionally, these drugs are associated with significant side effects. Myofibroblasts play a central role in the pathophysiology of pulmonary fibrosis, significantly contributing to its progression. Consequently, strategies aimed at inhibiting myofibroblast differentiation or promoting their dedifferentiation hold promise as effective treatments. This review examines the regulation of myofibroblast dedifferentiation, exploring various signaling pathways, regulatory targets, and potential pharmaceutical interventions that could provide new directions for therapeutic development.

TRPA1 as a potential factor and drug target in scleroderma: dermal fibrosis and alternative macrophage activation are attenuated in TRPA1-deficient mice in bleomycin-induced experimental model of scleroderma

BACKGROUND

Systemic sclerosis is a rheumatoid disease best known for its fibrotic skin manifestations called scleroderma. Alternatively activated (M2-type) macrophages are normally involved in the resolution of inflammation and wound healing but also in fibrosing diseases such as scleroderma. TRPA1 is a non-selective cation channel, activation of which causes pain and neurogenic inflammation. In the present study, we investigated the role of TRPA1 in bleomycin-induced skin fibrosis mimicking scleroderma.

METHODS

Wild type and TRPA1-deficient mice were challenged with intradermal bleomycin injections to induce a scleroderma-mimicking disease. Macrophages were investigated in vitro to evaluate the underlying mechanisms.

RESULTS

Bleomycin induced dermal thickening and collagen accumulation in wild type mice and that was significantly attenuated in TRPA1-deficient animals. Accordingly, the expression of collagens 1A1, 1A2, and 3A1 as well as pro-fibrotic factors TGF-beta, CTGF, fibronectin-1 and YKL-40, and M2 macrophage markers Arg1 and MRC1 were lower in TRPA1-deficient than wild type mice. Furthermore, bleomycin was discovered to significantly enhance M2-marker expression particularly in the presence of IL-4 in wild type macrophages in vitro, but not in macrophages harvested from TRPA1-deficient mice. IL-4-induced PPARγ-expression in macrophages was increased by bleomycin, providing a possible mechanism behind the phenomenon.

CONCLUSIONS

In conclusion, the results indicate that interfering TRPA1 attenuates fibrotic and inflammatory responses in bleomycin-induced scleroderma. Therefore, TRPA1-blocking treatment could potentially alleviate M2 macrophage driven diseases like systemic sclerosis and scleroderma.

Human umbilical cord mesenchymal stem cells combined with pirfenidone upregulates the expression of RGS2 in the pulmonary fibrosis in mice

Objective

The therapeutic effect of umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in combination with pirfenidone (PFD) on pulmonary fibrosis in mice and its possible mechanism were investigated.

Methods

C57BL/6 mice were randomly divided into six groups: control group, model group, P₁₀ group, P₃₀ group, P₁₀₀ group, and P₃₀₀ group. Modeled by tracheal intubation with 3 mg/kg bleomycin drip, each dose of PFD was administered daily by gavage from day 7 onwards. The mice were observed continuously for 21 days and survival was recorded. Lung tissues were collected on day 21, and hematoxylin–eosin (HE) and Masson staining were performed to assess morphological changes and collagen deposition in the lungs. Collagen content was measured by the Sircol method, and fibrosis marker levels were detected by PCR and Western blot. Another batch of C57BL/6 mice was then randomly divided into five groups: hUC-MSC control group, model group, P₁₀₀ group, hUC-MSC treatment group, and hUC-MSCs + P₃₀ group. On day 7, 5 × 10⁵ hUC-MSCs were injected into the tail vein, the mice were administered PFD gavage daily from day 7 onwards, and their survival was recorded. Lung tissues were collected on day 21 to detect pathological changes, the collagen content, and the expression of regulator of G protein signaling 2 (RGS2). Pulmonary myofibroblasts (MFBs) were divided into an MFB group and an MFB + hUC-MSCs group; different doses of PFD were administered to each group, and the levels of RGS2, intracellular Ca²⁺, and fibrosis markers were recorded for each group.

Results

Compared with other PFD group doses, the P₁₀₀ group had significantly improved mouse survival and lung pathology and significantly reduced collagen and fibrosis marker levels (p < 0.05). The hUC-MSCs + P₃₀ group had significantly improved mouse survival and lung pathology, significantly reduced collagen content and fibrosis marker levels (p < 0.05), and the efficacy was better than that of the P₁₀₀ and hUC-MSCs groups (p < 0.05). RGS2 expression was significantly higher in the MSCs + P₃₀ group compared with the P₁₀₀ and hUC-MSCs groups (p < 0.05). PFD increased RGS2 expression in MFBs (p < 0.05) in a dose-dependent manner. Compared with PFD and hUC-MSCs treatment alone, combination of hUC-MSCs and PFD increased RGS2 protein levels, significantly decreased intracellular Ca²⁺ concentration, and significantly reduced fibrosis markers.

Conclusion

The findings suggest that hUC-MSCs combined with low-dose PFD have a therapeutic effect better than that of the two treatments used separately. Its effect on attenuating bleomycin-induced pulmonary fibrosis in mice is related to the increase of RGS2.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02192-6.