Protective Effect of Casticin on Experimental Skin Wound Healing of Rats

Macrophage plasticity: signaling pathways, tissue repair, and regeneration

Macrophages are versatile immune cells with remarkable plasticity, enabling them to adapt to diverse tissue microenvironments and perform various functions. Traditionally categorized into classically activated (M1) and alternatively activated (M2) phenotypes, recent advances have revealed a spectrum of macrophage activation states that extend beyond this dichotomy. The complex interplay of signaling pathways, transcriptional regulators, and epigenetic modifications orchestrates macrophage polarization, allowing them to respond to various stimuli dynamically. Here, we provide a comprehensive overview of the signaling cascades governing macrophage plasticity, focusing on the roles of Toll-like receptors, signal transducer and activator of transcription proteins, nuclear receptors, and microRNAs. We also discuss the emerging concepts of macrophage metabolic reprogramming and trained immunity, contributing to their functional adaptability. Macrophage plasticity plays a pivotal role in tissue repair and regeneration, with macrophages coordinating inflammation, angiogenesis, and matrix remodeling to restore tissue homeostasis. By harnessing the potential of macrophage plasticity, novel therapeutic strategies targeting macrophage polarization could be developed for various diseases, including chronic wounds, fibrotic disorders, and inflammatory conditions. Ultimately, a deeper understanding of the molecular mechanisms underpinning macrophage plasticity will pave the way for innovative regenerative medicine and tissue engineering approaches.

Anti-osteoporosis activity of casticin in ovariectomized rats

Background

Postmenopausal osteoporosis (PMPO) is the most familiar type of osteoporosis, a silent bone disease. Casticin, a natural flavonoid constituent, improves osteoporosis in animal model. Nevertheless, the potential mechanism remains to be further explored.

Methods

A model of PMPO was established in rats treated with ovariectomy (OVX) and RAW 264.7 cells induced with receptor activator of nuclear factor kappa-B ligand (RANKL). The effect and potential mechanism of casticin on PMPO were addressed by pathological staining, measurement of bone mineral density (BMD), three-point bending test, serum biochemical detection, filamentous-actin (F-actin) ring staining, TRAcP staining, reverse transcription quantitative polymerase chain reaction, western blot and examination of oxidative stress indicators.

Results

The casticin treatment increased the femoral trabecular area, bone maturity, BMD, elastic modulus, maximum load, the level of calcium and estrogen with the reduced concentrations of alkaline phosphatase (ALP) and tumor necrosis factor (TNF)-α in OVX rats. An enhancement in the F-actin ring formation, TRAcP staining and the relative mRNA expression of NFATc1 and TRAP was observed in RANKL-induced RAW 264.7 cells, which was declined by the treatment of casticin. Moreover, the casticin treatment reversed the reduced the relative protein expression of Nrf2 and HO-1 and the concentrations of superoxide dismutase and glutathione peroxidase, and the increased content of malondialdehyde both in vivo and in vitro.

Conclusion

Casticin improved bone density, bone biomechanics, the level of calcium and estrogen, the release of pro-inflammatory factor and oxidative stress to alleviate osteoporosis, which was associated with the upregulation of Nrf2/HO-1 pathway.

Casticin promotes osteogenic differentiation of bone marrow stromal cells and improves osteoporosis in rats by regulating nuclear factor-κB/mitogen-activated protein kinase

BACKGROUND

Osteoporosis has influenced millions of people, especially postmenopausal women, which has become a big burden to the whole world. Although the diverse roles of casticin (CAS) on different diseases were identified, whether it was implicated with osteoporosis was unknown.

METHODS

A rat model of osteoporosis was established through dexamethasone (DEX) treatment and a cell model reflecting the osteogenic and osteoclast induction was constructed in bone marrow stromal cells (BMSCs). The calcification at the late stage of induction was measured via Alizarin Red S staining. Western blot was applied to evaluate the levels of proteins.

RESULTS

Hematoxylin and eosin staining revealed that the number of bone trabecular in DEX-induced osteoporosis rats was decreased, while increased doses of CAS treatment elevated the number of bone trabecular. CAS treatment alleviated DEX-induced osteoporosis in rats. Moreover, we found that CAS inhibited the nuclear factor-κB/mitogen-activated protein kinase (NF-κB/MAPK) pathway. In addition, CAS promoted osteogenic differentiation of BMSCs and reduced osteoclastogenesis of bone marrow monocytes. Finally, CAS was observed to retard the receptor activator of NFκ-B ligand-induced NF-κB/MAPK pathway.

CONCLUSION

CAS promoted osteogenic differentiation of BMSCs and improved osteoporosis in rats by regulating the NF-κB/MAPK pathway. This might shed a light into using CAS as a drug treating osteoporosis in the future.