Eupatilin attenuates TGF-β2-induced proliferation and epithelial-mesenchymal transition of retinal pigment epithelial cells

Loganic acid regulates the transition between epithelial and mesenchymal-like phenotypes by alleviating MnSOD expression in hepatocellular carcinoma cells

AIMS

Cancer metastasis is the major cause of cancer-related deaths. There are few prior studies reported on molecules targeting C-X-C chemokine receptor (CXCR) family and manganese superoxide dismutase (MnSOD). CXCRs are known to involve in angiogenesis, metastasis, cell survival and MnSOD is reported to be related in Epithelial-mesenchymal transition (EMT).

MAIN METHODS

Cell viability and cell proliferation were measured by MTT and BrdU assay. Protein expression level of CXCR4/7, MMP-2/9, MnSOD, and EMT markers were evaluated by Western blot analysis. mRNA levels of Snail and Occludin were analyzed by Real-time RT-qPCR. Expression of EMT markers in cells was observed by immunocytochemistry. Cell invasion and migrations were evaluated by wound healing assay and boyden chamber assay.

KEY FINDINGS

We noticed that LGA abolished proliferation, invasive ability, and cellular migration. LGA down-regulated the protein levels of mesenchymal markers such as Twist, Snail, Fibronectin, and Vimentin in CXCL12-treated HCC cells. It also suppressed the gelatinolytic activity of MMP-9/2. The amplification of MnSOD increased EMT-like phenotypes but with LGA treatment, these phenotypes were markedly attenuated. The overexpression of MnSOD increased the ROS levels significantly but ROS levels were decreased upon exposure to LGA and deletion of MnSOD suppressed the levels of various mesenchymal proteins.

SIGNIFICANCE

LGA could function as a novel anti-metastatic agent by suppressing metastasis and EMT process via attenuation of MnSOD expression in hepatocellular carcinoma cells.

Molecular mechanisms of TGFβ-mediated EMT of retinal pigment epithelium in subretinal fibrosis of age-related macular degeneration

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the elderly, affecting the macula of the retina and resulting in vision loss. There are two types of AMD, wet and dry, both of which cause visual impairment. Wet AMD is called neovascular AMD (nAMD) and is characterized by the formation of choroidal neovascular vessels (CNVs) in the macula. nAMD can be treated with intravitreal injections of vascular endothelial growth factor (VEGF) inhibitors, which help improve vision. However, approximately half the patients do not achieve satisfactory results. Subretinal fibrosis often develops late in nAMD, leading to irreversible photoreceptor degeneration and contributing to visual loss. Currently, no treatment exists for subretinal fibrosis, and the molecular mechanisms of fibrous tissue formation following neovascular lesions remain unclear. In this review, we describe the clinical features and molecular mechanisms of macular fibrosis secondary to nAMD. Myofibroblasts play an essential role in the development of fibrosis. This review summarizes the latest findings on the clinical features and cellular and molecular mechanisms of the pathogenesis of subretinal fibrosis in nAMD and discusses the potential therapeutic strategies to control subretinal fibrosis in the future.

Flavonoids in vegetables: improvement of dietary flavonoids by metabolic engineering to promote health

Flavonoids are the most abundant polyphenols in plants, and have antioxidant effects as well as other bioactivities (e.g., anti-inflammatory, anti-cancer, anti-allergic, and neuroprotective effects). Vegetables are rich in flavonoids and are indispensable in our daily diet. Moreover, the vegetables as chassis for producing natural products would emerge as a promising means for cost-effective and sustainable production of flavonoids. Understanding the metabolic engineering of flavonoids in vegetables allows us to improve their nutrient composition. In this review, a comprehensive overview of flavonoids in vegetables, including the characterized types and distribution, health-promoting effects, associated metabolic pathways, and applied metabolic engineering are provided. We also introduce breakthroughs in multi-omics approaches that pertain to the elucidation of flavonoids metabolism in vegetables, as well as prospective and potential genome-editing technologies. Based on the varied composition and content of flavonoids among vegetables, dietary suggestions are further provided for human health.

The mechanism of microglia-mediated immune inflammation in ischemic stroke and the role of natural botanical components in regulating microglia: A review

Ischemic stroke (IS) is one of the most fatal diseases. Neuroimmunity, inflammation, and oxidative stress play important roles in various complex mechanisms of IS. In particular, the early proinflammatory response resulting from the overactivation of resident microglia and the infiltration of circulating monocytes and macrophages in the brain after cerebral ischemia leads to secondary brain injury. Microglia are innate immune cells in the brain that constantly monitor the brain microenvironment under normal conditions. Once ischemia occurs, microglia are activated to produce dual effects of neurotoxicity and neuroprotection, and the balance of the two effects determines the fate of damaged neurons. The activation of microglia is defined as the classical activation (M1 type) or alternative activation (M2 type). M1 type microglia secrete pro-inflammatory cytokines and neurotoxic mediators to exacerbate neuronal damage, while M2 type microglia promote a repairing anti-inflammatory response. Fine regulation of M1/M2 microglial activation to minimize damage and maximize protection has important therapeutic value. This review focuses on the interaction between M1/M2 microglia and other immune cells involved in the regulation of IS phenotypic characteristics, and the mechanism of natural plant components regulating microglia after IS, providing novel candidate drugs for regulating microglial balance and IS drug development.

Artesunate inhibits the development of PVR by suppressing the TGF-β/Smad signaling pathway

Proliferative vitreoretinopathy (PVR) is the main cause of retinal detachment surgery failure. The epithelial-mesenchymal transition (EMT) induced by transforming growth factor (TGF-β2) plays an important role in the development of PVR. Artesunate has been widely studied as a treatment for ophthalmic diseases because of its antioxidant, anti-inflammatory, antiapoptotic and antiproliferative properties. The purpose of this study was to investigate the effects of artesunate on the TGF-β2-induced EMT in ARPE-19 cells and PVR development. We found that artesunate inhibited the proliferation and contraction of ARPE-19 cells after the EMT and the autocrine effects of TGF-β2 on ARPE-19 cells. Additionally, the levels of Smad3 and p-Smad3 were increased in clinical samples, and artesunate decreased the levels of Smad3 and p-Smad3 in ARPE-19 cells treated with TGF-β2. Artesunate also inhibited the occurrence and development of PVR in vivo. In summary, artesunate inhibits the occurrence and development of PVR by inhibiting the EMT in ARPE-19 cells.