Geniposide Enhances Macrophage Autophagy through Downregulation of TREM2 in Atherosclerosis.

Macrophage autophagy defect is closely related to the progression of atherosclerosis (AS) and is regulated by the triggering receptor expressed on myeloid cell 2 (TREM2). TREM2 is a key factor in the development of Alzheimer's disease (AD), the deficiency of which leads to anomalous autophagy in microglia. However, the role of TREM2 in the autophagy of plaque macrophages is still unclear. Geniposide (GP) can inhibit AS progression and enhance macrophage autophagy, although the underlying mechanisms remain unknown. We found that high-fat diet (HFD) feeding significantly increased TREM2 levels and inhibited autophagy in the macrophages of ApoE[Formula: see text] mice. TREM2 overexpression in RAW264.7 macrophages decreased autophagy via activation of mTOR signaling. GP inhibited the progression of AS in ApoE[Formula: see text] mice, reinforced macrophage autophagy, and downregulated TREM2 by inhibiting mTOR signaling. Taken together, augmenting the autophagy levels in plaque macrophages by inhibiting the TREM2/mTOR axis can potentially impede atherosclerotic progression. The promising therapeutic effects of GP seen in this study should be validated in future trials, and the underlying mechanisms have to be elucidated in greater detail.

Inhibition of the STAT3 Signaling Pathway Contributes to the Anti-Melanoma Activities of Shikonin.

BACKGROUND: Malignant melanoma is an extremely aggressive and metastatic cancer, and highly resistant to conventional therapies. Signal transducer and activator of transcription 3 (STAT3) signaling promotes melanoma development and progression, which has been validated as an effective target in melanoma treatment. Natural naphthoquinone shikonin is reported to exert anti-melanoma effects. However, the underlying mechanisms have not been fully elucidated. PURPOSE: This study aims to evaluate the anti-melanoma activities of shikonin and explore the involvement of STAT3 signaling in these effects. METHODS: Zebrafish tumor model was established to evaluate the anti-human melanoma effects of shikonin in vivo. MTT assay and colony formation assay were employed to investigate the anti-proliferative effects of shikonin on human melanoma A375 and A2058 cells. Flow cytometry was used to analyze cell cycle distribution and apoptosis induction. Wound healing assay and Transwell chamber assay were conducted to examine the cell migratory and invasive abilities. Immunofluorescence assay was used to observe F-actin, Tubulin, and STAT3 localization. Western blotting was used to determine the expression levels of proteins associated with apoptosis and key proteins in the STAT3 signaling pathway. Immunoblotting was performed in DSS cross-linked cells to determine the homo-dimerization of STAT3. Gelatin zymography was employed to evaluate the enzymatic activity of MMP-2 and MMP-9. Transient transfection was used to overexpress STAT3 in cell models. RESULTS: Shikonin suppressed melanoma growth in cultured cells and in zebrafish xenograft models. Shikonin induced melanoma cells apoptosis, inhibited cell migration and invasion. Mechanistic study indicated that shikonin inhibited the phosphorylation and homo-dimerization of STAT3, thus reduced its nuclear localization. Further study showed that shikonin decreased the levels of STAT3-targeted genes Mcl-1, Bcl-2, MMP-2, vimentin, and Twist, which are involved in melanoma survival, migration, and invasion. More importantly, overexpression of constitutively active STAT3 partially abolished the anti-proliferative, anti-migratory, and anti-invasive effects of shikonin. CONCLUSION: The anti-melanoma activity of shikonin is at least partially attributed to the inhibition on STAT3 signaling. These findings provide new insights into the anti-melanoma molecular mechanisms of shikonin, suggesting its potential in melanoma treatment.

Liang-Ge-San, a classic traditional Chinese medicine formula, protects against lipopolysaccharide-induced inflammation through cholinergic anti-inflammatory pathway.

Liang-Ge-San (LGS) is a classic formula in traditional Chinese medicine, which is widely used to treat acute lung injury (ALI), pharyngitis and amygdalitis in clinic. However, the underlying mechanisms remain poorly defined. In this study, we discovered that LGS exerted potent anti-inflammatory effects in lipopolysaccharide (LPS)-induced inflammation. We found that LGS significantly depressed the production of IL-6 and TNF-α in LPS-stimulated RAW 264.7 macrophage cells. The degradation and phosphorylation of IκBα and the nuclear translocation of NF-κB p65 were also inhibited. Moreover, LGS activated α7 nicotinic cholinergic receptor (α7nAchR). The blockage of α7nAchR by selective inhibitor methyllycaconitine (MLA) or α7nAchR siRNA attenuated the inhibitory effects of LGS on IκBα, NF-κB p65, IL-6 and TNF-α. Critically, LGS significantly inhibited inflammation in LPS-induced ALI rats through the activation of NF-κB signaling pathway. However, these protective effects could be counteracted by the treatment of MLA. Taken together, we first demonstrated anti-inflammatory effects of LGS both in vitro and in vivo through cholinergic anti-inflammatory pathway. The study provides a rationale for the clinical application of LGS as an anti-inflammatory agent and supports the critical role of cholinergic anti-inflammatory pathway in inflammation.

[Protective effect of licoflavone on gastric mucosa in rats with chronic superficial gastritis].

OBJECTIVE: To evaluate the protective effect of licoflavone on gastric mucosa in rats with chronic superficial gastritis and explore the possible mechanism. METHODS: SD rat models of chronic superficial gastritis was established by intragastric administration of 0.02% ammonia and long-term irregular diet. The rat models were then randomized into model group, vitacoenzyme group and 3 licoflavone groups of high, medium, and low doses. After 30 days of treatment, the gastric histopathology, mucosal lesions, scanning electron microscopy, mucin function production by the gastric mucosa epithelial cells, serum PGE(2) level and gastric microcirculation were assessed to evaluate the protective effect of licoflavone on gastric mucosa. RESULTS: Compared with normal control rats, the rat models of chronic superficial gastritis showed significantly higher gastric mucosal injury rate, histopathological scores and gastric mucin content. Licoflavone significantly ameliorated gastric pathology and increased serum PGE(2) level, enhanced acidic mucin secretion by the epithelial cells, and improved gastric microcirculation in the rat models. CONCLUSION: Licoflavone feeding suppresses gastric mucosa injury, protects and restores the injured mucosa in rats with chronic superficial gastritis, and these effects are related with the up-regulation of serum PGE(2) level.

Protection of a polysaccharide from Salvia miltiorrhiza, a Chinese medicinal herb, against immunological liver injury in mice.

This study was designed to evaluate the hepatoprotective effects of S. miltiorrhiza polysaccharides (SMPS) in immunological liver injury induced by Bacille-Calmette-Guerin (BCG) and lipopolysaccharide (LPS) in mice. SMPS effectively improved the liver index, spleen index and thymus index, reduced the serum levels of alanine aminotransferase, aspartate aminotransferase and nitric oxide, and restored liver homogenate contents of tumor necrosis factor-alpha and interleukin-1beta. The histopathological analysis suggested that SMPS reduced the degree of liver injury. The results suggest that SMPS play a protective role against immunological liver injury, which may have important implications for our understanding on the immunoregulatory mechanisms of polysaccharides.

[Protective effects of Hongbeiyegen against immunological liver injury in mice].

OBJECTIVE: To investigate the protective effects of Hongbeiyegen (HBYG) against immunological liver injury induced by bacille Calmette-Guerin (BCG) and lipopolysaccharide (LPS). METHODS: Immunological liver injury was induced in rats by BCG and LPS injected via the tail vein. The liver index, thymus index and spleen index were calculated and the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and nitric oxide (NO) and liver homogenate contents of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) were determined. RESULTS: HBYG significantly improved the liver index, thymus index and spleen index, and reduced the serum levels of ALT, AST and NO, and as the liver homogenate contents of TNF-alpha and IL-1beta. CONCLUSION: HBYG offers obvious protective effects against immunological injury liver in mice.