R-spondin3 promotes the tumor growth of choriocarcinoma JEG-3 cells

Astragalus polysaccharide improves diabetic ulcers by promoting M2-polarization of macrophages to reduce excessive inflammation via the β-catenin/ NF-κB axis at the late phase of wound-healing

Ethnopharmacological relevance

Astragalus polysaccharide (APS), the most biologically active ingredient of Astragali Radix, is used to treat diabetes mellitus (DM)-related chronic wounds in traditional Chinese medicine for several decades. This herb possesses an anti-inflammatory effect. Our study proved that APS can reduce excessive inflammation at the late phase of wound-healing in diabetic ulcers.

Aim of the study

To clarify the molecular mechanism of APS in promoting wound-healing via reducing excessive inflammation in diabetic ulcers during the late stages of wound-healing.

Methods and materials

The rat model of the diabetic ulcers was established via intraperitoneal injection of streptozocin (60 mg/kg). We detected the regulation of APS on diabetic ulcers by measuring wound-healing rates. Bioinformatics was used to predict the target genes of APS, and autodocking was used to predict the combination of APS and target genes. Immunohistochemistry, Enzyme-linked immunosorbent assay, Western blot, immunofluorescence staining, flow cytometry, and flow cytometric sorting were investigated.

Results

The results demonstrated that APS promoted wound-healing and inhibited excessive inflammation at the late phase of wound-healing in diabetic rats. Mechanistic findings showed that APS promoted the expression of β-catenin and Rspo3 while inhibiting the expression of NF-KB and GSK-3β, which leads to the transformation of M1-type macrophages into M2-type macrophages and thus reducing excessive inflammation at the late phase of wound-healing in diabetic ulcers.

Conclusion

We found an interesting finding that APS promoted the polarization of macrophages towards M2-type through the β-catenin/NF-κB axis to reduce excessive inflammation at the late phase of wound-healing. Therefore, APS may be a promising drug for treating diabetic ulcers in clinic.

R-spondin family biology and emerging linkages to cancer

The R-spondin protein family comprises four members (RSPO1-4), which are agonists of the canonical Wnt/β-catenin pathway. Emerging evidence revealed that RSPOs should not only be viewed as agonists of the Wnt/β-catenin pathway but also as regulators for tumor development and progression. Aberrant expression of RSPOs is related to tumorigenesis and tumor development in multiple cancers and their expression of RSPOs has also been correlated with anticancer immune cell signatures. More importantly, the role of RSPOs as potential target therapies and their implication in cancer progressions has been studied in the preclinical and clinical settings. These findings highlight the possible therapeutic value of RSPOs in cancer medicine. However, the expression pattern, effects, and mechanisms of RSPO proteins in cancer remain elusive. Investigating the many roles of RSPOs is likely to expand and improve our understanding of the oncogenic mechanisms mediated by RSPOs. Here, we reviewed the recent advances in the functions and underlying molecular mechanisms of RSPOs in tumor development, cancer microenvironment regulation, and immunity, and discussed the therapeutic potential of targeting RSPOs for cancer treatment. In addition, we also explored the biological feature and clinical relevance of RSPOs in cancer mutagenesis, transcriptional regulation, and immune correlation by bioinformatics analysis.KEY MESSAGESAberrant expressions of RSPOs are detected in various human malignancies and are always correlated with oncogenesis.Although extensive studies of RSPOs have been conducted, their precise molecular mechanism remains poorly understood.Bioinformatic analysis revealed that RSPOs may play a part in the development of the immune composition of the tumor microenvironment.

Endothelial cell-derived RSPO3 activates Gαi1/3-Erk signaling and protects neurons from ischemia/reperfusion injury

The current study explores the potential function and the underlying mechanisms of endothelial cell-derived R-spondin 3 (RSPO3) neuroprotection against ischemia/reperfusion-induced neuronal cell injury. In both neuronal cells (Neuro-2a) and primary murine cortical neurons, pretreatment with RSPO3 ameliorated oxygen and glucose deprivation (OGD)/re-oxygenation (OGD/R)-induced neuronal cell death and oxidative injury. In neurons RSPO3 activated the Akt, Erk and β-Catenin signaling cascade, but only Erk inhibitors reversed RSPO3-induced neuroprotection against OGD/R. In mouse embryonic fibroblasts (MEFs) and neuronal cells, RSPO3-induced LGR4-Gab1-Gαi1/3 association was required for Erk activation, and either silencing or knockout of Gαi1 and Gαi3 abolished RSPO3-induced neuroprotection. In mice, middle cerebral artery occlusion (MCAO) increased RSPO3 expression and Erk activation in ischemic penumbra brain tissues. Endothelial knockdown or knockout of RSPO3 inhibited Erk activation in the ischemic penumbra brain tissues and increased MCAO-induced cerebral ischemic injury in mice. Conversely, endothelial overexpression of RSPO3 ameliorated MCAO-induced cerebral ischemic injury. We conclude that RSPO3 activates Gαi1/3-Erk signaling to protect neuronal cells from ischemia/reperfusion injury.

Hypoxia blocks ferroptosis of hepatocellular carcinoma via suppression of METTL14 triggered YTHDF2-dependent silencing of SLC7A11

Residue hepatocellular carcinoma (HCC) cells enduring hypoxic environment triggered by interventional embolization obtain more malignant potential with little clarified mechanism. The N⁶ -methyladenosine (m⁶ A) biological activity plays essential roles in diverse physiological processes. However, its role under hypoxic condition remains largely unexplored. RT-qPCR and Western blot were used to evaluate METTL14 expression in hypoxic HCC cells. MDA assay and electronic microscopy photography were used to evaluate ferroptosis. The correlation between SLC7A11 and METTL14 was conducted by bioinformatical analysis. Flow cytometry was used to verify the effect of SLC7A11 on ROS production. Cell counting kit-8 assay was performed to detect cells proliferation ability. Hypoxia triggered suppression of METTL14 in a HIF-1α-dependent manner potently abrogated ferroptosis of HCC cells. Mechanistic investigation identified SLC7A11 was a direct target of METTL14. Both in vitro and in vivo assay demonstrated that METTL14 induced m⁶ A modification at 5'UTR of SLC7A11 mRNA, which in turn underwent degradation relied on the YTHDF2-dependent pathway. Importantly, ectopic expression of SLC7A11 strongly blocked METTL14-induced tumour-suppressive effect in hypoxic HCC. Our investigations lay the emphasis on the hypoxia-regulated ferroptosis in HCC cells and identify the HIF-1α /METTL14/YTHDF2/SLC7A11 axis as a potential therapeutic target for the HCC interventional embolization treatment.

α-Solanine Inhibits Proliferation, Invasion, and Migration, and Induces Apoptosis in Human Choriocarcinoma JEG-3 Cells In Vitro and In Vivo

α-Solanine, a bioactive compound mainly found in potato, exhibits anti-cancer activity towards multiple cancer cells. However, its effects on human choriocarcinoma have not been evaluated. In the present study, we investigated the effect of α-solanine on cell proliferation and apoptosis in human choriocarcinoma in vitro and in vivo. The results showed that α-solanine, at concentrations of 30 μM or below, did not affect the cell viability of the choriocarcinoma cell line JEG-3. However, colony formation was significantly decreased and cell apoptosis was increased in response to 30 μM α-solanine. In addition, α-solanine (30 μM) reduced the migration and invasion abilities of JEG-3 cells, which was associated with a downregulation of matrix metalloproteinases (MMP)-2/9. The in vivo findings provided further evidence of the inhibition of α-solanine on choriocarcinoma tumor growth. α-Solanine suppressed the xenograft tumor growth of JEG-3 cells, resulting in smaller tumor volumes and lower tumor weights. Apoptosis was promoted in xenograft tumors of α-solanine-treated mice. Moreover, α-solanine downregulated proliferative cellular nuclear antigen (PCNA) and Bcl-2 levels and promoted the expression of Bax. Collectively, α-solanine inhibits the growth, migration, and invasion of human JEG-3 choriocarcinoma cells, which may be associated with the induction of apoptosis.

α-Solanine Causes Cellular Dysfunction of Human Trophoblast Cells via Apoptosis and Autophagy

The trophoblast, an embryonic tissue, exerts a crucial role in the processes of implantation and placentation. Toxins in food can cause malfunction of trophoblasts, resulting in apoptosis, oxidative stress, and abnormal angiogenesis. α-solanine, a steroidal glycoalkaloid, has antitumor properties on several cancer cells. However, its effect on human trophoblasts has not been elucidated. In this study, human extravillous trophoblast HTR-8/SVneo cells were exposed to α-solanine. Cellular functions including proliferation, migration, invasion, tube formation, and apoptosis were assessed. To monitor autophagic flux, trophoblasts were transfected with a mCherry-GFP-LC3B vector using lentiviral transduction, and expression of autophagy-related biomarkers including Beclin 1, Atgl3, and microtubule-associated protein 1 light chain-3 (MAP1-LC3) were detected. The results show that application of 20 μM α-solanine or above inhibited the cell viability, migration, invasion, and tube formation of the human trophoblast. Cell cycle was arrested at S and G2/M phases in response to 30 μM α-solanine. α-solanine induced apoptosis of HTR-8/SVneo cells and triggered autophagy by increasing the autophagic gene expression and stimulating the formation of autophagosome and autophagic flux. In conclusion, α-solanine can impair the functions of human trophoblast cells via activation of cell apoptosis and autophagy.