HIF1A promotes miR-210/miR-424 transcription to modulate the angiogenesis in HUVECs and HDMECs via sFLT1 under hypoxic stress

Pectolinarigenin alleviates calcium oxalate-induced renal inflammation and oxidative stress by binding to HIF-1α

Calcium oxalate (CaOx) crystals are the main constituents of renal crystals in humans and induce tubular lumen damage in renal tubules, leading to renal calcium deposition and kidney stone formation. Oxidative stress and inflammation play important roles in regulating calcium oxalate-induced injury. Here, we evaluated the efficacy in inhibiting oxidation and inflammation of pectinolinarigenin, a biologically active natural metabolite, in CaOx nephrocalcinosis and further explored its targets of action. First, we developed cellular and mouse models of calcium oxalate renal nephrocalcinosis and identified the onset of oxidative stress and inflammation according to experimental data. We found that pectolinarigenin inhibited this onset while reducing renal crystal deposition. Network pharmacology was subsequently utilized to screen for hypoxia-inducible factor-1α (HIF-1α), a regulator involved in the body's release and over-oxidation of inflammatory factors. Finally, molecular docking, cellular thermal shift assay, and other experiments to detect HIF-1α expression showed that pectolinarigenin directly combined with HIF-1α and prevented downstream reactive oxygen species activation and release. Our results indicate that pectolinarigenin can target and inhibit HIF-1α-mediated inflammatory responses and oxidative stress damage and be a novel drug for CaOx nephrocalcinosis treatment.

Hypoxic microenvironment promotes diabetic wound healing by polarizing macrophages to the M2 phenotype in vivo

BACKGROUND

In diabetic wounds, M2 polarization of macrophages regulates the transition from an inflammatory phase to a proliferative phase. Prior investigations have demonstrated the potential of deferoxamine (DFO) in creating a localized hypoxic microenvironment, which could stimulate angiogenesis by promoting vascular endothelial growth factor (VEGF) secretion in diabetic wound healing. Nevertheless, there is still no clear information on whether this chemically induced hypoxic microenvironment modulates macrophage polarization to promote diabetic wound healing.

METHODS

The 18 diabetic mice were randomly divided into three groups: a control group (n = 6), a 100µM DFO group (n = 6), and a 200µM DFO group (n = 6). Subsequently, a full-thickness wound with a diameter of 1.00 cm was created on the dorsal region of the diabetic mice. Observe wound closure regularly during treatment. At the end of the observation, tissue specimens were collected for a series of experiments and analyses, including hematoxylin and eosin (H&E), Masson, immunofluorescent, and immunohistochemical staining. The role and mechanism of DFO in regulating macrophage polarization were studied using RAW264.7 cells.

RESULTS

In comparison to the control group, the administration of DFO notably facilitates wound healing in diabetic mice. In diabetic wounds, DFO increases blood supply by upregulating VEGF, which promotes angiogenesis. Additionally, The expression of HSP70 and CD206 were also upregulated by DFO in both vivo and in vitro, while iNOS expression was downregulated. Additionally, knk437 inhibited the expression of HSP70 in RAW264.7 cells, resulting in a reduction of M2 polarization and an increase in M1 polarization.

CONCLUSION

The induction of a hypoxic microenvironment by DFO has been found to exert a substantial influence on the process of diabetic wound healing. DFO treatment enhances the capacity of diabetic wounds to stimulate angiogenesis and modulate macrophage polarization that may be associated with HSP70 expression, thereby expediting the transition of these wounds from an inflammatory to a proliferative state.

The long non-coding RPPH1 is decreased in leukocytes and increased in plasma from women developing pre-eclampsia†

Previous studies show differentially expressed long non-coding RNA present in the placenta from women with pre-eclampsia, potentially playing a vital role in the pathogenesis of the complication. In a published microarray study, Ribonuclease P RNA component H1 was decreased in leukocytes from women that later developed pre-eclampsia. We hypothesized that Ribonuclease P RNA component H1 decreased during pregnancy in women developing pre-eclampsia and important for the development of the complication. We isolated RNA from extracellular vesicles, leukocytes and plasma using blood samples taken at weeks 22-24 and 36-38 in women who subsequently developed pre-eclampsia and from healthy pregnancy. The expression of Ribonuclease P RNA component H1 was quantified using qPCR. Expression of Ribonuclease P RNA component H1 at 22-24 weeks was further examined to investigate its discriminatory potential of subsequent pre-eclampsia and association with clinical markers. We found lower expression of Ribonuclease P RNA component H1 in leukocytes at 22-24 and 36-38 weeks amongst women who subsequent developed pre-eclampsia compared with those who did not, while increased Ribonuclease P RNA component H1 expression was found in plasma at 36-38 weeks. Pre-eclampsia risk factors could not account for this difference in the Ribonuclease P RNA component H1 expression. Prediction of pre-eclampsia at 22-24 weeks using Ribonuclease P RNA component H1 expression in leukocytes in addition to the screening algorithm used today had a significantly better performance. In conclusion, Ribonuclease P RNA component H1 expression in leukocytes was significantly decreased in women with pre-eclampsia, and the expression at 22-24 weeks associated with the subsequent development of pre-eclampsia. Ribonuclease P RNA component H1 in leukocytes may be a useful biomarker for prediction and/or early detection of pre-eclampsia and an unknown regulator of the signaling affecting immune cells.

Mono-(2-ethylhexyl) phthalate induces trophoblast hypoxia and mitochondrial dysfunction through HIF-1α-miR-210-3p axis in HTR-8/SVneo cell line

The exposure to the ubiquitous phthalate metabolite mono-(2-ethylhexyl) phthalate (MEHP) is connected to dysregulated trophoblast function and placenta health; however, the underlying mechanisms preluding this scenario remain to be elucidated. In this study, we explored the hypoxemic effects of MEHP on a human placental first-trimester trophoblast cell line (HTR-8/Svneo). MEHP-treated trophoblast cells displayed significantly increased levels of oxidative stress and hypoxia-inducible factor-1 alpha (HIF-1α) attributed by the induction of hypoxia. Further, HIF-1α exhibited higher DNA binding activity and upregulated gene expression of its downstream target vascular endothelial growth factor A (VEGFA). The hypoxia-induced microRNA miR-210-3p was also significantly increased upon MEHP treatment followed by disrupted mitochondrial ATP generation and membrane potential. This was identified to possibly be facilitated by lowered mitochondrial DNA copy number and inhibited expression of electron transport chain subunits, such as mitochondrial complex-IV. These results suggest potential adverse effects of MEHP exposure in a trophoblast cell line mediated by HIF-1α and the epigenetic modulator miR-210-3p. Chronic placental hypoxia and oxidative stress have long been implicated in the pathogenesis of pregnancy complications such as preeclampsia. As we've revealed genetic and epigenetic factors underscoring a potential mechanism induced by MEHP, this brings to light another significant implication of phthalate exposure on maternal and fetal health.

Targeting hypoxia signaling pathways in angiogenesis

Oxygen (O2) supply is constantly maintained by the vascular network for a proper tissue oxygenation. Hypoxia is the result of an increased O2 demand and/or decreased supply and is common in both physiological conditions and human diseases. Angiogenesis is one of the adaptive responses to hypoxia and is mainly regulated by the hypoxia-inducible factors, HIFs. These heterodimeric transcription factors are composed of one of three O2-dependent α subunits (HIF-1, HIF-2, and HIF-3) and a constitutively expressed O2-insensitive subunit (HIF-1β). Among them HIF-1α is the most characterized and its activity is tightly controlled. Under hypoxia, its intracellular accumulation triggers the transcription of several genes, involved in cell survival/proliferation, autophagy, apoptosis, cell metabolism, and angiogenesis. HIF pathway is also modulated by specific microRNAs (miRNAs), thus resulting in the variation of several cellular responses, including alteration of the angiogenic process. The pro-angiogenic activity of HIF-1α is not restricted to endothelial cells, as it also affects the behavior of other cell types, including tumor and inflammatory/immune cells. In this context, exosomes play a crucial role in cell-cell communication by transferring bio-active cargos such as mRNAs, miRNAs, and proteins (e.g., VEGFA mRNA, miR210, HIF-1α). This minireview will provide a synopsis of the multiple factors able to modulate hypoxia-induced angiogenesis especially in the tumor microenvironment context. Targeting hypoxia signaling pathways by up-to-date approaches may be relevant in the design of therapeutic strategies in those pathologies where angiogenesis is dysregulated.

A Combined Treatment of BMP2 and Soluble VEGFR1 for the Enhancement of Tendon-Bone Healing by Regulating Injury-Activated Skeletal Stem Cell Lineage

BACKGROUND

Bone morphogenetic protein 2 (BMP2) is an appealing osteogenic and chondrogenic growth factor for promoting tendon-bone healing. Recently, it has been reported that soluble vascular endothelial growth factor (VEGF) receptor 1 (sVEGFR1) (a VEGF receptor antagonist) could enhance BMP2-induced bone repair and cartilage regeneration; thus, their combined application may represent a promising treatment to improve tendon-bone healing. Moreover, BMP2 could stimulate skeletal stem cell (SSC) expansion and formation, which is responsible for wounded tendon-bone interface repair. However, whether the codelivery of BMP2 and sVEGFR1 increases tendon enthesis injury-activated SSCs better than does BMP2 alone needs further research.

PURPOSE

To study the effect of BMP2 combined with sVEGFR1 on tendon-bone healing and injury-activated SSC lineage.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 128 C57BL/6 mice that underwent unilateral supraspinatus tendon detachment and repair were randomly assigned to 4 groups: (1) untreated control group; (2) hydrogel group, which received a local injection of the blank hydrogel at the injured site; (3) BMP2 group, which received an injection of hydrogel with BMP2; and (4) BMP2 with sVEGFR1 group, which received an injection of hydrogel with BMP2 and sVEGFR1. Histology, micro-computed tomography, and biomechanical tests were conducted to evaluate tendon-bone healing at 4 and 8 weeks after surgery. In addition, flow cytometry was performed to detect the proportion of SSCs and their downstream differentiated subtypes, including bone, cartilage, and stromal progenitors; osteoprogenitors; and pro-chondrogenic progenitors within supraspinatus tendon enthesis at 1 week postoperatively.

RESULTS

The repaired interface in BMP2 with sVEGFR1 group showed a significantly improved collagen fiber continuity, increased fibrocartilage, greater newly formed bone, and elevated mechanical properties compared with the other 3 groups. There were more SSCs; bone, cartilage, and stromal progenitors; osteoprogenitors; and pro-chondrogenic progenitors in the BMP2 with sVEGFR1 group than that in the other groups.

CONCLUSION

Our study suggests that the combined delivery of BMP2 and sVEGFR1 could promote tendon-bone healing and stimulate the expansion of SSCs and their downstream progeny within the injured tendon-bone interface.

CLINICAL RELEVANCE

Combining BMP2 with sVEGFR1 may be a good clinical treatment for wounded tendon enthesis healing.

Sirtuin4 alleviates severe acute pancreatitis by regulating HIF-1α/HO-1 mediated ferroptosis

Acute pancreatitis (AP) is a common emergency of the digestive system and serious cases can develop into severe acute pancreatitis (SAP), which ortality rates up to 30%. Sirtuin4 (SIRT4) is a member of the sirtuin family, and plays a key role in inflammation and oxidative stress. However, the potential role of SIRT4 in SAP has yet to be elucidated. In the present study, we found that the expression level of SIRT4 in human AP was downregulated by screening a public database, suggesting that SIRT4 may play a role in AP. Subsequently, we used L-arginine (L-Arg) to induce SAP in SIRT4 knockout (SIRT4_KO) and SIRT4 overexpression (AAV_SIRT4) mice. The results showed that the pancreatic tissue injury and related lung and kidney injury were serious in SIRT4_KO mice after SAP induction, but were significantly reduced in AAV_SIRT4 mice. More importantly, we found that the levels of antioxidant factors GSH and SOD were decreased in SIRT4_KO mice, and the production of oxidative products and lipid peroxidation markers was increased, suggesting that SIRT4 was involved in inflammation and oxidative stress during SAP. Further studies showed that the absence or overexpression of SIRT4 affected the expression level of Hypoxia-inducible factor-1α (HIF-1α) after SAP induction, and regulated the expression of ferroptosis related proteins by mediating HIF-1α/HO-1 pathway. Collectively, our study revealed that SIRT4 plays a protective role in SAP by regulating the HIF-1α/HO-1 pathway to inhibit ferroptosis.

The HIFIA/LINC02913/IGF1R axis promotes the cell function of adipose-derived mesenchymal stem cells under hypoxia via activating the PI3K/AKT pathway

OBJECTIVE

Promoting angiogenesis is crucial for tissue repair. Adipose-derived mesenchymal stem cells (ADSCs) are endowed with the ability of paracrine secretion of various angiogenic cytokines and the differentiation potential into endothelium-like cells to directly participate in angiogenesis. ADSCs are key seed cells for promoting angiogenesis in regenerative medicine and tissue engineering. This study aimed to explore the role and mechanism of C9orf106 (LINC02913) in the angiogenesis of ADSCs.

METHODS

The microarray dataset GSE12884 was analyzed to identify the differentially expressed lncRNAs in ADSCs under normoxia and hypoxia. The expression of the key genes was detected using qRT-PCR, western blot assay (western blot), and immunofluorescence (IF) staining. The adipogenic ability and tube formation ability of ADSCs was detected using oil red O staining and tube formation assay, respectively. The regulatory relationship between hypoxia-inducible factor-1alpha (HIF1A) and LINC02913 was verified using chromatin immunoprecipitation (ChIP) assay and dual-luciferase reporter gene assay. A skin wound healing nude mice model was established. Hematoxylin and eosin (H&E) staining was applied to detect pathological skin damage. Immunohistochemistry (IHC) staining was used to determine the level of CD31 in skin tissues.

RESULTS

LINC02913 expression was decreased in ADSCs under hypoxia; LINC02913 overexpression inhibited the proliferation, adipogenic ability, endothelial differentiation ability, and tube formation ability of ADSCs. ChIP assay and dual-luciferase reporter gene assay results showed that HIF1A could directly bind to the LINC02913 promoter region to inhibit its transcription. Through RNAact prediction and analysis of the correlation with LINC02913 expression, it was found that IGF1R may directly interact with LINCO02913. The HIF1A/LINC02913/IGF1R axis could activate the PI3K/AKT pathway to promote the biological function of ADSCs. Hypoxia-ADSCs significantly promoted vascularization in the wounded skin. The regulatory effect of LINC02913/IGF1R axis on hypoxia-ADSCs treated skin wound healing were verified.

CONCLUSION

The HIF1A/LINC02913/IGF1R axis promoted the proliferation, adipogenic ability, and tube formation ability of ADSCs under hypoxia via activating the PI3K/AKT pathway.

Bioinformatic analysis and clinical diagnostic value of hsa_circ_0004099 in acute ischemic stroke

This study investigates the expression and effect of hsa_circ_0004099 in acute ischemic stroke (AIS). We conducted a case-controlled study that included 40 patients with AIS within 24 hours and 40 healthy subjects during the same period as a control group. Differentially expressed circular RNAs (circRNAs) were obtained using GEO2R, and the expression of hsa_circ_0004099 was verified using RT-PCR. Correlation analysis of the National Institutes of Health Stroke Scale (NIHSS) disease severity score and ischemic time with hsa_circ_0004099 expression levels was also performed. The receiver operating characteristic (ROC) curve of hsa_circ_0004099 was constructed, and bioinformatic analysis of hsa_circ_0004099 was performed. NIHSS scores negatively correlated with hsa_circ_0004099 levels (P<0.001, r = -0.7053), whereas infarct time was negatively correlated with hsa_circ_0004099 levels (P<0.001, r = -0.5130); hsa_circ_0004099 could benefit clinical diagnosis (area under the curve [AUC]: 0.923 [95% confidence interval [CI]: 0.8680-0.9904]). Kyoto encyclopedia of genes and genomes (KEGG) analysis showed that hsa_circ_0004099 was enriched in several cancer pathways, which were collectively enriched in four genes namely TCF7L2, NRAS, CTNNB1, and KRAS. Eight core proteins were screened using a protein-protein interaction (PPI) network namely SMAD4, HIF1A, CTNNB1, CDKN1B, CDK6, FOXO3, KRAS, and NRAS. hsa_circ_0004099 is a potential clinical diagnostic marker. In addition, the possible role of hsa_circ_0004099 in the pathogenesis of AIS was analyzed using bioinformatics, which provided a new potential molecular target for AIS treatment.

Expression patterns of serum MicroRNAs related to endothelial dysfunction in patients with subclinical hypothyroidism

BACKGROUND

Increasing evidence has shown that elevated Thyroid stimulating hormone (TSH) levels are positively correlated with atherosclerosis (ATH) in patients with subclinical hypothyroidism (SCH). Some researchers found that the dysfunction of Endothelial Cells (ECs) in SCH plays an important role in the pathogenesis of ATH in SCH, but the association remains controversial.

OBJECTIVES

To determine the expression profiles of serum microRNAs critical to the function of Endothelial cells (ECs) may help reanalyze the possible mechanism underlying ATH in SCH and the association between ATH and SCH.

METHODS

We used qRT-PCR to perform microRNA profiling and analysis in normal control subjects (NC), patients with SCH alone (SCH), patients with SCH and ATH (SCH+ATH), and patients with ATH without SCH (ATH).

RESULTS

Both miR-221-3p and miR-222-3p showed a decreasing expression trend between the SCH and SCH+ATH groups. In addition, miR-126-3p and miR-150-5p showed a stepwise decrease from the NC to SCH groups and then to the SCH+ATH or ATH group. miR-21-5p was unregulated in the SCH, SCH+ATH, and ATH groups. Furthermore, elevated levels of miR-21-5p in SCH+ATH group were higher than SCH and ATH group. No differences were found in the levels of miR-150, miR-126, miR-221 and miR-222 between the ATH and the SCH+ATH subjects.

CONCLUSIONS

miR-21-5p may be involved in the atherosclerosis process in patients with SCH (SCH and SCH+ATH groups). miR-150-5p may be sensitive risk markers for predicting endothelial dysfunction in patients with ATH (ATH and SCH+ATH groups).