microRNA-126 inhibits tube formation of HUVECs by interacting with EGFL7 and down-regulating PI3K/AKT signaling pathway

Comparative transcriptomic analysis of circulating endothelial cells in sickle cell stroke

Ischemic stroke (IS) is one of the most impairing complications of sickle cell anemia (SCA), responsible for 20% of mortality in patients. Rheological alterations, adhesive properties of sickle reticulocytes, leukocyte adhesion, inflammation and endothelial dysfunction are related to the vasculopathy observed prior to ischemic events. The role of the vascular endothelium in this complex cascade of mechanisms is emphasized, as well as in the process of ischemia-induced repair and neovascularization. The aim of the present study was to perform a comparative transcriptomic analysis of endothelial colony-forming cells (ECFCs) from SCA patients with and without IS. Next, to gain further insights of the biological relevance of differentially expressed genes (DEGs), functional enrichment analysis, protein-protein interaction network (PPI) construction and in silico prediction of regulatory factors were performed. Among the 2469 DEGs, genes related to cell proliferation (AKT1, E2F1, CDCA5, EGFL7), migration (AKT1, HRAS), angiogenesis (AKT1, EGFL7) and defense response pathways (HRAS, IRF3, TGFB1), important endothelial cell molecular mechanisms in post ischemia repair were identified. Despite the severity of IS in SCA, widely accepted molecular targets are still lacking, especially related to stroke outcome. The comparative analysis of the gene expression profile of ECFCs from IS patients versus controls seems to indicate that there is a persistent angiogenic process even after a long time this complication has occurred. Thus, this is an original study which may lead to new insights into the molecular basis of SCA stroke and contribute to a better understanding of the role of endothelial cells in stroke recovery.

Astragaloside IV promotes exosome secretion of endothelial progenitor cells to regulate PI3KR2/SPRED1 signaling and inhibit pyroptosis of diabetic endothelial cells

BACKGROUND AIMS

Treating chronic non-healing diabetic wounds and achieving complete skin regeneration has always been a critical clinical challenge.

METHODS

In order to address this issue, researchers conducted a study aiming to investigate the role of miR-126-3p in regulating the downstream gene PIK3R2 and promoting diabetic wound repair in endothelial progenitor cell (EPC)-derived extracellular vesicles. The study involved culturing EPCs with astragaloside IV, transfecting them with miR-126-3p inhibitor or mock plasmid, interfering with high glucose-induced damage in human umbilical vein endothelial cells (HUVECs) and treating diabetic skin wounds in rats.

RESULTS

The healing of rat skin wounds was observed through histological staining. The results revealed that treatment with miR-126-3p-overexpressing EPC-derived extracellular vesicles accelerated the healing of rat skin wounds and resulted in better tissue repair with slower scar formation. In addition, the transfer of EPC-derived extracellular vesicles with high expression of miR-126-3p to high glucose-damaged HUVECs increased their proliferation and invasion, reduced necrotic and apoptotic cell numbers and improved tube formation. In this process, the expression of angiogenic factors vascular endothelial growth factor (VEGF)A, VEGFB, VEGFC, basic fibroblast growth factor and Ang-1 significantly increased, whereas the expression of caspase-1, NRLP3, interleukin-1β, inteleukin-18, PIK3R2 and SPRED1 was suppressed. Furthermore, miR-126-3p was able to target and inhibit the expression of the PIK3R2 gene, thereby restoring the proliferation and migration ability of high glucose-damaged HUVEC.

CONCLUSIONS

In summary, these research findings demonstrate the important role of miR-126-3p in regulating downstream genes and promoting diabetic wound repair, providing a new approach for treating chronic non-healing diabetic wounds.

Role of regulatory non-coding RNAs in traumatic brain injury

Traumatic brain injury (TBI) is a potentially fatal health event that cannot be predicted in advance. After TBI occurs, it can have enduring consequences within both familial and social spheres. Yet, despite extensive efforts to improve medical interventions and tailor healthcare services, TBI still remains a major contributor to global disability and mortality rates. The prompt and accurate diagnosis of TBI in clinical contexts, coupled with the implementation of effective therapeutic strategies, remains an arduous challenge. However, a deeper understanding of changes in gene expression and the underlying molecular regulatory processes may alleviate this pressing issue. In recent years, the study of regulatory non-coding RNAs (ncRNAs), a diverse class of RNA molecules with regulatory functions, has been a potential game changer in TBI research. Notably, the identification of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and other ncRNAs has revealed their potential as novel diagnostic biomarkers and therapeutic targets for TBI, owing to their ability to regulate the expression of numerous genes. In this review, we seek to provide a comprehensive overview of the functions of regulatory ncRNAs in TBI. We also summarize regulatory ncRNAs used for treatment in animal models, as well as miRNAs, lncRNAs, and circRNAs that served as biomarkers for TBI diagnosis and prognosis. Finally, we discuss future challenges and prospects in diagnosing and treating TBI patients in the clinical settings.

Tetramethylpyrazine promotes angiogenesis and nerve regeneration and nerve defect repair in rats with spinal cord injury

Objective

This study evaluated the regulatory effect of Tetramethylpyrazine (TMP) on the spinal cord injury (SCI) rat model and clarified the neuroprotective mechanism of TMP on SCI.

Methods

An SCI rat model was generated and treated with TMP injections for two weeks. miR-497-5p and EGFL7 expression changes were evaluated, motor function recovery after SCI was assessed by BBB score test and footprint analysis, lesions of rat spinal cord were assessed by HE staining and TUNEL staining; angiogenesis was assessed by immunoblotting for CD31; inflammatory factor levels were detected by ELISA. EGFL7 was verified as a target of miR-497-5p by bioinformatics website analysis and luciferase reporter gene assay. H2O2-injured neurons were cultured in vitro to explore the effect of TMP.

Results

After SCI, miR-497-5p was upregulated while EGFL7 was downregulated in rats. TMP inhibited apoptosis and promoted angiogenesis, nerve regeneration, and repair of nerve defects by reducing miR-497-5p and increasing EGFL7 expression. miR-497-5p targeted EGFL7. In addition, TMP hindered neuronal inflammation and apoptosis induced by H2O2in vitro.

Conclusion

TMP promotes angiogenesis by downregulating miR-497-5p to target EGFL7, and promotes nerve regeneration and repair of nerve defects in rats with SCI.

LncRNA HOTAIR regulates the PI3K/AKT pathway via the miR-126-3p/PIK3R2 axis to participate in synovial angiogenesis in rheumatoid arthritis

BACKGROUND

The abnormal expression of long noncoding RNA (LncRNA) HOTAIR has been associated with synovial angiogenesis in rheumatoid arthritis (RA). The aim of this study is to investigate whether LncRNA HOTAIR plays a role in synovial angiogenesis in RA by regulating the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway through the miR-126-3p/PIK3R2 axis.

METHODS

In this study, we conducted in vitro experiments by designing overexpression plasmids and small interfering RNAs targeting LncRNA HOTAIR and then transfected them into rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS). We then co-cultured the RA-FLS with human umbilical vein endothelial cells (HUVEC) to establish a RA-FLS-induced HUVEC model. We investigated the effects of LncRNA HOTAIR on the proliferation, migration, lumen forming ability of HUVEC, as well as the expression of synovial endothelial cell markers, angiogenic factors, and the PI3K/AKT pathway. To validate the interactions between LncRNA HOTAIR, miR-126-3p, and PIK3R2, we used bioinformatics and luciferase reporter experiments. We also employed real-time fluorescence quantitative, Western blotanalysis, and immunofluorescence techniques to analyze the target genes and proteins.

RESULTS

The expression of LncRNA HOTAIR was upregulated in HUVEC induced by RA-FLS. The overexpression of LncRNA HOTAIR significantly increased the expression of vascular endothelial growth factor, basic fibroblast growth factor, CD34, and CD105 in HUVEC, promoting their proliferation, migration, and lumen formation. At the same time, the overexpression of LncRNA HOTAIR inhibited the expression of miR-126-3p, promoted the expression of PIK3R2, activated the PI3K/AKT pathway, and promoted the expression of PI3K, AKT and phosphorylated-AKT, while the silence of LncRNA HOTAIR reversed these expressions. Bioinformatics and double luciferase reporter gene experiments confirmed the targeting relationship among LncRNA HOTAIR, miR-126-3p, and PIK3R2. Finally, the rescue experiments showed that PI3K agonists could reverse the inhibitory effect of silent LncRNA HOTAIR on HUVEC.

CONCLUSION

LncRNA HOTAIR has the potential to activate the PI3K/AKT pathway, likely through the regulatory axis involving miR-126-3p/PIK3R2, consequently contributing to synovial angiogenesis in RA.

The emerging role of microRNA-126 as a potential therapeutic target in cancer: a comprehensive review

MicroRNA-126 (miR-126) has become a key player in the biology of cancer, playing a variety of functions in carcinogenesis and cancer development. The diagnostic and prognostic potential of miR-126 in diverse cancer types is summarized in this thorough analysis, with an emphasis on its role in tumor angiogenesis, invasion, metastasis, cell proliferation, apoptosis, and treatment resistance. MiR-126 dysregulation is linked to a higher risk of developing cancer and a worse prognosis. Notably, miR-126 affects tumor vascularization and development by targeting vascular endothelial growth factor-A (VEGF-A). Through its impact on genes involved in cell adhesion and migration, it also plays a vital part in cancer cell invasion and metastasis. Additionally, miR-126 controls drug resistance, apoptosis, and cell proliferation, which affects cancer cell survival and treatment response. It may be possible to develop innovative therapeutic approaches to stop tumor angiogenesis, invasion, and metastasis, as well as combat drug resistance by focusing on miR-126 or its downstream effectors. The versatility of miR-126's functions highlights the role that it plays in cancer biology. To understand the processes behind miR-126 dysregulation, pinpoint precise targets, and create efficient therapies, more investigation is required. Utilizing miR-126's therapeutic potential might have a significant influence on cancer treatment plans and patient outcomes.

Role of EGFL7 in human cancers: A review

EGFL7 is a proangiogenic factor. It has been widely described with having a vital role in tubulogenesis and regulation of angiogenesis, mainly during embryogenesis and organogenesis. It has been mainly associated with NOTCH pathway, but there are reports showing association with MAPK and integrin pathways. Given its association with angiogenesis and these other pathways, there are several studies associating EGFL7 with carcinogenesis. In fact, most of the studies have pointed to EGFL7 as an oncogene, and some of them suggest EGFL7 expression as a possible biomarker of prognosis or use for a patient's follow-up. Here, we review the molecular pathways which EGFL7 is associated and highlight several studies describing the role of EGFL7 in tumorigenesis, separated by tumor type. Besides its role on angiogenesis, EGFL7 may act in other pathways as oncogene, which makes it a possible biomarker and a candidate to targeted therapy.

Emerging effects of non-coding RNA in vascular endothelial cells during strokes

Vascular and neurological damage are the typical outcomes of ischemic strokes. Vascular endothelial cells (VECs), a substantial component of the blood-brain barrier (BBB), are necessary for normal cerebrovascular physiology. During an ischemic stroke (IS), changes in the brain endothelium can lead to a BBB rupture, inflammation, and vasogenic brain edema, and VECs are essential for neurotrophic effects and angiogenesis. Non-coding RNAs (nc-RNAs) are endogenous molecules, and brain ischemia quickly changes the expression patterns of several non-coding RNA types, such as microRNA (miRNA/miR), long non-coding RNA (lncRNA), and circular RNA (circRNA). Furthermore, vascular endothelium-associated nc-RNAs are important mediators in the maintenance of healthy cerebrovascular function. In order to better understand how VECs are regulated epigenetically during an IS, in this review, we attempted to assemble the molecular functions of nc-RNAs that are linked with VECs during an IS.

Non-coding RNAs and Exosomal Non-coding RNAs in Traumatic Brain Injury: the Small Player with Big Actions

Nowadays, there is an increasing concern regarding traumatic brain injury (TBI) worldwide since substantial morbidity is observed after it, and the long-term consequences that are not yet fully recognized. A number of cellular pathways related to the secondary injury in brain have been identified, including free radical production (owing to mitochondrial dysfunction), excitotoxicity (regulated by excitatory neurotransmitters), apoptosis, and neuroinflammatory responses (as a result of activation of the immune system and central nervous system). In this context, non-coding RNAs (ncRNAs) maintain a fundamental contribution to post-transcriptional regulation. It has been shown that mammalian brains express high levels of ncRNAs that are involved in several brain physiological processes. Furthermore, altered levels of ncRNA expression have been found in those with traumatic as well non-traumatic brain injuries. The current review highlights the primary molecular mechanisms participated in TBI that describes the latest and novel results about changes and role of ncRNAs in TBI in both clinical and experimental research.

Vitamin B2 Prevents Glucocorticoid-Caused Damage of Blood Vessels in Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a disorder that can cause collapse of the femoral head. The damage and dysfunction of femoral head microvascular endothelial cells are related to the pathogenesis of glucocorticoid-induced ONFH. Reports suggest that vitamin B₂ can promote osteoblast differentiation and prevent low bone mineral density and prevent reperfusion oxidative injury. To explore the effect and possible molecular mechanism of vitamin B₂ on the ONFH and Human Umbilical Vein Endothelial Cells (HUVECs), we performed a rat model of ONFH by dexamethasone. The rats were randomly divided into four groups: control group, vitamin B₂ group, dexamethasone group, and dexamethasone combined with vitamin B₂ treatment group. HUVECs were used to further prove the role and mechanism of vitamin B₂ in vitro. In patients, according to immunohistochemical and qRT-PCR of the femoral head, the angiogenic capacity of the ONFH femoral head is compromised. In vivo, it showed that vitamin B₂ could inhibit glucocorticoid-induced ONFH-like changes in rats by suppressing cell apoptosis, promoting the regeneration of blood vessels, and increasing bone mass. According to in vitro results, vitamin B₂ could induce the migration of HUVECs, enhance the expression of angiogenesis-related factors, and inhibit glucocorticoid-induced apoptosis. The underlying mechanism may be that vitamin B₂ activates the PI3K signaling pathway. Vitamin B₂ alleviated dexamethasone-induced ONFH, and vitamin B₂ could promote the proliferation and migration of HUVECs and inhibit their apoptosis by activating the PI3K/Akt signaling pathway. Vitamin B₂ may be a potentially effective treatment for ONFH.

Tetrahedral Framework Nucleic Acids Connected with MicroRNA-126 Mimics for Applications in Vascular Inflammation, Remodeling, and Homeostasis

The repair of damaged endothelium is crucial for vascular homeostasis maintenance, which comprises the recovery of early stage impaired endothelial cells and migration of surrounding unimpaired endothelial cells. MicroRNAs (miRNAs) play an indispensable role in balancing gene expression in organisms. For vascular tissues, miR-126 is one of the most important regulators and might have substantial application potential in maintaining vascular homeostasis. In this study, a type of sticky-end-modified tetrahedral framework nucleic acids (tFNAs-SE) was employed to successfully link the miR-126 5p mimic duplex, which was termed tFNAs-miR-126 5p mimics (tFNAs-MMs). Existing vascular endothelial growth factors (VEGF), tFNAs-MMs can improve cell viability, resist apoptosis, and recover the state and functions of LPS-induced impaired human umbilical vein endothelial cells (HUVECs). The angiogenesis ability of impaired HUVECs was recovered by tFNAs-MMs in vitro and in vivo. The mechanisms underlying these phenomena were demonstrated to be related to the downregulation of caspase3 and negative regulators of VEGF (SPRED1 and PIK3R2). Moreover, tFNAs-MMs promoted the migration and proliferation of HUVECs. Briefly, the strategy of sticky-end-modified tFNAs connecting miRNA mimics is available for miRNA gain of function, while tFNAs-MMs might be a promising agent for repairing early stage vascular damage and maintaining vascular homeostasis.

Protective role of wogonin following traumatic brain injury by reducing oxidative stress and apoptosis via the PI3K/Nrf2/HO‑1 pathway

Traumatic brain injury (TBI) is usually caused by accidental injuries and traffic accidents, with a very high mortality rate. Treatment and management following TBI are essential to reduce patient injury and help improve long‑term prognosis. Wogonin is a flavonoid compound with an antioxidant effect extracted from Scutellaria baicalensis Georgi. However, the function and mechanism of wogonin in protecting brain injury remain to be elucidated. The present study established a TBI model of Sprague‑Dawley rats and treated them with wogonin following trauma. The results showed that wogonin treatment significantly reduced neurobehavioral disorders, brain edema and hippocampal neuron damage caused by TBI. It was found that in TBI rats, administration of wogonin increased the levels of antioxidant factors glutathione, superoxide dismutase and catalase in the CA1 region of the hippocampus and significantly inhibited the production of malondialdehyde and reactive oxygen species. western blotting data showed that wogonin exerted antioxidant activity by downregulating the level of NOX² protein. In inhibiting cell apoptosis, wogonin upregulated the expression of Bcl‑2 protein in the hippocampal CA1 region of TBI rats and inhibited caspase‑3 and Bax proteins. Additionally, wogonin inhibited the progression of injury following TBI through the PI3K/Akt/nuclear factor‑erythroid factor 2‑related factor 2 (Nrf2)/heme oxygenase‑1 (HO‑1) signaling pathway. Wogonin increased the expression of phosphorylated Akt, Nrf2 and HO‑1 in the hippocampus of TBI rats. Following the administration of PI3K inhibitor LY294002, the upregulation of these proteins by wogonin was partly reversed. In addition, LY294002 partially reversed the regulation of wogonin on NOX², caspase‑3, Bax and Bcl‑2 proteins. Therefore, wogonin exerts antioxidant and anti‑apoptotic properties to prevent hippocampal damage following TBI, which is accomplished through the PI3K/Akt/Nrf2/HO‑1 pathway.

BAY61‑3606 attenuates neuroinflammation and neurofunctional damage by inhibiting microglial Mincle/Syk signaling response after traumatic brain injury

Neuroinflammatory processes mediated by microglial activation and subsequent neuronal damage are the hallmarks of traumatic brain injury (TBI). As an inhibitor of the macrophage‑inducible C‑type lectin (Mincle)/spleen tyrosine kinase (Syk) signaling pathway, BAY61‑3606 (BAY) has previously demonstrated anti‑inflammatory effects on some pathological processes, such as acute kidney injury, by suppressing the inflammatory macrophage response. In the present study, the potential effects of BAY on microglial phenotype and neuroinflammation after TBI were investigated. BAY (3 mg/kg) was first administered into mice by intraperitoneal injection after TBI induction in vivo and microglia were also treated with BAY (2 µM) in vitro. The levels of inflammatory factors in microglia were assessed using reverse transcription‑quantitative PCR and ELISA. Cortical neuron, myelin sheath, astrocyte and cerebrovascular endothelial cell markers were detected using immunofluorescence. The levels of components of the Mincle/Syk/NF‑κB signaling pathway [Mincle, phosphorylated (p)‑Syk and NF‑κB], in addition to proteins associated with inflammation (ASC, caspase‑1, TNF‑α, IL‑1β and IL‑6), apoptosis (Bax and Bim) and tight junctions (Claudin‑5), were measured via western blotting and ELISA. Migration and chemotaxis of microglial cells were evaluated using Transwell and agarose spot assays. Neurological functions of the mice were determined in vivo using the modified neurological severity scoring system and a Morris water maze. The results of the present study revealed that the expression levels of proteins in the Mincle/Syk/NF‑κB signaling pathway (including Mincle, p‑Syk and p‑NF‑κB), inflammatory cytokines (TNF‑α, IL‑1β and IL‑6), proteins involved in inflammation (ASC and caspase‑1), apoptotic markers (Bax and Bim) and the tight junction protein Claudin‑5 were significantly altered post‑TBI. BAY treatment reversed these effects in both the cerebral cortex extract‑induced cell model and the controlled cortical impact mouse model. BAY was also revealed to suppress activation of the microglial proinflammatory phenotype and microglial migration. In addition, BAY effectively attenuated TBI‑induced neurovascular unit damage and neurological function deficits. Taken together, these findings provided evidence that BAY may inhibit the Mincle/Syk/NF‑κB signaling pathway in microglia; this in turn could attenuate microglia‑mediated neuroinflammation and improve neurological deficits following TBI.

EGFL7 as a novel therapeutic candidate regulates cell invasion and anoikis in colorectal cancer through PI3K/AKT signaling pathway

BACKGROUND

Anoikis is a form of apoptosis, which inhibits metastatic cascade and deprives cancer cells with invasive capacity. Epidermal growth factor-like domain-containing protein 7 (EGFL7) is overexpressed in colorectal cancer (CRC) and is a potential biomarker for malignancy. The present study aimed was to investigate the effect and underlying mechanism of EGFL7 on CRC cell function.

METHODS

EGFL7 expression in mutable human CRC cell lines and normal intestinal epithelial cell line HIEC were measured by qRT-PCR. To investigate the biological functions of EGFL7, loss-of-function experiments were performed by transfecting EGFL7 siRNA into SW620 and LoVo cells. Western blot analysis, MTT, invasion and anoikis assay were used to explore the underlying mechanism of EGFL7.

RESULTS

EGFL7 was upregulated in several CRC cell lines as compared with normal intestinal epithelial cell line HIEC. Transfection of EGFL7 siRNA significantly decreased cell proliferation and invasion capacity of SW620 and LoVo cells. Additionally, EGFL7 inhibition markedly elevated anoikis through modulating anoikis marker proteins as reflected by increasing of cleaved-caspase-3 and cleaved-PAPR expression. Moreover, downregulation of EGFL7 inhibited PI3K and P-AKT expression. Furthermore, re-expression of PI3K remarkably reversed the effects of EGFL7 on SW620 cells.

CONCLUSION

Overall, our findings suggested that EGFL7 acts as an oncogene, regulated CRC invasion and anoikis through PI3K/AKT signaling, which provided a theoretical basis for EGFL7 as a potential therapeutic target of CRC treatment.

Meriolin1 induces cell cycle arrest, apoptosis, autophagy and targeting the Akt/MAPKs pathways in human neuroblastoma SH-SY5Y cells

OBJECTIVES

Meriolins, a kind of chemical hybrid between meridianins and variolins, have lately been determined as kinase inhibitors and reportedly have antitumour activity. However, there is currently no in-depth study for the action mechanism. This study aimed to elucidate the potentially antitumour action mechanism of Meriolin1 on human neuroblastoma (SH-SY5Y) cells.

METHODS

Firstly, cell viability was detected by MTT assay. Secondly, cell cycle, cell apoptosis, cell autophagy, reactive oxygen species and mitochondrial membrane potential (ΔΨm) were measured by flow cytometry. Then, cell cycle-associated proteins, Bcl-2 family proteins, Akt/MAPK proteins and autophagy-associated proteins expressions were evaluated by Western blot. Bcl-2 and Bax mRNA expressions were also evaluated by qRT-PCR. Furthermore, cell adhesion assay and Hoechst 33258 fluorescent staining were carried out to detect the effect of Meriolin1 on cell adhesion and morphology. Finally, to gain further insight into mechanism of action of Meriolin1 to CDK protein, the molecular docking study was performed by using the CDOCKER module of DS software.

KEY FINDINGS

Meriolin1 could exert the antitumour activity on SH-SY5Y cells by inducing cell cycle arrest, cell autophagy, the mitochondrion-dependent cell apoptosis and targeting the Akt/MAPKs signalling pathway.

CONCLUSIONS

Meriolin1 might be a promising therapeutic candidate for neuroblastoma.