miR-21 regulates ischemic neuronal injury via the p53/Bcl-2/Bax signaling pathway

1,25-D3 ameliorates ischemic brain injury by alleviating endoplasmic reticulum stress and ferroptosis: Involvement of vitamin D receptor and p53 signaling

Endoplasmic reticulum stress (ERS) and ferroptosis are linked to cerebral ischemia reperfusion injury (CIRI). The neuroprotective properties of 1α, 25-dihydroxyvitamin D3 (VitD3 or 1,25-D3) have been well established; however, the mechanism by which VitD3 treats CIRI through ERS and ferroptosis has not been examined. Hence, we developed middle cerebral artery occlusion/reperfusion (MCAO/R) model in SD rats to ascertain if VitD3 preconditioning mediates ERS and ferroptosis involving of p53 signaling. In this study, we observed that VitD3 can reduce infarction volume and cerebral edema, which leads to the improvement of nerve function. HE, Nissl and Tunel staining showed that VitD3 treatment significantly improved the morphology of neuronal cells and reduced their death. The expression and activation of Vitamin D receptor (VDR), PKR-like ER kinase (PERK), C/EBP-homologous protein (CHOP), p53, nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4) and reactive oxygen species (ROS) in the ischemic penumbral area were detected by real-time qPCR, Western-blotting and Elisa. The results showed that after VitD3 treatment, VDR increased, ERS-related indices (PERK, CHOP) significantly decreased and ferroptosis-related indices (Nrf2, GPX4) increased. As a VDRs antagonist, pyridoxal-5-phosphate (P5P) can partially block the neuroprotective effects of VitD3. Therefore, CIRI can induce ERS and ferroptosis in the ischemic penumbra area and VitD3 may ameliorate nerve damage in CIRI rats by up-regulating VDR, alleviating p53-associated ERS and ferroptosis.

HSPB1 alleviates acute-on-chronic liver failure via the P53/Bax pathway

The mortality rate of acute-on-chronic liver failure (ACLF) remains significantly elevated; hence, this study aimed to investigate the impact of heat shock protein family B (small) member 1 (HSPB1) on ACLF in vivo and in vitro and the underlying mechanism. This study used the ACLF mouse model, and liver damage extent was studied employing Masson trichrome, hematoxylin and eosin (H&E), Sirius red staining, and serum biochemical indices. Similarly, hepatocyte injury in lipopolysaccharide (LPS)-induced L02 cells was evaluated using cell counting kit-8 assay, enzymatic activity, flow cytometry, and TUNEL assay, while the underlying mechanism was investigated using western blot. Results showed that the morphology of liver tissue in ACLF mice was changed and was characterized by cirrhosis, fibrosis, collagen fiber deposition, inflammatory cell infiltration, and elevated liver injury indices. Moreover, HSPB1 was upregulated in both ACLF patients and mice, where overexpressing HSPB1 was found to inhibit ACLF-induced liver damage. Similarly, the HSPB1 expression in LPS-treated L02 cell lines was also increased, where overexpressing HSPB1 was found to promote cell viability, inhibit liver injury-related enzyme activity, and suppress apoptosis. Mechanistic investigations revealed that HSPB1 was responsible for inhibiting p-P53 and Bax protein levels, where activated P53 counteracted HSPB1's effects on cellular behaviors. In conclusion, HSPB1 attenuated ACLF-induced liver injury in vivo and inhibited LPS-induced hepatocyte damage in vitro, suggesting that HSPB1 may be a novel target for ACLF therapy.

Post-stroke cognitive impairment: exploring molecular mechanisms and omics biomarkers for early identification and intervention

Post-stroke cognitive impairment (PSCI) is a major stroke consequence that has a severe impact on patients' quality of life and survival rate. For this reason, it is especially crucial to identify and intervene early in high-risk groups during the acute phase of stroke. Currently, there are no reliable and efficient techniques for the early diagnosis, appropriate evaluation, or prognostication of PSCI. Instead, plenty of biomarkers in stroke patients have progressively been linked to cognitive impairment in recent years. High-throughput omics techniques that generate large amounts of data and process it to a high quality have been used to screen and identify biomarkers of PSCI in order to investigate the molecular mechanisms of the disease. These techniques include metabolomics, which explores dynamic changes in the organism, gut microbiomics, which studies host-microbe interactions, genomics, which elucidates deeper disease mechanisms, transcriptomics and proteomics, which describe gene expression and regulation. We looked through electronic databases like PubMed, the Cochrane Library, Embase, Web of Science, and common databases for each omics to find biomarkers that might be connected to the pathophysiology of PSCI. As all, we found 34 studies: 14 in the field of metabolomics, 5 in the field of gut microbiomics, 5 in the field of genomics, 4 in the field of transcriptomics, and 7 in the field of proteomics. We discovered that neuroinflammation, oxidative stress, and atherosclerosis may be the primary causes of PSCI development, and that metabolomics may play a role in the molecular mechanisms of PSCI. In this study, we summarized the existing issues across omics technologies and discuss the latest discoveries of PSCI biomarkers in the context of omics, with the goal of investigating the molecular causes of post-stroke cognitive impairment. We also discuss the potential therapeutic utility of omics platforms for PSCI mechanisms, diagnosis, and intervention in order to promote the area's advancement towards precision PSCI treatment.

Function of miR-21-5p derived from ADSCs-exos on the neuroinflammation after cerebral ischemia

INTRODUCTION

Cerebral ischemia (CI) induces a profound neuroinflammatory response, but the underlying molecular mechanism remains unclear. Exosomes from adipose-derived stem cells (ADSC-exos) have been found to play a crucial role in cell communication by transferring molecules including microRNAs (miRNAs), which have been shown to modulate the inflammatory response after CI and are viable molecular targets for altering brain function. The current study aimed to explore the contribution of ADSC-exosomal miR-21-5p to the neuroinflammation after CI.

METHODS

The differentially expressed miR-21-5p in CI was screened based on literature search. The target mRNAs of miR-21-5p were predicted using online databases and verified by luciferase reporter assay. Then, BV2 cells were treated with hemin to simulate the inflammatory response after CI, and its animal model was induced using the MCAO method. Ischemia was evaluated in rats using 2, 3, 5-triphenyl tetrazolium chloride (TTC) staining. ADSCs-exos were further isolated and identified by western blot analysis and transmission electron microscope.

RESULTS

MiR-21-5p was significantly down-regulated in CI and alleviated neuropathic damage after CI by the PIK3R1/PI3K/AKT signaling axis. And miR-21-5p derived from ADSCs-exos alleviated neuroinflammation after CI via promoting microglial M2 polarization.

CONCLUSION

We demonstrated that ADSC-exosomal miR-21-5p mitigated post-CI inflammatory response through the PIK3R1/PI3K/AKT signaling axis and could offer neuroprotection after CI through promoting polarization of M2 microglia.

Effects of Manganese and Iron, Alone or in Combination, on Apoptosis in BV2 Cells

The aim of study was to address the effects of manganese and iron, alone and in combination, on apoptosis of BV2 microglia cells, and to determine if combined exposure to these metals augments their individual toxicity. We used a murine microglial BV2 cell line. Cell cytotoxicity was analyzed by propidium iodide (PI) exclusion assay. Cell ROS production was analyzed by 2', 7'-dichlorofluorescin diacetate (DCFH-DA) probe staining. Pro-inflammatory cytokine production was monitored by ELISA. Cell apoptosis was analyzed by PE Annexin V/7-AAD staining. Mitochondrial membrane integrity was analyzed by flow cytometry. We used immunoblotting to analyze the effect of manganese, iron alone, or their combined exposure on the activation of caspase9, P53, Bax, and Bcl2 apoptosis signaling pathways. Caspase3 activity was determined using a Colorimetric. Manganese, iron, and their combined exposure for 24 h induced the activation of BV2 microglia cells and increased ROS production and the expression of the inflammatory cytokines, IL-1β and TNF-α. And we also found that the apoptosis rate increased, mitochondrial membrane potential decreased, apoptosis-related proteins caspase9, P53, Bax, and Bcl2 expression increased, and caspase3 activity increased. Furthermore, we found that combined manganese-iron cytotoxicity was lower than that induced by manganese exposure alone. Manganese, iron alone, or their combination exposure can induce apoptosis in glial cells. Iron can reduce the toxicity of manganese, and there is an antagonistic effect between manganese and iron.

Cerebral neurotoxicity of amino-modified polystyrene nanoplastics in mice and the protective effects of functional food Camellia pollen

Accumulating evidence suggests that nanoplastics contribute to an increased risk of brain damage, however, the precise underlying mechanisms remain unclear. Here, we subjected mice to long-term exposure to amino-modified polystyrene nanoplastics (APS-NPs). These nanoplastics were detected in the mouse brain; coupled with the observed upregulation of Alzheimer's disease-associated genes (APP and MAPT). To further explore nanoplastic damage mechanisms and the corresponding protective strategies against these mechanisms in vitro, we used hCMEC/D3 and HT22 cells. Results showed that APS-NPs disrupted tight junction proteins (Occludin and ZO-1) via TLR2/MMP9 axis, resulting in blood-brain barrier permeation; this was significantly mitigated by functional food Camellia pollen treatment. APS-NPs initiated iNOS and nNOS upregulation within neurons resulting in Sirtuin 1 deacetylase inactivation and CBP acetyltransferase stimulation, ultimately leading to Ac-Tau formation. This process was attenuated by Camellia pollen, which also ameliorated the APS-NPs-induced neuronal apoptosis mediated by the p53/Bax/Bcl-2 axis. Network pharmacology analysis of Camellia pollen offered a further theoretical understanding of its potential applications in preventing and treating nervous system disorders, such as Alzheimer's disease. This study established that Camellia pollen protects the brain against APS-NPs-mediated blood-brain barrier damage and alleviates neuronal apoptosis and Alzheimer's disease-like neurotoxicity. This study elucidates the mechanisms underlying polystyrene-induced brain damage and can be used to inform future prevention and treatment strategies.

Mechanisms of immune response and cell death in ischemic stroke and their regulation by natural compounds

Ischemic stroke (IS), which is the third foremost cause of disability and death worldwide, has inflammation and cell death as its main pathological features. IS can lead to neuronal cell death and release factors such as damage-related molecular patterns, stimulating the immune system to release inflammatory mediators, thereby resulting in inflammation and exacerbating brain damage. Currently, there are a limited number of treatment methods for IS, which is a fact necessitating the discovery of new treatment targets. For this review, current research on inflammation and cell death in ischemic stroke was summarized. The complex roles and pathways of the principal immune cells (microglia, astrocyte, neutrophils, T lymphocytes, and monocytes/macrophage) in the immune system after IS in inflammation are discussed. The mechanisms of immune cell interactions and the cytokines involved in these interactions are summarized. Moreover, the cell death mechanisms (pyroptosis, apoptosis, necroptosis, PANoptosis, and ferroptosis) and pathways after IS are explored. Finally, a summary is provided of the mechanism of action of natural pharmacological active ingredients in the treatment of IS. Despite significant recent progress in research on IS, there remain many challenges that need to be overcome.

Bile Acid Application in Cell-Targeting for Molecular Receptors in Relation to Hearing: A Comprehensive Review

Bile acids play important roles in the human body, and changes in their pool can be used as markers for various liver pathologies. In addition to their functional effects in modulating inflammatory responses and cellular survivability, the unconjugated or conjugated, secondary, or primary nature of bile acids accounts for their various ligand effects. The common hydrophilic bile acids have been used successfully as local treatment to resolve drug-induced cell damage or to ameliorate hearing loss. From various literature references, bile acids show concentration and tissue-dependent effects. Some hydrophobic bile acids act as ligands modulating vitamin D receptors, muscarinic receptors, and calcium-activated potassium channels, important proteins in the inner ear system. Currently, there are limited resources investigating the therapeutic effects of bile acid on hearing loss and little to no information on detecting bile acids in the remote ear system, let alone baseline bile acid levels and their prevalence in healthy and disease conditions. This review presents both hydrophilic and hydrophobic human bile acids and their tissue-specific effects in modulating cellular integrity, thus considering the possible effects and extended therapeutic applicability of bile acids to the inner ear tissue.

Protective effect of Cornuside on OGD/R injury in SH-SY5Y cells and its underlying mechanism

Apoptosis induced by oxygen-glucose deprivation/reperfusion (OGD/R) injury is the main cause of neuronal damage. Cornuside, a small-molecule cyclic enol ether terpene glycoside extracted from the dried fruit of mature Cornus officinalis Sieb. et Zucc., has vigorous anti-apoptotic and antioxidant effects. Previous studies have shown that Cornuside can reduce apoptosis and improve mitochondrial energy metabolism in cortical neurons of rats by inhibiting caspase-3 and calcium release. In this study, we treated SH-SY5Y cells with OGD/R to simulated ischemia/reperfusion (I/R) injury. Using high-throughput transcriptome sequencing, differentially expressed genes were analyzed in the OGD/R group versus the OGD/R + Cornuside (10 μmol/L) group to explore the neuroprotective mechanisms of Cornuside. The differentially expressed genes were mainly enriched in apoptosis signaling pathway, cell cycle, DNA damage and repair, and p38/JNK MAPK and p53 signaling pathways. The results showed that OGD/R significantly reduced the survival of SH-SY5Y cells, induced apoptosis, disrupted the nucleus, promoted the release of ROS, and led to cell cycle arrest. Cornuside reversed OGD/R-induced damage. By upregulating MAPK8IP1 and downregulating MAPK14, TP53INP1, and signaling pathway-related proteins (p-p38, p-JNK, and p-p53), Cornuside ameliorated cell damage induced by p38/JNK MAPK and p53 signaling pathways. Cornuside also downregulated apoptosis regulatory proteins (Bax, Bcl-2, caspase-3, caspase-9, and cytochrome c) and cell cycle regulatory proteins (cyclin B1, cyclin E, and p21).

Regulation of toll-like receptor (TLR) signaling pathways in atherosclerosis: from mechanisms to targeted therapeutics

Atherosclerosis, one of the life-threatening cardiovascular diseases (CVDs), has been demonstrated to be a chronic inflammatory disease, and inflammatory and immune processes are involved in the origin and development of the disease. Toll-like receptors (TLRs), a class of pattern recognition receptors that trigger innate immune responses by identifying pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs), regulate numerous acute and chronic inflammatory diseases. Recent studies reveal that TLRs have a vital role in the occurrence and development of atherosclerosis, including the initiation of endothelial dysfunction, interaction of various immune cells, and activation of a number of other inflammatory pathways. We herein summarize some other inflammatory signaling pathways, protein molecules, and cellular responses associated with TLRs, such as NLRP3, Nrf2, PCSK9, autophagy, pyroptosis and necroptosis, which are also involved in the development of AS. Targeting TLRs and their regulated inflammatory events could be a promising new strategy for the treatment of atherosclerotic CVDs. Novel drugs that exert therapeutic effects on AS through TLRs and their related pathways are increasingly being developed. In this article, we comprehensively review the current knowledge of TLR signaling pathways in atherosclerosis and actively seek potential therapeutic strategies using TLRs as a breakthrough point in the prevention and therapy of atherosclerosis.

Effect of RPL27 knockdown on the proliferation and apoptosis of human liver cancer cells

RPL27 is linked to the development of various diseases including malignant tumors. RPL27 may play an oncogenic function in hepatocellular carcinoma (HCC), but this is unknown. So, the aim of this study was to investigate how the human liver cancer cell lines SNU449 and HepG2 responded to RPL27 knockdown in terms of proliferation and apoptosis. SNU449 and HepG2 were cultured and infected with shCon and shRPL27 lentiviral particles to induce RPL27 knockdown, and then RPL27 expression was detected using qPCR and Western blot. Cell proliferation was measured using CCK8, cell cloning, cell scraping, and transwell migration and invasion, while apoptosis was measured using flow cytometry (FCM). The qPCR revealed that mRNA expression of RPL27 decreased after knocking down RPL27 in cells. The CCK8 and cell cloning assay confirmed that knocking down RPL27 significantly reduced cell viability. The cell scratch assay and transwell assays showed that the proliferation rate decreased after knocking down RPL27. A substantial increase in apoptotic cells was discovered by FCM. According to WB, RPL27 knockdown increased the expression of Bax and Caspase-3 while decreasing the expression of bcl-2. The findings showed that RPL27 knockdown inhibited cell proliferation in SNU449 and HepG2 via inducing apoptosis, proving that RPL27 is a novel gene linked with HCC and is crucial for both proliferation and apoptosis. These outcomes imply that RPL27 may be a potential target for liver cancer diagnosis and therapy.

Green synthesis of nanohydroxyapatite trough Elaeagnus angustifolia L. extract and evaluating its anti-tumor properties in MCF7 breast cancer cell line

BACKGROUND

One of the most common types of cancer in women is breast cancer. There are numerous natural plant-based products, which exert anti-tumoral effects including Elaeagnus Angustifolia (EA). It modulates cell-cycle process, heat-shock proteins expression, anti-proliferative properties, apoptosis induction, blocking of angiogenesis, and cell invasion inhibition. The current study aimed to synthesize and evaluate the anticancer effects of hydroalcoholic EA extract (HEAE), Nanohydroxyapatite (nHAp) and nHAp synthesized trough EA (nHA-EA) in MCF-7 breast cancer cell line.

METHODS

In the present study, HEAE preparation and green synthesis of nHA-EA was done and phase composition, functional groups, and crystallin phase of nHA-EA and nHAp were determined using Fourier-transform infrared (FTIR) and X-ray diffraction (XRD). The characteristics of synthesized nanoparticles including structural and morphological parameters were investigated using scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) techniques. Then, by using MTT-assay (Dimethylthiazoldiphenyltetrazolium), the in vitro cytotoxic and half maximal inhibitory concentration (IC50) of EA extract, nHAp, and nHA-EA in the MCF-7 breast cancer cell line was evaluated. Next, we assessed the expression of apoptosis-related genes Bax, Bcl2 and p53 using quantitative reverse-transcriptase polymerase-chain-reaction (qRT-PCR) and migration of MCF-7 cells by scratch assay.

RESULTS

The FTIR results demonstrated formation of nHAp and its interaction with HEAE during synthesis process. The XRD results of the synthesized nanoparticles showed similar XRD pattern of nHA-EA and nHAp and purity of synthesized nanomaterials. The average IC50 of HEAE, nHAp, and nHA-EA extract after treatment of cancer cells for 24 h was 400 µg/mL, 200 µg/mL, and 100 µg/mL, respectively. Our results revealed that nHA-EA significantly reduced the migration and invasion of the MCF-7 cells, in comparison to the nHAp and EA extract. Moreover, level of Bax/Bcl2 and p53 was significantly higher in the nHA-EA extract group in comparison to the EA extract and nHAp group.

CONCLUSION

Taken together, our results demonstrated that bioactive constituents of EA medicinal plant in form of nHA-EA particles, can effectively exerts potential anticancer and chemo preventive effect against breast cancer growth and can be proposed as a promising beneficial candidate for BC therapy. However, further investigations are required to discover what bioactive compounds are responsible for the chemo preventive effect of this extract.

Overexpression of Circ_0005585 Alleviates Cerebral Ischemia Reperfusion Injury via Targeting MiR-16-5p

Circular RNAs are implicated in the pathogenesis of ischemic stroke. In this work, we explored the modulation and potential mechanisms of action of circ_0005585 in ischemic stroke. Expression of circ_0005585 and miR-16-5p was assessed by quantitative real-time reverse transcription PCR. Ischemic stroke was modeled in mice by middle cerebral artery occlusion (MCAO). The infarct volume was assessed by triphenyl tetrazolium chloride staining. Neurological deficits were evaluated according to Neurological Severity Score. The permeability of the blood-brain barrier was assessed by Evan's blue leakage and brain water content. Apoptosis in brain tissues was measured by the TUNEL test. Relative expression of apoptosis-related proteins was evaluated by Western blotting. The direct interaction between circ_0005585 and miR-16-5p was verified by dual-luciferase reporter assay. The expression of circ_0005585 was lower in mice with MCAO. Lentivirus-mediated overexpression of circ_0005585 ameliorated the neurological deficits and decreased the infarction volume in MCAO mice. The brain water content and Evan's blue leakage through the blood-brain barrier were reduced. In addition, overexpression of circ_0005585 inhibited apoptosis in the cerebral tissues. Our results revealed direct interaction between circ_0005585 and miR-16-5p. Hence, circ_0005585 protects mouse brain during ischemic stroke by targeting miR-16-5p, which uncovers the pathogenesis of this pathology and opens new vitas for its therapy.

Targeting p53 for neuroinflammation: New therapeutic strategies in ischemic stroke

Ischemic stroke (IS) is characterized by high incidence, high recurrence, and high mortality and places a heavy burden on society and families. The pathological mechanisms of IS are complex, among which secondary neurological impairment mediated by neuroinflammation is considered to be the main factor in cerebral ischemic injury. At present, there is still a lack of specific therapies to treat neuroinflammation. The tumor suppressor protein p53 has long been regarded as a key substance in the regulation of the cell cycle and apoptosis in the past. Recently, studies have found that p53 also plays an important role in neuroinflammatory diseases, such as IS. Therefore, p53 may be a crucial target for the regulation of the neuroinflammatory response. Here, we provide a comprehensive review of the potential of targeting p53 in the treatment of neuroinflammation after IS. We describe the function of p53, the major immune cells involved in neuroinflammation, and the role of p53 in inflammatory responses mediated by these cells. Finally, we summarize the therapeutic strategies of targeting p53 in regulating the neuroinflammatory response after IS to provide new directions and ideas for the treatment of ischemic brain injury.

MiR-21 alleviates renal tubular epithelial cells injury induced by ischemia by targeting TLR4

Renal ischemia is the initial stage of kidney damage, leading to mitochondrial metabolism disorders and cell necrosis. In this study, we aimed to investigate the biological functions and potential mechanisms of miR-21 in protecting renal tubular epithelial cells from oxidative stress and apoptosis following oxygen glucose deprivation (OGD). Following an OGD injury, miR-21 levels increased in HK-2 renal tubular epithelial cells. Overexpression of miR-21 decreased the protein expressions of cleaved caspase-3, BAX, P53, cell apoptosis and increased Bcl-2 expression in HK-2 cells with OGD injury. In vivo studies found that miR-21 agomir reduced renal tissue apoptosis, while miR-21 antagomir increased it. In addition, overexpression of miR-21 reduced levels of reactive oxygen species (ROS), malondialdehyde (MDA) and lactate dehydrogenase (LDH) in HK-2 cells with OGD injury. However, miR-21 inhibition exhibited the opposite effect. A dual-luciferase reporter assay demonstrated that miR-21 directly regulates Toll-like receptor 4 (TLR4) by targeting the 3'-UTR of TLR4 mRNA. Overexpression of miR-21 led to decreased TLR4 protein expression, and TLR4 knockdown was shown to greatly increase AKT activity in HK-2 cells by in vitro kinase assay. Additionally, TLR4 knockdown promoted AKT phosphorylation and hypoxia-inducible factor-1α (HIF-1α) expression, while TLR4 overexpression inhibited these processes. Furthermore, AKT activation abolished the effect of TLR4 on HIF-1α, while AKT inhibition decreased the expression of TLR4 on HIF-1α in TLR4 knockdown HK-2 cells. Further study revealed that HIF-1α inhibition abolished the protective effect of miR-21 overexpression on ROS, LDH levels and cell apoptosis in HK-2 cells after OGD injury, which is indicated by increased levels of ROS and LDH, as well as increased cell apoptosis after HIF-1α inhibition in miR-21-treated HK-2 cells. In conclusion, miR-21 defends OGD-induced HK-2 cell injury via the TLR4/AKT/HIF-1α axis.

Granulosa cells undergo BPA-induced apoptosis in a miR-21-independent manner

Bisphenol A (BPA) is a harmful endocrine disrupting compound that alters not only classical cellular mechanisms but also epigenetic mechanisms. Evidence suggests that BPA-induced changes in microRNA expression can explain, in part, the changes observed at both the molecular and cellular levels. BPA is toxic to granulosa cells (GCs) as it can activate apoptosis, which is known to contribute to increased follicular atresia. miR-21 is a crucial antiapoptotic regulator in GCs, yet the exact function in a BPA toxicity model remains unclear. BPA was found to induce bovine GC apoptosis through the activation of several intrinsic factors. BPA reduced live cells counts, increased late apoptosis/necrosis, increased apoptotic transcripts (BAX, BAD, BCL-2, CASP-9, HSP70), increased the BAX/Bcl-2 ratio and HSP70 at the protein level, and induced caspase-9 activity at 12 h post-exposure. miR-21 inhibition increased early apoptosis and, while it did not influence transcript levels or caspase-9 activity, it did elevate the BAX/Bcl-2 protein ratio and HSP70 in the same manner as BPA. Overall, this study shows that miR-21 plays a molecular role in regulating intrinsic mitochondrial apoptosis; however, miR-21 inhibition did not make the cells more sensitive to BPA. Therefore, apoptosis induced by BPA in bovine GCs is miR-21 independent.

Circ_0000566 contributes oxygen-glucose deprivation and reoxygenation (OGD/R)-induced human brain microvascular endothelial cell injury via regulating miR-18a-5p/ACVR2B axis

Circular RNAs (circRNAs) exert regulatory roles in cerebrovascular disease. Human brain microvascular endothelial cells (HBMECs) participated in brain vascular dysfunction in ischemic stroke. Herein, the functions of circ_0000566 in oxygen-glucose deprivation and reoxygenation (OGD/R)-induced HBMECs were investigated. The expression of circ_0000566, miR-18a-5p, and Activin receptor type 2B (ACVR2B) was measured via quantitative real-time PCR (qRT-PCR). Cell Counting Kit-8 (CCK-8) and flow cytometry assays were utilized to detect cell viability and cell apoptosis. Western blot assay was employed to measure the levels of apoptotic-related proteins and ACVR2B. The secretion of IL-1β, IL-6, and TNF-α was detected via corresponding kits. The relationship between miR-18a-5p and circ_0000566 or ACVR2B was examined via dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Circ_0000566 and ACVR2B were highly expressed, while miR-18a-5p was down-regulated in OGD/R-treated HBMECs. OGD/R treatment promoted HBMECs apoptosis and inflammation and suppressed cell viability, which could be attenuated by silencing of circ_0000566. Circ_0000566 acted as a miR-18a-5p sponge to contribute to OGD/R-induced HBMECs injury. ACVR2B served as a direct target of miR-18a-5p, and ACVR2B overexpression might abolish the inhibitory role of miR-18a-5p on OGD/R-treated HBMEC injury. Circ_0000566 sponged miR-18a-5p to regulate OGD/R-induced HBMECs injury via regulating ACVR2B expression.

An Enriched Environment Promotes Motor Function through Neuroprotection after Cerebral Ischemia

Stroke seriously affects human health. Many studies have shown that enriched environment (EE) can promote functional recovery after stroke, but the intrinsic mechanisms remain unclear. In order to study the internal mechanisms of EE involved in functional recovery after ischemic stroke and which mechanism plays a leading role in the recovery of limb function after cerebral infarction, key proteins potentially involved in neuronal protection and synaptic remodeling in the ischemic penumbra have been investigated. In this study, adult C57BL/6 mice after permanent middle cerebral artery occlusion (pMCAO) were assigned to the EE and standard housing (SH) groups 3 days after operation. The EE house was spacious that contained a large variety of small toys; the SH was a normal sized cage. Sham-operated mice without artery occlusion were housed under standard conditions and were fed a normal diet. On days 3, 7, 14, and 21, postoperative motor functional recovery was tested using the modified neurological severity score (mNSS) and the Rotarod test. The expression of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), growth-associated protein-43 (GAP-43), and synaptophysin (SYN) was examined by western blotting and immunofluorescence staining. The motor functional recovery (based on the mNSS and Rotarod test 3, 7, 14, and 21 days post operation) of mice in the EE group improved significantly compared to the SH group. The expression of GAP-43 and SYN and the ratio of Bcl-2/Bax were all upregulated in the EE group compared to the SH group. In addition, we also explored the relationship between neuronal protection and synaptic remodeling in the EE-mediated recovery of limb function after cerebral infarction by correlation analysis. Correlation analysis showed that compared with the increase of Bcl-2/Bax ratio, the increased expression of GAP-43 and SYN was more closely related to the recovery of limb function in ischemic mice. These data support the hypothesis that EE can promote the process of improvement of limb dysfunction induced by ischemic stroke, and this behavior restoration may, via promoting neuroprotection in the ischemic penumbra, be dependent on the regulation of the expression of GAP-43, SYN, Bcl-2, and Bax. A limitation of the study was that we only observed several representative key indicators of synaptic remodeling and neuronal apoptosis, without an in-depth study of the potential mechanisms involved.

MiR-21-5p protects against ischemic stroke by targeting IL-6R

Background

Ischemic stroke is a brain dysfunction disease caused by vascular obstruction. The expression of many kinds of microRNAs (miRNAs) is related to ischemic stroke. MiRNA has the ability to reduce or save ischemic injury. Therefore, we aimed to explore the protective miRNA in the ischemia-reperfusion process.

Methods

The Gene Expression Omnibus (GEO) peripheral RNA sequencing (RNA-seq) datasets of ischemic stroke patients were analyzed to search for differentially expressed miRNAs in the ischemia-reperfusion process. The expression level of miRNA in 60 patients with ischemic stroke and 23 age-matched healthy control inpatients was tested by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The significantly changed miRNAs were verified through comparison of the peripheral blood of healthy people and patients of the hospital. The in-vitro ischemia-reperfusion model was established through oxygen-glucose deprivation (OGD) treated HEMC-1 cells. The cell viabilities and cell apoptosis are detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. Apoptosis-related proteins including Bcl-2, Bax, caspase-3, and caspase-9 expression levels were verified by western blot. Predict the combination of hsa-miR-21-5p and interleukin-6 receptor (IL-6R) through TargetScan database, clone the 2964-2961 site of IL-6R-3'-untranslated region (3'-UTR), establish IL-6R-3'-UTR and IL-6R-3'-UTR mutant plasmids, copy and clone wild type and mutant IL-6R-3'-UTR into luciferase report vector pGL3 respectively, and detect the activity of luciferase. The expression of hsa-miR-21-5p was regulated by using hsa-miR-21-5p mimic and hsa-miR-21-5p inhibitor.

Results

Through RNA-seq analysis, it was revealed that "hsa-miR-548ar-3p", "hsa-miR-651-5p", "hsa-miR-142-3p", "hsa-miR-21-5p", and "hsa-miR-30e-5p" were notably lower in ischemia patients, and that "hsa-miR-21-5p" was significantly decreased in the peripheral blood of hospital patients. Luciferase assay showed that hsa-miR-21-5p could directly bind to the 3'-UTR of the IL-6R gene and inhibit IL-6R translation; the level of IL-6R was also elevated in patients. In the OGD-treated HMEC-1 cells, overexpressed hsa-miR-21-5p mimic could enhance cell viabilities and decrease cell apoptosis. Moreover, IL-6R overexpression could reduce the protective effects of hsa-miR-21-5p.

Conclusions

In the peripheral blood of ischemia patients, hsa-miR-21-5p is significantly decreased and IL-6R is elevated. The "hsa-miR-21-5p" could bind to the IL-6R gene and suppress IL-6R expression, thus alleviating the damage of OGD treatment in HMEC-1 cells.

Cell Death Mechanisms in Cerebral Ischemia-Reperfusion Injury

Ischemic stroke is one of the major causes of morbidity and mortality, affecting millions of people worldwide. Inevitably, the interruption of cerebral blood supply after ischemia may promote a cascade of pathophysiological processes. Moreover, the subsequent restoration of blood flow and reoxygenation may further aggravate brain tissue injury. Although recombinant tissue plasminogen activator (rt-PA) is the only approved therapy for restoring blood perfusion, the reperfusion injury and the narrow therapeutic time window restrict its application for most stroke patients. Increasing evidence indicates that multiple cell death mechanisms are relevant to cerebral ischemia-reperfusion injury, including apoptosis, necrosis, necroptosis, autophagy, pyroptosis, ferroptosis, and so on. Therefore, it is crucial to comprehend various cell death mechanisms and their interactions. In this review, we summarize the various signaling pathways underlying cerebral ischemia-reperfusion injury and elaborate on the crosstalk between the different mechanisms.

Pre-Exposure to Environmental Enrichment Protects against Learning and Memory Deficits Caused by Infrasound Exposure

With the development of industrialization in recent years, infrasound has become an important component of public noise. To date, diverse studies have revealed the negative effects of infrasound on the central nervous system (CNS), especially the learning and memory ability. It is widely reported that environmental enrichment (EE) ameliorates the learning and memory deficits in different models of brain injury. Therefore, the present study was designed to determine the possible benefits of pre-exposure to EE in preventing functional deficits following infrasound exposure and their related mechanism. Adult male rats were given enriched or standard housing for 30 days. Following enrichment, the rats were exposed to 16 Hz, 130 dB infrasound for 14 days, and then their learning and memory ability was assessed. Changes to neuroinflammation, apoptosis, and oxidative stress in the hippocampus were also detected. Our results showed that the infrasound-induced deficit in learning and memory was attenuated significantly in EE pre-exposed rats. Pre-exposure to EE could induce a decrease in proinflammatory cytokines and increased anti-inflammatory cytokines and antioxidant properties in the hippocampus. Moreover, pre-exposure to EE also exerted antiapoptosis functions by upregulating the B-cell lymphoma/leukemia-2 (Bcl-2) level and downregulating the P53 level in the hippocampus. In conclusion, the results of the present study suggested that EE is neuroprotective when applied before infrasound exposure, resulting in an improved learning and memory ability by enhancing antioxidant, anti-inflammatory, and antiapoptosis capacities.

Role of sirtuin 1 in the brain development in congenital hypothyroidism rats via the regulation of p53 signaling pathway

The present study aimed to investigate the expression, role, and underlying mechanism of action of sirtuin 1 (SIRT1) in congenital hypothyroidism (CH). A CH model was established in rats, and neuronal cells were isolated from the hippocampal tissues of normal rats. Free thyroxine (fT4) and thyroid-Stimulating hormone (TSH) concentrations were determined to confirm CH model conduction. The cognitive behavior of rats with CH was examined using open field and forced swimming tests. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to detect the expression levels of SIRT1, p53, B-cell lymphoma-extra-large (Bcl-xl), Bcl-2-associated X (Bax), and cytochrome c in the hippocampal tissues and neuronal cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and flow cytometry were performed to evaluate cell viability and apoptosis, respectively. The results revealed that SIRT1 was expressed at low levels in the hippocampal tissues of rats with CH. Moreover, overexpression of SIRT1 in the hippocampal tissues of rats with CH and improved rat behavior, while reducing the CH-induced nerve cell apoptosis. In addition, this overexpression increased the viability, inhibited apoptosis, and reduced the expression of p53, Bax, and cytochrome c, while increasing the expression of Bcl-xl in cultured neurons. In contrast, SIRT1-small interfering RNA exhibited the opposite effects in cultured neurons. In conclusion, SIRT1 plays a role in the occurrence and development of CH by regulating nerve cell apoptosis.

Roles of MicroRNA-21 in Skin Wound Healing: A Comprehensive Review

MicroRNA-21 (miR-21), one of the early mammalian miRNAs identified, has been detected to be upregulated in multiple biological processes. Increasing evidence has demonstrated the potential values of miR-21 in cutaneous damage and skin wound healing, but lack of a review article to summarize the current evidence on this issue. Based on this review, relevant studies demonstrated that miR-21 played an essential role in wound healing by constituting a complex network with its targeted genes (i.e., PTEN, RECK. SPRY1/2, NF-κB, and TIMP3) and the cascaded signaling pathways (i.e., MAPK/ERK, PI3K/Akt, Wnt/β-catenin/MMP-7, and TGF-β/Smad7-Smad2/3). The treatment effectiveness developed by miR-21 might be associated with the promotion of the fibroblast differentiation, the improvement of angiogenesis, anti-inflammatory, enhancement of the collagen synthesis, and the re-epithelialization of the wound. Currently, miRNA nanocarrier systems have been developed, supporting the feasibility clinical feasibility of such miR-21-based therapy. After further investigations, miR-21 may serve as a potential therapeutic target for wound healing.

Direct Interaction of miRNA and circRNA with the Oncosuppressor p53: An Intriguing Perspective in Cancer Research

Simple Summary

MicroRNAs and circular RNAs, which are single-stranded non-coding RNAs, play a key role as regulators at post-transcriptional level. Abnormal levels or dysregulation of miRNA or circRNA are linked to several cancerous pathologies. Starting from the evidence that some miRNAs and circRNAs are involved in the regulatory networks of the tumor suppressor protein p53, the possibility that a functional inhibition of p53 could arise from a direct interaction between p53 and oncogenic miRNAs or circRNAs was explored. Along this direction, the experimental evidence of the interaction between p53 and miRNAs and/or circRNAs is reviewed and discussed in connection with the development of new anticancer strategies.

Abstract

MicroRNAs (miRNAs) are linear single-stranded non-coding RNAs oligonucleotides, widely distributed in cells, playing a key role as regulators of gene expression at post-transcriptional level. Circular RNAs (circRNAs) are single-stranded RNA oligonucleotides forming a covalently closed continuous loop, which confers them a high structural stability and which may code for proteins or act as gene regulators. Abnormal levels or dysregulation of miRNA or circRNA are linked to several cancerous pathologies, so that they are receiving a large attention as diagnostic and prognostic tools. Some miRNAs and circRNAs are strongly involved in the regulatory networks of the transcription factor p53, which plays a pivotal role as tumor suppressor. Overexpression of miRNAs and/or circRNAs, as registered in a number of cancers, is associated to a concomitant inhibition of the p53 onco-suppressive function. Among other mechanisms, it was recently suggested that a functional inhibition of p53 could arise from a direct interaction between p53 and oncogenic miRNAs or circRNAs; a mechanism that might be reminiscent of the p53 inhibition by some E3 ubiquitin ligase such as MDM2 and COP1. Such evidence might deserve important implications for restoring the p53 anticancer functionality, and pave the way to intriguing perspectives for novel therapeutic strategies. In the present paper, the experimental evidence of the interaction between p53 and miRNAs and/or circRNAs is reviewed and discussed in connection with the development of new anticancer approaches.