Noncanonical functions of microRNAs in the nucleus.

MicroRNAs (miRNAs) are small noncoding RNAs (ncRNAs) that play their roles in the regulation of physiological and pathological processes. Originally, it was assumed that miRNAs only modulate gene expression posttranscriptionally in the cytoplasm by inducing target mRNA degradation. However, with further research, evidence shows that mature miRNAs also exist in the cell nucleus, where they can impact gene transcription and ncRNA maturation in several ways. This review provides an overview of novel models of nuclear miRNA functions. Some of the models remain to be verified by experimental evidence, and more details of the miRNA regulation network remain to be discovered in the future.

[Baicalin improves inflammatory response of human microglia by regulating cAMP-PKA-NF-κB/CREB pathway].

This study aims to investigate the effects of baicalein(BAI) on lipopolysaccharide(LPS)-induced human microglial clone 3(HMC3) cells, with a focus on suppressing inflammatory responses and elucidating the potential mechanism underlying the therapeutic effects of BAI on ischemic stroke via modulating the cAMP-PKA-NF-κB/CREB pathway. The findings have significant implications for the application of traditional Chinese medicine in treating cerebral ischemic diseases. First, the safe dosage of BAI was screened, and then an inflammation model was established with HMC3 cells by induction with LPS for 24 h. The cells were assigned into a control group, a model group, and high-, medium-, and low-dose(5, 2.5, and 1.25 µmol·L~(-1), respectively) BAI groups. The levels of superoxide dismutase(SOD) and malondialdehyde(MDA) in cell extracts, as well as the levels of interleukin-1ß(IL-1ß), IL-6, tumor necrosis factor-α(TNF-α), and cyclic adenosine monophosphate(cAMP) in the cell supernatant, were measured. Western blot was performed to determine the expression of protein kinase A(PKA), phosphorylated cAMP-response element binding protein(p-CREB), and nuclear factor-kappa B p65(NF-κB p65). Hoechst 33342/PI staining was employed to assess cell apoptosis. High and low doses of BAI were used for treatment in the research on the mechanism. The results revealed that BAI at the concentrations of 10 µmol·L~(-1) and below had no impact on normally cultured HMC3 cells. LPS induction at 200 ng·mL~(-1) for 24 h reduced the SOD activity and increased the MDA content in HMC3 cells. However, 5, 2.5, and 1.25 µmol·L~(-1) BAI significantly increased the SOD activity and 5 µmol·L~(-1) BAI significantly decreased the MDA content. In addition, BAI ameliorated the M1 polarization of HMC3 cells induced by LPS, as indicated by cellular morphology. The results of ELISA demonstrated that BAI significantly lowered the levels of TNF-α, IL-1ß, IL-6, and cAMP in the cell supernatant. Western blot revealed that BAI up-regulated the protein levels of PKA and p-CREB while down-regulating the expression of NF-κB p65. Hoechst 33342/PI staining results indicated that BAI mitigated the apoptosis of HMC3 cells. Overall, the results indicated that BAI had protective effects on the HMC3 cells induced by LPS, and could inhi-bit inflammatory response and improve cell apoptosis, which might be related to the regulation of the cAMP-PKA-NF-κB/CREB pathway.

[Mechanism of Buyang Huanwu Decoction in protecting ischemic myocardium by regulating platelet autophagy in rats with acute myocardial infarction].

This study explored the effects of Buyang Huanwu Decoction(BYHWD) on platelet activation and differential gene expression after acute myocardial infarction(AMI). SD rats were randomly divided into a sham-operated group, a model group, a positive drug(aspirin) group, and a BYHWD group. Pre-treatment was conducted for 14 days with a daily oral dose of 1.6 g·kg~(-1) BYHWD and 0.1 g·kg~(-1) aspirin. The AMI model was established using the high ligation of the left anterior descending coronary artery method. The detection indicators included myocardial infarct size, heart function, myocardial tissue pathology, peripheral blood flow perfusion, platelet aggregation rate, platelet membrane glycoprotein CD62p expression, platelet transcriptomics, and differential gene expression. The results showed that compared with the sham-operated group, the model group showed reduced ejection fraction and cardiac output, decreased peripheral blood flow, and increased platelet aggregation rate and CD62p expression, and activated platelets. At the same time, TXB_2 content increased and 6-keto-PGF1α content decreased in serum. Compared with the model group, BYHWD increased ejection fraction and cardiac output, improved blood circulation in the foot and tail regions and cardiomyocytes arrangement, reduced myocardial infarct size and inflammatory infiltration, down-regulated platelet aggregation rate and CD62p expression, reduced serum TXB_2 content, and increased 6-keto-PGF1α content. Platelet transcriptome sequencing results revealed that BYHWD regulated mTOR-autophagy pathway-related genes in platelets. The differential gene expression levels were detected using real-time quantitative PCR. BYHWD up-regulated mTOR, down-regulated autophagy-related FUNDC1 and PINK genes, and up-regulated p62 gene expression. The results demonstrated that BYHWD could regulate platelet activation, improve blood circulation, and protect ischemic myocardium in AMI rats, and its mechanism is related to the regulation of the mTOR-autophagy pathway in platelets.

[Baicalin treats cerebral ischemia reperfusion-induced brain edema in rats by inhibiting TRPV4 and AQP4 of astrocytes].

This study aims to explore the pharmacodynamic effect of baicalin on rat brain edema induced by cerebral ischemia reperfusion injury and discuss the mechanism from the perspective of inhibiting astrocyte swelling, which is expected to serve as a refe-rence for the treatment of cerebral ischemia with Chinese medicine. To be specific, middle cerebral artery occlusion(suture method) was used to induce cerebral ischemia in rats. Rats were randomized into normal group, model group, high-dose baicalin(20 mg·kg~(-1)) group, and low-dose baicalin(10 mg·kg~(-1)) group. The neurobehavior, brain index, brain water content, and cerebral infarction area of rats were measured 6 h and 24 h after cerebral ischemia. Brain slices were stained with hematoxylin and eosin(HE) for the observation of pathological morphology of cerebral cortex after baicalin treatment. Enzyme-linked immunosorbent assay(ELISA) was employed to determine the content of total L-glutathione(GSH) and glutamic acid(Glu) in brain tissue, Western blot to measure the content of glial fibrillary acidic protein(GFAP), aquaporin-4(AQP4), and transient receptor potential vanilloid type 4(TRPV4), and immunohistochemical staining to observe the expression of GFAP. The low-dose baicalin was used for exploring the mechanism. The experimental results showed that the neurobehavioral scores(6 h and 24 h of cerebral ischemia), brain water content, and cerebral infarction area of the model group were increased, and both high-dose and low-dose baicalin can lower the above three indexes. The content of GSH dropped but the content of Glu raised in brain tissue of rats in the model group. Low-dose baicalin can elevate the content of GSH and lower the content of Glu. According to the immunohistochemical staining result, the model group demonstrated the increase in GFAP expression, and swelling and proliferation of astrocytes, and the low-dose baicalin can significantly improve this situation. The results of Western blot showed that the expression of GFAP, TRPV4, and AQP4 in the cerebral cortex of the model group increased, and the low-dose baicalin reduce their expression. The cerebral cortex of rats in the model group was severely damaged, and the low-dose baicalin can significantly alleviate the damage. The above results indicate that baicalin can effectively relieve the brain edema caused by cerebral ischemia reperfusion injury in rats, possibly by suppressing astrocyte swelling and TRPV4 and AQP4.

[Protection of salidroside on endothelial cell barrier in cerebral ischemia-reperfusion model rats].

This study aims to observe the therapeutic effect of salidroside on cerebral ischemia-reperfusion(I/R) model rats, and to specifically explore the protection of salidroside on endothelial cell barrier after I/R and the mechanism. In the experiment, SD rats were randomized into sham group, model group, and high-, medium-, and low-dose(10, 5, and 2.5 mg·kg~(-1)) salidroside groups. The suture method was used to induce I/R in rats. The infarct area, neurobehavioral evaluation, and brain water content were used to evaluate the efficacy of salidroside. As for the experiment on the mechanism, high-dose and low-dose salidroside groups were designed. The pathological morphology was observed based on hematoxylin and eosin(HE) staining, and ultrastructure of vascular endothelial cells based on transmission electron microscopy. The content of nitric oxide(NO) in serum, four indexes of blood coagulation, and the content of von Willebrand factor(vWF) in plasma were measured. Western blot(WB) and immunofluorescence(IF) were employed to determine the expression of tight junction proteins(ZO-1, occluding, and claudin-1) and matrix metalloproteinase 9(MMP-9) in the cortex. The results showed that the model group had obvious neurological deficit, obvious infarct in the right brain tissue, and significant increase in water content in brain tissue compared with the sham group. Compared with the model group, high-dose and low-dose salidroside groups showed decrease in neurobehavioral score, and the high-, medium-, and low-dose salidroside groups demonstrated obviously small infarct area and significant decrease in water content in brain tissue. The results of HE staining and transmission electron microscopy showed that rats had necrosis of neurons, damage of original physiological structure of endothelial cells, and disintegration of the tight junction between endothelial cells after I/R compared with the sham group. Compared with the model group, the high-dose and low-dose salidroside groups showed alleviation of neuron injury and intact physiological structure of endothelial cells. The model group had significantly lower serum level of NO, significantly higher plasma levels of vWF and fibrinogen(FIB), and significantly shorter thrombin time(TT) and prothrombin time(PT) than the sham group. Compared with model group, the high-dose and low-dose salidroside groups increased the serum content of NO in serum, decreased the plasma levels of FIB and vWF, and significantly prolonged TT and PT. WB and IF results showed that the model group had significantly lower levels of ZO-1, occluding, and claudin-1 among endothelial cells and significantly higher level of MMP-9 than the sham group. Compared with the model group, high-dose and low-dose salidroside significantly increased the levels of ZO-1, occluding, and claudin-1 in the cortex. The above experimental results show that salidroside has clear therapeutic effect on I/R rats and protects the brain. To be specific, it alleviates the damage of endothelial cells by increasing NO synthesis in endothelial cells, inhibiting coagulation reaction and MMP-9 expression, up-regulating the expression of ZO-1, occludin, and claudin-1, thereby protecting the brain.

[Effects of Qilong Capsules on myocardial fibrosis and insufficient blood circulation in ischemic cardiomyopathy with Qi deficiency and blood stasis].

Protective effect of Qilong Capsules(QL) on the myocardial fibrosis and blood circulation of rats with coronary heart disease of Qi deficiency and blood stasis type was investigated. Sleep deprivation and coronary artery ligation were used to construct a disease-symptom combination model, and 60 SD rats were divided into sham operation(sham) group, syndrome(S) group, disease and syndrome(M) group and QL group randomly. The treatment group received administration of QL 0.4 g·kg~(-1)·d~(-1). Other groups were given the same amount of normal saline. The disease indexes of each group [left ventricular end diastolic diameter(LVESD), left ventricular end systolic diameter(LVEDD), left ventricular ejection fraction(LVEF), left ventricular axis shortening rate(LVFS), myocardial histopathology, platelet morphology, peripheral blood flow] and syndrome indexes(tongue color, pulse, grip power) were detected. In sham group, cardiomyocytes and myocardial fibers were arranged neatly and densely with clear structures. The tongues' color in sham were light red, and the pulse shape were regular. RGB is a parameter reflected the brightness of the image of the tongue. In the S group, the amplitude and frequency of the animal's pulse increased accompanied by decreasing R,G,B, however, the decreased R,G,B was accompanied by reduced pulse amplitude in M group. And in M group, we observed fuzzy cell morphology, hypertrophied myocytes, disordered arrangement of cardiomyocytes and myocardial fibers, reduced peripheral blood flow and increased collagen volume fraction(CVF). Increased LVESD and LVEDD, and decreased LVEF and LVFS represented cardiac function in S group was significantly lower than that in sham. In QL group, the tongue's color was red and the pulse was smooth. The myocardial fibers of the QL group were arranged neatly and secreted less collagen. It improved the blood circulation in the sole and tail, and reversed the increasing of LVEDD, LVESD and the decreasing of LVEF and LVFS of M group. Platelets in M and S group showed high reactivity, and QL could decrease aggregation risk. In conclusion, Qilong Capsules has an obvious myocardial protective effect on ischemic cardiomyopathy, which may inhibit the degree of myocardial fibrosis and reduce platelet reactivity.

[Effects of Buyang Huanwu Decoction on neurovascular units after cerebral ischemia: a review].

Buyang Huanwu Decoction, a representative prescription in traditional Chinese medicine(TCM) for tonifying Qi and activating blood, has been proved to be effective in preventing and treating acute cerebral infarction(ACI). It consists of Astragali Radix, Angelicae Sinensis Radix, Paeoniae Radix Rubra, Pheretima, Chuanxiong Rhizoma, Carthami Flos, and Persicae Semen, possessing multiple active ingredients. The neurovascular unit is a functionally and structurally interdependent multicellular complex composed of neurons-glial cells-blood vessels. It plays an important role in the pathological changes of cerebral ischemia and the permeability variation of the blood-brain barrier. In recent years, Buyang Huanwu Decoction has been found to protect the integrity of neurovascular units and improve the permeability of the blood-brain barrier, thereby alleviating stroke and other diseases caused by cerebral ischemia. This paper collated and summarized the protective effects of Buyang Huanwu Decoction on neurovascular units.

[Research progress of change of platelet in blood stasis syndrome and effect of traditional Chinese medicine].

The traditional Chinese medicine(TCM) syndrome of blood stasis refers to blood stagnation in meridians and viscera, with the main symptoms of pain, mass, bleeding, purple tongue, and unsmooth pulse. Cardiovascular and cerebrovascular diseases are among the major chronic diseases seriously harming the health of the Chinese. Among the coronary heart disease and stroke patients, most demonstrate the blood stasis syndrome. Platelet is considered to be one of the necessary factors in thrombosis, which closely relates to the TCM syndrome of blood stasis and the occurrence of cardiovascular and cerebrovascular diseases. The clinical and laboratory research on platelet activation and aggregation has been paid more and more attention. Its purpose is to treat and prevent blood stasis syndrome. In this study, the authors analyzed the research on the dysfunctions of platelets in blood stasis syndrome, biological basis of TCM blood stasis syndrome, and the effect of blood-activating stasis-resolving prescriptions on platelets, aiming at providing a reference for exploring the mechanism of platelet intervention in the treatment of TCM blood stasis syndrome and the pathways and targets of Chinese medicine in the prevention and treatment of the syndrome.

Chiral Recognition on Bare Gold Surfaces by Quartz Crystal Microbalance.

Quartz crystal microbalance (QCM) is one of the powerful tools for the studies of molecular recognition and chiral discrimination. Its efficiency mainly relies on the design of the functional sensitive layer on the electrode surface. However, the organic sensitive layer may easily cause dissipation of oscillation or detachment and weaken the signal transfer during the molecular recognition processes. In this work, we reveal for the first time that the bare metal surface without the organic selector layer has the capability for chiral recognition in the QCM system. During the adsorption of various chiral amino acids, relatively higher selectivity of D-enantiomers on gold (Au) surface was shown by the QCM detection. Based on analyses of the surface crystalline structure and density functional theory calculations, we demonstrate that the chiral nature of Au surface plays an important role in the selective binding of specific D-amino acids. These results may open new insights on chiral detection by QCM system. It will also promote the construction of novel chiral sensing systems with both efficient detection and separation capability.

[Effect of Ginkgo biloba extract (EGb50) on mitochondrial function in SH-SY5Y cells after hypoxia/reoxygenation injury].

Ischemic cerebrovascular disease and cerebral ischemia/reperfusion injury threaten the health of human being. We studied the protective effect of Ginkgo biloba extract 50 (EGb50) on the mitochondrial function in SH-SY5Y cells after hypoxia/reoxygenation (H/R) injury and explored its mechanisms, so as to provide new ideas for studies on the treatment for ischemic cerebrovascular disease. We established the H/R injury model in SH-SY5Y cells after administrating EGb50. Subsequently, the mitochondrial membrane potential and the concentration of intracellular Ca²âº were measured by flow cytometer. The levels of optic atrophy1 (Opa1) and dynamin-like protein 1 (Drp1) were evaluated by immunofluorescence and western blot. The results showed that the mitochondrial membrane potential was decreased and the level of intracellular Ca²âº was increased after H/R injury. Moreover, the expression of mitochondrial fusion protein Opa1 was decreased, while the expression of mitochondrial fission protein Drp1 was increased. However, EGb50 significantly increased the mitochondrial membrane potential and suppressed the level of intracellular Ca²âº. In addition, EGb50 increased the expression of Opa1 and decreased the expression of Drp1. The results demonstrated that EGb50 has a neuroprotective effect on SH-SY5Y cells after H/R injury, and could improve the energy metabolism and mitochondrial function. The underlying mechanisms may be associated with the regulation of mitochondrial fusion and fission, which provided data support for the treatment of ischemic cerebrovascular disease with EGb50.

[Effect of Sailuotong capsule on mitochondrial dynamics in focal cerebral ischemia/reperfusion rats].

To observe the protective effect and mechanism of Sailuotong capsule in focal cerebral ischemia/reperfusion. The 90 min middle cerebral artery occlusion (MCAO) reperfusion model was established. The expressions of dynamin-related protein 1 ( Drp1) and optic atrophy 1 (Opa1) were tested by Western blot. The transmission electron microscope was used to observe the changes in the mitochondrial ultra-structure. The pathological morphological changes were observed through the HE staining. The immunohistochemical method was used to test Drp1 and Opa1 expressions. Sailuotong capsule (33, 16.5 mg x kg(-1), ig) can inhibit the abnormal mitochondrial fission and fusion in the cortical area on the ischemia side and the mitochondrial fission gene expression and promote the mitochondrial fusion gene Opa1 expression, so as to alleviate the energy metabolism disorder caused by ischemia/reperfusion. Sailuotong capsule can inhibit the abnormal mitochondrial dynamics in peri-ischemic regions and maintain the normal morphology of mitochondria, which may be the mechanism of Sailuotong capsule in promoting the self-recovery function in the ischemic brain region.

Panax notoginseng saponins stimulates the differentiation and neurite development of C17.2 neural stem cells against OGD/R injuries via mTOR signaling.

Ischemic stroke remains a major disease worldwide, and most stroke patients often suffer from serious sequelae. Endogenous neurogenesis matters in the repair and regeneration of impaired neural cells after stroke. We have previously reported in vivo that PNS could strengthen the proliferation and differentiation of neural stem cells (NSCs), modulate synaptic plasticity and protect against ischemic brain injuries in cerebral ischemia rats, which could be attributed to mTOR signaling activation. Next, to obtain further insights into the function mechanism of PNS, we evaluated the direct influence of PNS on the survival, differentiation and synaptic development of C17.2 NSCs in vitro. The oxygen glucose deprivation/reperfusion (OGD/R) model was established to mimic ischemic brain injuries. We found that after OGD/R injuries, PNS improved the survival of C17.2 cells. Moreover, PNS enhanced the differentiation of C17.2 cells into neurons and astrocytes, and further promoted synaptic plasticity by significantly increasing the expressions of synapse-related proteins BDNF, SYP and PSD95. Meanwhile, PNS markedly activated the Akt/mTOR/p70S6K pathway. Notably, the mTOR inhibitor rapamycin pretreatment could reverse these desirable results. In conclusion, PNS possessed neural differentiation-inducing properties in mouse C17.2 NSCs after OGD/R injuries, and Akt/mTOR/p70S6K signaling pathway was proved to be involved in the differentiation and synaptic development of C17.2 cells induced by PNS treatment under the in vitro ischemic condition. Our findings offer new insights into the mechanisms that PNS regulate neural plasticity and repair triggered by NSCs, and highlight the potential of mTOR signaling as a therapeutic target for neural restoration after ischemic stroke.

Metabolomics-Based Effects of a Natural Product on Remyelination After Cerebral Ischemia Injury Via GABABR-pCREB-BDNF Pathway.

BACKGROUND: Yi-Qi-Tong-Luo Granules (YQTLs) is a natural compound of Traditional Chinese Medicine authorized by China Food and Drug Administration (CFDA). These granules are employed in the convalescent stage of cerebral infarction and render notable clinical efficacy. This study aims to uncover the underlying mechanisms of YQTLs on remyelination after cerebral ischemia injury. MATERIALS AND METHODS: We established cerebral ischemia model in rats using microsphere-induced multiple cerebral infarction (MCI). We evaluated the pharmacological effects of YQTLs on MCI rats, through Morri's water maze test, open field test, hematoxylin and eosin staining, and glycine silver immersion. We employed liquid chromatography mass spectrometry metabolomics to identify differential metabolites. Enzyme-linked immunosorbent assay was utilized to measure the release of neurotrophins, while immunofluorescence staining was used to assess oligodendrocyte precursor cells differences and myelin regeneration. We used Western blotting to validate the protein expression of remyelination-associated signaling pathways. RESULTS: YQTLs significantly improves cognitive function following cerebral ischemia injury. Pathological tissue staining revealed that YQTLs administration inhibits neuronal denaturation and neurofibrillary tangles. We identified 141 differential metabolites among the sham, MCI, and YQTLs-treated MCI groups. Among these metabolites, neurotransmitters were identified, and notably, gamma-aminobutyric acid (GABA) showed marked improvement in the YQTLs group. The induction of neurotrophins, such as brain-derived neurotrophic factor (BDNF) and PDGFAA, upregulation of olig2 and MBP expression, and promotion of remyelination were evident in YQTLs-treated MCI groups. Gamma-aminobutyric acid B receptors (GABABR), pERK/extracellular regulated MAP kinase, pAKT/protein kinase B, and pCREB/cAMP response element-binding were upregulated following YQTLs treatment. CONCLUSION: YQTLs enhance the binding of GABA to GABABR, thereby activating the pCREB/BDNF signaling pathway, which in turn increases the expression of downstream myelin-associated proteins and promotes remyelination and cognitive function.

Shuangshen ningxin formula attenuates cardiac microvascular ischemia/reperfusion injury through improving mitochondrial function.

ETHNOPHARMACOLOGICAL RELEVANCE: Shuangshen Ningxin Formula (SSNX) is a traditional Chinese medicine formula used to treat myocardial ischemia-reperfusion injury (MIRI). A randomized controlled trial previously showed that SSNX reduced cardiovascular events, and experiments have also verified that SSNX attenuated ischemia-reperfusion (I/R) injury. However, the mechanism of SSNX in the treatment of microvascular I/R injury is still unclear. AIM OF THE STUDY: To determine whether SSNX protects the microvasculature by regulating I/R induction in rats and whether this effect depends on the regulation of NR4A1/Mff/Drp1 pathway. METHODS: The anterior descending coronary artery was ligated to establish a rat MIRI model with 45 min of ischemia and 24 h of reperfusion. The rats were subjected to a 7-day pretreatment with SSNX and nicorandil, after which their cardiac function and microvascular functional morphology were evaluated through diverse methods, including hematoxylin and eosin (HE) staining, wheat germ agglutinin (WGA) staining, and transmission electron microscopy. Cell apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Additionally, serum levels of ET-1 and eNOS were determined through an enzyme-linked immunosorbent assay (ELISA). The expression levels of NR4A1, Mff, and proteins related to mitochondrial fission were examined by Western blot (WB). Cardiac microcirculation endothelial cells (CMECs) were cultured and the oxygen-glucose deprivation/reoxygenation (OGD/R) model was duplicated. Following treatment with SSNX and DIM-C-pPhOH, an NR4A1 inhibitor, cell viability was assessed. Fluorescence was used to evaluate mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (MPTP) opening. Moreover, vascular endothelial function was evaluated through transendothelial electrical resistance (TEER), Transwell assays and tube formation assays. RESULTS: The results showed that SSNX reduced the infarction area and no-flow area, improved cardiac function, mitigated pathological alterations, increased endothelial nitric oxide synthase expression, protected endothelial function, and attenuated microvascular damage after I/R injury. I/R triggered mitochondrial fission and apoptotic signaling in CMECs, while SSNX restored mitochondrial fission to normal levels and inhibited mitochondrial apoptosis. A study using CMECs revealed that SSNX protected endothelial function after OGD/R, attenuating the increase in NR4A1/Mff/Drp1 protein and inactivating VDAC1, HK2, cytochrome c (cyt-c) and caspase-9. Research also shows that SSNX can affect CMEC cell migration and angiogenesis, reduce mitochondrial membrane potential damage, and inhibit membrane opening. Moreover, DIM-C-pPhOH, an NR4A1 inhibitor, partially imitated the effect of SSNX. CONCLUSION: SSNX has a protective effect on the cardiac microvasculature by inhibiting the NR4A1/Mff/Drp1 pathway both in vivo and in vitro.

Hydroxysafflor Yellow A Inhibits Pyroptosis and Protecting HUVECs from OGD/R via NLRP3/Caspase-1/GSDMD Pathway.

OBJECTIVE: To observe the protective effect and mechanism of hydroxyl safflower yellow A (HSYA) from myocardial ischemia-reperfusion injury on human umbilical vein endothelial cells (HUVECs). METHODS: HUVECs were treated with oxygen-glucose deprivation reperfusion (OGD/R) to simulate the ischemia reperfusion model, and cell counting kit-8 was used to detect the protective effect of different concentrations (1.25-160 µ mol/L) of HSYA on HUVECs after OGD/R. HSYA 80 µ mol/L was used for follow-up experiments. The contents of inflammatory cytokines interleukin (IL)-18, IL-1 ß, monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor α (TNF-α) and IL-6 before and after administration were measured by enzyme-linked immunosorbent assay. The protein expressions of toll-like receptor, NOD-like receptor containing pyrin domain 3 (NLRP3), gasdermin D (GSDMD) and GSDMD-N-terminal domain (GSDMD-N) before and after administration were detected by Western blot. NLRP3 inflammasome inhibitor cytokine release inhibitory drug 3 sodium salt (CRID3 sodium salt, also known as MCC950) and agonist were added, and the changes of NLRP3, cysteine-aspartic acid protease 1 (Caspase-1), GSDMD and GSDMD-N protein expressions were detected by Western blot. RESULTS: HSYA inhibited OGD/R-induced inflammation and significantly decreased the contents of inflammatory cytokines IL-18, IL-1 ß, MCP-1, TNF-α and IL-6 (P<0.01 or P<0.05). At the same time, by inhibiting NLRP3/Caspase-1/GSDMD pathway, HSYA can reduce the occurrence of pyroptosis after OGD/R and reduce the expression of NLRP3, Caspase-1, GSDMD and GSDMD-N proteins (P<0.01). CONCLUSIONS: The protective effect of HSYA on HUVECs after OGD/R is related to down-regulating the expression of NLRP3 inflammasome and inhibiting pyroptosis.

Molecular co-assembly of multicomponent peptides for the generation of nanomaterials with improved peroxidase activities.

Molecular self-assembly of peptides provides an effective approach for the fabrication of biomimetic enzymes in recent years. However, due to sophisticated architectures of native peroxidases, precise mimicking of the structure of hemin pockets within peroxidases with a single component of peptide is a great challenge. Herein, we decided to explore the potential of multicomponent peptide assembly to prepare artificial peroxidases with biomimetic hemin pockets. Hydrophobic peptides (e.g., KH, QH, NH, NHNH and NHNHNH) provide a supramolecular scaffold to form an appropriate hydrophobic binding pocket, and a proximal histidine ligand to bind hemin through the coordination between imidazole and hemin iron. A peptide with hydrophilic residues (e.g., NapFFHEKRH) was incorporated to supply distal histidine residues and hydrophilic amino acids in the distal pocket to promote H2O2 binding and stabilize a high oxidation state. Due to the synergistic molecular interactions, the components of NH, NapFFHEKRH and hemin could self-assemble into nanostructures with biomimetic microenvironments for increased substrate binding and catalytic rates of TMB oxidation, compared to the catalytic system of NHhemin without NapFFHEKRH. This work illustrates an approach for fabricating artificial peroxidases with biomimetic structural features and improved catalytic activities from co-assembly of multicomponent peptides.

Bioactive peptides for anticancer therapies.

Cancer is a serious concern in public health worldwide. Numerous modalities including surgery, radiotherapy, and chemotherapy, have been used for cancer therapies in clinic. Despite progress in anticancer therapies, the usage of these methods for cancer treatment is often related to deleterious side effects and multidrug resistance of conventional anticancer drugs, which have prompted the development of novel therapeutic methods. Anticancer peptides (ACPs), derived from naturally occurring and modified peptides, have received great attention in these years and emerge as novel therapeutic and diagnostic candidates for cancer therapies, because of several advantages over the current treatment modalities. In this review, the classification and properties of ACPs, the mode of action and mechanism of membrane disruption, as well as the natural sources of bioactive peptides with anticancer activities were summarised. Because of their high efficacy for inducing cancer cell death, certain ACPs have been developed to work as drugs and vaccines, evaluated in varied phases of clinical trials. We expect that this summary could facilitate the understanding and design of ACPs with increased specificity and toxicity towards malignant cells and with reduced side effects to normal cells.

Protective effects of baicalin against L-glutamate-induced oxidative damage in HT-22 cells by inhibiting NLRP3 inflammasome activation via Nrf2/HO-1 signaling.

Objectives: To explore the ability and underlying molecular mechanisms involved in the protective effects of Baicalin (BA) against L-Glutamate-induced mouse hippocampal neuron cell line HT-22. Materials and Methods: The cell injury model of HT-22 cells was induced by L-glutamate, and cell viability and damage were detected by CCK-8 and LDH assays. Generation of intracellular reactive oxygen species (ROS) was measured by DCFH-DA in situ fluorescence method. The SOD activity and MDA concentration in the supernatants were determined by WST-8 and colorimetric method, respectively. Furthermore, Western blot and real-time qPCR analysis were utilized to detect the expression levels of the Nrf2/HO-1 signaling pathway and NLRP3 inflammasome proteins and genes. Results: L-Glutamate exposure induced cell injuries in HT-22 cells, and the concentration of 5 mM L-Glutamate was chosen to be the modeling condition. Co-treatment with BA significantly promoted cell viability and reduced LDH release in a dose-dependent manner. In addition, BA attenuated the L-Glutamate-induced injuries by decreasing the ROS production and MDA concentration, while increasing the SOD activity. Moreover, we also found that BA treatment up-regulated the gene and protein expression of Nrf2 and HO-1, and then inhibited the expression of NLRP3. Conclusion: Our study found that BA could relieve oxidative stress damage of HT-22 cells induced by L-Glutamate, and the mechanism might be related to the activation of Nrf2/HO-1 and inhibition of NLRP3 inflammasome.

Association of genetic variants of CircCHST15 with oral squamous cell carcinoma in the Chinese Han population.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is the most common cancer in the oral cavity. The relationship between the genetic susceptibility of circCHST15 and OSCC remains unclear. METHODS: Genetic variants of circCHST15 were screened using a genotyping analysis from 1044 patients with OSCC and 3199 healthy participants. The circCHST15 expression was detected in 32 pairs of OSCC tissues. The circular RNA quantitative trait locus analysis and the reporter gene assay were performed for verification. RESULTS: The circCHST15 expression was upregulated in OSCC (Wilcoxon p < 1e-3). The genotyping analysis screened out 61 loci in circCHST15 associated with the risk of OSCC. After adjustment and annotation, rs28707473 (A > C, odds ratio = 1.21, 95% CI: 1.076-1.361, p = 1.453e-3) was selected. This genetic variation could elevate the circCHST15 expression level possibly by altering the structure of circular RNAs and affecting transcription factor binding. CONCLUSIONS: The results of this study suggested that genetic variants of circCHST15 may contribute to OSCC susceptibility.

The glymphatic system: a new perspective on brain diseases.

The glymphatic system is a brain-wide perivascular pathway driven by aquaporin-4 on the endfeet of astrocytes, which can deliver nutrients and active substances to the brain parenchyma through periarterial cerebrospinal fluid (CSF) influx pathway and remove metabolic wastes through perivenous clearance routes. This paper summarizes the composition, overall fluid flow, solute transport, related diseases, affecting factors, and preclinical research methods of the glymphatic system. In doing so, we aim to provide direction and reference for more relevant researchers in the future.