Extracellular vesicle-derived TP53BP1, CD34, and PBX1 from human peripheral blood serve as potential biomarkers for the assessment and prediction of vascular aging

BACKGROUND

Vascular aging is an important pathophysiological basis for the senescence of various organs and systems in the human body, and it is a common pathogenetic trigger for many chronic diseases in the elderly.

METHODS

The extracellular vesicles (EVs) from young and aged umbilical vein endothelial cells were isolated and identified by qPCR the differential expression levels of 47 mRNAs of genes closely related to aging in the two groups.

RESULTS

There were significant differences in the expression levels of 18 genes (we noted upregulation in PLA2G12A, TP53BP1, CD144, PDE11A, FPGT, SERPINB4, POLD1, and PPFIBP2 and downregulation in ATP2C2, ROBO2, RRM2, GUCY1B1, NAT1-14, VEGFR2, WTAPP1, CD146, DMC1, and GRIK2). Subsequent qPCR identification of the above-mentioned genes in PBMCs and plasma-EVs from the various age groups revealed that the trend in expression levels in peripheral blood plasma-EVs of the different age groups was approximately the same as that in PBMCs. Of these mRNAs, the expression of four genes-PLA2G12A, TP53BP1, OPRL1, and KIAA0895-was commensurate with increasing age. In contradistinction, the expression trend of four genes (CREG1, PBX1, CD34, and SLIT2) was inversely proportional to the increase in age. Finally, by taking their intersection, we determined that the expression of TP53BP1 was upregulated with increasing human age and that CD34 and PBX1 were downregulated with increasing age.

CONCLUSION

Our study indicates that human peripheral blood plasma-EV-derived TP53BP1, CD34, and PBX1 potentially comprise a noninvasive biomarker for assessing and predicting vascular aging.

Capsaicin inhibits A7r5 cell senescence via the mitochondrial carrier protein Slc25a12

Aging of vascular smooth muscle cells (VSMCs) is the principal factor responsible for the loss of vascular function, and continuous exposure to high glucose is one of the key factors contributing to the aging of VSMCs. This study established a high glucose-induced senescence model of the A7r5 cell line and used transcriptome sequencing to screen the regulatory target genes of high glucose-induced cellular senescence. The study revealed that the expression of the Slc25a12 gene, which belongs to the solute carrier family 25 member 12, was notably reduced following damage caused by high glucose levels. This inhibition was shown to cause mitochondrial malfunction and cellular senescence. The encoded product of the Slc25a12 gene is a mitochondrial carrier protein that binds to calcium and aids in transporting aspartate for glutamate exchange within the inner mitochondrial membrane. Mitochondrial dysfunction compromises the cell's capacity to resist oxidation and repair damage, and is an inherent element in hastening cellular aging. Moreover, our findings validated that the transient receptor potential vanilloid 1 (TRPV1) agonist capsaicin hindered the decrease in Slc25a12 expression, prevented mitochondrial dysfunction, and blocked cellular senescence. Could the regulation of Slc25a12 expression by capsaicin restore cellular mitochondrial function and restrict senescence? In vitro tests have verified that interference with A7r5 Slc25a12 noticeably diminishes capsaicin's effectiveness in repairing mitochondrial function and inhibiting senescence. The findings indicate that capsaicin delays mitochondrial dysfunction and therefore hinders cellular senescence by regulating the mitochondrial membrane protein Slc25a12 in the A7r5 cell line.

[Impact of social support for schizophrenia patients on their quality of life and family life satisfaction]

Objective: To explore the relationship of social support to patients with schizophrenia, family burden with patients' quality of life and family life satisfaction. Methods: Multi-stage stratified cluster random sampling was used to select 358 patients with schizophrenia and 358 patients' family members in Gansu Province who met the inclusion criteria were included. The Social Support Rating Scale, Family Burden Scale, Satisfaction with Life Scale and Quality of Life Scale were used in the survey. AMOS 24.0 was used to explore the pathway of influence of family burden on social support to patients with schizophrenia, patients' quality of life and patients' family life satisfaction. Results: There was a two-by-two significant correlation between patients' access to social support, family burden, patients' life quality and family life satisfaction (P<0.05), and the total score of the social support scale negatively predicted the total score of the life quality scale (β=-0.28, P<0.05) and positively predicted the total score of the life satisfaction scale (β=0.52, P<0.05). Family burden was a full mediator between the social support to the patient and the patient's quality of life, and as a partial mediator between the social support to the patient and the family's life satisfaction. Conclusions: Social support to people with schizophrenia is a significant predictor of their quality of life and family life satisfaction. Family burden mediates the relationship of social support to patients with their quality of life and family life satisfaction. Interventions can focus on increasing social support for the patient and reducing the burden on the patient's family to improve the patient's quality of life and increase the satisfaction of the patient's family.

RS-5645 attenuates inflammatory cytokine storm induced by SARS-CoV-2 spike protein and LPS by modulating pulmonary microbiota

An inflammatory cytokine storm is considered an important cause of death in severely and critically ill COVID-19 patients, however, the relationship between the SARS-CoV-2 spike (S) protein and the host's inflammatory cytokine storm is not clear. Here, the qPCR results indicated that S protein induced a significantly elevated expression of multiple inflammatory factor mRNAs in peripheral blood mononuclear cells (PBMCs), whereas RS-5645 ((4-(thiophen-3-yl)-1-(p-tolyl)-1H-pyrrol-3-yl)(3,4,5-trimethoxyphenyl)methanone) attenuated the expression of the most inflammatory factor mRNAs. RS-5645 also significantly reduced the cellular ratios of CD45+/IFNγ+, CD3+/IFNγ+, CD11b+/IFNγ+, and CD56+/IFNγ+ in human PBMCs. In addition, RS-5645 effectively inhibited the activation of inflammatory cells and reduced inflammatory damage to lung tissue in mice. Sequencing results of 16S rRNA v3+v4 in mouse alveolar lavage fluid showed that there were 494 OTUs overlapping between the alveolar lavage fluid of mice that underwent S protein+ LPS-combined intervention (M) and RS-5645-treated mice (R), while R manifested 64 unique OTUs and M exhibited 610 unique OTUs. In the alveoli of group R mice, the relative abundances of microorganisms belonging to Porphyromonas, Rothia, Streptococcus, and Neisseria increased significantly, while the relative abundances of microorganisms belonging to Psychrobacter, Shimia, and Sporosarcina were significantly diminished. The results of KEGG analysis indicated that the alveolar microbiota of mice in the R group can increase translation and reduce the activity of amino acid metabolism pathways. COG analysis results indicated that the abundance of proteins involved in ribosomal structure and biogenesis related to metabolism was augmented in the alveolar microbiota of the mice in the R group, while the abundance of proteins involved in secondary metabolite biosynthesis was significantly reduced. Therefore, our research results showed that RS-5645 attenuated pulmonary inflammatory cell infiltration and the inflammatory storm induced by the S protein and LPS by modulating the pulmonary microbiota.

TRPV1 sustains microglial metabolic reprogramming in Alzheimer's disease

As the brain-resident innate immune cells, reactive microglia are a major pathological feature of Alzheimer's disease (AD). However, the exact role of microglia is still unclear in AD pathogenesis. Here, using metabolic profiling, we show that microglia energy metabolism is significantly suppressed during chronic Aβ-tolerant processes including oxidative phosphorylation and aerobic glycolysis via the mTOR-AKT-HIF-1α pathway. Pharmacological activation of TRPV1 rescues Aβ-tolerant microglial dysfunction, the AKT/mTOR pathway activity, and metabolic impairments and restores the immune responses including phagocytic activity and autophagy function. Amyloid pathology and memory impairment are accelerated in microglia-specific TRPV1-knockout APP/PS1 mice. Finally, we showed that metabolic boosting with TRPV1 agonist decreases amyloid pathology and reverses memory deficits in AD mice model. These results indicate that TRPV1 is an important target regulating metabolic reprogramming for microglial functions in AD treatment.

PPARα Targeting GDF11 Inhibits Vascular Endothelial Cell Senescence in an Atherosclerosis Model

Atherosclerosis (AS) is a complex vascular disease that seriously harms the health of the elderly. It is closely related to endothelial cell aging, but the role of senescent cells in atherogenesis remains unclear. Studies have shown that peroxisome proliferator-activated receptor alpha (PPARα) inhibits the development of AS by regulating lipid metabolism. Our previous research showed that PPARα was involved in regulating the repair of damaged vascular endothelial cells. Using molecular biology and cell biology approaches to detect senescent cells in atherosclerosis-prone apolipoprotein E-deficient (Apoe -/-) mice, we found that PPARα delayed atherosclerotic plaque formation by inhibiting vascular endothelial cell senescence, which was achieved by regulating the expression of growth differentiation factor 11 (GDF11). GDF11 levels declined with age in several organs including the myocardium, bone, central nervous system, liver, and spleen in mice and participated in the regulation of aging. Our results showed that PPARα inhibited vascular endothelial cell senescence and apoptosis and promoted vascular endothelial cell proliferation and angiogenesis by increasing GDF11 production. Taken together, these results demonstrated that PPARα inhibited vascular endothelial cell aging by promoting the expression of the aging-related protein GDF11, thereby delaying the occurrence of AS.

MicroRNA-146b-5p overexpression attenuates premature ovarian failure in mice by inhibiting the Dab2ip/Ask1/p38-Mapk pathway and γH2A.X phosphorylation

OBJECTIVE

To examine the role of high-fat and high-sugar (HFHS) diet-induced oxidative stress, which is a risk factor for various diseases, in premature ovarian failure (POF).

MATERIALS AND METHODS

Ovarian granulosa cells (OGCs) were isolated from mice and cultured in medium supplemented with HFHS and poly (lactic-co-glycolic acid) (PLGA)-cross-linked miR-146b-5p nanoparticles (miR-146@PLGA). RNA and protein expression levels were examined using quantitative real-time polymerase chain reaction and Western blotting, respectively. HFHS diet-induced POF model mice were administered miR-146@PLGA.

RESULTS

The ovarian tissue of mice fed a HFHS diet exhibited the typical pathological characteristics of POF. HFHS supplementation induced oxidative stress injury in the mouse OGCs, activation of the Dab2ip/Ask1/p38-Mapk signalling pathway and phosphorylation of γH2A.X in vitro and in vivo. The results of the luciferase reporter assay revealed that miR-146 specifically downregulated p38-Mapk14 expression. Meanwhile, co-immunoprecipitation and Western blot analyses revealed that HFHS supplementation upregulated nuclear p38-Mapk14 expression and consequently enhanced γH2A.X (Ser139) phosphorylation. The HFHS diet-induced POF mouse model treated with miR-146@PLGA exhibited downregulated p38-Mapk14 expression in the OGCs, mitigated OGC ageing and alleviated the symptoms of POF.

CONCLUSIONS

This study demonstrated that HFHS supplementation activates the Dab2ip/Ask1/p38-Mapk signalling pathway and promotes γH2A.X phosphorylation by inhibiting the expression of endogenous miR-146b-5p, which results in OGC ageing and POF development.

Bushen Jiangzhi formula reduces atherosclerosis in apoE-/- mice through autophagy

OBJECTIVE

To study the effect of Bushen Jiangzhi formula (BSJZF) on atherosclerosis (AS) in apolipoprotein E knockout (apoE-/-) mice and the underlying mechanism.

METHODS

We used a high fat diet to induce AS in apoE-/- mice. The mice were randomly divided into four groups: model, BSJZF, atorvastatin, and 3-methyladenine groups. Syngeneic C57BL/6 mice of the same age were used for the control group. Autophagosomes in the aorta were examined by transmission electron microscopy. Morphology, lipid accumulation, and collagen deposition in the aorta were examined by hematoxylin and eosin, Oil Red O, and Masson's staining, respectively. Serum levels of tumor necrosis factor alpha (TNF-), interferon gamma (IFN-), and interleukin 10 (IL-10) were measured by enzyme-linked immunoassays. Protein expression of microtubule-associated protein light chain 3 (LC3), Beclin 1, and p62 in the aorta were examined by Western blot analyses.

RESULTS

ApoE-/- mice fed a high fat diet exhibited AS symptoms including less autophagosomes in the aorta, higher serum levels of TNF-a, IFN-r, and p62, and lower serum levels of IL-10, LC3, and Beclin 1. Treatment with BSJZF significantly reduced the area of the aortic plaque, decreased expression of TNF-a, IFN-r, and p62, and increased expression of IL-10, LC3, and Beclin 1.

CONCLUSION

Our findings suggest that BSJZF promotes autophagy and reduces inflammation by regulating the expression of autophagy-related proteins LC3, Beclin 1, and p62, thereby effectively treating AS.

The potassium channel KCa3.1 represents a valid pharmacological target for microgliosis-induced neuronal impairment in a mouse model of Parkinson's disease

Background

Recent studies described a critical role for microglia in Parkinson’s disease (PD), where these central nerve system resident immune cells participate in the neuroinflammatory microenvironment that contributes to dopaminergic neurons loss in the substantia nigra. Understanding the phenotype switch of microgliosis in PD could help to identify the molecular mechanism which could attenuate or delay the progressive decline in motor function. KCa3.1 has been reported to regulate the “pro-inflammatory” phenotype switch of microglia in neurodegenerative pathological conditions.

Methods

We here investigated the effects of gene deletion or pharmacological blockade of KCa3.1 activity in wild-type or KCa3.1^−/− mice after treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a mouse model of PD. MPTP-induced PD mouse model was subjected to the rotarod test to evaluate the locomotor ability. Glia activation and neuron loss were measured by immunostaining. Fluo-4 AM was used to measure cytosolic Ca²⁺ level in 1-methyl-4-phenylpyridinium (MPP⁺)-induced microgliosis in vitro.

Results

We report that treatment of MPTP-induced PD mouse model with gene deletion or pharmacological blockade of KCa3.1 with senicapoc improves the locomotor ability and the tyrosine hydroxylase (TH)-positive neuron number and attenuates the microgliosis and neuroinflammation in the substantia nigra pars compacta (SNpc). KCa3.1 involves in store-operated Ca²⁺ entry-induced Ca²⁺ overload and endoplasmic reticulum stress via the protein kinase B (AKT) signaling pathway during microgliosis. Gene deletion or blockade of KCa3.1 restored AKT/mammalian target of rapamycin (mTOR) signaling both in vivo and in vitro.

Conclusions

Taken together, these results demonstrate a key role for KCa3.1 in driving a pro-inflammatory microglia phenotype in PD.

Identification of a novel regulatory pathway for PPARα by RNA-seq characterization of the endothelial cell lipid peroxidative injury transcriptome

Endothelial dysfunction caused by endothelial cell injuries is the initiating factor for atherosclerosis (AS), and lipid peroxidative injury is one of a dominant factor for AS pathogenesis. Using RNA-seq, we compared changes in transcriptome expression before and after endothelial cell injury, and found 311 differentially expressed genes (DEGs), of which 258 genes were upregulated and 53 genes were downregulated. The protein–protein interactions (PPIs) between the genes were analysed using the STRING database, and a PPI network of DEGs was constructed. The relationship distributions among these PPIs were analysed by performing network node statistics. We found that in the top 20 DEGs with high connected protein nodes in the PPI network, 16 were upregulated and 4 were downregulated. Gene ontology (GO) functional enrichment analysis and KEGG pathway enrichment analysis on the DEGs were also performed. By comparing the upregulated expressed genes with high connected protein nodes in the PPI network to those related to endothelial cell lipid damage and repair in the GO analysis, we identified seven genes (NOX4, PPARA, CCL2, PDGFB, IL8, VWF, CD36) and verified their expression levels by real-time polymerase chain reaction. The protein interactions between the seven genes were then analysed using the STRING database. The results predicted that CCL2 interacts with NOX4, PPARα, PDGFβ and VWF individually. Thus, we examined the protein expression levels of CCL2, NOX4, PPARα, PDGFβ and VWF, and found that the expression levels of all proteins were significantly upregulated after the lipid peroxidative injury, with CCL2 and PPARα exhibiting the highest expression levels. Therefore, we investigated the interregulatory relationship between CCL2 and PPARα and their roles in the repair of endothelial cell injury. With the help of gene overexpression and knockdown techniques, we discovered that PPARα promotes the repair of endothelial cell injury by upregulating CCL2 expression in human umbilical vein endothelial cells but that CCL2 cannot regulate PPARα expression. Therefore, we believe that PPARα participates in the repair of endothelial cell lipid peroxidative injury through regulating the expression of CCL2.

Quercetin protects against atherosclerosis by regulating the expression of PCSK9, CD36, PPARγ, LXRα and ABCA1

The aim of this study was to investigate the mechanisms through which quercetin protects against atherosclerosis (AS) in apoE‑/‑ mice by regulating the expression of proprotein convertase subtilisin/kexin type 9 (PCSK9), cluster of differentiation 36 (CD36), peroxisome proliferator‑activated receptor γ (PPARγ), liver X receptor α (LXRα) and ATP binding cassette transporter A1 (ABCA1). We established an animal model of high‑fat diet induced AS using apoE‑/‑ mice. H&E, Oil Red O and Masson's trichrome staining were performed on aortic sinus and liver tissue sections to evaluate the histopathology, lipid accumulation and collagen deposition, respectively. Filipin staining was performed to detect free cholesterol (FC) in the aortic sinus. ELISA was performed to measure the serum levels of lipids including total cholesterol (TC), triglyceride (TG), high‑density lipoprotein‑cholesterol (HDL‑C), low‑density lipoprotein‑cholesterol (LDL‑C) and oxidized low‑density lipoprotein (oxLDL), as well as the levels of inflammatory cytokines, including tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and IL‑10. Western blot analysis was performed to analyze the protein expression levels of PCSK9, CD36, PPARγ, LXRα and ABCA1 in both the aorta and liver tissue. H&E staining revealed the presence of atherosclerotic plaques in the aortic sinus. Oil Red O staining revealed the existence of massive red‑stained lipids in the aortic sinus and Masson's trichrome staining revealed decreased collagen fibers and increased plaque instability. Filipin staining revealed that free cholesterol levels in the aorta sinus were increased. In addition, H&E staining suggested hepatocyte structural disorder in the model group, and Oil Red O staining revealed a cytoplasm filled with lipid droplets, which contained a large amount of red‑stained lipids. Masson's trichrome staining revealed that the liver tissue of the model group had fewer collagen fibers compared with that of the control group. Moreover, the mice in the model group had higher serum TC, LDL‑C, oxLDL, TNF‑α and IL‑6 levels, and lower IL‑10 levels. The protein expression levels of PCSK9 and CD36 were increased, while those of PPARγ, LXRα and ABCA1 were decreased in the aortas and livers of the model group mice. However, treatment with quercetin attenuated all these effects. On the whole, these results demonstrate that quercetin prevents the development of AS in apoE‑/‑ mice by regulating the expression of PCSK9, CD36, PPARγ, LXRα and ABCA1.

Efficacy of Shoushen granule on adenosine triphosphate binding cassette transporter A1, proprotein convertase subtilisin/kexin type 9 and toll-like receptor 4/nuclear factor kappa-B signaling pathway in ApoE-knockout mice

OBJECTIVE

To evaluate the efficacy of Shoushen granule, prepared with four Chinese medicinals, on the targeted regulation of adenosine triphosphate binding cassette transporter A1 (ABCA1) through proprotein convertase subtilisin/kexin type 9 (PCSK9) and toll-like receptor 4 (TLR4) / nuclear factor kappa-B (NF-κB) signaling pathway to affect atherosclerosis (AS) in ApoE-knockout (ApoE-/-) mice.

METHODS

ApoE-/- mice fed with a high-fat diet were used for AS modeling and divided into Model, Shoushen, and Atorvastatin groups. C57BL/6J mice at the same age and background strain were included in the Control group. Western blot and immunohistochemistry were used to measure ABCA1, PCSK9, TLR4, and NF-κB protein expression in mouse aortas. Enzyme-linked immuno sorbent assay was used to measure mouse serum tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), monocyte chemoattractant protein 1 (MCP-1), and intercellular cell adhesion molecule-1 (ICAM-1) expression. Serum lipid profiles and histopathology were also assessed. Shoushen granule were composed of Heshouwu (Radix Polygoni Multiflori) 15 g, Gouqizi (Fructus Lycii) 15 g, Sheng shanzha (Raw Fructus Crataegus Pinnatifidae) 10 g, and Sanqi (Radix Notoginseng) 3 g.

RESULTS

ApoE-/- mice fed with a high-fat diet had notable AS lesions, with reduced ABCA1 and IL-10 levels, elevated PCSK9, TLR4, NF-κB, TNF-α, MCP-1, and ICAM-1 expression, and increased total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) contents. With drug interventions, the areas of AS plaques were significantly reduced, the ABCA1 and IL-10 levels were increase, while the PCSK9, TLR4, NF-κB, TC, and LDL-C contents, and the TNF-α, MCP-1, and ICAM-1 expression were reduced.

CONCLUSION

Shoushen granule effectively interfered with AS development by antagonizing the expression of key factors of the PCSK9 and TLR4/NF-κB signaling pathway to upregulate ABCA1 expression.

Anti-atherosclerotic effects of LXRα agonist through induced conversion of M1 macrophage to M2

Liver X receptor alpha (LXRα) plays important roles in lipid metabolism and inflammation. Therefore, it is essential for protection against atherosclerosis (AS). In AS plaques, the key cells involved in lipid metabolism and inflammation are macrophages. However, the mechanism by which LXRα regulates macrophage involvement in AS formation remains unclear. In this study, we first confirmed the effects of an LXRα agonist (T0901317) and antagonist (GSK2033) on foam cell formation and inflammation in vivo and in vitro. Indeed, T0901317 reduced the number of macrophages in AS plaques and decreased the number of migrated macrophages, as assessed using an in vitro transwell assay. Next, we investigated the relationship between the reduction in macrophages in AS plaques and cytokine levels or foam cell formation. The results show that T0901317 reduced the number of high cholesterol-induced M1 macrophages by converting them into M2 macrophages in vivo and in vitro. Due to this phenotypic transition of macrophages, the inflammatory response was alleviated, and lipid metabolism was enhanced in AS plaques. This effect was achieved by promoting the expression of reverse transporters (ATP-binding cassette transporter member 1 and ATP-binding cassette subfamily G member 1) and inhibiting the phosphorylation of nuclear factor-κB-mediated phosphorylation.

EriB targeted inhibition of microglia activity attenuates MPP+ induced DA neuron injury through the NF-κB signaling pathway

Accumulating evidence indicates that microglia activation is associated with an increased risk for developing Parkinson’s disease (PD). With the progressive and selective degeneration of dopaminergic (DA) neurons, proinflammatory cytokines are elevated in the substantia nigra (SN) of PD patients. Thus, anti-inflammation has become one of the therapeutic strategies of PD. Eriocalyxin B (EriB), a diterpenoid isolated from Isodoneriocalyx, was previously reported to have anti-inflammatory effects. MPTP mouse model and MPP⁺ cell model were prepared to detect the role of EriB in regulating microglia activation and neuron protection. Midbrain tissue and primary cultured microglia and neuron were used to examine microglia activation and neuron damage by immunofluorescence, real-time PCR, western-blot and Elisa assay. Open field activity test was to evaluate the changes of behavioral activity in MPTP-induced PD mouse model. EriB was efficacious in protecting DA neurons by inhibiting microglia activation in PD mice model. Treatment with EriB led to amelioration of disordered sports of PD mice model, which correlated with reduced microglia-associated inflammation and damaged DA neurons. EriB treatment abolished MPP⁺ induced microglia activation damages to DA neurons in a microglia and DA neurons co-culture system. The underlying mechanism of EriB-induced protective effects involved inhibition of microglia associated proinflammatory cytokines production through the phenotypic shift of microglial cells as well as activator of transcription and nuclear factor-κB (NF-κB) signaling pathways. These findings demonstrate that EriB exerts potent anti-inflammatory effects through selective modulation of microglia activation by targeting NF-κB signaling pathways, thus exerting the protective effect against on MPP⁺-induced DA neurons injury. This study may provide insights into the promising therapeutic role of EriB for PD.

Ca2+-dependent endoplasmic reticulum stress correlation with astrogliosis involves upregulation of KCa3.1 and inhibition of AKT/mTOR signaling

BACKGROUND

The intermediate-conductance Ca²⁺-activated K⁺ channel KCa3.1 was recently shown to control the phenotype switch of reactive astrogliosis (RA) in Alzheimer's disease (AD).

METHODS

KCa3.1 channels expression and cell localization in the brains of AD patients and APP/PS1 mice model were measured by immunoblotting and immunostaining. APP/PS1 mice and KCa3.1^-/-/APP/PS1 mice were subjected to Morris water maze test to evaluate the spatial memory deficits. Glia activation and neuron loss was measured by immunostaining. Fluo-4AM was used to measure cytosolic Ca²⁺ level in β-amyloid (Aβ) induced reactive astrocytes in vitro.

RESULTS

KCa3.1 expression was markedly associated with endoplasmic reticulum (ER) stress and unfolded protein response (UPR) in both Aβ-stimulated primary astrocytes and brain lysates of AD patients and APP/PS1 AD mice. The KCa3.1 channel was shown to regulate store-operated Ca²⁺ entry (SOCE) through an interaction with the Ca²⁺ channel Orai1 in primary astrocytes. Gene deletion or pharmacological blockade of KCa3.1 protected against SOCE-induced Ca²⁺ overload and ER stress via the protein kinase B (AKT) signaling pathway in astrocytes. Importantly, gene deletion or blockade of KCa3.1 restored AKT/mechanistic target of rapamycin signaling both in vivo and in vitro. Consistent with these in vitro data, expression levels of the ER stress markers 78-kDa glucose-regulated protein and CCAAT/enhancer-binding protein homologous protein, as well as that of the RA marker glial fibrillary acidic protein were increased in APP/PS1 AD mouse model. Elimination of KCa3.1 in KCa3.1^-/-/APP/PS1 mice corrected these abnormal responses. Moreover, glial activation and neuroinflammation were attenuated in the hippocampi of KCa3.1^-/-/APP/PS1 mice, as compared with APP/PS1 mice. In addition, memory deficits and neuronal loss in APP/PS1 mice were reversed in KCa3.1^-/-/APP/PS1 mice.

CONCLUSIONS

Overall, these results suggest that KCa3.1 is involved in the regulation of Ca²⁺ homeostasis in astrocytes and attenuation of the UPR and ER stress, thus contributing to memory deficits and neuronal loss.

Genome-wide identification of genes involved in polyamine biosynthesis and the role of exogenous polyamines in Malus hupehensis Rehd. under alkaline stress

Polyamines (PAs) in plants are growth substrates with functions similar to phytohormones. Although they contribute to diverse processes, little is known about their role in stress responses, especially for perennial woody plants. We conducted a genome-wide investigation of 18 sequences involved in PA biosynthesis in the genome of apple (Malus domestica). Further analysis was performed to construct a phylogenetic tree, analyze their protein motifs and gene structures. In addition, we developed their expression profiles in response to stressed conditions. Both MDP0000171041 (MdSAMDC1) and MDP0000198590 (MdSPDS1) were induced by alkaline, salt, ABA, cold, and dehydration stress treatments, suggesting that these genes are the main contributors to activities of S-adenosylmethionine decarboxylase (EC 4.1.1.50) and spermidine synthase (EC 2.5.1.16) in apple. Changes in PA biosynthesis under stress conditions indicated that spermidine and spermine are more essential than putrescine for apple, especially when responding to alkaline or salt stress. When seedlings of M. hupehensis Rehd. were supplied with exogenous PAs, their leaves showed less chlorosis under alkaline stress when compared with untreated plants. This application also inhibited the decline in SPAD levels and reduced relative electrolyte leakage in those stressed seedlings, while increasing their concentration of active iron. These results suggest that the alteration in PA biosynthesis confers enhanced tolerance to alkaline stress in M. hupehensis Rehd.

Salidroside slows the progression of EA.hy926 cell senescence by regulating the cell cycle in an atherosclerosis model

Aging is the major risk factor for diseases of the cardiovascular system, such as coronary atherosclerotic heart disease, but little is known about the relationship between atherosclerosis (AS) and age-related declines in vascular structure and function. Here, we used histological analyses in combination with molecular biology techniques to show that lipid deposition in endothelial cell was accompanied by aging and growth arrest. Endothelial cell senescence is sufficient to cause AS; however, we found that salidroside reduced intracellular lipid deposition, slowed the progression of endothelial cell senescence and inhibited the expression of the senescence-related molecules and phosphorylated the retinoblastoma (Rb) protein. Further study confirmed that salidroside increased the percent of S phase cells in oxidized low-density lipoprotein (ox-LDL)-treated endothelial cells. Collectively, vascular endothelial cell function declined with age and AS, and our data suggested that salidroside prevented ox-LDL-treated endothelial cell senescence by promoting cell cycle progression from G0/G1 phase to S phase via Rb phosphorylation. We demonstrated for the first time the complex interactions between AS and endothelial cell senescence, and we believe that salidroside represents a promising therapy for senescence-related AS.

Exogenous Melatonin Alleviates Alkaline Stress in Malus hupehensis Rehd. by Regulating the Biosynthesis of Polyamines

Since melatonin was identified in plants decades ago, much attention has been devoted to discovering its role in plant science. There is still a great deal to learn about the functional importance of melatonin, as well as its functional mode. In this paper, we examine the role of melatonin treatment in the response of Malus hupehensis Rehd. to alkaline conditions. Stressed seedlings showed chlorosis and suppressed growth. However, this phenotype was ameliorated when 5 µM melatonin was added to the irrigation solution. This supplementation was also associated with a reduction in cell membrane damage and maintenance of a normal root system architecture. Fewer reactive oxygen species (ROS) were accumulated due to the enhanced scavenging activity of antioxidant enzymes superoxide dismutase, peroxidase, and catalase. In addition, alkaline-stressed seedlings that received the melatonin supplement accumulated more polyamines compared with untreated seedlings. Transcript levels of six genes involved in polyamine synthesis, including SAMDC1, -3, and -4, and SPDS1, -3, and -5, -6, were upregulated in response to melatonin application. All of these results demonstrate that melatonin has a positive function in plant tolerance to alkaline stress because it regulates enzyme activity and the biosynthesis of polyamines.

The peiminine stimulating autophagy in human colorectal carcinoma cells via AMPK pathway by SQSTM1

Autophagy is a conserved catabolic process, which functions in maintenance of cellular homeostasis in eukaryotic cells. The self-eating process engulfs cellular long-lived proteins and organelles with double-membrane vesicles, and forms a so-called autophagosome. Degradation of contents via fusion with lysosome provides recycled building blocks for synthesis of new molecules during stress, e.g. starvation. Peiminine is a steroidal alkaloid extracted from Fritillaria thunbergii which is widely used in Traditional Chinese Medicine. Previously, peiminine has been identified to induce autophagy in human colorectal carcinoma cells. In this study, we further investigated whether peiminine could induce autophagic cell death via activating autophagy-related signaling pathway AMPK-mTOR-ULK by promoting SQSTM1(P62). Xenograft tumor growth in vivo suggested that both peiminine and starvation inhibit the growth of tumor size and weight, which was prominently enhanced when peiminine and starvation combined. The therapeutical effect of peiminine in cancer treatment is to be expected.

High expression of cyclooxygenase-2 in uterine fibroids and its correlation with cell proliferation

OBJECTIVE

To investigate the expression of cyclooxygenase-2 (COX-2) in uterine fibroids and healthy uterine smooth muscle as well as its role in the pathogenesis of uterine fibroids.

METHODS

We collected uterine fibroid tissues and their paired adjacent healthy uterine smooth muscle tissues from 30 cases of uterine fibroids. We used immunohistochemistry and quantitative real-time PCR, as well as western blot to detect COX-2 expression. Using the COX-2 inhibitors NS-398 and celecoxib, we observed the response to the inhibitors in the healthy and fibroid smooth muscle cell pairs.

RESULTS

COX-2 was detected by immunohistochemistry in both uterine fibroids and uterine smooth muscle, with higher immunoreactivity in uterine fibroids; the positive index of the smooth muscle cells was 11.90 and the positive index of uterine fibroids cells was 46.50 (P<0.05). The expression of COX-2 mRNA in uterine fibroids was higher (0.122±0.062) than in normal smooth muscle tissue (0.025±0.009; P<0.05). Also, the western blot results showed that COX-2 expression was significantly higher in uterine fibroid cases, as compared to the expression in uterine smooth muscle. Immunofluorescence showed that the occurrence of COX-2 was obviously higher in smooth muscle cells of uterine fibroids than in the healthy smooth muscle cells. NS-398 or celecoxib significantly inhibited the proliferation of smooth muscle cells of uterine fibroids, but did not inhibit the proliferation of healthy smooth muscle cells. Accordingly, NS-398 or celecoxib significantly reduced the expression of the downstream metabolite of COX-2, PGE2, in the smooth muscle cells of uterine fibroids, but not in healthy smooth muscle cells.

CONCLUSION

COX-2 expression in uterine fibroids was significantly higher than in healthy uterine smooth muscles. The inhibition of COX-2 activity significantly reduced the proliferation of smooth muscle cells of the uterine fibroids, suggesting that COX-2 plays an important role in the pathogenesis of uterine fibroids.

Temporospatial expression and cellular localization of oligodendrocyte myelin glycoprotein (OMgp) after traumatic spinal cord injury in adult rats

Traumatic spinal cord injury (SCI) leads to permanent neurological deficits, which, in part, is due to the inability of mature axons to regenerate in the mammalian central nervous system (CNS). The oligodendrocyte myelin glycoprotein (OMgp) is one of the myelin-associated inhibitors of neurite outgrowth in the CNS. To date, limited information is available concerning its expression following SCI, possibly due to the lack of a reliable antibody against it. Here we report the generation of a highly specific OMgp polyclonal antibody from the rabbit. Using this antibody, we found that OMgp was almost exclusively expressed in the CNS. Following a moderately contusive SCI using a New York University impactor (10 g rod dropped from a height of 12.5 mm), both OMgp mRNA and protein levels were elevated at 1 and 7 days post-SCI, respectively, and peaked at 28 days compared to those of the sham-operated controls. Spatially, OMgp was expressed throughout the entire rostrocaudal extension of a 10 mm long spinal segment with the highest expression seen at the injury epicenter. OMgp was exclusively localized in neurons and oligodendrocytes in the normal and sham-operated controls with an increased expression found in these cells following SCI. OMgp was not expressed in astrocytes or microglia in all groups. Thus, our study has provided evidence for temporospatial expression and cellular localization of OMgp following SCI and suggested that this molecule may contribute to the overall inhibition of axonal regeneration.

[Fusion expression of cecropin X including the cleavage of FXa in Escherichia coli]

PCR method was used to introduce the code sequence of Factor Xa cleavage site to the 5' end of cecropin CMIV mutant gene X, then the gene was cloned into the expression vector pGEX-KG, and was highly expressed in E. coli BL21 by IPTG induction. The fusion protein was purified by affinity-chromatography and was cleaved by Factor Xa. Cecropin X with antibacterial activity was obtained after purified by ion-exchange chromatography.

Preliminary study on the cleavage of fusion protein GST-CMIV with palladium(II) complex

A novel method for post-treatment of gene-engineered proteins is reported. A coden of Cys-His unit is introduced into the N-terminal of cecropin CMIV by using PCR. The gene is expressed in E. coli fused with GST. After purification, the fusion protein is cleaved by [Pd(en)(H2O)2]2+ at the His-Arg bond and the cecropin CMIV with antibacterial activity is obtained. The preliminary results held some promise of success for application of the palladium(II) complex as cleavage agent for the production of peptide drugs from gene-engineering fusion proteins.

The terminal structure plays an important role in the biological activity of cecropin CMIV

Antibacterial peptides have received increasing attention as a new pharmaceutical substance. But the molecular mechanism of lysis is still poorly understood. CMIV gene and mutant CMIV gene in GST fusion system were expressed. After cleaving with different cleavage reagents, the peptide with an excess of N-terminus and with an un-amidated C-terminus stopped the activity while the peptide with an excess Asn at the C-terminus had the activity level the same as natural CMIV. The results showed that the terminal structure of cecropin CMIV played an important role in its biological activity.

Renaturation, purification, and characterization of human plasminogen activator inhibitor type 2 (PAI-2) accumulated at high level in Escherichia coli

Plasminogen activator inhibitor 2 (PAI-2) is an important regulator of plasminogen activation, which inhibits both tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). In this study we have developed a high-level expression system by inserting a modified PAI-2 gene downstream of the T7 promoter. The expression level of recombinant PAI-2 amounted to 55-60% of total microbial protein. By efficient renaturation and one-step purification, the recombinant protein was purified to homogeneity. The specific activity and yield of recombinant PAI-2 reached 33,000 IU/mg and 10 mg per gram wet weight of Escherichia coli cells, respectively. The second-order rate constant for uPA was 2.6-2.8 x 10(6) M(-1) x s(-1).

High-level expression of cecropin CMIV in E. coli from a fusion construct containing the human tumor necrosis factor

Cecropin CMIV gene was fused to the 3'-terminus of the mutated tumor necrosis factor (TNFb) gene and the fusion gene was directly under the control of an inducible T7 promoter in pET-11d. This fusion gene was overexpressed in Escherichia coli with an expression level of approximate 40%-50% of total cellular proteins, and was produced mainly in the form of inclusion body. Peptide with antibacterial activity was obtained by cleaving the fusion protein with CNBr.