Saponins from Panax japonicus improve neuronal mitochondrial injury of aging rats.

CONTEXT: Panax japonicus is the dried rhizome of Panax japonicus C.A. Mey. (Araliaceae). Saponins from Panax japonicus (SPJ) exhibit anti-oxidative and anti-aging effects. OBJECTIVE: We evaluated the neuroprotective effects of SPJ on aging rats. MATERIALS AND METHODS: Sprague-Dawley rats (18-months-old) were randomly divided into aging and SPJ groups (n = 8). Five-month-old rats were taken as the adult control (n = 8). The rats were fed a normal chow diet or the SPJ-containing diet (10 or 30 mg/kg) for 4 months. An in vitro model was established by d-galactose (d-Gal) in the SH-SY5Y cell line and pretreated with SPJ (25 and 50 µg/mL). The neuroprotection of SPJ was evaluated via Nissl staining, flow cytometry, transmission electron microscopy and Western blotting in vivo and in vitro. RESULTS: SPJ improved the neuronal degeneration and mitochondrial morphology that are associated with aging. Meanwhile, SPJ up-regulated the protein levels of mitofusin 2 (Mfn2) and optic atrophy 1 (Opa1) and down-regulated the protein level of dynamin-like protein 1 (Drp1) in the hippocampus of aging rats (p < 0.05 or p < 0.01 vs. 22 M). The in vitro studies also demonstrated that SPJ attenuated d-Gal-induced cell senescence concomitant with the improvement in mitochondrial function; SPJ, also up-regulated the Mfn2 and Opa1 protein levels, whereas the Drp1 protein level (p < 0.05 or p < 0.01 vs. d-Gal group) was down-regulated. DISCUSSION AND CONCLUSIONS: Further research on the elderly population will contribute to the development and utilization of SPJ for the treatment of neurodegenerative disorders.

[The mechanism of microcystin leucine-arginine (MC-LR)-induced injury of Sertoli cell immune response and biological behavior].

Microcystin-leucine arginine (MC-LR), a potentially carcinogenic toxin, is produced by Cyanobacteria such as Microcystis and Ananabacteria during water bloom. Increasing evidence demonstrated that MC-LR induces male reproductive toxicity, mainly by inducing germ cell apoptosis, destroying cell cytoskeleton, interfering with DNA damage repair pathway, and damaging blood-testicular barrier (BTB), which eventually lead to male sterility. Testicular Sertoli cells are the somatic cells that directly contact with spermatogenic cells in seminiferous tubules. They not only regulate immune response to maintain testicular immune homeostasis by secreting a variety of cytokines and immunosuppressive factors, but also provide the protective effects of spermatogenic cells by forming BTB. MC-LR induces inflammation and apoptosis of Sertoli cells, and destroys the integrity of the BTB, and then causes spermatogenesis dysfunction.

Redox metabolism maintains the leukemogenic capacity and drug resistance of AML cells.

Rewiring of redox metabolism has a profound impact on tumor development, but how the cellular heterogeneity of redox balance affects leukemogenesis remains unknown. To precisely characterize the dynamic change in redox metabolism in vivo, we developed a bright genetically encoded biosensor for H2O2 (named HyPerion) and tracked the redox state of leukemic cells in situ in a transgenic sensor mouse. A H2O2-low (HyPerion-low) subset of acute myeloid leukemia (AML) cells was enriched with leukemia-initiating cells, which were endowed with high colony-forming ability, potent drug resistance, endosteal rather than vascular localization, and short survival. Significantly high expression of malic enzymes, including ME1/3, accounted for nicotinamide adenine dinucleotide phosphate (NADPH) production and the subsequent low abundance of H2O2. Deletion of malic enzymes decreased the population size of leukemia-initiating cells and impaired their leukemogenic capacity and drug resistance. In summary, by establishing an in vivo redox monitoring tool at single-cell resolution, this work reveals a critical role of redox metabolism in leukemogenesis and a potential therapeutic target.

Perfluorooctanoic acid induces tight junction injury of Sertoli cells by blocking autophagic flux.

Perfluorooctanoic acid (PFOA), a man-made chemical widely used in consumers, could cause male reproductive toxicity by disrupting blood-testis barrier (BTB) integrity. Autophagy in Sertoli cells is essential for regulation of spermatogenesis and BTB. However, it remains a mystery that whether PFOA-induced BTB injury is associated with autophagy in Sertoli cells. In this study, we found that PFOA dose-dependently disrupted tight junction (TJ) function in Sertoli cells in vivo and in vitro. Furthermore, the results from transmission electron microscopy, Western blot and immunofluorescence analysis revealed that PFOA induced the accumulation of autophagosome in testicular Sertoli cells as well as TM4 cells. Further study confirmed that autophagosome accumulation resulted from the blockage of autophagic degradation because of disruption of autophagosome and lysosome fusion via downregulation of the expression of α-SNAP. In parallel, the overexpressed MMP9 was also observed in vivo and in vitro. Conversely, overexpression of α-SNAP inhibited the expression of MMP9 in TM4 cells. In conclusion, PFOA blocks autophagic flux through downregulating the expression levels of α-SNAP in Sertoli cells, and then induces the accumulation of MMP9 leading to disruption of TJ function. This finding will provide clues for effective prevention and treatment of PFOA-induced male reproductive toxicity.

Changes of Colon in Rats with Different Ages in Response to Lipopolysaccharide.

BACKGROUND: Lipopolysaccharide (LPS) is an endotoxin that causes inflammation, and the content of LPS increases gradually during the process of aging. Whether the response of the colon to LPS stimulation will increase with age is yet unknown. OBJECTIVE: The study investigated the effects of LPS stimulation on the colon of adult and aging rats. METHOD: 43 healthy male SD rats were divided into 4 different groups: adult group and LPS-stimulated adult group at the age of 4 months, and aging group and LPS-stimulated aging group at the age of 22 months. Rats were stimulated by intraperitoneal injection of LPS (1mg/kg) for 24 h. The morphological changes of the colon were observed, and intestinal inflammatory response, tight junction proteins, apoptosis, and proliferation in intestinal epithelial cells were detected. RESULTS: A series of morphology changes occurred in the colon of adult rats after LPS stimulation, the higher inflammatory response (TLR4, NF-κB, and IL-1ß), changes in the protein levels of tight junctions (ZO-1, Claudin1, and Claudin2), and increased apoptosis (Bax, Bcl2) and proliferation (PCNA) of intestinal epithelial cells. The above changes were also found in aging rats. LPS stimulation further promotes the above changes to some extent in the colon of aging rats. CONCLUSION: A series of colon changes in rats was significantly damaged during LPS stimulation and aging, and these changes were further aggravated to some extent in LPS-stimulated aging rats.

Fuzzy supertertiary interactions within PSD-95 enable ligand binding.

The scaffold protein PSD-95 links postsynaptic receptors to sites of presynaptic neurotransmitter release. Flexible linkers between folded domains in PSD-95 enable a dynamic supertertiary structure. Interdomain interactions within the PSG supramodule, formed by PDZ3, SH3, and Guanylate Kinase domains, regulate PSD-95 activity. Here we combined discrete molecular dynamics and single molecule Förster resonance energy transfer (FRET) to characterize the PSG supramodule, with time resolution spanning picoseconds to seconds. We used a FRET network to measure distances in full-length PSD-95 and model the conformational ensemble. We found that PDZ3 samples two conformational basins, which we confirmed with disulfide mapping. To understand effects on activity, we measured binding of the synaptic adhesion protein neuroligin. We found that PSD-95 bound neuroligin well at physiological pH while truncated PDZ3 bound poorly. Our hybrid structural models reveal how the supertertiary context of PDZ3 enables recognition of this critical synaptic ligand.

Relief Effects of Icariin on Inflammation-Induced Decrease of Tight Junctions in Intestinal Epithelial Cells.

Inflammatory cytokines including TNF-α and IL-1ß impair intestinal barrier function in aging by disrupting intestinal tight junction integrity. Icariin (ICA) has a variety of pharmacological effects. Indeed, ICA produces anti-inflammatory, anti-oxidative stress, and inhibitory effects on microRNA (miRNA) expression. This study was to explore whether ICA could alleviate inflammation-associated intestinal barrier function impairment in aging and its underlying mechanism. Of particular interest, network pharmacology prediction indicated the potential therapeutic impacts of ICA for the treatment of colitis. Then, rats were used to study whether ICA has a protective effect on the reduction of tight junctions caused by inflammatory cytokines. Next, Caco-2 cell monolayers were used to explore the mechanism by which ICA alleviates the down-regulation of tight junctions. Network pharmacology prediction revealed that ICA alleviated colitis via suppressing oxidative stress. After ICA intervention, expressions of inflammatory cytokines were reduced, but tight junctions, antioxidant enzymes in aging rats were up-regulated. ICA reversed the TNF-α-induced decrease in abundance of Occludin protein in Caco-2 cell monolayers. Meanwhile, ICA alleviated the increase in permeability and expression of miR-122a. However, the protective effect of ICA was markedly attenuated after transfection with miR-122a mimics. In conclusion, ICA reduced the expressions of Occludin, Claudin1, and Claudin5 in colon, which were related to the reduction of TNF-α and IL-1ß and alleviation of colonic in vivore. And ICA attenuated TNF-α-induced Occludin disruption and epithelial barrier impairment by decreasing miR-122a expression in Caco-2 cell monolayers.

Icariin attenuates perfluorooctane sulfonate-induced testicular toxicity by alleviating Sertoli cell injury and downregulating the p38MAPK/MMP9 pathway.

Perfluorooctane sulfonate (PFOS) is widely recognized as causing Sertoli cell injury and testicular toxicity in males. Icariin is a flavonoid from Epimedium, which effectively improves spermatogenesis disturbance induced by several factors in clinic. However, it is unclear whether icariin improves PFOS-induced testicular toxicity. In vivo, fifty-two male mice were randomly separated into four groups: normal control group, model group, and low and high doses of icariin-treated groups, with 13 mice in each group. Except for the normal control group, the mice in the model group and icariin-treated groups were administered PFOS (10 mg kg-1) by gavage daily for 28 consecutive days, and concurrently treated with a diet containing different doses of icariin (0, 5 or 20 mg kg-1). In vitro, TM4 cells were treated with 150 µM PFOS to induce Sertoli cell injury, and were then utilized for icariin treatment. Our results demonstrated that icariin attenuated PFOS-induced testicular toxicity by increasing the testicular, epididymal and seminal vesicle weights, epididymal and seminal vesicle indices, sperm parameters, and seminiferous epithelium height. In addition, icariin improved the PFOS-induced blood-testis barrier (BTB) disruption by alleviating the Sertoli cell junctional injury, but without affecting Sertoli cell numbers in the testis of mice. Moreover, icariin increased the expression levels of tight junction proteins (ZO-1, Occludin and Claudin-11) and gap junction proteins (CX43 and p-CX43), and decreased the expression levels of p-p38MAPK and matrix metalloproteinase 9 (MMP9) both in vivo and in vitro. Furthermore, alleviation of the Sertoli cell injury by icariin exerted similar effects as SB203580 (an inhibitor of p38MAPK) in TM4 cells. This study revealed that icariin effectively reduces PFOS-induced testicular toxicity by alleviating the Sertoli cell injury and downregulating the p38MAPK/MMP9 pathway, indicating that icariin may be an attractive dietary supplement for the intervention of PFOS-induced testicular dysfunction.

Structure and conformational dynamics of Clostridioides difficile toxin A.

Clostridioides difficile toxin A and B (TcdA and TcdB) are two major virulence factors responsible for diseases associated with C. difficile infection (CDI). Here, we report the 3.18-Å resolution crystal structure of a TcdA fragment (residues L843-T2481), which advances our understanding of the complete structure of TcdA holotoxin. Our structural analysis, together with complementary single molecule FRET and limited proteolysis studies, reveal that TcdA adopts a dynamic structure and its CROPs domain can sample a spectrum of open and closed conformations in a pH-dependent manner. Furthermore, a small globular subdomain (SGS) and the CROPs protect the pore-forming region of TcdA in the closed state at neutral pH, which could contribute to modulating the pH-dependent pore formation of TcdA. A rationally designed TcdA mutation that trapped the CROPs in the closed conformation showed drastically reduced cytotoxicity. Taken together, these studies shed new lights into the conformational dynamics of TcdA and its roles in TcdA intoxication.

Changes in the tight junctions of the testis during aging: Role of the p38 MAPK/MMP9 pathway and autophagy in Sertoli cells.

Impaired tight junction (TJ) function and autophagy and the activated p38 mitogen-activated protein kinase (MAPK)/matrix metalloproteinase 9 (MMP9) pathway in Sertoli cells cause spermatogenic disorders. However, it is unclear whether reduced TJ barrier function and autophagy and the activated p38 MAPK/MMP9 pathway in Sertoli cells are closely associated with age-related testicular dysfunction. Thus, we evaluated these changes in Sertoli cells using 6-, 12-, 18-, and 24-month-old Sprague-Dawley rats. The results showed that testicular morphology gradually degenerated, as evidenced by increased exfoliated germ cells, decreased seminiferous tubule diameter and seminiferous epithelium height, and reduced the numbers of spermatogonia, primary spermatocytes and spermatids during the process of aging. In addition, the TJs formed by adjacent Sertoli cells were progressively destroyed accompanied by an abnormal ultrastructure and decreased expression of the TJ proteins zonula occludens-1 (ZO-1), occludin, and claudin-11 with aging. Furthermore, the expression of phosphorylated p38MAPK and MMP-9 in Sertoli cells and testis gradually increased, and the expression of occludin co-localizated with MMP-9 progressively decreased. Meanwhile, autophagy levels also gradually decreased, including decreased autophagic vacuole formation and weak expression of light chain 3 (LC3) and autophagy-related 5 (Atg5) in Sertoli cells. Taken together, our results indicate that aging causes impaired TJ barrier function and degeneration of seminiferous tubules. The mechanism might be related to the activated p38MAPK/MMP9 pathway and inactivated autophagy in Sertoli cells.

The Role of LncRNA TUG1 in Obesity-related Diseases.

As the living standards of people are increasingly improved, obesity has become a hotspot in our daily life. Obesity has been found as a chronic and recurrent disease with serious adverse consequences. Over the past few years, several articles indicated that long non-coding RNA taurine increased gene 1 (lncRNA TUG1), a useful RNA, which was indicated to show a relationship to obesity- related disease occurrence and development. Exosomes are recognized as an emerging research field that includes substances actively involved in regulating the molecular mechanisms of disease. This review summarizes the current relevant TUG1 in different molecular pathways of obesityassociated diseases, the correlation between exosomes and TUG1, or obesity-associated diseases. The aim is to explore TUG1 as a novel target for obesity, which can deepen the knowledge regarding the epigenetic regulation pathway. Furthermore, it is expected to focus on diseases associated with obesity treatment and diagnosis.

Activation of NLRP3-Caspase-1 pathway contributes to age-related impairments in cognitive function and synaptic plasticity.

Aging is characterized by a progressive deterioration in physiological functions that is associated with cognitive decline as well as other physical functional impairments. Microglia activation leading to neuroinflammation has been generally recognized as playing a critical role in the development of age-related cognitive decline. NLRP3 inflammasome in microglia is fundamental for IL-1ß maturation and subsequent inflammatory events. However, it remains unknown whether NLRP3 activation contributes to aging-induced cognitive decline in vivo. Here, our study demonstrated that aging rats showed declined cognitive function and impaired synaptic plasticity as well as decreased density of dendritic spines. Importantly, our data demonstrated strongly enhanced expression of NLRP3, ASC and Caspase-1 in the hippocampus of aged rats as well as decreased AMPA receptor and phosphorylated levels of CaMKII and CREB in the hippocampus of natural aging rats. Furthermore, NLRP3 inflammasome inhibitor elevated the surface expression of AMPA receptor and the phosphorylated levels of CaMKII, CREB in hippocampus, and finally contributed to the attenuation of hippocampal long-term potentiation (LTP) deficits and the improvement of cognitive decline of natural aging rats. These results revealed an important role for the NLRP3-Caspase-1 pathway in aging-induced cognitive decline and suggested that inhibition of NLRP3 inflammasome represented a novel therapeutic intervention for aging-related cognitive impairment.

Saponins from Panax japonicus attenuate cognitive impairment in ageing rats through regulating microglial polarisation and autophagy.

CONTEXT: Panax japonicus is the dried rhizome of Panax japonicus C.A. Mey. (Araliaceae). Saponins from Panax japonicus (SPJ) exhibit anti-inflammatory and antioxidative effects. OBJECTIVE: To explore the neuroprotective effect of SPJ on natural ageing of rat. MATERIALS AND METHODS: Sprague-Dawley (SD) rats 18-month-old were divided into ageing control, ageing treated with SPJ 10 or 30 mg/kg (n = 8). Five-month-old rats were taken as the adult control (n = 8). Rats were fed regular feed or feed containing SPJ for 4 months. Cognitive level was evaluated by Morris water maze (MWM) test. The mechanisms of SPJ's neuroprotection were evaluated by transmission electron microscope, western blot analysis, and immunofluorescence in vivo and in vitro. RESULTS: SPJ attenuated ageing-induced cognitive impairment as indicated by elevated number of times crossing the target platform (from 1.63 to 3.5) and longer time spent in the target platform quadrant (from 1.33 to 1.98). Meanwhile, SPJ improved the morphology of microglia and synapse, and activated M2 microglia polarisation including increased hippocampus levels of CD206 (from 0.98 to 1.47) and YM-1 (from 0.67 to 1.1), and enhanced autophagy-related proteins LC3B (from 0.48 to 0.82), Beclin1 (from 0.32 to 0.51), Atg5 (from 0.22 to 0.89) whereas decreased p62 level (from 0.71 to 0.45) of ageing rats. In vitro study also showed that SPJ regulated the microglial polarisation and autophagy. DISCUSSION AND CONCLUSIONS: SPJ improved cognitive deficits of ageing rats through attenuating microglial inflammation and enhancing microglial autophagy, which could be used to treat neurodegenerative disorders.

Caloric restriction ameliorates high-fat diet induced cognitive deficits through attenuating neuroinflammation via the TREM2-PI3K/AKT signaling pathway.

Prolonged high-fat diet (HFD) feeding impairs cognitive function in rodents. However, the mechanism of caloric restriction (CR) for remedying HFD-induced cognitive dysfunction remains elusive. In the present study, we investigated the effect of CR on HFD-induced cognitive dysfunction and its possible mechanism. BALB/c mice were fed with HFD for 16 weeks and subsequently subjected to CR for 12 weeks. After cognitive function was evaluated by behavioral tests such as Morris water maze and three-chamber paradigm tests, the mice were sacrificed. The prefrontal cortex and hippocampus were rapidly harvested and deposited at -80 °C. The neuroprotective mechanisms of CR on HFD-induced cognitive deficits were evaluated by histopathological and electron microscopy observations, western blotting and immunofluorescence. Compared with the normal control group, HFD mice exhibited obvious cognitive deficits, glucose tolerance impairment, neuronal degeneration and abnormalities of synaptic ultrastructure in the cortex and hippocampus. CR treatment improved cognitive dysfunction and histopathological changes as well as increased the cognition-related protein levels of PSD-95, synaptophysin and BDNF. Meanwhile, HFD increased the protein levels of pro-inflammatory factors including iNOS, COX-2 and IL-1ß but decreased the protein levels of anti-inflammatory factors such as CD206, TGF-ß, Ym-1 and Arg 1 in the prefrontal cortex and hippocampus, downregulated the protein levels of TREM2 and PI3K and decreased the phosphorylation level of AKT, which can be reversed by CR treatment. Therefore, our results indicated that CR ameliorated cognitive deficits of mice induced by a high-fat diet. The underlying mechanism is associated with the attenuation of the neuroinflammatory response mediated by the TREM2-PI3K/AKT signaling pathway.

The dynamic changes of Nrf2 mediated oxidative stress, DNA damage and base excision repair in testis of rats during aging.

Accumulation of oxidative stress, DNA damage and impaired DNA repair appear to play critical roles in the decline of testicular function with aging. However, when those factors begin to lose control in testis during aging has not yet been well understood. This study was designed to assess the changes of oxidative stress and DNA damage status, and DNA repair capacity in testis during aging. Thus, male Sprague-Dawley rats at 3, 9, 15 and 24 months of age were used to delineate the dynamic changes in testicular weight and index, testosterone concentration, testicular histology, Nrf2-mediated oxidative stress, DNA damage, DNA repair and apoptosis. Results showed that testicular weight and index, testosterone concentration and spermatid number progressively declined from 9 to 24 months of age. Similarly, seminiferous tubule diameters and seminiferous epithelium heights gradually diminished with aging. Nrf2-mediated antioxidant defense ability was significantly impaired in testis with increasing age including decreased the activity of SOD and the expression levels of Nrf2, HO-1 and NQO-1, and increased the contents of MDA. In addition, DNA damage including DNA single-strand breaks (SSBs) and DNA double-strand breaks (DSBs) also progressively increased accompanied by increased levels of 8-hydroxydeoxyguanosine (8-OHdG) and γ-H2AX, and activated ATM/Chk2 and ATR/Chk1 pathway. Consistent with the results of Nrf2 pathway, the expression levels of APE1, OGG1 and XRCC1 involved in base excision DNA repair (BER) pathway increased from 3 to 9 months of age, and then gradually decreased after 9 months of age. Finally, TUNEL and Western blot results further confirmed germ cell apoptosis progressively increased from 3 to 24 months of age as evidenced by decreased ratio of Bcl-2/Bax and levels of Bcl-2 expression, and increased Bax expression levels. Taken together, our results suggest that downregulation of antioxidant ability mediated by Nrf2 pathway and impairment of BER capacity might correlate with increased DNA damage, and then induce declining testicular function during aging after adult.

Saponins from Panax japonicus alleviate HFD-induced impaired behaviors through inhibiting NLRP3 inflammasome to upregulate AMPA receptors.

Obesity is characterized by a condition of low-grade chronic inflammation that facilitates development of numerous comorbidities and dysregulation of brain homeostasis. It is reported that obesity can lead to behavioral alterations such as cognitive decline and depression-like behaviors both in humans and rodents. Saponins from panax japonicus (SPJ) have been reported to exhibit anti-inflammatory action in mouse model of diet-induced obesity. We evaluated the neuroprotection of SPJ on high fat diet (HFD) induced impaired behaviors such as memory deficit and depressive-like behaviors, and explored the underlying mechanisms. 6-week male Balb/c mice were divided into normal control group (NC, 17% total calories from fat), HFD group (60% total calories from fat), and HFD treated with SPJ groups (orally gavaged with dosages of 15 mg/kg and 45 mg/kg), respectively. After treatment for 16 weeks, behavioral tests were performed to evaluate the cognition and depression-like behaviors of the mice. The underling mechanisms of SPJ on HFD-induced impaired behaviors were investigated through histopathological observation, Western blot analysis and immunofluorescence. Our results showed that HFD-fed mice caused behavioral disorders, neuronal degeneration as well as elevated neuroinflammation, which was partly involved in NLRP3 inflammasome that finally resulted in decreased protein levels of AMPA receptors and down-regulated phosphorylated levels of CaMKII and CREB in cortex and hippocampus. All the above changes in cortex and hippocampus induced by HFD were mitigated by SPJ treatment. SPJ treatment alleviated HFD-induced recognitive impairment and depression-like behaviors of mice, which could be partly due to the capacity of SPJ to mitigate neuroinflammation through inhibition of NLRP3 inflammasome and upregulation of AMPA receptors signaling pathway.

Common markers of testicular Sertoli cells.

INTRODUCTION: Sertoli cells play central roles in the development of testis formation in fetuses and the initiation and maintenance of spermatogenesis in puberty and adulthood, and disorders of Sertoli cell proliferation and/or functional maturation can cause male reproductive disorders at various life stages. It's well documented that various genes are either overexpressed or absent in Sertoli cells during the conversion of an immature, proliferating Sertoli cell to a mature, non-proliferating Sertoli cell, which are considered as Sertoli cell stage-specific markers. Thus, it is paramount to choose an appropriate Sertoli cell marker that will be used not only to identify the developmental, proliferative, and maturation of Sertoli cell status in the testis during the fetal period, prepuberty, puberty, or in the adult, but also to diagnose the mechanisms underlying spermatogenic dysfunction. AREAS COVERED: In this review, we principally enumerated 5 categories of testicular Sertoli cell markers - including immature Sertoli cell markers, mature Sertoli cell markers, immature/mature Sertoli cell markers, Sertoli cell functional markers, and others. EXPERT OPINION: By delineating the characteristics and applications of more than 20 Sertoli cell markers, this review provided novel Sertoli cell markers for the more accurate diagnosis and mechanistic evaluation of male reproductive disorders.

Saponins from Panax japonicus ameliorate age-related renal fibrosis by inhibition of inflammation mediated by NF-κB and TGF-ß1/Smad signaling and suppression of oxidative stress via activation of Nrf2-ARE signaling.

BACKGROUND: The decreased renal function is known to be associated with biological aging, of which the main pathological features are chronic inflammation and renal interstitial fibrosis. In previous studies, we reported that total saponins from Panax japonicus (SPJs) can availably protect acute myocardial ischemia. We proposed that SPJs might have similar protective effects for aging-associated renal interstitial fibrosis. Thus, in the present study, we evaluated the overall effect of SPJs on renal fibrosis. METHODS: Sprague-Dawley (SD) aging rats were given SPJs by gavage beginning from 18 months old, at 10 mg/kg/d and 60 mg/kg/d, up to 24 months old. After the experiment, changes in morphology, function and fibrosis of their kidneys were detected. The levels of serum uric acid (UA), ß2-microglobulin (ß2-MG) and cystatin C (Cys C) were assayed with ELISA kits. The levels of extracellular matrix (ECM), matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), inflammatory factors and changes of oxidative stress parameters were examined. RESULTS: After SPJs treatment, SD rats showed significantly histopathological changes in kidneys accompanied by decreased renal fibrosis and increased renal function; As compared with those in 3-month group, the levels of serum UA, Cys C and ß2-MG in 24-month group were significantly increased (p < 0.05). Compared with those in the 24-month group, the levels of serum UA, Cys C and ß2-MG in the SPJ-H group were significantly decreased. While ECM was reduced and the levels of MMP-2 and MMP-9 were increased, the levels of TIMP-1, TIMP-2 and transforming growth factor-ß1 (TGF-ß1)/Smad signaling were decreased; the expression level of phosphorylated nuclear factor kappa-B (NF-κB) was down-regulated with reduced inflammatory factors; meanwhile, the expression of nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) signaling was aggrandized. CONCLUSION: These results suggest that SPJs treatment can improve age-associated renal fibrosis by inhibiting TGF-ß1/Smad, NFκB signaling pathways and activating Nrf2-ARE signaling pathways and that SPJs can be a potentially valuable anti-renal fibrosis drug.

[Effect of total saponins from Panax japonicus on non-alcoholic steatohepatitis by regulating autophagy].

Non-alcoholic steatohepatitis(NASH) was induced by high-sugar and high-fat diet in mice to investigate the intervention effect of total saponins from Panax japonicus(TSPJ) and explore its possible mechanism. Mice were fed with high-sugar and high-fat diet to establish NASH model, and intervened with different doses of TSPJ(15, 45 mg·kg~(-1)). The animals were fed for 26 weeks. The histomorphology and pathological changes of liver tissues were observed by HE staining. The transcriptional expression levels of miR-199 a-5 p, autophagy related gene 5(ATG5) and inflammatory cytokines interleukin-6(IL-6), interleukin-1ß(IL-1ß) and tumor necrosis factor α(TNF-α) in mouse liver were measured by quantitative Real-time polymerase chain reaction(qRT-PCR). Western blot was used to detect the expression of autophagy-related proteins ATG5, P62/SQSTM1(P62), and microtubule-associated protein light chain 3(LC3)-I/Ⅱ proteins in mouse liver. The expression of P62 protein was detected by immunofluorescence staining. In order to verify the targeting regulation relationship between miR-199 a-5 p and ATG5, miR mimic/inhibitor NC and miR-199 a-5 p mimic/inhibitor were transfected into Hepa 1-6 cells, and the expression of ATG5 mRNA and protein was detected. pMIR-reportor ATG5-3'UTR luciferase reporter gene plasmid was constructed and co-transfected with miR mimic/inhibitor NC and miR-199 a-5 p mimic/inhibitor into Hepa 1-6 cells to detect luciferase activity. In vivo, HE staining in the model group showed typical fatty degeneration and inflammatory infiltration, with increased expression of miR-199 a-5 p and decreased expression of ATG5 mRNA and protein. The expression of autophagy-associated protein P62 increased significantly, the ratio of LC3Ⅱ/Ⅰ decreased, and the transcriptional expression of inflammatory factors increased significantly. After the intervention by TSPJ, the pathological performance of liver tissue was significantly improved, the expression of miR-199 a-5 p decreased and the expression of ATG5 mRNA and protein increased, the expression of autophagy-associated protein P62 decreased significantly, the ratio of LC3Ⅱ/Ⅰ increased, and the transcriptional expression of inflammatory cytokines IL-6, IL-1ß and TNF-α decreased significantly. In vitro, it was found that the expression of ATG5 mRNA and protein and luciferase activity decreased significantly in miR-199 a-5 p overexpression cells, while after inhibition of miR-199 a-5 p expression, the expression level of ATG5 mRNA and protein and luciferase activity increased. The results showed that TSPJ can improve NASH in mice fed with high-sugar and high-fat diet, and its mechanism may be related to the regulation of miR-199 a-5 p/ATG5 signal pathway, the regulation of autophagy activity and the improvement of inflammatory response of NASH.

Strong valley splitting ind0two-dimensional SnO induced by magnetic proximity effect.

Strong magnetic interfacial coupling in van der Waals heterostructures is important for designing novel electronic devices. Besides the most studied transition metal dichalcogenides (TMDCs) materials, we demonstrate that the valley splitting can be activated in two-dimensional tetragonald0metal oxide, SnO, via the magnetic proximity effect by EuBrO. In SnO/EuBrO, the valley splitting of SnO can reach ∼46 meV, which is comparable to many TMDCs and equivalent to an external magnetic field of 800 T. In addition, the valley splitting can be further enhanced by adjusting interlayer distance and applying uniaxial strains. A design principle of new spintronic device based on this unique electronic structure of SnO/EuBrO has been proposed. Our findings indicate that SnO is a promising material for future valleytronics applications.