ABSTRACT
In engineered photonic lattices, topological photonic (TP) modes present a promising avenue for designing waveguides with suppressed backscattering. However, the integration of the TP modes in electromagnetic systems has faced longstanding challenges. The primary obstacle is the insufficient development of high-efficiency coupling technologies between the TP modes and the conventional transmission modes. This dilemma leads to significant scattering at waveguide terminals when attempting to connect the TP waveguides with other waveguides. In this study, a topological photonic substrate-integrated waveguide (TPSIW) is proposed that can seamlessly integrate into traditional microstrip line systems. It successfully addresses the matching problem and demonstrates efficient coupling of both even and odd TP modes with the quasi-transverse electromagnetic modes of microstrip lines, resulting in minimal energy losses. In addition, topological leaky states are introduced through designed slots on the TPSIW top surface. These slots enable the creation of TP leaky-wave antennas with beam steering capabilities. A wireless link based on TPSIWs are further established that enables the transmission of distinct signals toward different directions. This work is an important step toward the integration of TP modes in microwave systems, unlocking the possibilities for the development of high-performance wireless devices.
ABSTRACT
BACKGROUND: The leading cause of end-stage renal disease (ESRD) is diabetic nephropathy (DN). Podocyte damage is an early event in the development of DN. Currently, there is no effective treatment strategy that can slow the progression of DN or reverse its onset. The role of mesenchymal stem cells (MSCs) transplantation in diabetes and its complications has been extensively studied, and diabetic nephropathy has been a major focus. Irbesartan exerts reno-protective effects independent of lowering blood pressure, can reduce the incidence of proteinuria in rats, and is widely used clinically. However, it remains undetermined whether the combined utilization of the angiotensin II receptor antagonist irbesartan and MSCs could enhance efficacy in addressing DN. METHODS: A commonly used method for modeling type 2 diabetic nephropathy (T2DN) was established using a high-fat diet and a single low-dose injection of STZ (35 mg/kg). The animals were divided into the following 5 groups: (1) the control group (CON), (2) the diabetic nephropathy group (DN), (3) the mesenchymal stem cells treatment group (MSCs), (4) the irbesartan treatment group (Irb), and (5) the combined administration group (MSC + Irb). MSCs (2 × 106 cells/rat) were injected every 10 days through the tail vein for a total of three injections; irbesartan (30 mg/kg/d) was administered by gavage. Additionally, the safety and homing of mesenchymal stem cells were verified using positron emission tomography (PET) imaging. RESULTS: The combination treatment significantly reduced the UACR, kidney index, IGPTT, HOMA-IR, BUN, serum creatine, and related inflammatory factor levels and significantly improved renal function parameters and the expression of proteins related to glomerular podocyte injury in rats. Moreover, MSCs can homing target to damaged kidneys. CONCLUSIONS: Compared to the administration of MSCs or irbesartan alone, the combination of MSCs and irbesartan exerted better protective effects on glomerular podocyte injury, providing new ideas for the clinical application of mesenchymal stem cells.
Subject(s)
Diabetes Mellitus, Experimental , Diabetic Nephropathies , Irbesartan , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Podocytes , Animals , Irbesartan/pharmacology , Irbesartan/therapeutic use , Podocytes/drug effects , Podocytes/pathology , Mesenchymal Stem Cell Transplantation/methods , Rats , Mesenchymal Stem Cells/metabolism , Diabetes Mellitus, Experimental/therapy , Diabetes Mellitus, Experimental/complications , Diabetic Nephropathies/therapy , Diabetic Nephropathies/drug therapy , Male , Umbilical Cord/cytology , Rats, Sprague-Dawley , Humans , Transplantation, Heterologous , Biphenyl Compounds/pharmacology , Biphenyl Compounds/therapeutic useABSTRACT
Non-alcoholic fatty liver disease (NAFLD) was a chronic complication of type 2 diabetes mellitus (T2DM), and this comorbid disease lacked therapeutic drugs. Semen Ziziphi Spinosae (SZS) was the seed of Ziziphus jujuba var. Spinosa (Bunge) Hu ex H.F. Chow, and it could alleviate the symptoms of T2DM patients. As a triterpene saponin, Jujuboside A (Ju A) was the main active substance isolated from SZS and could improve hyperglycemia of diabetic mice. However, it was still unknown whether Ju A has protective effects on T2DM-associated NAFLD. Our study showed that Ju A attenuated T2DM-associated liver damage by alleviating hepatic lipid accumulation, inflammatory response, and oxidative stress in the liver of db/db mice, and high glucose (HG) and free fatty acid (FFA) co-stimulated human hepatocellular carcinomas (HepG2) cells. Along with the improved hyperglycemia and liver injury, Ju A restrained Yin Yang 1 (YY1)/cytochrome P450 2E1 (CYP2E1) signaling in vivo and in vitro. YY1 overexpression intercepted the protective effects of Ju A on T2DM-induced liver injury via promoting hepatic lipid accumulation, inflammatory response, and oxidative stress. While, the blocking effect of YY1 overexpression on Ju A's hepatoprotective effect was counteracted by further treatment of CYP2E1 specific inhibitor diethyldithiocarbamate (DDC) in vitro. In-depth mechanism research showed that Ju A through YY1/CYP2E1 signaling promoted hepatic fatty acid ß-oxidation, and inhibited inflammatory response and oxidative stress by activating peroxisome proliferator-activated receptor alpha (PPARα), leading to the improvement of T2DM-associated NAFLD. Ju A might be a potential agent in the treatment and health care of T2DM-associated liver disease, especially NAFLD.
Subject(s)
Cytochrome P-450 CYP2E1 , Diabetes Mellitus, Type 2 , Inflammation , Lipid Metabolism , Liver , Non-alcoholic Fatty Liver Disease , Oxidative Stress , Signal Transduction , YY1 Transcription Factor , Oxidative Stress/drug effects , Animals , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/drug therapy , Humans , Signal Transduction/drug effects , Mice , Male , Cytochrome P-450 CYP2E1/metabolism , Hep G2 Cells , Lipid Metabolism/drug effects , Inflammation/drug therapy , Inflammation/metabolism , Liver/metabolism , Liver/drug effects , Liver/pathology , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/metabolism , YY1 Transcription Factor/metabolism , Mice, Inbred C57BL , Saponins/pharmacology , Saponins/therapeutic useABSTRACT
Long noncoding RNAs play an important role in several pathogenic processes in diabetic nephropathy, but the relationship with epithelial-mesenchymal transition in DN is unclear. Herein, we found that KIFAP3-5:1 expression was significantly down-regulated in DN plasma samples, db/db mouse kidney tissues and high glucose treated renal tubular epithelial cells compared to normal healthy samples and untreated cells. Overexpression of KIFAP3-5:1 improved renal fibrosis in db/db mice and rescued epithelial-mesenchymal transition of high glucose cultured renal tubular epithelial cells. The silence of KIFAP3-5:1 will exacerbate the progression of EMT. Mechanistically, KIFAP3-5:1 was confirmed to directly target to the -488 to -609 element of the PRRX1 promoter and negatively modulate PRRX1 mRNA and protein expressions. Furthermore, rescue assays demonstrated that the knockdown of PRRX1 counteracted the KIFAP3-5:1 low expression-mediated effects on EMT in hRPTECs cultured under high glucose. The plasma KIFAP3-5:1 of DN patients is highly correlated with the severity of renal dysfunction and plays an important role in the prediction model of DN diseases. These findings suggested that KIFAP3-5:1 plays a critical role in regulation of renal EMT and fibrosis through suppress PRRX1, and highlight the clinical potential of KIFAP3-5:1 to assist in the diagnosis of diabetic nephropathy.
Subject(s)
Diabetic Nephropathies , Epithelial-Mesenchymal Transition , Homeodomain Proteins , Kidney Tubules , RNA, Long Noncoding , Epithelial-Mesenchymal Transition/genetics , Diabetic Nephropathies/genetics , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/pathology , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Animals , Humans , Mice , Kidney Tubules/metabolism , Kidney Tubules/pathology , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Male , Epithelial Cells/metabolism , Epithelial Cells/pathology , Glucose/metabolism , Glucose/pharmacology , Fibrosis , Mice, Inbred C57BL , Female , Middle AgedABSTRACT
As one of the most significant pathological changes of diabetic nephropathy (DN), tubulointerstitial fibrosis (TIF) had a close relationship with tubulointerstitial inflammation (TI), and the occurrence of TI could have resulted from the disrupted tight junctions (TJs) of renal tubular epithelial cells (RTECs). Studies have demonstrated that sodium butyrate (NaB), a typical short chain fatty acid (SCFA), played an important regulatory role in intestinal TJs and inflammation. In this study, our in vivo and in vitro results showed that accompanied by TI, renal tubular TJs were gradually disrupted in the process of DN-related TIF. In HG and LPS co-cultured HK-2 cells and db/db mice, NaB treatment regained the TJs of RTECs via the sphingosine 1-phosphate receptor-1 (S1PR1)/AMPK signaling pathway, relieving inflammation. Small interfering RNA of S1PR1, S1PR1 antagonist W146 and agonist SEW2871, and AMPK agonist AICAR were all used to further confirm the essential role of the S1PR1/AMPK signaling pathway in NaB's TJ protection in RTECs in vitro. Finally, NaB administration not only improved the renal function and TIF, but also relieved the TI of db/db mice. These findings suggested that the use of NaB might be a potential adjuvant treatment strategy for DN-associated TIF, and this protective effect was linked to the TJ modulation of RTECs via the S1PR1/AMPK signaling pathway, leading to the improvement of TI.
Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , Mice , Animals , Diabetic Nephropathies/drug therapy , Diabetic Nephropathies/metabolism , Butyric Acid/pharmacology , Butyric Acid/metabolism , AMP-Activated Protein Kinases/metabolism , Tight Junctions/metabolism , Epithelial Cells/metabolism , Fibrosis , Diabetes Mellitus/metabolismABSTRACT
Removal of Expression of Concern for 'Sodium butyrate ameliorated diabetic nephropathy-associated tubulointerstitial inflammation by modulating tight junction of renal tubular epithelial cells' by Tingting Yang et al., Food Funct., 2022, Accepted Manuscript, https://doi.org/10.1039/D2FO00940D.
ABSTRACT
The occurrence of benign prostate hyperplasia (BPH) was related to disrupted sex steroid hormones, and metformin (Met) had a clinical response to sex steroid hormone-related gynaecological disease. However, whether Met exerts an antiproliferative effect on BPH via sex steroid hormones remains unclear. Here, our clinical study showed that along with prostatic epithelial cell (PEC) proliferation, sex steroid hormones were dysregulated in the serum and prostate of BPH patients. As the major contributor to dysregulated sex steroid hormones, elevated dihydrotestosterone (DHT) had a significant positive relationship with the clinical characteristics of BPH patients. Activation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) by Met restored dysregulated sex steroid hormone homeostasis and exerted antiproliferative effects against DHT-induced proliferation by inhibiting the formation of androgen receptor (AR)-mediated Yes-associated protein (YAP1)-TEA domain transcription factor (TEAD4) heterodimers. Met's anti-proliferative effects were blocked by AMPK inhibitor or YAP1 overexpression in DHT-cultured BPH-1 cells. Our findings indicated that Met would be a promising clinical therapeutic approach for BPH by inhibiting dysregulated steroid hormone-induced PEC proliferation.
ABSTRACT
AIMS: FoxO1 is an important factor in the ß-cell differentiation in type 2 diabetes mellitus (T2DM). Sirt3 is found to be involved in FoxO1 function. This study investigated the role of Sirt3 in the ß-cell dedifferentiation and its mechanism. METHODS: Twelve-week-old db/db mice and INS1 cells transfected with Sirt3-specific short hairpin RNA (shSirt3) were used to evaluate the dedifferentiation of ß-cell. Insulin levels were measured by enzyme linked immunosorbent assay. The proteins of Sirt3, T-FoxO1, Ac-FoxO1 and differentiation indexes such as NGN3, OCT4, MAFA were determined by western blot or immunofluorescence staining. The combination of Sirt3 and FoxO1 was determined by the co-immunoprecipitation assay. The transcriptional activity of FoxO1 was detected by dual luciferase reporter assay. RESULTS: Both the in vivo and in vitro results showed that Sirt3 was decreased along with ß-cell dedifferentiation and decreased function of insulin secretion under high glucose conditions. When Sirt3 was knocked down in INS1 cells, increased ß-cell dedifferentiation and lowered insulin secretion were observed. This effect was closely related to the amount loss and the decreased deacetylation of FoxO1, which resulted in a reduction in transcriptional activity. CONCLUSION: Downregulation of Sirt3 contributes to ß-cell dedifferentiation in high glucose via FoxO1. Intervention of Sirt3 may be an effective approach to prevent ß-cell failure in T2DM.
Subject(s)
Diabetes Mellitus, Type 2 , Insulin-Secreting Cells , Sirtuin 3 , Animals , Mice , Cell Dedifferentiation , Diabetes Mellitus, Type 2/metabolism , Down-Regulation , Glucose/metabolism , Insulin/metabolism , Insulin-Secreting Cells/metabolism , Sirtuin 3/genetics , Sirtuin 3/metabolismABSTRACT
Ample evidence reveals that glycolysis is crucial to tumor progression; however, the underlying mechanism of its drug resistance is still worth being further explored. TRAF6, an E3 ubiquitin ligase, is well recognized to overexpress in various types of cancer, which predicts a poor prognosis. In our study, we discovered that TRAF6 was expressed more significantly in the case of triple-negative breast cancer (TNBC) than in other of breast cancers, promoting chemoresistance to paclitaxel; that inhibited TRAF6 expression in the chemoresistant TNBC (TNBC-CR) cells enhanced the sensitivity by decreasing glucose uptake and lactate production; that TRAF6 regulated glycolysis and facilitated chemoresistance via binding directly to PKM2; and that overexpressing PKM2 in the TNBC-CR cells with TRAF6 knocked down regained significantly TRAF6-dependent drug resistance and glycolysis. Additionally, we verified that TRAF6 could facilitate PKM2-mediated glycolysis and chemoresistance in animal models and clinical tumor tissues. Thus, we identified the novel function of TRAF6 to promote glycolysis and drug resistance in TNBC with the regulation of PKM2, which could provide a potential molecular target for TNBC treatment.
Subject(s)
Triple Negative Breast Neoplasms , Humans , Animals , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/genetics , Paclitaxel/pharmacology , Paclitaxel/therapeutic use , TNF Receptor-Associated Factor 6 , Drug Resistance, Neoplasm/genetics , Cell Line, Tumor , Glycolysis , Cell Proliferation , Gene Expression Regulation, NeoplasticABSTRACT
Diabetic encephalopathy (DE) is a central nervous complication of diabetes mellitus which is characterized by cognitive impairment and neurochemical abnormalities. However, no effective approaches are available to prevent its progression and development. PDE4D serves many functions in the pathogenesis of neurodegenerative diseases involving PKA signaling. This study illustrated the role of PDE4D in DE and investigated whether resveratrol protected against DE via inhibiting PDE4D. db/db male mice and hippocampus cell line (HT22) were used to investigate the role of PDE4D and the protective effect of resveratrol on cognitive function under high glucose (HG). PDE4D overexpression or knockdown lentivirus and PKA specific inhibitor H89 were used to further identify the indispensable role of PDE4D/PKA signaling pathway in resveratrol's amelioration effect of neurotoxicity. Resveratrol attenuated cognitive impairment in db/db mice, reduced PDE4D protein, restored the impaired mitochondrial function in db/db mice. The in vitro study also confirmed the neuroprotective effect of resveratrol on neurotoxicity. PDE4D overexpression resulted in cell injury and downregulation of cAMP, PKA and pDrp1(Ser637) under normal condition. In contrast, PDE4D knockdown improved cell injury and elevated cAMP, PKA and pDrp1(Ser637) levels caused in HG-cultured HT22 cells. PDE4D over-expression blunted the improvement effects of resveratrol on PKA, pDrp1(Ser637) and mitochondrial function. Moreover, PKA inhibitor H89 blunted the inhibitory effects of resveratrol on pDrp1(Ser637) and mitochondrial function in HG-treated HT22. These data indicated that resveratrol may improve cognitive impairment in db/db mice by modulating mitochondrial function through the PDE4D dependent pathway.
Subject(s)
Diabetes Mellitus , Signal Transduction , Mice , Animals , Male , Resveratrol/pharmacology , Sulfonamides/pharmacologyABSTRACT
Chromobox protein homolog 4 (CBX4) is a component of the Polycomb group (PcG) multiprotein Polycomb repressive complexes 1 (PRC1), which is participated in several processes including growth, senescence, immunity, and tissue repair. CBX4 has been shown to have diverse, even opposite functions in different types of tissue and malignancy in previous studies. In this study, we found that CBX4 deletion promoted lung adenocarcinoma (LUAD) proliferation and progression in KrasG12D mutated background. In vitro, over 50% Cbx4L/L, KrasG12D mouse embryonic fibroblasts (MEFs) underwent apoptosis in the initial period after Adeno-Cre virus treatment, while a small portion of survival cells got increased proliferation and transformation abilities, which we called selected Cbx4-/-, KrasG12D cells. Karyotype analysis and RNA-seq data revealed chromosome instability and genome changes in selected Cbx4-/-, KrasG12D cells compared with KrasG12D cells. Further study showed that P15, P16 and other apoptosis-related genes were upregulated in the primary Cbx4-/-, KrasG12D cells due to chromosome instability, which led to the large population of cell apoptosis. In addition, multiple pathways including Hippo pathway and basal cell cancer-related signatures were altered in selected Cbx4-/-, KrasG12D cells, ultimately leading to cancer. We also found that low expression of CBX4 in LUAD was associated with poorer prognosis under Kras mutation background from the human clinical data. To sum up, CBX4 deletion causes genomic instability to induce tumorigenesis under KrasG12D background. Our study demonstrates that CBX4 plays an emerging role in tumorigenesis, which is of great importance in guiding the clinical treatment of lung adenocarcinoma.
Subject(s)
Adenocarcinoma of Lung , Ligases , Lung Neoplasms , Polycomb Repressive Complex 1 , Animals , Humans , Mice , Adenocarcinoma of Lung/genetics , Carcinogenesis/genetics , Cell Transformation, Neoplastic/genetics , Chromosomal Instability , Fibroblasts , Genomic Instability/genetics , Ligases/genetics , Lung Neoplasms/genetics , Polycomb Repressive Complex 1/geneticsABSTRACT
To explore the role of PDE4D in diabetic nephropathy (DN) and investigate whether resveratrol protects against DN via inhibiting PDE4D. Diabetic db/db mouse and glomerular mesangial cell line (GMCs) were used to investigate the role of PDE4D and the protective effect of resveratrol on renal fibrosis under high glucose (HG) environment. Resveratrol alleviated the progress of DN via inhibiting mitochondrial fragmentation and restoring the expression of PDE4D, PKA, phosphorylated Drp1-Ser637 and Drp1 in kidney of db/db mice. In HG-exposed GMCs, resveratrol treatment decreased the expression of PDE4D, increased PKA level, and inhibited Drp1-mediated mitochondrial fission. In contrast, PDE4D over-expression blunted the inhibitory effects of resveratrol on Drp1 expression and mitochondrial fission. Moreover, PKA inhibitor H89 blunted the effects of resveratrol on phosphorylated Drp1-Ser637 expression and mitochondrial fission in HG-treated GMCs. Inhibition of mitochondrial fission with Drp1 inhibitor Mdivi-1 alleviated mitochondrial dysfunction in GMCs under HG. These findings indicate PDE4D plays an important role in the process of DN. Resveratrol attenuates the development of DN by preventing mitochondrial fission through inhibiting PDE4D, which regulates the expression of phosphorylated Drp1-Ser637 directly.
Subject(s)
Diabetes Mellitus, Experimental , Diabetic Nephropathies , Mice , Animals , Diabetic Nephropathies/drug therapy , Resveratrol/pharmacology , Mitochondrial Dynamics , Diabetes Mellitus, Experimental/metabolism , Mesangial Cells/metabolismABSTRACT
The development of diabetic nephropathy (DN) could be promoted by the occurrence of tubulointerstitial fibrosis (TIF), which has a close relationship with mitochondrial dysfunction of renal tubular epithelial cells (RTECs). As a key regulator of metabolic homeostasis, Yin Yang 1 (YY1) plays an important role not only in regulating the fibrosis process but also in maintaining the mitochondrial function of pancreatic ß-cells. However, it was not clear whether YY1 participated in maintaining mitochondrial function of RTECs in early DN-associated TIF. In this study, we dynamically detected mitochondrial functions and protein expression of YY1 in db/db mice and high glucose (HG)-cultured HK-2 cells. Our results showed that comparing with the occurrence of TIF, the emergence of mitochondrial dysfunction of RTECs was an earlier even, besides the up-regulated and nuclear translocated YY1. Correlation analysis showed YY1 expressions were negatively associated with PGC-1α in vitro and in vivo. Further mechanism research demonstrated the formation of mTOR-YY1 heterodimer induced by HG up-regulated YY1, the nuclear translocation of which inactivated PGC-1α by binding to the PGC-1α promoter. Overexpression of YY1 induced mitochondrial dysfunctions in normal glucose-cultured HK-2 cells and 8-weeks-old db/m mice. While, dysfunctional mitochondria induced by HG could be improved by knockdown of YY1. Finally, downregulation of YY1 could retard the progression of TIF by preventing mitochondrial functions, resulting in the improvement of epithelial-mesenchymal transition (EMT) in early DN. These findings suggested that YY1 was a novel regulator of mitochondrial function of RTECs and contributed to the occurrence of early DN-associated TIF.
ABSTRACT
BACKGROUND: Hepatic lipid accumulation was a major promoter for the further development of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes (T2DM). mTOR/YY1 signaling pathway regulated many metabolic processes in different organs, and played an important role in hepatic lipid metabolism. Thus, targeting mTOR/YY1 signaling pathway might be a novel therapeutic strategy of T2DM-associated NALFD. PURPOSE: To investigate the effects and the mechanism of quercetin against T2DM-associated NAFLD. STUDY DESIGN AND METHODS: The combine abilities of 24 flavonoid compounds with mTOR were detected by computer virtual screening (VS) and molecular modeling. mTOR/YY1 signaling pathway was examined in the liver of db/db mice, and high glucose (HG) and free fatty acid (FFA) co-cultured HepG2 cells. YY1 overexpression lentivirus vector and mTOR specific inhibitor rapamycin were used to further identify the indispensable role of mTOR/YY1 signaling pathway in quercetin's amelioration effect of hepatic lipid accumulation in vitro. Clinical studies, luciferase assay and chromatin immunoprecipitation (ChIP) assay were all carried out to investigate the potential mechanisms by which quercetin exerted its amelioration effect of hepatic lipid accumulation. RESULTS: Quercetin had the strongest ability to combine with mTOR and could competitively occupy its binding pocked. Along with the alleviated hepatic injury by quercetin, mTOR/YY1 signaling pathway was down-regulated in vivo and in vitro. However, the alleviation effect of quercetin against hepatic lipid accumulation was inhibited by YY1 overexpression in vitro. Mechanistically, the down-regulated nuclear YY1 induced by quercetin directly bound to CYP7A1 promoter and activated its transcription, resulting in the restoration of cholesterol homeostasis via the conversion of cholesterol-to-bile acids (BAs). CONCLUSION: The hepatoprotective effect of quercetin on T2DM-associated NAFLD was linked to the restoration of cholesterol homeostasis by the conversion of cholesterol-to-BAs via down-regulating mTOR/YY1 signaling pathway, leading to the increased CYP7A1 activity.
Subject(s)
Diabetes Mellitus, Type 2 , Non-alcoholic Fatty Liver Disease , Mice , Animals , Non-alcoholic Fatty Liver Disease/drug therapy , Quercetin/pharmacology , Quercetin/therapeutic use , Bile Acids and Salts/metabolism , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Liver/metabolism , Signal Transduction , TOR Serine-Threonine Kinases/metabolism , Cholesterol/metabolism , Lipid Metabolism , Cholesterol 7-alpha-Hydroxylase/metabolismABSTRACT
The overall objective of this study was to investigate the mechanism of inflammation on chondrocyte injury and the protective effect of catalpol on chondrocytes in an inflammatory environment. Chondrocytes were isolated and cultured from the knee joints of three-day-old newborn mice. Alcian Blue staining and the immunocytochemistry staining of type II collagen were used to identify the purity of chondrocytes. Primary chondrocytes were stimulated by IL-1ß (10 ng/mL) and subjected to transcriptome analysis. Differentially expressed genes (DEGs) were further analyzed based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. In this experimental study, we performed the viability assay to determine the effects of different concentrations of catalpol on the cell viability of chondrocytes. Chondrocytes were seeded in six-well plates and exposed to 10 µM catalpol 2 h prior to treatment with IL-1ß (10 ng/mL). Quantitative real-time (qPCR) and Western blotting were performed to evaluate the RNA and protein expression, respectively. Based on the results of transcriptomics analysis, we found the NOD2 signaling pathway, the NF-kappa B signaling pathway, and the MAPK signaling pathway showed significant changes in chondrocyte damage caused by inflammation. Catalpol (10 µM and 100 µM) could significantly reduce NO, IL-6, IL-1ß, and TNF-α in supernatant of chondrocytes. Catalpol significantly inhibited the mRNA expression of IL-1, IL-6, and IL-12 in chondrocytes induced by IL-1ß. Catalpol markedly inhibited MMP3, MMP13 mRNA, and protein levels. Catalpol could significantly reduce TNF-α mRNA levels in inflammatory chondrocytes. Inflammation causes significant increases in mRNA levels and protein levels of NOD2, mRNA levels, and protein levels were markedly suppressed by catalpol. In addition, catalpol could significantly increase IKBα protein levels and significantly lower intranuclear P65 levels. Catalpol significantly lowered the phosphorylation protein levels of ERK, p38, and JNK. Our transcriptomic analysis demonstrated that the activation of NOD2 and its downstream pathways, NF-κB and MAPK, is an important cause of the inflammatory injury to chondrocytes induced by IL-1ß. Catalpol inhibited the activation of the NOD2 signaling pathway, which reduced the phosphorylation of ERK, p38, and JNK, inhibited the degradation of IκBα, inhibited p65 translocation into the nucleus, reduced the release of inflammatory cytokines, and attenuated the inflammatory damage to chondrocytes.
Subject(s)
NF-kappa B , Osteoarthritis , Mice , Animals , NF-kappa B/metabolism , Chondrocytes , Tumor Necrosis Factor-alpha/metabolism , Transcriptome , Interleukin-6/metabolism , Osteoarthritis/genetics , Signal Transduction , Inflammation , Gene Expression Profiling , RNA, Messenger , Interleukin-1beta/metabolism , Cells, CulturedABSTRACT
The development of diabetic nephropathy (DN) could be promoted by the occurrence of tubulointerstitial fibrosis (TIF), which had a closely relationship with mitochondrial dysfunction of renal tubular epithelial cells (RTECs). As a key regulator of metabolic homeostasis, Yin Yang 1 (YY1) played an important role not only in regulating fibrosis process, but also in maintaining mitochondrial function of pancreatic ß cells. However, it was not clear whether YY1 participated in maintaining mitochondrial function of RTECs in early DN-associated TIF. In this study, we dynamically detected mitochondrial functions and protein expression of YY1 in db/db mice and high glucose (HG)-cultured HK-2 cells. Our results showed that comparing with the occurrence of TIF, the emergence of mitochondrial dysfunction of RTECs was an earlier even, besides the up-regulated and nuclear translocated YY1. Correlation analysis showed YY1 expressions were negatively associated with PGC-1α in vitro and in vivo. Further mechanism research demonstrated the formation of mTOR-YY1 heterodimer induced by HG upregulated YY1, the nuclear translocation of which inactivated PGC-1α by binding to the PGC-1α promoter. Overexpression of YY1 induced mitochondrial dysfunctions in normal glucose cultured HK-2 cells and 8-week-old db/m mice. While, dysfunctional mitochondria induced by HG could be improved by knockdown of YY1. Finally, downregulation of YY1 could retard the progression of TIF by preventing mitochondrial functions, resulting in the improvement of epithelial-mesenchymal transition (EMT) in early DN. These findings suggested that YY1 was a novel regulator of mitochondrial function of RTECs and contributed to the occurrence of early DN-associated TIF .
Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , Mice , Animals , Diabetic Nephropathies/genetics , Diabetic Nephropathies/metabolism , Gene Expression Regulation , Mitochondria/metabolism , Fibrosis , Glucose/pharmacology , Glucose/metabolism , Epithelial-Mesenchymal Transition , Diabetes Mellitus/metabolism , Diabetes Mellitus/pathologyABSTRACT
BACKGROUND: The mechanisms underlying synaptic injury and anxiety-like behavioral changes caused by diabetes and the strategies to reverse these changes are not well understood. OBJECTIVES: This study examined the neuroprotective effects of hesperidin on anxiety-like behaviors in diabetic rats and investigated the underlying mechanisms from the perspective of the PKA/CREB pathway. METHODS: Rats with streptozotocin-induced diabetes were treated orally with hesperidin (50 and 150 mg/kg) for 10 weeks. The elevated plus maze (EPM), hole board test (HBT), and marbleburying test (MBT) were used to assess anxiety-like behaviors. We further examined the effects of hesperidin on the PKA/CREB pathway in vivo and in vitro. RESULTS: The results show that supplementation with hesperidin exerted anxiolytic effects on the diabetic rats, as evidenced by increased percentages of open arm entries and time spent in the open arms in the EPM; decreased numbers of hole visits in the HBT; decreased numbers of marbles buried; and increased expression of PKA, CREB, BDNF, and synaptic proteins in the amygdala and hippocampus of diabetic rats. Hesperidin was found to reverse the imbalance in the PKA/CREB/BDNF pathway. In vitro, we found that the PKA inhibitor H89 reversed the protective effects of hesperidin against cell injury and reversed the HG-induced expression of PKA, pCREB/CREB, and BDNF. CONCLUSION: Our results demonstrated that hesperidin could ameliorate the anxiety-like behaviors of diabetic rats and that activating the PKA/CREB/BDNF pathway contributed to the beneficial effects. This study may provide important insights into the mechanisms underlying anxiety-like behaviors in diabetes and identify new therapeutic targets for clinical treatment.
Subject(s)
Anti-Anxiety Agents , Diabetes Mellitus, Experimental , Hesperidin , Animals , Rats , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/drug therapy , Anti-Anxiety Agents/pharmacology , Anti-Anxiety Agents/therapeutic use , Hesperidin/pharmacology , Hesperidin/therapeutic use , Streptozocin , Brain-Derived Neurotrophic FactorABSTRACT
FADD, a classical apoptotic signaling adaptor, has recently been reported to exhibit a series of non-apoptotic functions. Here, we report that FADD may play a critical role in the development of renal fibrosis. Neutrophil infiltration in the renal interstitial part, glomerular mesangial cell proliferation, and base-membrane thickening were observed in FADD-D mice by H&E, PAS, and PASM staining. Immunofluorescence analysis revealed that macrophage infiltration was significantly enhanced in FADD-D mice. Renal fibrosis might be induced by IgA nephritis in FADD-D mice as evidenced by increased Ki67 and type IV collagen. Additionally, the levels of α-SMA, Fibronectin, and Vimentin were also found to be elevated. Mechanism study indicated that the TLR4/myD88/NF-κB signaling pathway was activated in FADD-D mice. Moreover, FADD phosphorylation activated the mTOR and TGF-ß/Smad pathway and accelerated the process of epithelial mesenchymal transition. Further studies indicated that the TGF-ß1 pathway was also activated and the process of EMT was accelerated in both FADD-disrupted HEK293 cells and FADD-deficient MES cells. Thus, we concluded that FADD phosphorylation could lead to IgA nephritis and eventually result in renal fibrosis. Taken together, our study provides evidence, for the first time, that FADD, especially in its phosphorylated form, has an effect on the development of renal fibrosis.Abbreviations: FADD: FAS-associated protein with death domain; DED: death effector domain; DD: death domain; CKD: chronic kidney disease; ECM: extracellular matrix; ESRD: end-stage renal disease; RRT: renal replacement therapy; H&E: hematoxylin and eosin; PASM: periodic acid silver methenamine.
Subject(s)
Kidney Diseases , Nephritis , Mice , Humans , Animals , Epithelial-Mesenchymal Transition , Phosphorylation , HEK293 Cells , Kidney Diseases/metabolism , Transforming Growth Factor beta1/metabolism , Fibrosis , Immunoglobulin A/metabolism , Fas-Associated Death Domain Protein/metabolism , Fas-Associated Death Domain Protein/pharmacologyABSTRACT
BACKGROUND: Diabetic kidney disease (DKD) is one of the most common complications of diabetes, with approximately 30-40% of patients with type 1 diabetes mellitus and 20% of patients with type 2 diabetes mellitus eventually developing DKD. If DKD is not controlled in the early clinical stage and proteinuria develops, the disease will progress to end-stage renal disease. The pathogenesis of DKD remains largely unknown and is multifactorial, likely due to interactions between genetic and environmental factors. Familial clustering also supports a critical role of hereditary factors in DKD. The development of gene detection technology has promoted the exploration of DKD susceptibility genes in different cohorts of patients with diabetes. Identifying susceptibility genes can provide insights into the pathogenesis of DKD, as well as a basis for its clinical diagnosis and therapy. RESULTS: Numerous candidate gene loci have been found to be associated with DKD, many of which play critical regulatory roles in the pathogenesis of this disease, including genes involved in glycol-metabolism, lipid metabolism, the renin-angiotensin-aldosterone system, inflammation and oxidative stress. In this review, we summarize the functions of several susceptibility genes involved in the development of DKD. CONCLUSION: Based on our findings, we recommend that studying susceptibility gene polymorphisms can lead to a better understanding of the pathogenesis of DKD and could help prevent this disease or improve its outcomes.