scholarly journals Magnoflorine Ameliorates Inflammation and Fibrosis in Rats With Diabetic Nephropathy by Mediating the Stability of Lysine-Specific Demethylase 3A

2020 ◽  
Vol 11 ◽  
Author(s):  
Liang Chang ◽  
Qi Wang ◽  
Jiannan Ju ◽  
Yue Li ◽  
Qiao Cai ◽  
...  

Diabetic nephropathy (DN) represents one of the most devastating complications for patients with diabetes. The anti-diabetic activities of Magnoflorine (MF) were reported, with underlying mechanism unknown. Lysine-specific demethylase 3A (KDM3A) was identified in the renal injuries. In the current study, we investigated the functional role of MF in DN progression with the involvement of KDM3A. We reported that in the animal model of DN induced by streptozotocin (STZ) injection, MF attenuated inflammatory response and fibrosis in the kidneys. In cultured mesangial cells, MF similarly ameliorated abnormal proliferation and lowered the expression of inflammation- and fibrosis-related factors stimulated by high glucose (HG) treatment. Upon MF treatment, there was a decline in KDM3A-positive cells in renal tissues of rats, accompanying an augment in KDM3A ubiquitination. KDM3A upregulation in vitro by a proteasome inhibitor MG132 comparably dampened the inhibitory role of MF in inflammatory response and fibrosis. Further analyses revealed that MF increased transforming growth factor β-induced factor 1 (TGIF1) transcriptional activity by promoting ubiquitination and degradation of KDM3A, thus inhibiting the activation of TGF-β1/Smad2/3 signaling pathway. TGIF1 silencing weakened the repressive role of MF in mesangial cells as well. In conclusion, MF contributes to TGIF1 transcription via an epigenetic mechanism.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Lai-Ming Yung ◽  
Samuel D Paskin-Flerlage ◽  
Ivana Nikolic ◽  
Scott Pearsall ◽  
Ravindra Kumar ◽  
...  

Introduction: Excessive Transforming Growth Factor-β (TGF-β) signaling has been implicated in pulmonary arterial hypertension (PAH), based on activation of TGF-β effectors and transcriptional targets in affected lungs and the ability of TGF-β type I receptor (ALK5) inhibitors to improve experimental PAH. However, clinical use of ALK5 inhibitors has been limited by cardiovascular toxicity. Hypothesis: We tested whether or not selective blockade of TGF-β and Growth Differentiation Factor (GDF) ligands using a recombinant TGFβ type II receptor extracellular domain Fc fusion protein (TGFBRII-Fc) could impact experimental PAH. Methods: Male SD rats were injected with monocrotaline (MCT) and received vehicle or TGFBRII-Fc (15 mg/kg, twice per week, i.p.). C57BL/6 mice were treated with SU-5416 and hypoxia (SUGEN-HX) and received vehicle or TGFBRII-Fc. RNA-Seq was used to profile transcriptional changes in lungs of MCT rats. Circulating levels of GDF-15 were measured in 241 PAH patients and 41 healthy controls. Human pulmonary artery smooth muscle cells were used to examine signaling in vitro . Results: TGFBRII-Fc is a selective ligand trap, inhibiting the ability of GDF-15, TGF-β1, TGF-β3, but not TGF-β2 to activate SMAD2/3 in vitro . In MCT rats, prophylactic treatment with TGFBRII-Fc normalized expression of TGF-β transcriptional target PAI-1, attenuated PAH and vascular remodeling. Delayed administration of TGFBRII-Fc in rats with established PAH at 2.5 weeks led to improved survival, decreased PAH and remodeling at 5 weeks. Similar findings were observed in SUGEN-HX mice. No valvular abnormalities were found with TGFBRII-Fc treatment. RNA-Seq revealed GDF-15 to be the most highly upregulated TGF-β ligand in the lungs of MCT rats, with only modest increases in TGF-β1 and no change in TGF-β2/3 observed, suggesting a dominant role of GDF-15 in the pathophysiology of this model. Plasma levels of GDF-15 were significantly increased in patients with diverse etiologies of WHO Group I PAH. Conclusions: These findings demonstrate that a selective TGF-β/GDF-15 trap attenuates experimental PAH, remodeling and mortality, without causing valvulopathy. These data highlight the potential role of GDF-15 as a pathogenic molecule and therapeutic target in PAH.


2020 ◽  
Vol 69 (12) ◽  
pp. 1215-1234
Author(s):  
Hanxu Zeng ◽  
Xiangming Qi ◽  
Xingxin Xu ◽  
Yonggui Wu

Abstract Objective and design Macrophages exhibit strong phenotypic plasticity and can mediate renal inflammation by polarizing into an M1 phenotype. They play a pivotal role in diabetic nephropathy (DN). Here, we have investigated the regulatory role of transforming growth factor β-activated kinase 1-binding protein 1 (TAB1) in glycolysis and activation of macrophages during DN. Methods TAB1 was inhibited using siRNA in high glucose (HG)-stimulated bone marrow-derived macrophages (BMMs) and lentiviral vector-mediated TAB1 knockdown was used in streptozotocin (STZ)-induced diabetic mice. Western blotting, flow cytometry, qRT-PCR, ELISA, PAS staining and immunohistochemical staining were used for assessment of TAB1/nuclear factor-κB (NF-κB)/hypoxia-inducible factor-1α (HIF-1α), iNOS, glycolysis, inflammation and the clinical and pathological manifestations of diabetic nephropathy. Results We found that TAB1/NF-κB/HIF-1α, iNOS and glycolysis were up-regulated in BMMs under HG conditions, leading to release of further inflammatory factors, Downregulation of TAB1 could inhibit glycolysis/polarization of macrophages and inflammation in vivo and in vitro. Furthermore, albuminuria, the tubulointerstitial damage index and glomerular mesangial expansion index of STZ-induced diabetic nephropathy mice were decreased by TAB1 knockdown. Conclusions Our results suggest that the TAB1/NF-κB/HIF-1α signaling pathway regulates glycolysis and activation of macrophages in DN.


2007 ◽  
Vol 404 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Ivan Alfano ◽  
Parvez Vora ◽  
Rosemary S. Mummery ◽  
Barbara Mulloy ◽  
Christopher C. Rider

GDNF (glial cell-line-derived neurotrophic factor), and the closely related cytokines artemin and neurturin, bind strongly to heparin. Deletion of a basic amino-acid-rich sequence of 16 residues N-terminal to the first cysteine of the transforming growth factor β domain of GDNF results in a marked reduction in heparin binding, whereas removal of a neighbouring sequence, and replacement of pairs of other basic residues with alanine had no effect. The heparin-binding sequence is quite distinct from the binding site for the high affinity GDNF polypeptide receptor, GFRα1 (GDNF family receptor α1), and heparin-bound GDNF is able to bind GFRα1 simultaneously. The heparin-binding sequence of GDNF is dispensable both for GFRα1 binding, and for activity for in vitro neurite outgrowth assay. Surprisingly, the observed inhibition of GDNF bioactivity with the wild-type protein in this assay was still found with the deletion mutant lacking the heparin-binding sequence. Heparin neither inhibits nor potentiates GDNF–GFRα1 interaction, and the extracellular domain of GFRα1 does not bind to heparin itself, precluding heparin cross-bridging of cytokine and receptor polypeptides. The role of heparin and heparan sulfate in GDNF signalling remains unclear, but the present study indicates that it does not occur in the first step of the pathway, namely GDNF–GFRα1 engagement.


2004 ◽  
Vol 286 (1) ◽  
pp. F134-F143 ◽  
Author(s):  
Shinya Mizuno ◽  
Toshikazu Nakamura

Diabetic nephropathy is now the leading cause of end-stage renal diseases, and glomerular sclerotic injury is an initial event that provokes renal dysfunction during processes of diabetes-linked kidney disease. Growing evidence shows that transforming growth factor-β1 (TGF-β1) plays a key role in this process, especially in eliciting hypertrophy and matrix overaccumulation. Thus it is important to find a ligand system to antagonize the TGF-β1-mediated pathogenesis under high-glucose conditions. Herein, we provide evidence that hepatocyte growth factor (HGF) targets mesangial cells, suppresses TGF-β1 production, and minimizes glomerular sclerotic changes, using streptozotocin-induced diabetic mice. In our murine model, glomerular sclerogenesis (such as tuft area expansion and collagen deposition) progressed between 6 and 10 wk after the induction of hyperglycemia, during a natural course of diabetic disease. Glomerular HGF expression levels in the diabetic kidney transiently increased but then declined below a basal level, with manifestation of glomerular sclerogenesis. When anti-HGF IgG was injected into mice for 2 wk (i.e., from weeks 4 to 6 after onset of hyperglycemia), these glomerular changes were significantly aggravated. When recombinant HGF was injected into the mice for 4 wk (i.e., between 6 and 10 wk following streptozotocin treatment), the progression of glomerular hypertrophy and sclerosis was almost completely inhibited, even though glucose levels remained unchanged (>500 mg/dl). Even more important, HGF repressed TGF-β1 production in glomerular mesangial cells even under hyperglycemic conditions both in vitro and in vivo. Consequently, not only albuminuria but also tubulointerstitial fibrogenesis were attenuated by HGF. Overall, HGF therapy inhibited the onset of renal dysfunction in the diabetic mice. On the basis of these findings, we wish to emphasize that HGF plays physiological and therapeutic roles in blocking renal fibrogenesis during a course of diabetic nephropathy.


2007 ◽  
Vol 204 (3) ◽  
pp. 467-474 ◽  
Author(s):  
Göran Karlsson ◽  
Ulrika Blank ◽  
Jennifer L. Moody ◽  
Mats Ehinger ◽  
Sofie Singbrant ◽  
...  

Members of the transforming growth factor β (TGF-β) superfamily of growth factors have been shown to regulate the in vitro proliferation and maintenance of hematopoietic stem cells (HSCs). Working at a common level of convergence for all TGF-β superfamily signals, Smad4 is key in orchestrating these effects. The role of Smad4 in HSC function has remained elusive because of the early embryonic lethality of the conventional knockout. We clarify its role by using an inducible model of Smad4 deletion coupled with transplantation experiments. Remarkably, systemic induction of Smad4 deletion through activation of MxCre was incompatible with survival 4 wk after induction because of anemia and histopathological changes in the colonic mucosa. Isolation of Smad4 deletion to the hematopoietic system via several transplantation approaches demonstrated a role for Smad4 in the maintenance of HSC self-renewal and reconstituting capacity, leaving homing potential, viability, and differentiation intact. Furthermore, the observed down-regulation of notch1 and c-myc in Smad4−/− primitive cells places Smad4 within a network of genes involved in the regulation HSC renewal.


2003 ◽  
Vol 284 (1) ◽  
pp. F144-F154 ◽  
Author(s):  
Jennifer L. Gooch ◽  
Jeffrey L. Barnes ◽  
Sergio Garcia ◽  
Hanna E. Abboud

Diabetic nephropathy is characterized by the rapid onset of hypertrophy and ECM expansion. Previously, we showed that calcineurin phosphatase is required for hypertrophy and ECM synthesis in cultured mesangial cells. Therefore, we examined the effect of calcineurin inhibition on renal hypertrophy and ECM accumulation in streptozotocin-induced diabetic rats. After 2 wk of diabetes, calcineurin protein was increased in whole cortex and glomeruli in conjunction with increased phosphatase activity. Daily administration of cyclosporin A blocked accumulation of both calcineurin protein and calcineurin activity. Also associated with calcineurin upregulation was nuclear localization of the calcineurin substrate NFATc1. Inhibition of calcineurin reduced whole kidney hypertrophy and abolished glomerular hypertrophy in diabetic rats. Furthermore, calcineurin inhibition substantially reduced ECM accumulation in diabetic glomeruli but not in cortical tissue, suggesting a differential effect of calcineurin inhibition in glomerular vs. extraglomerular tissue. Corresponding increases in fibronectin mRNA and transforming growth factor-β mRNA were observed in tubulointerstitium but not in glomeruli. In summary, calcineurin plays an important role in glomerular hypertrophy and ECM accumulation in diabetic nephropathy.


2000 ◽  
Vol 15 (1) ◽  
pp. 68-81 ◽  
Author(s):  
Sarah L. Dallas ◽  
Douglas R. Keene ◽  
Scott P. Bruder ◽  
Juha Saharinen ◽  
Lynn Y. Sakai ◽  
...  

2002 ◽  
Vol 70 (12) ◽  
pp. 6911-6918 ◽  
Author(s):  
Antonio J. Buendía ◽  
Laura Del Río ◽  
Nieves Ortega ◽  
Joaquín Sánchez ◽  
María C. Gallego ◽  
...  

ABSTRACT The resolution of Chlamydophila abortus (Chlamydia psittaci serotype 1) infection is dependent on gamma interferon and CD8+ T cells, and classically, B cells have been considered to play a minimal role in host defense. The role of B cells in the immune response was studied by using a model of infection in mice with genetically modified immunoglobulin M transmembrane domains (μMT). In the absence of B cells, infection with C. abortus leads to an acute severe fatal disease that involves a disseminated intravascular coagulation syndrome. μMT mice displayed an increased level of proinflammatory cytokines in serum, and an increased number of neutrophils was observed in the lesions. The possible deleterious role of neutrophils in the pathogenesis of disease in μMT mice was determined by depletion of the neutrophils with the monoclonal antibody RB6-8C5. This led to an enhancement of the bacterial burden and early mortality in both μMT and wild-type mice, while necrotic lesions remained. Analysis of the presence of immunoregulatory cytokines showed significantly lower levels of transforming growth factor β in the sera of μMT mice. However, mice lacking mature B cells were able to establish a specific immune response that protected them from a secondary challenge. Taken together, these data suggest an immunomodulatory role for B cells in the early events of C. abortus primary infection that can protect mice against an exaggerated inflammatory response.


2012 ◽  
Vol 303 (8) ◽  
pp. F1145-F1150 ◽  
Author(s):  
Harmeet Kaur ◽  
Alexander Chien ◽  
Ishwarlal Jialal

Diabetes is a proinflammatory state. The pattern recognition receptors, Toll-like receptors (TLRs), are increased in diabetic patients and have been suggested to play a role in diabetic nephropathy (DN). Progression of DN involves altered mesangial cell (MC) function with an expansion of the mesangial matrix. There is a paucity of data examining the role of TLR and its expression in MC. We hypothesize the expression of TLRs in the mesangium might be an important factor contributing to mesangium expansion and nephropathy. Thus we evaluated the effect of high glucose on TLR2 and TLR4 expression in mouse mesangial cells (MMC) in vitro. Exposure of MMC to 25 mM glucose for 24 h resulted in increased TLR4 mRNA and cell surface receptor expression compared with 5.5 mM glucose ( P < 0.05). Interestingly, we were not able to detect expression of TLR2 in MMC. Furthermore, expression of a TLR4 downstream signaling cascade including myeloid differentiation factor 88 (MyD88), interferon regulatory factor 3 (IRF3), and Toll interleukin receptor domain containing adaptor inducing interferon-β (TRIF)-related adaptor molecule (TRAM) were significantly increased in cells exposed to 25 mM glucose ( P < 0.05). There was also a significant increase in NF-κB activation along with increased secretion of inflammatory cytokines IL-6 and monocyte chemotactic protein-1. Levels of transforming growth factor-β were also significantly increased in the presence of 25 mM glucose ( P < 0.05). Collectively, these data suggest that hyperglycemia activates TLR4 expression and activity in MC and could contribute to DN.


2002 ◽  
Vol 30 (2) ◽  
pp. 107-111 ◽  
Author(s):  
C. D. Richards ◽  
C. Kerr ◽  
L. Tong ◽  
C. Langdon

Metabolism of the extracellular matrix (ECM) is a complex process that becomes disregulated in disease states characterized by chronic inflammation of joints, as is seen in rheumatoid arthritis or fibrosis of the lung. The participation of certain cytokines in this process is generally accepted (transforming growth factor-β induces fibrosis), while the roles of other cytokines are less clear. Oncostatin M (OSM) is a member of the interleukin-6/leukaemia inhibitory factor (or gp130) cytokine family, and its participation in inflammation and the regulation of ECM metabolism is supported by a number of activities identified in vitro, including regulation of matrix metallo-proteinase-1 and tissue inhibitor of metalloproteinases-1. Local overexpression of transforming growth factor-β has been shown to be fibrogenic in mouse lung, whereas local OSM over-expression via intra-articular administration has been shown to induce a pannus-like inflammatory response in the synovium of mouse knee joints. Here we examine the effects of OSM in the context of those of transforming growth factor-β using an established adenovirus vector that expresses mOSM (AdmOSM). We administered the virus intra-nasally into Balb/C mice to achieve high expression of OSM in the lung, and examined the effects at various time points. AdmOSM resulted in a vigorous inflammatory response by day 7 which was characterized by an elevation of neutrophil and mononuclear cell numbers and a marked increase in collagen deposition. These data support the use of such systems to study the ECM in vivo, and indicate a potential role for OSM in inflammatory responses that can modulate steady-state ECM deposition in Balb/C mice.


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