Interstitial fibrosis is an important contributor to graft loss in chronic renal allograft injury. Inflammatory macrophages are associated with fibrosis in renal allografts, but how these cells ...contribute to this damaging response is not clearly understood. Here, we investigated the role of macrophage-to-myofibroblast transition in interstitial fibrosis in human and experimental chronic renal allograft injury. In biopsy specimens from patients with active chronic allograft rejection, we identified cells undergoing macrophage-to-myofibroblast transition by the coexpression of macrophage (CD68) and myofibroblast (
-smooth muscle actin
-SMA) markers. CD68
/
-SMA
cells accounted for approximately 50% of the myofibroblast population, and the number of these cells correlated with allograft function and the severity of interstitial fibrosis. Similarly, in C57BL/6J mice with a BALB/c renal allograft, cells coexpressing macrophage markers (CD68 or F4/80) and
-SMA composed a significant population in the interstitium of allografts undergoing chronic rejection. Fate-mapping in Lyz2-Cre/Rosa26-Tomato mice showed that approximately half of
-SMA
myofibroblasts in renal allografts originated from recipient bone marrow-derived macrophages. Knockout of
protected against interstitial fibrosis in renal allografts and substantially reduced the number of macrophage-to-myofibroblast transition cells. Furthermore, the majority of macrophage-to-myofibroblast transition cells in human and experimental renal allograft rejection coexpressed the M2-type macrophage marker CD206, and this expression was considerably reduced in
-knockout recipients. In conclusion, our studies indicate that macrophage-to-myofibroblast transition contributes to interstitial fibrosis in chronic renal allograft injury. Moreover, the transition of bone marrow-derived M2-type macrophages to myofibroblasts in the renal allograft is regulated
a Smad3-dependent mechanism.
Transforming growth factor‐β (TGF‐β) is the key player in tissue fibrosis. However, antifibrotic therapy targeting this multifunctional protein may interfere with other physiological processes to ...cause side effects. Thus, precise therapeutic targets need to be identified by further understanding the underlying mechanisms of TGF‐β1 signalling during fibrogenesis. Equilibrium of Smad signalling is crucial for TGF‐β‐mediated renal fibrosis, where Smad3 is pathogenic but Smad2 and Smad7 are protective. The activation of TGF‐β1/Smad signalling triggers extracellular matrix deposition, and local myofibroblast generation and activation. Mechanistic studies have shown that TGF‐β/Smad3 transits the microRNA profile from antifibrotic to profibrotic and therefore promotes renal fibrosis via regulating non‐coding RNAs at transcriptional levels. More importantly, disease‐specific Smad3‐dependent long non‐coding RNAs have been recently uncovered from mouse kidney disease models and may represent novel precision therapeutic targets for chronic kidney disease. In this review, mechanisms of TGF‐β‐driven renal fibrosis via non‐coding RNAs and their translational capacities will be discussed in detail.
TGF‐β1/Smad3 signaling promotes renal fibrosis via transcriptional regulation. TGF‐β1 triggers the development and progression of renal fibrosis in the injured kidney by regulating the expression levels of both pro‐fibrotic and anti‐fibrotic genes at transcriptional level via Smad3 activation.
Natural killer (NK) cell is a powerful malignant cells killer, providing rapid immune responses via direct cytotoxicity without the need of antigen processing and presentation. It plays an essential ...role in preventing early tumor, metastasis and minimal residual disease. Although adoptive NK therapies achieved great success in clinical trials against hematologic malignancies, their accumulation, activation, cytotoxic and immunoregulatory functions are severely impaired in the immunosuppressive microenvironment of solid tumors. Now with better understandings of the tumor evasive mechanisms from NK-mediated immunosurveillance, immunotherapies targeting the key molecules for NK cell dysfunction and exhaustion have been developed and tested in both preclinical and clinical studies. In this review, we introduce the challenges that NK cells encountered in solid tumor microenvironment (TME) and the therapeutic approaches to overcome these limitations, followed by an outline of the recent preclinical advances and the latest clinical outcomes of NK-based immunotherapies, as well as promising strategies to optimize current NK-targeted immunotherapies for solid tumors.
Renal inflammation and fibrosis are key pathological features of acute kidney injury (AKI) and chronic kidney disease (CKD). Smad3 is a critical mediator of TGF-β signaling and plays a pathogenic ...role in both renal inflammation and fibrosis. Smad3 can be activated not only by TGF-β1 but also by many stress molecules including angiotensin II (Ang II), advanced end products (AGEs), and C-reactive protein (CRP) under disease conditions. In addition, Smad3 can interact with other signaling pathways, such as the ERK/p38 MAPK and NF-κB pathways, to mediate renal inflammation and fibrosis. Mechanistically, Smad3 transcriptionally regulates many downstream target genes including microRNAs and long non-coding RNAs to cause cell death, inflammation, and fibrosis. Thus, targeting Smad3 or its downstream genes specifically related to renal inflammation and fibrosis should provide a novel therapeutic strategy to combat kidney diseases.
Renal inflammation is an initial pathological process during progressive renal injury regardless of the initial cause. Macrophage migration inhibitory factor (MIF) is a truly proinflammatory stress ...mediator that is highly expressed in a variety of both inflammatory cells and intrinsic kidney cells. MIF is released from the diseased kidney immediately upon stimulation to trigger renal inflammation by activating macrophages and T cells, and promoting the production of proinflammatory cytokines, chemokines, and stress molecules via signaling pathways involving the CD74/CD44 and chemokine receptors CXCR2, CXCR4, and CXCR7 signaling. In addition, MIF can function as a stress molecule to counter-regulate the immunosuppressive effect of glucocorticoid in renal inflammation. Given the critical position of MIF in the upstream inflammatory cascade, this review focuses on the regulatory role and molecular mechanisms of MIF in kidney diseases. The therapeutic potential of targeting MIF signaling to treat kidney diseases is also discussed.
Transforming growth factor β1 (TGF-β1) plays a promoting role in tumor growth via a mechanism associated with hyperactive Smad3 and suppressed Smad7 signaling in the tumor microenvironment. We report ...that retrieving the balance between Smad3 and Smad7 signaling with asiatic acid (AA, a Smad7 inducer) and naringenin (NG, a Smad3 inhibitor) effectively inhibited tumor progression in mouse models of invasive melanoma (B16F10) and lung carcinoma (LLC) by promoting natural killer (NK) cell development and cytotoxicity against cancer. Mechanistically, we found that Smad3 physically bound Id2 and IRF2 to suppress NK cell production and NK cell-mediated cytotoxicity against cancer. Treatment with AA and NG greatly inhibited Smad3 translation and phosphorylation while it restored Smad7 expression, and, therefore, it largely promoted NK cell differentiation, maturation, and cytotoxicity against cancer via Id2/IRF2-associated mechanisms. In contrast, silencing Id2 or IRF2 blunted the protective effects of AA and NG on NK cell-dependent anti-cancer activities. Thus, treatment with AA and NG produced an additive effect on inactivating TGF-β1/Smad3 signaling, and, therefore, it suppressed melanoma and lung carcinoma growth by promoting NK cell immunity against cancer via a mechanism associated with Id2 and IRF2.
Lian et al. identified a novel immunotherapy with the combination of asiatic acid (AA) and naringenin (NG), which effectively suppressed tumor progression. The anti-cancer mechanism mainly hinged on the capability of AA and NG to rebalance Smad3/Smad7 signaling in NK cells, thus largely promoting Id2/IRF2-dependent NK cell maturation and cytotoxicity against cancer.
Transforming growth factor β (TGF-β)/Smad3 signaling plays a role in tissue fibrosis. We report here that Erbb4-IR is a novel long non-coding RNA (lncRNA) responsible for TGF-β/Smad3-mediated renal ...fibrosis and is a specific therapeutic target for chronic kidney disease. Erbb4-IR was induced by TGF-β1 via a Smad3-dependent mechanism and was highly upregulated in the fibrotic kidney of mouse unilateral ureteral obstructive nephropathy (UUO). Silencing Erbb4-IR blocked TGF-β1-induced collagen I and alpha-smooth muscle actin (α-SMA) expressions in vitro and effectively attenuated renal fibrosis in the UUO kidney by blocking TGF-β/Smad3 signaling. Mechanistic studies revealed that Smad7, a downstream negative regulator of TGF-β/Smad signaling, is a target gene of Erbb4-IR because a binding site of Erbb4-IR was found on the 3′ UTR of Smad7 gene. Mutation of this binding site prevented the suppressive effect of Erbb4-IR on the Smad7 reporter activity; in contrast, overexpression of Erbb4-IR largely inhibited Smad7 but increased collagen I and α-SMA transcriptions. Thus, kidney-specific silencing of Erbb4-IR upregulated renal Smad7 and thus blocked TGF-β/Smad3-mediated renal fibrosis in vivo and in vitro. In conclusion, the present study identified that Erbb4-IR is a novel lncRNA responsible for TGF-β/Smad3-mediated renal fibrosis by downregulating Smad7. Targeting Erbb4-IR may represent a precise therapeutic strategy for progressive renal fibrosis.
Feng et al. characterize a novel Smad3-dependent long non-coding RNA Erbb4-IR and further demonstrate its role in promoting renal fibrosis in a mouse unilateral ureteral obstruction model. Erbb4-IR binds and represses the promoter of Smad7, thereby enhancing TGF-β1/Smad3-mediated fibrogenesis. Erbb4-IR may represent a precision therapeutic target for chronic kidney disease.
Diabetic cardiomyopathy (DCM) is a common diabetic complication characterized by diastolic relaxation abnormalities, myocardial fibrosis and chronic heart failure. Although TGF‐β/Smad3 signalling has ...been shown to play a critical role in chronic heart disease, the role and mechanisms of Smad3 in DCM remain unclear. We reported here the potential role of Smad3 in the development of DCM by genetically deleting the Smad3 gene from db/db mice. At the age of 32 weeks, Smad3WT‐db/db mice developed moderate to severe DCM as demonstrated by a marked increase in the left ventricular (LV) mass, a significant fall in the LV ejection fraction (EF) and LV fractional shortening (FS), and progressive myocardial fibrosis and inflammation. In contrast, db/db mice lacking Smad3 (Smad3KO‐db/db) were protected against the development of DCM with normal cardiac function and undetectable myocardial inflammation and fibrosis. Interestingly, db/db mice with deleting one copy of Smad3 (Smad3 ± db/db) did not show any cardioprotective effects. Mechanistically, we found that deletion of Smad3 from db/db mice largely protected cardiac Smad7 from Smurf2‐mediated ubiquitin proteasome degradation, thereby inducing IBα to suppress NF‐kB‐driven cardiac inflammation. In addition, deletion of Smad3 also altered Smad3‐dependent miRNAs by up‐regulating cardiac miR‐29b while suppressing miR‐21 to exhibit the cardioprotective effect on Smad3KO‐db/db mice. In conclusion, results from this study reveal that Smad3 is a key mediator in the pathogenesis of DCM. Targeting Smad3 may be a novel therapy for DCM.
Transforming growth factor (TGF)-β/Smad3 signaling is highly activated in kidneys of patients with type 2 diabetic nephropathy (T2DN), however, the precise role of Smad3 in the pathogenesis of ...diabetic nephropathy remains unclear.
Smad3 knockout (KO)-db/db mice were generated by intercrossing of male and female double-heterozygous Smad3+/− db/m mice. Renal functions including urinary albumin excretion and serum creatinine were determined. Renal histological injury including renal fibrosis and inflammation were examined by periodic acid Schiff (PAS), periodic acid-silver methenamine (PASM), and immunohistochemistry (IHC) staining.
Smad3 knockout (KO)-db/db mice were protected from the development of diabetic kidney injury, characterized by the normal levels of urinary albumin excretion and serum creatinine without any evidence for renal fibrosis and inflammation. In contrast, Smad3 wild-type (WT) db/db and Smad3+/− db/db mice developed progressively decline in renal function over the 12 to 32-week time course, including increased microalbuminuria and elevated levels of serum creatinine. Pathologically, Smad3 WT db/db and Smad3+/− db/db mice exhibited a marked deposition of collagen-I (colI), collagen-IV(col-IV), and an increased infiltration of F4/80+ macrophages in kidney. Mechanistically, Smad3 deficiency decreased the lncRNA Erbb4-IR transcription, while increased miR-29b transcription and therefore protected the kidney from progressive renal injury in db/db mice.
Results from this study imply that Smad3 may represent as a novel and effective therapeutic target for T2DN.
•Smad3 deficiency prevents renal dysfunction in type 2 diabetic nephropathy.•Smad3 deficiency prevents renal fibrosis and inflammation in type 2 diabetic nephropathy.•Smad3 deficiency decreased the lncRNA Erbb4-IR transcription, while increased miR-29b transcription.
IL-17A is a pro-inflammatory cytokine that plays important role in inflammatory disease pathology and tumor microenvironment. The aim of this study is to investigate the effect of IL-17A on the ...progression of hepatocellular carcinoma (HCC).
Expression pattern of IL-17A in clinical HCC samples (n = 43) was determined by immunohistochemistry staining. Transcript levels of MMP2, MMP9 and IL-17A were measured in another 50 pairs (including tumor and related non-tumor tissues) HCC samples. Cell growth, focus formation, cell migration, invasion and western blot assays were used to characterize the functional and signaling mechanisms in IL-17A-treated HCC. Association study was used to identify clinical significance of IL-17A in HCC. Compared with paired non-tumor tissue, higher frequency of IL-17A-positive cells was detected in tumor tissues in HCCs with metastasis, and the frequency of IL-17A-positive cells was also significantly associated with poor prognosis of HCC (P = 0.01). Functional study found that IL-17A could promote HCC cell migration and invasion. Further molecular analysis also showed that IL-17A could upregulate MMP2 and MMP9 expression via NF-κB signaling activation.
IL-17A could promote HCC metastasis by the upregulation of MMP2 and MMP9 expression via activating NF-κB signaling pathway.
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