Cilomilast Ameliorates Renal Tubulointerstitial Fibrosis by Inhibiting the TGF-β1-Smad2/3 Signaling Pathway

Nephrectomy Induces Severe Bone Loss in Mice Expressing Constitutively Active TGFβ Receptor Type I

Transforming growth factor beta (TGF-β), a master regulator of renal fibrosis, is the hallmark of chronic kidney disease (CKD) progression, and CKD worsens bone remodeling. However, the effects of the dysregulation of TGF-β signaling on bone remodeling during CKD have not been investigated. Here, we determined the effects of TGF-β receptor I (TβRI) overexpression under the control of Mx1-Cre on bone remodeling in CKD mice (Mx1;TβRICA-CKD mice). Our results demonstrated that kidney fibrosis and serum urea nitrogen levels were elevated in Mx1;TβRICA-CKD mice compared to WT-CKD, indicating that TβRI overexpression exacerbated renal injury during CKD. Serum calcium was decreased, while PTH was enhanced, in Mx1;TβRICA-CKD mice. Mx1;TβRICA-CKD mice displayed severe osteopenia as assessed by uCT in both femurs and mandibles. An histomorphometric analysis showed that tibial cancellous bone volume was decreased in Mx1;TβRICA-CKD. Likewise, mRNA expression levels of an osteoclastogenesis marker, Tnfsf11/Tnfrsf11b, was increased, and osteoblast marker genes Runx2 and Sp7 were decreased in Mx1;TβRICA-CKD mice. Mx1;TβRICA-CKD mice displayed increased inflammatory cytokines levels. Together, our results indicated that in the setting of CKD, TβRI overexpression induced both CKD progression and the dysregulation of bone remodeling, leading to severe bone loss. As such, these data provide an avenue for the future development of therapeutics for CKD-induced osteoporosis.

Evaluating anti-inflammatory and anti-oxidative potentialities of the chloroform fraction of Asparagus racemosus roots against cisplatin induced acute kidney injury

ETHNOPHARMACOLOGICAL RELEVANCE

Acute kidney injury (AKI), a global public health concern that increases the risk of death, end-stage renal disease, and prolonged hospital admissions. As of this point, supportive measures like fluid resuscitation and replacement therapy for renal failure are the only treatments available for treating AKI. Asparagus racemosus (AR) also known as Shatavari, belongs to family Liliaceae and is considered exceptional in Ayurvedic medicine due to its versatility in treating and preventing a variety of illnesses.

AIM OF THE STUDY

The purpose of this study is to determine the effectiveness of chloroform fraction of Asparagus racemosus (CFAR) against cisplatin (CP) induced AKI.

MATERIALS AND METHODS

HPLC was used to analyze the presence of bioactive phytocompounds in CFAR using standard quercetin. Further LC-MS study indicated the existence of different bioactive compounds. Normal Rat Kidney (NRK-52E) cells were used to study the nephroprotective effect of CFAR. Cells were untreated, treated or cotreated with CP (20 μM) and CFAR (5, 25, 50, 100, 200 and 400μg/mL) for 24 h. After 24 h of treatment, cell viability assay and assay of apoptosis parameters were performed. The CFAR at the dose of 50 mg, 100 mg and 200 mg/kg/day was administered orally for 15 days and acute kidney injury was induced in rats by intraperitoneal injection of CP (10 mg/kg body weight) at the 10th day of experimentation. Biochemical studies were performed to evaluate kidney function; protein expression by Western blot and mRNA expression of related gene were studied from the kidney tissues to evaluate the effects of CFAR. Histopathological analysis was done to investigate the structural abnormalities and fibrosis of renal tissues.

RESULT

Our result reported that CFAR contain many bioactive phytomolecules having many pharmacological properties. Cell viability assay and assay of apoptosis reported that different doses of CFAR could reduced CP-induced cell death and cell apoptosis. The levels of kidney injury markers (BUN, sCr and eGFR), inflammatory markers (Interleukin-18, KIM-1, Cys-C, NF-kB and NGAL), and antioxidant markers (SOD, GSH, CAT, Nrf2 and Bcl2) and lipid peroxidation (MDA) were settled to a normal level by the oral administration of high doses (100 and 200 mg/kg body weight) of CFAR after intraperitoneal injection of CP as suggested by biochemical, histopathological, protein and gene expression studies.

CONCLUSION

In conclusion, CFAR at the high doses (100 and 200 mg/kg body weight) could able to protect the kidneys from CP induced oxidative stress and inflammation due to presence of bioactive phytomolecules that prevent the activation of oxidative stress induced signalling cascades leading to kidney damage.

A multi-modal fusion model with enhanced feature representation for chronic kidney disease progression prediction

Artificial intelligence (AI)-based multi-modal fusion algorithms are pivotal in emulating clinical practice by integrating data from diverse sources. However, most of the existing multi-modal models focus on designing new modal fusion methods, ignoring critical role of feature representation. Enhancing feature representativeness can address the noise caused by modal heterogeneity at the source, enabling high performance even with small datasets and simple architectures. Here, we introduce DeepOmix-FLEX (Fusion with Learning Enhanced feature representation for X-modal or FLEX in short), a multi-modal fusion model that integrates clinical data, proteomic data, metabolomic data, and pathology images across different scales and modalities, with a focus on advanced feature learning and representation. FLEX contains a Feature Encoding Trainer structure that can train feature encoding, thus achieving fusion of inter-feature and inter-modal. FLEX achieves a mean AUC of 0.887 for prediction of chronic kidney disease progression on an internal dataset, exceeding the mean AUC of 0.727 using conventional clinical variables. Following external validation and interpretability analyses, our model demonstrated favorable generalizability and validity, as well as the ability to exploit markers. In summary, FLEX highlights the potential of AI algorithms to integrate multi-modal data and optimize the allocation of healthcare resources through accurate prediction.

GDH1 exacerbates renal fibrosis by inhibiting the transcriptional activity of peroxisome proliferator-activated receptor gamma

Renal fibrosis is the common outcome of practically all progressive forms of chronic kidney disease (CKD), a significant societal health concern. Glutamate dehydrogenase (GDH) 1 is one of key enzymes in glutamine metabolism to catalyze the reversible conversion of glutamate to α-ketoglutarate and ammonia. However, its function in renal fibrosis has not yet been proven. In this study, GDH1 expression was significantly downregulated in kidney tissues of both children with kidney disease and animal models of CKD. In vivo, the use of R162 (a GDH1 inhibitor) significantly improved renal fibrosis, as indicated by Sirius red and Masson trichrome staining. These findings are consistent with the impaired expression of fibrosis indicators in kidneys from both the unilateral ureteral obstruction (UUO) and 5/6 nephrectomy (5/6 Nx) models. In vitro, silencing GDH1 or pretreatment with R162 inhibited the induction of fibrosis indicators in tissue kidney proximal tubular cells (TKPTS) treated with Transforming growth factor Beta 1 (TGF-β1), whereas activating GDH1 worsened TGF-β1's induction impact. Using RNA-sequence, luciferase reporter assays and Biacore analysis, we demonstrated that GDH1 interacts with Peroxisome proliferator-activated receptor gamma (PPARγ) and blocks its transcriptional activity, independent of the protein's expression. Additionally, R162 treatment boosted PPARγ transcriptional activity, and blocking of this signaling pathway reversed R162's protective effect. Finally, we discovered that R162 treatment or silencing GDH1 greatly lowered reactive oxygen species (ROS) and lipid accumulation. These findings concluded that suppressing GDH1 or R162 treatment could prevent renal fibrosis by augmenting PPARγ transcriptional activity to control lipid accumulation and redox balance.

Methylglyoxal-derived hydroimidazolone-1/RAGE axis induces renal oxidative stress and renal fibrosis in vitro and in vivo

Advanced glycation end products (AGEs) are important contributors to the progression of chronic kidney diseases (CKD), including renal fibrosis. Although the relationship between AGEs and renal fibrosis has been well studied, the mechanisms of individual AGE-induced renal injury remain poorly understood. This study investigated the adverse effect of methylglyoxal-derived hydroimidazolone-1 (MG-H1), a methylglyoxal (MG)-derived AGE generated by the glycation of MG and arginine residues, on kidney damage. We aimed to elucidate the molecular mechanisms of MG-H1-mediated renal injury and fibrosis, focusing on the receptor for AGEs (RAGE) signaling and its effects on the Wnt/β-catenin pathway, MAPK pathway, and inflammatory responses. Our results suggest that the MG-H1/RAGE axis plays a significant role in the pathogenesis of CKD and its downstream events involving MAPK kinase-related factors and inflammatory factors. MG-H1 treatment modulated the expression of inflammatory cytokines (TNF-α, IL-6, and IL-1β) and MAPK proteins (ERK1/2, JNK, and p38).

Accumulation of Renal Fibrosis in Hyperuricemia Rats Is Attributed to the Recruitment of Mast Cells, Activation of the TGF-β1/Smad2/3 Pathway, and Aggravation of Oxidative Stress

Renal fibrosis is relentlessly progressive and irreversible, and a life-threatening risk. With the continuous intake of a high-purine diet, hyperuricemia has become a health risk factor in addition to hyperglycemia, hypertension, and hyperlipidemia. Hyperuricemia is also an independent risk factor for renal interstitial fibrosis. Numerous studies have reported that increased mast cells (MCs) are closely associated with kidney injury induced by different triggering factors. This study investigated the effect of MCs on renal injury in rats caused by hyperuricemia and the relationship between MCs and renal fibrosis. Our results reveal that hyperuricemia contributes to renal injury, with a significant increase in renal MCs, leading to renal fibrosis, mitochondrial structural disorders, and oxidative stress damage. The administration of the MCs membrane stabilizer, sodium cromoglycate (SCG), decreased the expression of SCF/c-kit, reduced the expression of α-SMA, MMP2, and inhibited the TGF-β1/Smad2/3 pathway, thereby alleviating renal fibrosis. Additionally, SCG reduced renal oxidative stress and mitigated mitochondrial structural damage by inhibiting Ang II production and increasing renal GSH, GSH-Px, and GR levels. Collectively, the recruitment of MCs, activation of the TGF-β1/Smad2/3 pathway, and Ang II production drive renal oxidative stress, ultimately promoting the progression of renal fibrosis in hyperuricemic rats.

Neferine ameliorates hypertensive vascular remodeling modulating multiple signaling pathways in spontaneously hypertensive rats

BACKGROUND

Neferine exhibits therapeutic effects on anti-hypertension. However, the effect of neferine on hypertensive vascular remodeling remains unexplored. Therefore, the current study was to investigate the effect of neferine on hypertensive vascular remodeling and its underlying mechanisms.

METHODS

Total 30 male spontaneously hypertensive rats (SHRs) were divided randomly into five groups, including SHR, Neferine-L (2.5 mg/kg/day), Neferine-M (5 mg/kg/day), Neferine-H (10 mg/kg/day), and Valsartan (10 mg/kg/day) groups (n = 6 for each group). Wistar Kyoto (WKY) rats were set as control group (n = 6). Noninvasive blood pressure system, ultrasound, hematoxylin and eosin staining, masson trichrome staining were used to detect the blood pressure, pulse wave velocity (PWV), pathological changes and collagen content in abdominal aortas of SHRs. RNA-sequencing and immunohistochemistry(IHC) analyses were used to identify and verify the differentially expressed transcripts and activation of associated signaling pathways in SHRs.

RESULTS

Various concentrations of neferine or valsartan treatment substantially reduced the elevation of blood pressure, PWV, and abdominal aortic thickening of SHRs. RNA-sequencing and KEGG analyses recognized 441 differentially expressed transcripts and several enriched pathways (including PI3K/AKT and TGF-β/Smad2/3 signaling pathways) after neferine treatment. Masson trichromatic staining and IHC analysis demonstrated that neferine treatment decreased the collagen content and down-regulated the protein expression of PCNA, collagen I & III, and fibronectin, as well as p-PI3K, p-AKT, TGF-β1 and p-Smad2/3 in abdominal aortic tissues of SHRs.

CONCLUSION

Neferine treatment exhibits therapeutic effects on anti-hypertension and reduces vascular remodeling, as well as suppresses the abnormal activation of multiple signaling pathways, including PI3K/AKT and TGF-β1/Smad2/3 pathways.

Gastrodin attenuates renal injury and collagen deposition via suppression of the TGF-β1/Smad2/3 signaling pathway based on network pharmacology analysis

Background: Gastrodin has been widely used clinically in China as an antihypertensive drug. However, its effect on hypertensive renal injury is yet to be elucidated. The current study aimed to investigate the effects of gastrodin on hypertensive renal injury and its underlying mechanisms by network pharmacology analysis and validation in vivo and in vitro. Methods: A total of 10 spontaneously hypertensive rats (SHRs) were randomly categorized into the following two groups: SHR and SHR + Gastrodin groups. Wistar Kyoto (WKY) rats were used as the control group (n = 5). The SHR + Gastrodin group was intragastrically administered gastrodin (3.5 mg/kg/day), and the rats in both WKY and SHR groups were intragastrically administered an equal amount of double-distilled water for 10 weeks. Hematoxylin-eosin, Masson's trichrome, and Sirius red staining were used to detect the pathological changes and collagen content in the renal tissues. Network pharmacology analysis was performed to explore its potential targets and related pathways. In vitro, the CCK-8 assay was used to determine the cell viability. Immunohistochemistry and western-blotting analyses were employed to assess the protein expression associated with renal fibrosis and transforming growth factor-β1 (TGF-β1) pathway-related proteins in the renal tissues or in TGF-β1-stimulated rat kidney fibroblast cell lines (NRK-49F). Results: Gastrodin treatment attenuates renal injury and pathological alterations in SHRs, including glomerular sclerosis and atrophy, epithelial cell atrophy, and tubular dilation. Gastrodin also reduced the accumulation of collagen in the renal tissues of SHRs, which were confirmed by downregulation of α-SMA, collagen I, collagen III protein expression. Network pharmacology analysis identified TGFB1 and SMAD2 as two of lead candidate targets of gastrodin on against hypertensive renal injury. Consistently, gastrodin treatment downregulated the increase of the protein expression of TGF-β1, and ratios of both p-Smad2/Smad2 and p-Samd3/Smad3 in renal tissues of SHRs. In vitro, gastrodin (25-100 μM) treatment significantly reversed the upregulation of α-SMA, fibronectin, collagen I, as well as p-Smad2 and p-Smad3 protein expressions without affecting the cell viability of TGF-β1 stimulated NRK-49F cells. Conclusion: Gastrodin treatment significantly attenuates hypertensive renal injury and renal fibrosis and suppresses TGF-β1/Smad2/3 signaling in vivo and in vitro.

Interleukin-19 upregulates fibronectin and collagen I expression via the NF-κB-Smad2/3 pathway in fibroblasts of patients with chronic rhinosinusitis

BACKGROUND

Tissue remodeling is a prominent characteristic of chronic rhinosinusitis (CRS). Excess deposition of fibronectin (FN) and collagen (Col) I by fibroblasts is crucial for the pathologic tissue remodeling in CRS without nasal polyps (CRSsNP). Increased interleukin (IL)-19 level in patients with CRS had been demonstrated in our previous studies. Here, we aimed to evaluate the role of IL-19 in mediating FN and Col I expression in CRS.

METHODS

Nasal mucosal tissue samples were collected from patients with CRS with nasal polyps (CRSwNP), CRSsNP, and controls. The expression of IL-19, vimentin, FN, and Col I were detected using immunohistochemistry and immunofluorescence. Primary human nasal fibroblasts were treated with IL-19, then the activation of Smad2/3, NF-κB and relevant pathways, and the expression of FN and Col I were measured.

RESULTS

Expression levels of vimentin, FN, and Col I were significantly increased in nasal tissues from patients with CRSsNP compared with CRSwNP and control subjects. Moreover, IL-19 co-localized with FN and Col Ι in nasal tissues. IL-19-treated fibroblasts had increased production of FN and Col I, which was associated with the activated Smad2/3 and NF-κB pathways. Moreover, Smad2/3 activation was mediated by the NF-κB pathway in IL-19-treated fibroblasts.

CONCLUSIONS

IL-19 promotes FN and Col I production via the activated NF-κB-Smad2/3 pathway in fibroblasts, leading to fibrosis and collagen deposition in patients with CRS.

Protective Effects of Carnosol on Renal Interstitial Fibrosis in a Murine Model of Unilateral Ureteral Obstruction

Renal fibrosis is a common feature of chronic kidney disease and is a promising therapeutic target. However, there is still limited treatment for renal fibrosis, so the development of new anti-fibrotic agents is urgently needed. Accumulating evidence suggest that oxidative stress and endoplasmic reticulum (ER) stress play a critical role in renal fibrosis. Carnosol (CS) is a bioactive diterpene compound present in rosemary plants and has potent antioxidant and anti-inflammatory properties. In this study, we investigated the potential effects of CS on renal injury and fibrosis in a murine model of unilateral ureteral obstruction (UUO). Male C57BL/6J mice underwent sham or UUO surgery and received intraperitoneal injections of CS (50 mg/kg) daily for 8 consecutive days. CS improved renal function and ameliorated renal tubular injury and interstitial fibrosis in UUO mice. It suppressed oxidative injury by inhibiting pro-oxidant enzymes and activating antioxidant enzymes. Activation of ER stress was also attenuated by CS. In addition, CS inhibited apoptotic and necroptotic cell death in kidneys of UUO mice. Furthermore, cytokine production and immune cell infiltration were alleviated by CS. Taken together, these findings indicate that CS can attenuate renal injury and fibrosis in the UUO model.

TGF-β/Smad Signaling Pathway in Tubulointerstitial Fibrosis

Chronic kidney disease (CKD) was a major public health problem worldwide. Renal fibrosis, especially tubulointerstitial fibrosis, is final manifestation of CKD. Many studies have demonstrated that TGF-β/Smad signaling pathway plays a crucial role in renal fibrosis. Therefore, targeted inhibition of TGF-β/Smad signaling pathway can be used as a potential therapeutic measure for tubulointerstitial fibrosis. At present, a variety of targeting TGF-β1 and its downstream Smad proteins have attracted attention. Natural products used as potential therapeutic strategies for tubulointerstitial fibrosis have the characteristics of acting on multiple targets by multiple components and few side effects. With the continuous research and technique development, more and more molecular mechanisms of natural products have been revealed, and there are many natural products that inhibited tubulointerstitial fibrosis via TGF-β/Smad signaling pathway. This review summarized the role of TGF-β/Smad signaling pathway in tubulointerstitial fibrosis and natural products against tubulointerstitial fibrosis by targeting TGF-β/Smad signaling pathway. Additionally, many challenges and opportunities are presented for inhibiting renal fibrosis in the future.

Effects of secretome derived from macrophages exposed to calcium oxalate crystals on renal fibroblast activation

The association between kidney stone disease and renal fibrosis has been widely explored in recent years but its underlying mechanisms remain far from complete understanding. Using label-free quantitative proteomics (nanoLC-ESI-LTQ-Orbitrap MS/MS), this study identified 23 significantly altered secreted proteins from calcium oxalate monohydrate (COM)-exposed macrophages (COM-MP) compared with control macrophages (Ctrl-MP) secretome. Functional annotation and protein-protein interactions network analysis revealed that these altered secreted proteins were involved mainly in inflammatory response and fibroblast activation. BHK-21 renal fibroblasts treated with COM-MP secretome had more spindle-shaped morphology with greater spindle index. Immunofluorescence study and gelatin zymography revealed increased levels of fibroblast activation markers (α-smooth muscle actin and F-actin) and fibrotic factors (fibronectin and matrix metalloproteinase-9 and -2) in the COM-MP secretome-treated fibroblasts. Our findings indicate that proteins secreted from macrophages exposed to COM crystals induce renal fibroblast activation and may play important roles in renal fibrogenesis in kidney stone disease.

Fluorofenidone attenuates paraquat‑induced pulmonary fibrosis by regulating the PI3K/Akt/mTOR signaling pathway and autophagy

Paraquat (PQ) is a widely used herbicide that is severely toxic to humans and animals. Pulmonary fibrosis is a disorder that can result from PQ poisoning. Fluorofenidone (AKF‑PD) is a novel small molecule pyridone drug with a widespread and clear anti‑organ fibrosis effect; however, its mechanism of action on PQ poisoning‑induced pulmonary fibrosis is not clear. The purpose of the present study was to investigate the protective effect and underlying mechanism of AKF‑PD on PQ poisoning‑induced pulmonary fibrosis. Human alveolar epithelial cells (HPAEpiC) and Sprague‑Dawley rats were treated with AKF‑PD in the presence or absence of PQ. Hematoxylin‑eosin and Masson staining were used to observe the morphological changes in lung tissue. Cell Counting Kit‑8 and lactate dehydrogenase assays were used to evaluate the viability of HPAEpiC cells. ELISA was used to detect inflammatory factors and the collagen content. Finally, the effects of AKF‑PD on pulmonary fibrosis, as well as the underlying mechanisms, were evaluated via western blotting, reverse transcription‑quantitative PCR and immunofluorescence analysis. AKF‑PD effectively alleviated PQ‑induced pulmonary fibrosis and reduced the expression of oxidative stress and inflammatory factors. Moreover, AKF‑PD treatment effectively inhibited the PI3K/Akt/mTOR signaling pathway and upregulated autophagy. Overall, these findings suggested that AKF‑PD can alleviate PQ‑induced inflammation and pulmonary fibrosis by inhibiting the PI3K/Akt/mTOR signaling pathway and by upregulating autophagy.