Poricoic acid A suppresses TGF-β1-induced renal fibrosis and proliferation via the PDGF-C, Smad3 and MAPK pathways

Current status of drugs targeting PDGF/PDGFR

As an important proangiogenic factor, platelet-derived growth factor (PDGF) and its receptor PDGFR are highly expressed in a variety of tumors, fibrosis, cardiovascular and neurodegenerative diseases. Targeting the PDGF/PDGFR pathway is therefore a promising therapeutic strategy. At present, a variety of PDGF/PDGFR targeted drugs with potential therapeutic effects have been developed, mainly including PDGF agonists, inhibitors targeting PDGFR and proteolysis targeting chimera (PROTACs). This review clarifies the structure, biological function and disease correlation of PDGF and PDGFR, and it discusses the current status of PDGFR-targeted drugs, so as to provide a reference for subsequent research.

Potential therapeutic medicines for renal fibrosis: Small-molecule compounds and natural products

Renal fibrosis is the pathological change process of chronic kidney disease deteriorating continuously. When the renal organ is stimulated by external stimuli, it will trigger the damage and phenotypic changes of some intrinsic cells in the kidney. When the body's autoimmune regulation or external treatment is not prompted enough to restore the organ, the pathological process is gradually aggravating, inducing a large amount of intracellular collagen deposition, which leads to the appearance of fibrosis and scarring. The renal parenchyma (including glomeruli and tubules) begins to harden, making it difficult to repair the kidney lesions. In the process of gradual changes in the kidney tissue, the kidney units are severely damaged and the kidney function shows a progressive decline, eventually resulting in the clinical manifestation of end-stage renal failure, namely uremia. This review provides a brief description of the diagnosis, pathogenesis, and potential therapeutic inhibitors of renal fibrosis. Since renal fibrosis has not yet had a clear therapeutic target and related drugs, some potential targets and relevant inhibitors are discussed, especially pharmacological effects and interactions with targets. Some existing natural products have potential efficacy for renal fibrosis, which is also roughly summarized, hoping that this article would have reference significance for the treatment of renal fibrosis.

Ling-Gui-Qi-Hua formula alleviates left ventricular myocardial fibrosis in rats with heart failure with preserved ejection fraction by blocking the transforming growth factor-β1 /Smads signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ling-Qui-Qi-Hua (LGQH) decoction, composed of Poria cocos (Schw.) Wolf, Cinnamomum cassia (L.) J. Presl, Paeonia veitchii Lynch, and Atractylodes macrocephala Koidz., is a compound formula derived from Ling-Gui-Zhu-Gan decoction recorded in the Treatise on Febrile and Miscellaneous. It has shown cardioprotective effects on patients or rats with heart failure with preserved ejection fraction (HFpEF). Nevertheless, the active ingredients of LGQH and its anti-fibrotic mechanism remain unknown.

AIM OF THE STUDY

To determine the active ingredients in LGQH decoction and verify that LGQH decoction may inhibit left ventricular (LV) myocardial fibrosis in HFpEF rats by blocking the transforming growth factor-β1 (TGF-β1)/Smads signaling pathway from the perspective of animal experiments.

MATERIALS AND METHODS

First, liquid chromatography-mass spectrometry (LC-MS) technology was used to identify active components in the LGQH decoction. Secondly, a rat model of the metabolic syndrome-associated HFpEF phenotype was established and subsequently received LGQH intervention. The mRNA and protein expression of targets in the TGF-β1/Smads pathway were detected by quantitative real-time polymerase chain reaction and western blot analysis. Finally, molecular docking was conducted to examine the interactions between the active ingredients in the LGQH decoction and key proteins of the TGF-β1/Smads pathways.

RESULTS

According to LC-MS analysis, the LGQH decoction contained 13 active ingredients. In animal experiments, LGQH attenuated LV hypertrophy, enlargement, and diastolic function in HEpEF rats. Mechanically, LGQH not only down-regulated TGF-β1, Smad2, Smad3, Smad4, α-SMA, Coll I, and Coll III mRNA expressions and TGF-β1, Smad2, Smad3, P-Smad2/Smad3, Smad4, α-SMA, and Coll I protein expressions, but also up-regulated Smad7 mRNA and protein expressions, which ultimately led to myocardial fibrosis. Furthermore, molecular docking confirmed that 13 active ingredients in the LGQH decoction have excellent binding activities to the critical targets of the TGF-β1/Smads pathway.

CONCLUSION

LGQH is a modified herbal formulation with multiple active ingredients. It might alleviate LV remodeling and diastolic dysfunction and inhibit LV myocardial fibrosis by blocking TGF-β1/Smads pathways in HFpEF rats.

PDGF-C promotes cell proliferation partially via downregulating BOP1

Platelet-derived growth factor C (PDGF-C) is a member of PDGF/VEGF family, which is well-known for important functions in the vascular system. It is widely reported that PDGF-C is able to modulate cell proliferation. However, it is still not very clear about this cell modulating mechanism at the molecular level. In a screening of factors regulated by PDGF-C protein, we fished out a factor called block of proliferation 1 (BOP1), which is a pivotal regulator of ribosome biogenesis and cell proliferation. In this study, we investigated the regulation of BOP1 by PDGF-C and its role in modulating cell proliferation. We found that BOP1 was downregulated at both mRNA and protein levels in cells treated with PDGF-C-containing conditioned medium. On the other hand, BOP1 was upregulated in PDGF-C deficient mice. Furthermore, we confirmed that overexpression of BOP1 inhibited HEK293A cell proliferation, whereas knockdown of BOP1 promoted cell proliferation. The mitogenic effect of PDGF-C could be attenuated by downregulation of BOP1. Our results demonstrate a clear PDGF-C-BOP1 signaling that modulates cell proliferation.

Fibrotic Diseases of the Human Urinary and Genital Tract: Current Understanding and Potential Strategies for Treatment

Fibrosis is a disease condition characterized by abnormalities of the extracellular matrix, such as accumulation of the transforming growth factor β, infiltration by myofibroblasts, deposition of collagen, and a generalized dysregulation of collagen maturation. It can severely impair the function of organs by replacing normal tissue with a highly collagenized matrix, thereby reducing the elasticity and compliance of tissues. Fibrotic diseases of the genitourinary tract present relevant problems in healthcare, and their principles of pathophysiology remain unclarified; hence, the armamentarium for prevention and treatment is limited. These diseases include renal fibrosis, Peyronie's disease and ureteral and urethral strictures due to perturbations in the process of wound healing in response to injuries. Such deteriorations may contribute to obstructive uropathies or sexual dysfunction. This review provides a brief overview of the most frequent fibrotic diseases of the genitourinary system and of how the pathophysiology is related to symptoms, and also highlights potential therapeutic strategies to address the abnormal deposition of collagen. Although the understanding of factors associated with fibrotic conditions of the urinary and genital tract is still limited, some beneficial advances have been made. Further research will serve to provide a more comprehensive insight into factors responsible for the development of fibrotic tissue deposition.

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (Paxlovid^TM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

Effects of salvianolic acid A and salvianolic acid B in renal interstitial fibrosis via PDGF-C/PDGFR-α signaling pathway

BACKGROUND

Renal interstitial fibrosis (RIF) is the main pathological feature of end-stage renal disease (ESRD) caused by various chronic kidney diseases (CKD), and is closely related to renal dysfunction and patient prognosis. Salvianolic acid A (Sal A) and salvianolic acid B (Sal B), isolated from traditional Chinese medicine Salviae miltiorrhizae, have been confirmed to have anti-fibrotic effects on liver, cardiac and kidney. However, the precise molecular mechanism underlying the nephroprotective effects of Sal A and Sal B, and whether there is a difference between the two in RIF are still unclear.

PURPOSE

This study investigated the pharmacological effects of Sal A and Sal B in RIF and explore the underlying mechanisms by in vivo and in vitro experiments.

METHODS

The nephroprotective effects of Sal A, Sal B and Sal A+B were evaluated by assessing the parameters related to kidney function such as renal histology, renal function, urinary protein NAG, urinary β2 microglobulin. In addition, RIF-related markers such as CTCF and Par3 were also detected. Thereafter, the related protein or gene levels of PDGF-C/PDGFR-α signaling pathways, apoptosis and endoplasmic reticulum stress (ERS) were determined by western blot, real-time PCR, flow cytometry or immunofluorescence staining.

RESULTS

In vivo, the results showed that Sal A, Sal B and Sal A+B partially improved kidney dysfunction, increased the expression of Par-3 and reduced the expression of CTGF, PDGF-C and PDGFR-α. In vitro, the results also showed that Sal A, Sal B and Sal A+B reversed apoptosis and ERS in HSA-induced HK-2 cells via regulating PDGF-C/PDGFR-α signaling pathway.

CONCLUSION

This article revealed a novel mechanism linking PDGF-C/PDGFR-α signaling pathway to RIF and suggested that Sal A, Sal B and Sal A+B were considered as potential therapeutic agents for the amelioration of RIF.

Jinlian Xiaodu Decoction Protects against Bleomycin-Induced Pulmonary Fibrosis in Rats

Background

Jinlian Xiaodu Decoction (JXD) was reported to have anti-inflammatory and lung protection effects. This study aimed to explore the role and mechanism of JXD on bleomycin (BLM)-induced pulmonary fibrosis (PF).

Methods

The UHPLC-Q/TOF-MS system was applied to analyze JXD composition. The PF model was established by BLM intratracheal administration in Wistar rats. Subsequently, BLM-treated rats were intragastrically administered with dexamethasone (DXM, 1 g/kg/d) or JXD (3.5, 7 or 14 g/kg/d). Next, the lung coefficient was calculated; H&E, Masson, and TUNEL staining were used for lung morphological analysis and apoptosis assessment. Bronchoalveolar lavage fluid (BALF) biochemical analysis was conducted to count the inflammatory cell number. The expression of inflammatory factors mRNA in the lung tissue and BALF were measured by qRT-PCR. The content and activity of oxidative stress-related proteins were detected. The expression of PF-related, apoptosis-related, and TGF-β1 pathway-related protein were assessed by immunohistochemistry or Western blot.

Results

Twenty-six compounds were identified from JXD in both negative and positive ion modes. In BLM-induced rats, JXD reduced the lung coefficient and alleviated PF injury. JXD decreased inflammatory cell count and TNF-α, IL-1β, IL-6, and MCP-1 content. Meanwhile, JXD blunted BLM-induced oxidative stress and a high level of HYP. Furthermore, TUNEL analysis found that JXD inhibited cell apoptosis and increased Bcl-2/Bax ratio in BLM-induced lung. Moreover, JXD relieved the role of BLM on α-SMA, TGF-β1, collagen I, fibronectin, E-cadherin protein expression, and the phosphorylation of Smad2/3 in PF rat.

Conclusion

This study revealed the protective effect and possible element of JXD on BLM-caused PF.

Research Progress of Chinese Herbal Medicine Intervention in Renal Interstitial Fibrosis

Chronic kidney diseases usually cause renal interstitial fibrosis, the prevention, delay, and treatment of which is a global research hotspot. However, no definite treatment options are available in modern medicine. Chinese herbal medicine has a long history, rich varieties, and accurate treatment effects. Hitherto, many Chinese herbal medicine studies have emerged to improve renal interstitial fibrosis. This paper reviews the mechanisms of renal interstitial fibrosis and recent studies on the disease intervention with Chinese herbal medicine through literature search, intend to reveal the importance of Chinese herbal medicine in renal interstitial fibrosis. The results show that Chinese herbal medicine can improve renal interstitial fibrosis, and the effects of Chinese herbal medicine on specific pathological mechanisms underlying renal interstitial fibrosis have been explored. Additionally, the limitations and advantages of Chinese herbal medicine in the treatment of renal interstitial fibrosis, possible research directions, and new targets of Chinese herbal medicine are discussed to provide a basis for studies of renal interstitial fibrosis.

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.

Isolation and identification of the components in Cybister chinensis Motschulsky against inflammation and their mechanisms of action based on network pharmacology and molecular docking

ETHNOPHARMACOLOGICAL RELEVANCE

Cybister chinensis Motschulsky belongs to the family Dytiscidae. As a traditional Chinese medicine, the insect is called Longshi in the folk and is commonly used to treat enuresis in children and frequent urination in the elderly.

AIM OF THE STUDY

Inflammation is involved in chronic kidney disease. The previous study proved ethanol extract of C. chinensis exhibited anti-inflammation effects in the Doxorubicin-induced kidney disease. However, the material basis and their possible mechanism of the insect were still unclear. Thus, we aimed to separate the active compounds of the ethanol extract from C. chinensis and to investigate their possible mechanism of anti-inflammation by network pharmacology and molecular docking.

MATERIALS AND METHODS

The insect was extracted with 75% ethanol to produce ethanol extracts and then were extracted by petroleum ether, ethyl acetate and n-butanol respectively. Silica gel column chromatography and preparative HPLC were applied to separate the compounds of the extract. The compounds were characterized and identified by NMR and mass. The compound associated genes were collected by BATMAN-TCM database and the inflammation associated genes were obtained through DigSee database. The protein-protein interaction (PPI) network was carried out via Search Tool for the Retrieval of Interacting Genes/Protein (STRING) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) target pathway analysis was performed in Database for Annotation, Visualization and Integrated Discovery (DAVID). The possible mechanism of compounds against inflammation was investigated by molecular docking. Finally, the anti-inflammatory effect of the representative compound was verified by the LPS-induced Raw 264.7 cell inflammatory model. TNF-α, IL-1β and IL-6 of the cell supernatants were analyzed via using ELISA kits and the key proteins in JAK2/STAT3 signaling pathway were verified via the Western blot assays.

RESULTS

Among crude extracts from C. chinensis, ethyl acetate extract showed the obvious anti-inflammatory effects. Nine compounds were isolated from ethyl acetate extract of Cybister chinensis for the first time, including benzoic acid (1), hydroxytyrosol (2), protocatechualdehyde (3), N-[2-(4-hydroxyphenyl)ethyl]acetamide (4), (2E)-3-phenylprop-2-enoic acid (5), 3-phenylpropionic acid (6), methyl 3,4-dihydroxybenzoate (7), 1,4-diphenyl butane-2,3-diol (8) and p-N,N-dimethylaminobenzaldehyde (9). After searching in the database, 1079 compound associated genes and 467 inflammation associated genes were found. The 137 common targets covered 77 signaling pathways, in which HIF-1 signaling pathway, TNF signaling pathway, influenza A, PI3K/Akt signaling pathway, NOD-like receptor signaling pathway, MAPK signaling pathway, Toll-like receptor signaling pathway and Jak-STAT signaling pathway were important for inflammation. Molecular docking studies showed compound 1, 4, 5, 6, 7 and 8 were the potential inhibitors of JAK2 protein. In addition, the in vitro test showed compound 5 reduced the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in a dose-dependent manner. Furthermore, it was found that compound 5 inhibited the expression of p-JAK2 and p-STAT3 in LPS-induced RAW264.7 cells in a dose-dependent manner.

CONCLUSIONS

Based on the network pharmacology and molecular docking, the study suggested that C. chinensis could relieve the inflammation based on the multi-compounds and multi-pathways, which provided the foundation for the medicinal application of C. chinensis.

Chorioamnionitis Causes Kidney Inflammation, Podocyte Damage, and Pro-fibrotic Changes in Fetal Lambs

BACKGROUND

Perinatal complications, such as prematurity and intrauterine growth restriction, are associated with increased risk of chronic kidney disease. Although often associated with reduced nephron endowment, there is also evidence of increased susceptibility for sclerotic changes and podocyte alterations. Preterm birth is frequently associated with chorioamnionitis, though studies regarding the effect of chorioamnionitis on the kidney are scarce. In this study, we aim to unravel the consequences of premature birth and/or perinatal inflammation on kidney development using an ovine model.

METHODS

In a preterm sheep model, chorioamnionitis was induced by intra-amniotic injection of lipopolysaccharide (LPS) at either 2, 8, or 15 days prior to delivery. Control animals received intra-amniotic injections of sterile saline. All lambs were surgically delivered at 125 days' gestation (full term is 150 days) and immediately euthanized for necropsy. Kidneys were harvested and processed for staining with myeloperoxidase (MPO), Wilms tumor-1 (WT1) and alpha-smooth muscle actine (aSMA). mRNA expression of tumor necrosis factor alpha (TNFA), Interleukin 10 (IL10), desmin (DES), Platelet derived growth factor beta (PDGFB), Platelet derived growth factor receptor beta (PDGFRB), synaptopodin (SYNPO), and transforming growth factor beta (TGFB) was measured using quantitative PCR.

RESULTS

Animals with extended (but not acute) LPS exposure had an inflammatory response in the kidney. MPO staining was significantly increased after 8 and 15 days (p = 0.003 and p = 0.008, respectively). Expression of TNFA (p = 0.016) and IL10 (p = 0.026) transcripts was increased, peaking on day 8 after LPS exposure. Glomerular aSMA and expression of TGFB was increased on day 8, suggesting pro-fibrotic mesangial activation, however, this was not confirmed with PDFGB or PDGFRB. The number of WT1 positive nuclei in the glomerulus, as well as expression of synaptopodin, decreased, indicating podocyte injury.

CONCLUSION

We report that, in an ovine model of prematurity, LPS-induced chorioamnionitis leads to inflammation of the immature kidney. In addition, this process was associated with podocyte injury and there are markers to support pro-fibrotic changes to the glomerular mesangium. These data suggest a potential important role for antenatal inflammation in the development of preterm-associated kidney disease, which is frequent.

Protective effect and mechanism of Shenkang injection on adenine-induced chronic renal failure in rats

Purpose:

To investigate the protective effects of Shenkang injection (SKI) on adenine-induced chronic renal failure (CRF) in rat.

Methods:

Sprague Dawley rats were randomly divided into five groups: control, model, and SKI groups (5, 10, 20 mL/kg). Rats in model and SKI groups were treated with adenine i.g. at a dose of 150 mg/kg every day for 12 weeks to induce CRF. Twelve weeks later, SKI was administered to the rat i.p. for four weeks. The effects of SKI on kidney injury and fibrosis were detected.

Results:

SKI inhibited the elevation of the urine level of N-acetyl-b-D-glucosaminidase, kidney injury molecule-1, beta-2-microglobulin, urea protein in CRF rats. The serum levels of uric acid and serum creatinine increased and albumin decreased in the model group, which was prevented by SKI. SKI inhibited the release of inflammatory cytokines and increasing the activities of antioxidant enzymes in serum. SKI inhibited the expression of transforming growth factor-β1, vascular cell adhesion molecule 1, intercellular adhesion molecule 1, collagen I, collagen III, endothelin-1, laminin in kidney of CRF rats.

Conclusions:

SKI protected against adenine-induced kidney injury and fibrosis and exerted anti-inflammatory, and antioxidant effects in CRF rats.