Role of artesunate in TGF‑β1‑induced renal tubular epithelial‑mesenchymal transdifferentiation in NRK‑52E cells

Artesunate Exerts Organ- and Tissue-Protective Effects by Regulating Oxidative Stress, Inflammation, Autophagy, Apoptosis, and Fibrosis: A Review of Evidence and Mechanisms

The human body comprises numerous organs and tissues operating in synchrony, it facilitates metabolism, circulation, and overall organismal function. Consequently, the well-being of our organs and tissues significantly influences our overall health. In recent years, research on the protective effects of artesunate (AS) on various organ functions, including the heart, liver, brain, lungs, kidneys, gastrointestinal tract, bones, and others has witnessed significant advancements. Findings from in vivo and in vitro studies suggest that AS may emerge as a newfound guardian against organ damage. Its protective mechanisms primarily entail the inhibition of inflammatory factors and affect anti-fibrotic, anti-aging, immune-enhancing, modulation of stem cells, apoptosis, metabolic homeostasis, and autophagy properties. Moreover, AS is attracting a high level of interest because of its obvious antioxidant activities, including the activation of Nrf2 and HO-1 signaling pathways, inhibiting the release of reactive oxygen species, and interfering with the expression of genes and proteins associated with oxidative stress. This review comprehensively outlines the recent strides made by AS in alleviating organismal injuries stemming from various causes and protecting organs, aiming to serve as a reference for further in-depth research and utilization of AS.

[Qingshen Granules-medicated serum reduces transdifferentiation of NRK-52E cells by miR-23b-5p-mediated activation of the Nrf2 pathway]

OBJECTIVE

TTo investigate the targeted regulation of the Nrf2 pathway by miR-23b-5p in transdifferentiation of rat renal tubular epithelial NRK-52E cells induced by transforming growth factor β1(TGF-β1)and the effect of Qingshen Granulesmedicated serum for alleviating transdifferentiation of NRK-52E cells.

METHODS

NRK-52E cells with TGF-β1-induced transdifferentiation were transfected with miR-23b-5p mimic, miR-23b-5p inhibitor or the negative control(NC)siRNA and then treated with of Qingshen Granules-medicated serum.CCK8 assay was used to detectthe changes in viability of NRK-52E cells.The targeting relationship between miR-23b-5p and Nrf2 was verified using a dual luciferase reporter gene assay.The expressions of Nrf2, Keap1 and α-SMA mRNAs and proteins in the treated cells were detected with RT-qPCR and Western blotting, and ROS production in the cells was detected with flow cytometry.

RESULTS

Transfection of NRK-52E cells with miR-23b-5p mimic significantly increased the expression of Nrf2 mRNA, while inhibition of miR-23b-5p obviously lowered Nrf2 mRNA in the cells.Rno-miR-23b-5p significantly down-regulated the luciferase activity of Rno-Nrf2-wt but not that of Rno-Nrf2-mu(P<0.05).Treatment with TGF-β1 significantly decreased the expressions of miR-23b-5p and Nrf2 and increased the expressions of Keap1, α-SMA and ROS in NRK-52E cells(P<0.05), and these changes were obviously ameliorated by treatment with 20% Qingshen Granules-medicated serum for 24 h.Transfection of the cells with miR-23b-mimic significantly decreased the expressions of Keap1, α-SMA and ROS(P<0.05), which were further decreased by treatment with the medicated serum(P<0.05).

CONCLUSION

Qingshen Granules-medicated serum reduces transdifferentiation of NRK-52E cells via miR-23b-5pmediated activation of the Nrf2 pathway.

Artemisinin attenuates type 2 diabetic cardiomyopathy in rats through modulation of AGE-RAGE/HMGB-1 signaling pathway

Diabetes mellitus is a common metabolic disorder. About two-thirds of diabetic patients develop diabetic cardiomyopathy (DCM), which becomes a challenging issue as it severely threatens the patient's life. Hyperglycemia and the resulting advanced glycated end products (AGE) and their receptor (RAGE)/High Mobility Group Box-1 (HMGB-1) molecular pathway are thought to be key players. Recently, artemisinin (ART) has gained more attention owing to its potent biological activities beyond its antimalarial effect. Herein, we aim to evaluate the effect of ART on DCM and the possible underlying mechanisms. Twenty-four male Sprague-Dawley rats were divided into: control, ART, type 2 diabetic and type 2 diabetic treated with ART groups. At the end of the research, the ECG was recorded, then the heart weight to body weight (HW/BW) ratio, fasting blood glucose, serum insulin and HOMA-IR were evaluated. Cardiac biomarkers (CK-MB and LDH), oxidative stress markers, IL-1β, AGE, RAGE and HMGB-1 expression were also measured. The heart specimens were stained for H&E as well as Masson's trichrome. DCM induced disturbances in all studied parameters; contrary to this, ART improved these insults. Our study concluded that ART could improve DCM through modulation of the AGE-RAGE/HMGB-1 signaling pathway, with subsequent impacts on oxidative stress, inflammation and fibrosis. ART could therefore be a promising therapy for the management of DCM.

Therapeutic Implications of Ferroptosis in Renal Fibrosis

Renal fibrosis is a common feature of chronic kidney disease (CKD), and can lead to the destruction of normal renal structure and loss of kidney function. Little progress has been made in reversing fibrosis in recent years. Ferroptosis is more immunogenic than apoptosis due to the release and activation of damage-related molecular patterns (DAMPs) signals. In this paper, the relationship between renal fibrosis and ferroptosis was reviewed from the perspective of iron metabolism and lipid peroxidation, and some pharmaceuticals or chemicals associated with both ferroptosis and renal fibrosis were summarized. Other programmed cell death and ferroptosis in renal fibrosis were also firstly reviewed for comparison and further investigation.

Hyperosmotic stress induces epithelial-mesenchymal transition through rearrangements of focal adhesions in tubular epithelial cells

Epithelial-mesenchymal transition (EMT) of tubular epithelial cells is a hallmark of renal tubulointerstitial fibrosis and is associated with chronic renal injury as well as acute renal injury. As one of the incidences and risk factors for acute renal injury, increasing the osmolality in the proximal tubular fluid by administration of intravenous mannitol has been reported, but the detailed mechanisms remain unclear. Hyperosmotic conditions caused by mannitol in the tubular tissue may generate not only osmotic but also mechanical stresses, which are known to be able to induce EMT in epithelial cells, thereby contributing to renal injury. Herein, we investigate the effect of hyperosmolarity on EMT in tubular epithelial cells. Normal rat kidney (NRK)-52E cells were exposed to mannitol-induced hyperosmotic stress. Consequently, the hyperosmotic stress led to a reduced expression of the epithelial marker E-cadherin and an enhanced expression of the mesenchymal marker, α-smooth muscle actin (α-SMA), which indicates an initiation of EMT in NKR-52E cells. The hyperosmotic condition also induced time-dependent disassembly and rearrangements of focal adhesions (FAs) concomitant with changes in actin cytoskeleton. Moreover, prevention of FAs rearrangements by cotreatment with Y-27632, a Rho-associated protein kinase inhibitor, could abolish the effects of hyperosmotic mannitol treatment, thus attenuating the expression of α-SMA to the level in nontreated cells. These results suggest that hyperosmotic stress may induce EMT through FAs rearrangement in proximal tubular epithelial cells.

Therapeutic and delivery strategies of phytoconstituents for renal fibrosis

Chronic kidney disease (CKD) is one of the most common diseases endangering human health and life. By 2030, 14 per 100,000 people may die from CKD. Renal fibrosis (RF) is an important intermediate link and the final pathological change during CKD progression to the terminal stage. Therefore, identifying safe and effective treatment methods for RF has become an important goal. In 2018, the World Health Organization introduced traditional Chinese medicine into its effective global medical program. Various phytoconstituents that affect the RF process have been extracted from different plants. Here, we review the potential therapeutic capabilities of active phytoconstituents in RF treatment and discuss how phytoconstituents can be structurally modified or combined with other ingredients to enhance efficiency and reduce toxicity. We also summarize phytoconstituent delivery strategies to overcome renal barriers and improve bioavailability and targeting.

The Therapeutic Effect of Artemisinin and Its Derivatives in Kidney Disease

Artemisinin (ARS) and its derivatives (ARSs) are recommended as the first-line antimalarial drugs for the treatment of malaria. Besides antimalarial function, its potent anti-inflammatory and immunoregulatory properties, as well as the ability to regulate oxidative stress have brought them to a prominent position. As researchers around the world are continually exploring the unknown biological activities of ARS derivatives, experimental studies have shown much progress in renal therapy. This review aims to give a brief overview of the current research on ARSs applications for kidney treatment with the evaluation of therapeutic properties and potential molecular mechanisms.

m6A-induced lncRNA MALAT1 aggravates renal fibrogenesis in obstructive nephropathy through the miR-145/FAK pathway

Renal fibrosis is a key factor in chronic kidney disease (CKD). Long non-coding RNAs (lncRNAs) play important roles in the physiological and pathological progression of human diseases. However, the roles and underlying mechanisms of lncRNAs in renal fibrosis still need to be discovered. In this study, we first displayed the increased lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression in renal fibrosis in patients with obstructive nephropathy (ON). Then we found that transforming growth factor beta 1 (TGF-β1) induced epithelial-mesenchymal transition (EMT) and extracellular matrix (ECM) protein deposition, which promoted the viability, proliferation and migration of human renal proximal tubular epithelial (HK2) cells. Next, MALAT1/miR-145/focal adhesion kinase (FAK) pathway was confirmed to play an importment role in TGF-β1-induced renal fibrosis. In addition, the MALAT1/miR-145/FAK pathway was involved in the effect of dihydroartemisinin (DHA) on TGF-β1-induced renal fibrosis in vitro and in vivo. Furthermore, m⁶A methyltransferase methyltransferase-like 3 (METTL3) was shown to be the main methyltransferase of m⁶A modification on MALAT1.

[Role of TGF-β1/ILK/FSP1 signaling pathway in cyclosporin A-induced epithelialmesenchymal transition in cultured renal tubular epithelial cells]

OBJECTIVE

To explore the role of transforming growth factor-β1/integrin-linked kinase/fibroblast-specific protein 1 (TGF- β1/ILK/FSP1) signaling pathway in cyclosporine A (CsA)-induced renal tubular epithelial cell transdifferentiation.

METHODS

Rat renal tubular epithelial NRK-52E cells were induced with 1 mg/L CsA, treated with TGF-β1 inhibitor (SB431542, 10 μmol/L), or transfected with the ILK-RNAi lentiviral expression vector (ILKshRNA) or a negative control vector before CsA induction. The expressions of TGF-β1, ILK and FSP-1 mRNAs and proteins in the cells were detected using real-time PCR and Western blotting. The positive cells for α-SMA expression were detected by immunohistochemistry.

RESULTS

Compared with the blank control cells, the cells treated with CsA showed significantly increased levels of TGF-β1, ILK and FSP-1 mRNAs and proteins (P < 0.05). The expressions of TGF-β1, ILK and FSP-1 were significantly lower in TGF-β1 inhibitor group than in CsA group (P < 0.05). The levels of ILK and FSP-1 were significantly decreased after shRNA-mediated ILK silencing (P < 0.05). The number of positive cells for α-SMA was significantly lower in cells treated with SB431542 and in cells with ILK silencing than in the cells treated with CsA alone (P < 0.05).

CONCLUSIONS

The activation of TGF-β1/ILK/FSP-1 signaling pathway is an important mechanism for CsA-induced transdifferentiation in rat renal tubular epithelial cells. ILK participates in CsA-induced epithelialmesenchymal transition of renal tubular epithelial cells.

Synthesis of Piperine Analogs Containing Isoxazoline/Pyrazoline Scaffold and Their Pesticidal Bioactivities

In continuation of our program to discover new potential pesticidal agents, thirty-one piperine analogs containing isoxazoline/pyrazoline scaffold were prepared, and confirmed by infrared spectra, proton/carbon-13 nuclear magnetic resonance spectra, and high-resolution mass spectra. The structures of compounds VIIb and VIIIc were further determined by ¹H-¹H COSY spectra. Especially the configuration of compound VIIIc was unambiguously confirmed by single-crystal X-ray diffraction. Their pesticidal activities were evaluated against three serious and typically crop-threatening agricultural pests, Tetranychus cinnabarinus Boisduval (spider mite), Mythimna separata Walker (Oriental armyworm), and Plutella xylostella Linnaeus (diamondback moth). Compounds VIIIb and VIIIc exhibited greater than 40-fold more potent acaricidal activity than the lead compound piperine against T. cinnabarinus. Notably, compounds VIa-c exhibited more pronounced oral toxicity against P. xylostella than toosendanin; compounds VIb and VIc displayed more promising growth inhibitory activity against M. separata than toosendanin. It demonstrated that the methylenedioxy and isoxazoline scaffolds were important for the oral toxicity and growth inhibitory activity against P. xylostella and M. separata, respectively; the ethylenedioxy and isoxazoline scaffolds were vital for the acaricidal activity against T. cinnabarinus. Moreover, compounds VIb, VIIf, and VIIIc showed very low toxicity against NRK-52E cells.

Artesunate ameliorates high glucose-induced rat glomerular mesangial cell injury by suppressing the TLR4/NF-κB/NLRP3 inflammasome pathway

Inflammatory response is important for the development and progression of diabetic nephropathy (DN). Artesunate (ART), an antimalarial drug, possesses anti-inflammatory effect and exhibits protective effect on chronic kidney diseases. However, the effect of ART on DN is unknown. The aim of the present study was to evaluate the effect and the molecular mechanism of ART on DN in an in vitro model. The rat mesangial cell line, HBZY-1, was induced by high glucose (HG; 30 mM d-glucose) in the presence or absence of ART (15 and 30 μg/ml) and incubated for 24 h. We found that HG induced the proliferation of HBZY-1 cells, while treatment with ART inhibited the cell proliferation. Treatment with ART inhibited HG-induced inflammatory cytokines production and expression of extracellular matrix (ECM). Besides, HG induced reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and inhibited the superoxide dismutase (SOD) activity of HBZY-1 cells, and the effects were attenuated by ART treatment. ART decreased HG-induced the expression levels of toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), nuclear factor κB (NF-κB) p-p65, and nod-like receptor protein 3 (NLRP3). Inhibition of the TLR4/NF-κB pathway suppressed NLRP3 inflammasome in HBZY-1 cells. In conclusion, ART exhibited protective effect on HG-induced HBZY-1 cells by inhibiting the inflammatory response, oxidative stress and ECM accumulation. The TLR4/NF-κB/NLRP3 inflammasome pathway was involved in the protective effect of ART. The results suggested that ART might be a potential therapy agent for the DN treatment.