The Role of NF-κB and Bax/Bcl-2/Caspase-3 Signaling Pathways in the Protective Effects of Sacubitril/Valsartan (Entresto) against HFD/STZ-Induced Diabetic Kidney Disease

Exploring the anti-inflammatory and antiapoptotic properties of phloroglucinol on pancreatic cells in diabetic models: In silico and in vivo study

Pancreatic cell damage in diabetes mellitus is closely linked to inflammation and apoptosis. This study aimed to investigate the protective effects of phloroglucinol on pancreatic cells in a streptozotocin-induced diabetic model by assessing its anti- inflammatory and anti-apoptotic mechanisms. Phloroglucinol ligand and the structures of Bax, Bcl-2, and caspase-3 proteins were sourced from the PubChem database. Molecular docking was performed using Autodock Tools and docking results were analyzed with PyRx software. In addition, during the in vivo study, the BALB/c mice were grouped into four categories: healthy control, untreated streptozotocin-induced diabetic, and streptozotocin-induced diabetic treated with two doses of oral phloroglucinol at 100 mg/kg and 200 mg/kg body weight. After 28 days, pancreatic tissues were collected for flow cytometric analysis of NF-κB, IL-6, TNF-α, and apoptotic markers (Bax, Bcl-2, and caspase-3). The docking simulations revealed specific binding interactions: phloroglucinol interacted with Bcl-2 via amino acid residues of ALA90 and TYR139, with Bax via ALA42, LEU45, ALA46, LEU47, PRO130, and ILE133, and with caspase-3 through ARG64, SER120, GLN161, CYS163, and ARG207. The binding affinities for Bax, Bcl-2, and caspase-3 were -5.0, -4.7, and -4.9 kcal/mol, respectively. In vivo, results showed that streptozotocin significantly elevated inflammatory cytokines NF-κB, TNF-α, and IL-6, along with apoptotic markers in pancreatic cells (p<0.05) compared to healthy controls. Phloroglucinol administration at 200 mg/kg significantly reduced TNF-α, NF-κB and IL- 6 levels. Phloroglucinol also prevented streptozotocin-induced pancreatic cell damage through anti-apoptotic effects by downregulating Bax and caspase-3 and upregulating Bcl-2. These findings suggest that phloroglucinol may offer protective benefits in diabetic conditions by modulating apoptotic and inflammatory pathways.

Cardiometabolic effects of sacubitril/valsartan in a rat model of heart failure with preserved ejection fraction

The promising results obtained in the PARADIGM-HF trial prompted the approval of sacubitril/valsartan (SAC/VAL) as a first-in-class treatment for heart failure with reduced ejection fraction (HFrEF) patients. The effect of SAC/VAL treatment was also studied in patients with heart failure with preserved ejection fraction (HFpEF) and, although improvements in New York Heart Association (NYHA) class, HF hospitalizations, and cardiovascular deaths were observed, these results were not so promising. However, the demand for HFpEF therapies led to the approval of SAC/VAL as an alternative treatment, although further studies are needed. We aimed to elucidate the effects of a 9-week SAC/VAL treatment in cardiac function and metabolism using a preclinical model of HFpEF, the Zucker Fatty and Spontaneously Hypertensive (ZSF1) rats. We found that SAC/VAL significantly improved diastolic function parameters and modulated respiratory quotient during exercise. Ex-vivo studies showed that SAC/VAL treatment significantly decreased heart, liver, spleen, and visceral fat weights; cardiac hypertrophy and percentage of fibrosis; lipid infiltration in liver and circulating levels of cholesterol and sodium. Moreover, SAC/VAL reduced glycerophospholipids, cholesterol, and cholesteryl esters while increasing triglyceride levels in cardiac tissue. In conclusion, SAC/VAL treatment improved diastolic and hepatic function, respiratory metabolism, reduced hypercholesterolemia and cardiac fibrosis and hypertrophy, and was able to modulate cardiac metabolic profile. Our findings might provide further insight into the therapeutic benefits of SAC/VAL treatment in obese patients with HFpEF.

Capsaicin reduces blood glucose and prevents prostate growth by regulating androgen, RAGE/IGF-1/Akt, TGF-β/Smad signalling pathway and reversing epithelial-mesenchymal transition in streptozotocin-induced diabetic mice

Type 2 diabetes mellitus (T2DM) is a metabolic disease. Diabetes increases the risk of benign prostatic hyperplasia (BPH). Capsaicin is extracted from chili peppers and possesses many pharmacological properties, including anti-diabetic, pain-relieving, and anti-cancer properties. This study aimed to investigate the effects of capsaicin on glucose metabolism and prostate growth in T2DM mice and uncover the related mechanisms. Mice model of diabetes was established by administering a high-fat diet and streptozotocin. Oral administration of capsaicin for 2 weeks inhibited prostate growth in testosterone propionate (TP)-treated mice. Furthermore, oral administration of capsaicin (5 mg/kg) for 2 weeks decreased fasting blood glucose, prostate weight, and prostate index in diabetic and TP-DM mice. Histopathological alterations were measured using hematoxylin & eosin (H&E) staining. The protein expression of 5α-reductase type II, androgen receptor (AR), and prostate-specific antigen (PSA) were upregulated in diabetic and TP-DM mice, but capsaicin reversed these effects. Capsaicin decreased the protein expression of p-AKT, insulin-like growth factor-1 (IGF-1), IGF-1R, and the receptor for advanced glycation end products (RAGE) in diabetic and TP-DM mice. Capsaicin also regulated epithelial-mesenchymal transition (EMT) and modulated the expression of fibrosis-related proteins, including E-cadherin, N-cadherin, vimentin, fibronectin, α-SMA, TGFBR2, TGF-β1, and p-Smad in TP-DM mice. In this study, capsaicin alleviated diabetic prostate growth by attenuating EMT. Mechanistically, capsaicin affected EMT by regulating RAGE/IGF-1/AKT, AR, and TGF-β/Smad signalling pathways. These results provide with new therapeutic approach for treating T2DM or T2DM-induced prostate growth.

The potential role of Tirzepatide as adjuvant therapy in countering colistin-induced nephro and neurotoxicity in rats via modulation of PI3K/p-Akt/GSK3-β/NF-kB p65 hub, shielding against oxidative and endoplasmic reticulum stress, and activation of p-CREB/BDNF/TrkB cascade

Although colistin has a crucial antibacterial activity in treating multidrug-resistant gram-negative bacteria strains; it exhibited renal and neuronal toxicities rendering its use a challenge. Previous studies investigated the incretin hormones either glucose-dependent insulinotropic polypeptide (GIP) or glucagonlike peptide-1 (GLP-1) for their neuroprotective and nephroprotective effectiveness. The present study focused on investigating Tirzepatide (Tirze), a dual GLP-1/GIP agonist, as an adjuvant therapy in the colistin treatment protocol for attenuating its renal and neuronal complications. Rats were divided into; The normal control group, the colistin-treated group received colistin (300,000 IU/kg/day for 7 days; i.p.). The Tirze-treated group received Tirze (1.35 mg/kg on the 1,4,7thdays; s.c.) and daily colistin. Tirze effectively enhanced histopathological alterations, renal function parameters, and locomotor activity in rats. Tirze mechanistically acted via modulating various signaling axes evolved under the insult of phosphatidylinositol 3-kinases (PI3K)/phosphorylated protein kinase-B (p-Akt)/ glycogen synthase kinase (GSK)3-β hub causing mitigation of nuclear factor (NF)-κB (NF-κB) / tumor necrosis factor-α (TNF-α), increment of nuclear factor erythroid 2-related factor 2 (Nrf2)/ glutathione (GSH), downregulation of ER stress-related biomarkers (activation transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP)), antiapoptotic effects coupling with reduction of glial fibrillary acidic protein (GFAP) immunoreactivity and enhancement of phosphorylated c-AMP response element-binding (p-CREB) / brain-derived neurotrophic factor (BDNF)/tyrosine kinase B (TrkB) neuroprotective pathway. Briefly, Tirze exerts a promising role as adjuvant therapy in the colistin treatment protocol for protection against colistin's nephro- and neurotoxicity according to its anti-inflammatory, antioxidant, and antiapoptotic impacts besides its ability to suppress ER stress-related biomarkers.

Investigating cerebral neurovascular responses to hyperglycemia in a rat model of type 2 diabetes using multimodal assessment techniques

To study neurovascular function in type 2 diabetes mellitus (T2DM), we established a high-fat diet/streptozotocin (HFD/STZ) rat model. Electrocorticography-laser speckle contrast imaging (ECoG-LSCI) revealed that the somatosensory-evoked potential (SSEP) amplitude and blood perfusion volume were significantly lower in the HFD/STZ group. Cortical spreading depression (CSD) velocity was used as a measure of neurovascular function, and the results showed that the blood flow velocity and the number of CSD events were significantly lower in the HFD/STZ group. In addition, to compare changes during acute hyperglycemia and hyperglycemia, we used intraperitoneal injection (IPI) of glucose to induce transient hyperglycemia. The results showed that CSD velocity and blood flow were significantly reduced in the IPI group. The significant neurovascular changes observed in the brains of rats in the HFD/STZ group suggest that changes in neuronal apoptosis may play a role in altered glucose homeostasis in T2DM.

Empagliflozin alone and in combination with metformin mitigates diabetes-associated renal complications

Diabetes mellitus is a major public health concern, often leading to undiagnosed micro- and macrovascular complications, even in patients with controlled blood glucose levels. Recent evidence suggests that empagliflozin and metformin have renoprotective effects in addition to their hypoglycemic action. This study investigated the potential protective effect of empagliflozin and metformin on diabetic renal complications. Forty-two adult male Sprague Dawley rats were randomized into six groups: normal control, diabetic control, metformin (250 mg/kg), empagliflozin (10 mg/kg), and combination therapy groups. Type 2 diabetes was induced in rats by a single intraperitoneal injection of streptozotocin (40 mg/kg) following two weeks of 10% fructose solution in their drinking water. Blood glucose, creatinine, urea nitrogen, inflammatory markers (IL-6, TNF-α), and renal tissue caspase-3 were assessed after eight weeks. Blood glucose, urea, creatinine, serum IL-6, TNF-α, and tissue caspase-3 were significantly decreased in the treatment groups compared to the diabetic group. The histopathological findings revealed that treatment with empagliflozin and/or metformin improved the damage in the renal tissue caused by diabetes-induced nephropathy. Moreover, co-administration of empagliflozin and metformin resulted in even better outcomes. Our data revealed that empagliflozin and metformin could improve renal function and decrease inflammation and apoptosis in diabetic animals, delaying the progression of diabetic nephropathy. Combined treatment with metformin and empagliflozin proved to have an additive protective action on renal tissue.

Tanshinone IIA improves Alzheimer's disease via RNA nuclear-enriched abundant transcript 1/microRNA-291a-3p/member RAS oncogene family Rab22a axis

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative condition characterized by oxidative stress and neuroinflammation. Tanshinone IIA (Tan-IIA), a bioactive compound isolated from Salvia miltiorrhiza plants, has shown potential neuroprotective effects; however, the mechanisms underlying such a function remain unclear.

AIM

To investigate potential Tan-IIA neuroprotective effects in AD and to elucidate their underlying mechanisms.

METHODS

Hematoxylin and eosin staining was utilized to analyze structural brain tissue morphology. To assess changes in oxidative stress and neuroinflammation, we performed enzyme-linked immunosorbent assay and western blotting. Additionally, the effect of Tan-IIA on AD cell models was evaluated in vitro using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Genetic changes related to the long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1)/microRNA (miRNA, miR)-291a-3p/member RAS oncogene family Rab22a axis were assessed through reverse transcription quantitative polymerase chain reaction.

RESULTS

In vivo, Tan-IIA treatment improved neuronal morphology and attenuated oxidative stress and neuroinflammation in the brain tissue of AD mice. In vitro experiments showed that Tan-IIA dose-dependently ameliorated the amyloid-beta 1-42-induced reduction of neural stem cell viability, apoptosis, oxidative stress, and neuroinflammation. In this process, the lncRNA NEAT1 - a potential therapeutic target - is highly expressed in AD mice and downregulated via Tan-IIA treatment. Mechanistically, NEAT1 promotes the transcription and translation of Rab22a via miR-291a-3p, which activates nuclear factor kappa-B (NF-κB) signaling, leading to activation of the pro-apoptotic B-cell lymphoma 2-associated X protein and inhibition of the anti-apoptotic B-cell lymphoma 2 protein, which exacerbates AD. Tan-IIA intervention effectively blocked this process by inhibiting the NEAT1/miR-291a-3p/Rab22a axis and NF-κB signaling.

CONCLUSION

This study demonstrates that Tan-IIA exerts neuroprotective effects in AD by modulating the NEAT1/miR-291a-3p/Rab22a/NF-κB signaling pathway, serving as a foundation for the development of innovative approaches for AD therapy.

Sacubitril/valsartan ameliorates tubulointerstitial fibrosis by restoring mitochondrial homeostasis in diabetic kidney disease

BACKGROUND

Tubulointerstitial fibrosis plays an important role in the progression of diabetic kidney disease (DKD). Sacubitril/valsartan (Sac/Val) exerts a robust beneficial effect in DKD. However, the potential functional effect of Sac/Val on tubulointerstitial fibrosis in DKD is still largely unclear.

METHODS

Streptozotocin-induced diabetic mice were given Sac/Val or Val by intragastric administration once a day for 12 weeks. The renal function, the pathological changes of tubule injury and tubulointerstitial fibrosis, as well as mitochondrial morphology of renal tubules in mice, were evaluated. Genome-wide gene expression analysis was performed to identify the potential mechanisms. Meanwhile, human tubular epithelial cells (HK-2) were cultured in high glucose condition containing LBQ657/valsartan (LBQ/Val). Further, mitochondrial functions and Sirt1/PGC1α pathway of tubular epithelial cells were assessed by Western blot, Real-time-PCR, JC-1, MitoSOX or MitoTracker. Finally, the Sirt1 specific inhibitor, EX527, was used to explore the potential effects of Sirt1 signaling in vivo and in vitro.

RESULTS

We found that Sac/Val significantly ameliorated the decline of renal function and tubulointerstitial fibrosis in DKD mice. The enrichment analysis of gene expression indicated metabolism as an important modulator in DKD mice with Sac/Val administration, in which mitochondrial homeostasis plays a pivotal role. Then, the decreased expression of Tfam and Cox IV;, as well as changes of mitochondrial function and morphology, demonstrated the disruption of mitochondrial homeostasis under DKD conditions. Interestingly, Sac/Val administration was found to restore mitochondrial homeostasis in DKD mice and in vitro model of HK-2 cells. Further, we demonstrated that Sirt1/PGC1α, a crucial pathway in mitochondrial homeostasis, was activated by Sac/Val both in vivo and in vitro. Finally, the beneficial effects of Sac/Val on mitochondrial homeostasis and tubulointerstitial fibrosis was partially abolished in the presence of Sirt1 specific inhibitor.

CONCLUSIONS

Taken together, we demonstrate that Sac/Val ameliorates tubulointerstitial fibrosis by restoring Sirt1/PGC1α pathway-mediated mitochondrial homeostasis in DKD, providing a theoretical basis for delaying the progression of DKD in clinical practice.

[Carnosine protects against diabetic nephropathy in rats by activating the AKT/mTOR pathway and restoring autophagy in the renal tissue]

OBJECTIVE

To explore the mechanisms mediating the protective effect of carnosine against nephropathy in rats with diabetes mellitus (DM).

METHODS

Rat models of DM established by high-fat diet feeding and streptozotocin injection were randomized into DM group and 3 treatment groups with daily carnosine treatment at 100, 300, and 900 mg/kg. Body weight and blood glucose level changes of the rats were measured regularly. After the treatment, 24-h urine, serum samples and kidneys of the rats were collected to measure urine volume, urine protein content, blood creatinine, and kidney mass; renal pathology was observed using HE staining, and MDA content and SOD activity in the kidney tissues were detected. Western blotting was performed to detect the protein expressions of p-AKT, AKT, p-mTOR, mTOR, LC3 and p62 in the kidney tissues.

RESULTS

Compared with normal control rats, the diabetic rats exhibited dull and wet hair and showed decreased body weight, increased blood glucose, urinary protein content, 24-h urine volume, blood creatinine, and kidney mass with obvious swelling and deformation of the glomeruli, narrowing of the renal tubules, decreased SOD activity and increased MDA content, lowered p-mTOR/mTOR and p-AKT/AKT ratios and increased LC3 Ⅱ/Ⅰ ratio and p62 protein expression in the kidney tissue. The diabetic rats receiving carnosine treatments had dry hair with normal luster and showed increased body weight and slightly decreased blood glucose, urinary protein content, 24-h urine volume, blood creatinine, and kidney mass. The treatment also improved renal pathology, increased SOD activity, decreased MDA content, increased p-mTOR/mTOR and p-AKT/AKT ratios and lowered LC3 Ⅱ/Ⅰ ratio and p62 protein expression in renal tissue of the diabetic rats.

CONCLUSION

Carnosine offers protection against nephropathy in rats with DM possibly by inhibiting oxidative stress, activating the AKT/mTOR pathway, and restoring autophagy in the kidneys.

Protective effect of eriodictyol against hyperglycemia-induced diabetic nephropathy in rats entails antioxidant and anti-inflammatory effects mediated by activating Nrf2

The pathogenesis of diabetic nephropathy (DN) involves cellular activation of oxidative stress and inflammation. Eriodictyol is a citrus-derived flavonoid with multiple pharmacological and protective effects in various conditions. The protective role of Eriodictyol against diabetes and diabetic nephropathy is less investigated. The current research aimed to explore the role of eriodictyol in protecting against DN prompted by streptozotocin in male rats and investigate some possible mechanisms of action. Diabetes was brought about in rats by an i.p injection of a lone dose (65 mg/kg). Five groups of rats were included (n = 8 each) as control (non-diabetic), eriodictyol (20 mg/kg, orally), STZ-diabetic, STZ + eriodictyol (20 mg/kg, orally), and STZ + eriodictyol (20 mg/kg, orally) + ML385 (30 µg/kg, i.p.). Kidney histology and the levels of some markers of kidney function, renal oxidative stress, and renal inflammation were analyzed in all groups of rats. Treatment with eriodictyol prevented the damage in the renal glomeruli and tubules and reduced renal immune cell infiltration in STZ-treated animals. It also spiked urinary creatinine excretion and reduced urine volume and urinary levels of albumin, monocyte chemoattractant protein 1 (MCP-1), urinary kidney injury molecule-1 (KIM-1), and nephrin in these diabetic rats. In addition, eriodictyol stimulated the nuclear protein accumulation of Nrf2 and boosted the expression of superoxide dismutase (SOD), glutathione (GSH), heme oxygenase-1 (HO-1), and catalase (CAT) in the diabetic rat kidneys. In concomitance, it reduced the nuclear levels of NF-κB and levels of interleukine-6 (IL-6), malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) and attenuated the reduction in renal ATP levels and the increase in the mitochondria transition pore opening (mtTPT). However, the administration of eriodictyol did not affect rats' body weights and fasting glucose and insulin levels but significantly reduced serum levels of cholesterol, triglycerides, LDL-c, and oxidized LDL-c (ox-LDL-c). In conclusion, eriodictyol prevents STZ-induced nephropathy by a hypolipidemic effect and concomitant antioxidant and anti-inflammatory effects mediated by activating Nrf2/NF-κB/antioxidant axis.

LCZ696 (sacubitril/valsartan) mitigates cyclophosphamide-induced premature ovarian failure in rats; the role of TLR4/NF-κB/NLRP3/Caspase-1 signaling pathway

AIM

Cyclophosphamide (CP) is used to treat a variety of cancers and autoimmune illnesses. CP has been found to frequently cause premature ovarian failure (POF). The study's objective was to assess LCZ696's potential for protection against CP-induced POF in a rat model.

MAIN METHODS

Rats were randomly assigned into seven groups as follows: control, valsartan (VAL), LCZ696, CP, CP + VAL, CP + LCZ696, and CP + triptorelin (TRI). Ovarian malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), interleukin-18 (IL-18), IL-1β, and tumor necrosis factor-alpha (TNF-α) were assessed using ELISA. Serum anti-mullerian hormone (AMH), estrogen, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were also measured using ELISA. The expression of NLRP3/Caspase-1/GSDMD C-NT and TLR4/MYD88/NF-B P65 proteins was estimated using western blot assay. The histopathology of the ovaries was also investigated. The estrous cycle, body, and ovarian weights were also monitored.

KEY FINDINGS

CP treatment significantly elevated levels of MDA, IL-18, IL-1β, TNF-α, FSH, LH, and up-regulated TLR4/NF-κB/NLRP3/Caspase-1 proteins, as compared to the control group, however, ovarian follicles count, and levels of GSH, SOD, AMH, and estrogen were reduced with CP administration. All the aforementioned biochemical and histological abnormalities were considerably alleviated by the LCZ696 therapy compared to valsartan alone.

SIGNIFICANCE

LCZ696 effectively mitigated CP-induced POF, offering promising protection that could be related to its suppression power on NLRP3-induced pyroptosis and TLR4/NF-B P65 pathway.

Oxidative stress: A common pathological state in a high-risk population for osteoporosis

Osteoporosis is becoming a major concern in the field of public health. The process of bone loss is insidious and does not directly induce obvious symptoms. Complications indicate an irreversible decrease in bone mass. The high-risk populations of osteoporosis, including postmenopausal women, elderly men, diabetic patients and obese individuals need regular bone mineral density testing and appropriate preventive treatment. However, the primary changes in these populations are different, increasing the difficulty of effective treatment of osteoporosis. Determining the core pathogenesis of osteoporosis helps improve the efficiency and efficacy of treatment among these populations. Oxidative stress is a common pathological state secondary to estrogen deficiency, aging, hyperglycemia and hyperlipemia. In this review, we divided oxidative stress into the direct effect of reactive oxygen species (ROS) and the reduction of antioxidant enzyme activity to discuss their roles in the development of osteoporosis. ROS initiated mitochondrial apoptotic signaling and suppressed osteogenic marker expression to weaken osteogenesis. MAPK and NF-κB signaling pathways mediated the positive effect of ROS on osteoclast differentiation. Antioxidant enzymes not only eliminate the negative effects of ROS, but also directly participate in the regulation of bone metabolism. Additionally, we also described the roles of proinflammatory factors and HIF-1α under the pathophysiological changes of inflammation and hypoxia, which provided a supplement of oxidative stress-induced osteoporosis. In conclusion, our review showed that oxidative stress was a common pathological state in a high-risk population for osteoporosis. Targeted oxidative stress treatment would greatly optimize the therapeutic schedule of various osteoporosis treatments.