Mechanisms mediating the cardioprotective effect of carvedilol in cadmium induced cardiotoxicity. Role of eNOS and HO1/Nrf2 pathway

Implementing losartan potassium-laden pegylated nanocubic vesicles as a novel nanoplatform to alleviate cisplatin-induced nephrotoxicity via blocking apoptosis and activating the wnt/β-catenin/TCF-4 pathway

AIMS

Losartan potassium-laden pegylated nanocubic vesicles (LP-NCVs-PEG) have an intriguing kidney-targeted nanoplatform for acute renal injury via blocking apoptosis and activating wnt/β-catenin pathway.

MAIN METHODS

Utilizing a thin-film hydration methodology established on 42 full factorial design to produce LP loaded nanocubic formulations (LP-NCVs) which composed mainly from L-α-phosphatidylcholine and poloxamer. The optimization process was designed to select the formulation with maximum entrapment efficiency (EE %), maximum in-vitro drug release (Q8h), and minimum vesicle size (VS). The optimum formulation was then pegylated to obtain LP-NCVs-PEG formulation that shields NCVs from the harsh ecosystem of the stomach, improves their oral drug delivery performance and targets the proximal renal tubules with no systemic toxicity. Male albino rats were injected with Cisplatin (6 mg/kg, i.p.) alone or with LP-formulations (5 mg/kg/day). Kidney injury markers, inflammatory markers, apoptotic markers. Besides renal tissue expression of Wnt, β-Catenin, GSK-3β, renal RNA gene expression of TCF-4, LEF-1 and histopathology were also analyzed to display pharmacological study.

KEY FINDINGS

The pharmacokinetics studies demonstrated that LP-NCVs-PEG boosted LP bioavailability approximately 3.61 times compared to LP oral solution. Besides LP-NCVs-PEG may have an intriguing kidney-targeted nanoplatform for acute renal injury via decreased renal toxicity markers, renal expression of LEF-1, GSK3-β, caspase, TNF-α, NF-κB and TUNEL expression. Alternatively, increased renal tissue level of Bcl-2, wnt, β-catenin and TCF-4.

SIGNIFICANCE

LP-NCVs-PEG improved LP pharmacokinetics targeting the kidney and improved injury by activating wnt/β-catenin/TCF-4 pathway, blocking apoptosis, inflammation and renal toxicity markers suggesting it might be successful nephroprotective adjuvant therapy.

Sacubitril/valsartan alleviates sepsis-induced myocardial injury in rats via dual angiotensin receptor-neprilysin inhibition and modulation of inflammasome/caspase 1/IL1β pathway

Sepsis is a life-threatening situation that ultimately affects cardiac function, leading to cardiomyopathy and myocardial injury as a result of uncontrolled response to infection.Till now, there is limited effective treatment to rescue those cases. Thus, novel therapeutic strategies should be identified to achieve better outcomes for septic patients. For the first time, we aimed to evaluate the effect of sacubitril/valsartan (Sac/Val) on sepsis-induced cardiac injury. Wistar male adult albino rats were randomly divided into four groups; Group I received the vehicle; Group II was given the vehicle plus 1 ml saline containing viable Escherichia coli (E. coli) (2.1 × 109 cfu) by intraperitoneal (i.p.) injection on the 1st and 2nd days; Group III received i.p. injection as group II plus oral administration of Sac/Val (30 mg/kg/day) and Nitro- ω-L-arginine (L-NNA) (25 mg/kg/day) for 7 days. Group IV was administered i.p. injection as group II plus oral administration of Sac/Val (30 mg/kg/day) for 7 days. Our data (n = 10) revealed successful induction of sepsis as it showed a significant increase in the measured cardiac enzymes, malondialdehyde (MDA), angiotensin II (Ang II), neprilysin, inflammasome, caspase 1, interleukin (IL)1β, and caspase 3 with cardiac histopathological changes, but there was a significant decrease in the antioxidants and blood pressure (BP). Co-administration of Sac/Val could obviously improve these changes. Interestingly, L-NNA given group showed a decrease in the cardioprotective effect of Sac/Val. Sac/Val could ameliorate sepsis induced cardiac damage via inhibition of Ang II and neprilysin with anti-inflammatory, anti-oxidant and anti-apoptotic properties.

Mechanistic insights into carvedilol's potential protection against doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is an anthracycline chemotherapy drug widely employed in the treatment of various cancers, known for its potent antineoplastic properties but often associated with dose-dependent cardiotoxicity, limiting its clinical use. This review explores the complex molecular details that determine the heart-protective effectiveness of carvedilol in relation to cardiotoxicity caused by DOX. The harmful effects of DOX on heart cells could include oxidative stress, DNA damage, iron imbalance, disruption of autophagy, calcium imbalance, apoptosis, dysregulation of topoisomerase 2-beta, arrhythmogenicity, and inflammatory responses. This review carefully reveals how carvedilol serves as a strong protective mechanism, strategically reducing each aspect of cardiac damage caused by DOX. Carvedilol's antioxidant capabilities involve neutralizing free radicals and adjusting crucial antioxidant enzymes. It skillfully manages iron balance, controls autophagy, and restores the calcium balance essential for cellular stability. Moreover, the anti-apoptotic effects of carvedilol are outlined through the adjustment of Bcl-2 family proteins and activation of the Akt signaling pathway. The medication also controls topoisomerase 2-beta and reduces the renin-angiotensin-aldosterone system, together offering a thorough defense against cardiotoxicity induced by DOX. These findings not only provide detailed understanding into the molecular mechanisms that coordinate heart protection by carvedilol but also offer considerable potential for the creation of targeted treatment strategies intended to relieve cardiotoxicity caused by chemotherapy.

Effect of New Antidiabetics on Steatosis in Nerve Tissues and Nerve Conduction Velocity: Possible Role of Nerve Growth Factor (NGF)/Synaptophysin and Nrf2/HO-1 Pathways

OBJECTIVES

The current study aims to investigate the impact of the GLP1 analog (semaglutide) and SGLT2 inhibitor (dapagliflozin) on nerve functions, morphology, and the underlying mechanisms involving nerve growth factor (NGF)/synaptophysin and Nrf2/HO-1 pathways in obese rats.

METHODS

Forty male Sprague Dawley rats, aged six to eight weeks, were classified into five groups; normal group (high-fat diet {HFD} for 12 weeks, metformin group (HFD for 12 weeks + metformin in last four weeks), dapagliflozin group (HFD for 12 weeks +dapagliflozin in last four weeks, semaglutide group (HFD for 12 weeks + semaglutide in last four weeks). At the end of the experiment, the sciatic nerve was collected for nerve conduction study, oxidative stress marker (malondialdehyde, i.e., MDA), real-time polymerase chain reaction (PCR) study (for HO-1 and Nrf2), oil red O staining, electron microscopic examination and immunohistochemistry for NGF and synaptophysin.

RESULTS

The HFD group showed a significant rise in blood glucose, serum lipids, homeostatic model assessment (HOMA) index, lipid deposition in nerve tissues, and lipid peroxidation (MDA) in nerve tissues with significant attenuation in nerve conduction velocity (NCV), the expression of Nrf2 and HO-1 genes and significant attenuation in area stained with NGF and synaptophysin. On the other hand, pretreatment with either dapagliflozin or semaglutide led to considerable enhancement in the deteriorated serum and nerve tissue parameters and reversed the pathological changes.

CONCLUSION

New antidiabetic drugs like SGLT2 inhibitors (more powerful) and GLP1 analog might have neuroprotective beneficial effects besides controlling the glycemic state in obese rats. This effect may result from reduced oxidative stress and increased Nrf2 levels, HO-1, synaptophysin, and NGF in the nerve tissues of obese rats.

Heme Oxygenase-1, Cardiac Senescence, and Myocardial Infarction: A Critical Review of the Triptych

PURPOSE

Heme oxygenase-1 (HO-1) is a crucial enzyme in heme metabolism, facilitating the breakdown of heme into biliverdin, carbon monoxide, and free iron. Renowned for its potent cytoprotective properties, HO-1 showcases notable antioxidant, anti-inflammatory, and anti-apoptotic effects. In this review, the authors aim to explore the profound impact of HO-1 on cardiac senescence and its potential implications in myocardial infarction (MI).

RESULTS

Recent research has unveiled the intricate role of HO-1 in cellular senescence, characterized by irreversible growth arrest and functional decline. Notably, cardiac senescence has emerged as a pivotal factor in the development of various cardiovascular conditions, including MI. Notably, cardiac senescence has emerged as an important factor in the development of various cardiovascular conditions, including myocardial infarction (MI). The accumulation of senescent cells, spanning vascular endothelial cells, vascular smooth muscle cells, cardiomyocytes, and progenitor cells, poses a significant risk for cardiovascular diseases such as vascular aging, atherosclerosis, myocardial infarction, and ventricular remodeling. Inhibition of cardiomyocyte senescence not only reduces senescence-associated inflammation but also impacts other myocardial lineages, hinting at a broader mechanism of propagation in pathological remodeling. HO-1 has been shown to improve heart function and mitigate cardiomyocyte senescence induced by ischemic injury and aging. Furthermore, HO-1 induction has been found to alleviate H2O2-induced cardiomyocyte senescence. As we grow in our understanding of antiproliferative, antiangiogenic, anti-aging, and vascular effects of HO-1, we see the potential to exploit potential links between individual susceptibility to cardiac senescence and myocardial infarction.

CONCLUSIONS

This review investigates strategies for upregulating HO-1, including gene targeting and pharmacological agents, as potential therapeutic approaches. By synthesizing compelling evidence from diverse experimental models and clinical investigations, this study elucidates the therapeutic potential of targeting HO-1 as an innovative strategy to mitigate cardiac senescence and improve outcomes in myocardial infarction, emphasizing the need for further research in this field.

Sacubitril/valsartan cardioprotective effect against cisplatin-induced cardiotoxicity via modulation of VEGF/eNOS and TLR4/TNFα/IL6 signalling pathways

OBJECTIVES

Drug-induced cardiac injury is a potentially preventable cause of heart failure. Cisplatin (CIS) is a widely used chemotherapeutic agent complicated with cardiotoxicity that limits its clinical application so we aimed to evaluate the suspected cardioprotective effect of sacubitril/valsartan (Sac/Val) against CIS cardiotoxic injury.

METHODS

Forty male rats of Wistar albino species were divided into four groups. group I received the vehicle; group II was given the vehicle plus CIS (10 mg/kg) single i.p. on fifth day; group III was given Sac/Val (30 mg/kg/d) orally for 7 days plus CIS (10 mg/kg) single i.p. on fif5th day; group IV was given the same as group III plus nitro-ω-L-arginine (L-NNA) (25 mg/kg/d) orally for 7 days.

KEY FINDINGS

CIS-induced cardiotoxicity and L-NNA co-administered group showed significant increases in cardiac enzymes, toxic histopathological features, elevated heart weights, angiotensin II (Ang II), neprilysin, malondialdehyde (MDA), inflammatory mediators, blood pressure (BP) and caspase 3 expressions, but there are significant decreases in the antioxidant parameters, vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS). However, the co-administration of Sac/Val could ameliorate these changes of CIS.

CONCLUSION

Sac/Val has an important cardioprotective effect against CIS cardiotoxicity with the involvement of eNOS.

Potentilla anserina polysaccharide alleviates cadmium-induced oxidative stress and apoptosis of H9c2 cells by regulating the MG53-mediated RISK pathway

Oxidative stress plays a crucial role in cadmium (Cd)-induced myocardial injury. Mitsugumin 53 (MG53) and its mediated reperfusion injury salvage kinase (RISK) pathway have been demonstrated to be closely related to myocardial oxidative damage. Potentilla anserina L. polysaccharide (PAP) is a polysaccharide with antioxidant capacity, which exerts protective effect on Cd-induced damage. However, it remains unknown whether PAP can prevent and treat Cd-induced cardiomyocyte damages. The present study was desgined to explore the effect of PAP on Cd-induced damage in H9c2 cells based on MG53 and the mediated RISK pathway. For in vitro evaluation, cell viability and apoptosis rate were analyzed by CCK-8 assay and flow cytometry, respectively. Furthermore, oxidative stress was assessed by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining and using superoxide dismutase (SOD), catalase (CAT), and glutathione/oxidized glutathione (GSH/GSSG) kits. The mitochondrial function was measured by JC-10 staining and ATP detection assay. Western blot was performed to detect the expression of proteins related to MG53, the RISK pathway, and apoptosis. The results indicated that Cd increased the levels of reactive oxygen species (ROS) in H9c2 cells. Cd decreased the activities of SOD and CAT and the ratio of GSH/GSSG, resulting in decreases in cell viability and increases in apoptosis. Interestingly, PAP reversed Cd-induced oxidative stress and cell apoptosis. Meanwhile, Cd reduced the expression of MG53 in H9c2 cells and inhibited the RISK pathway, which was mediated by decreasing the ratio of p-Akt^Ser473/Akt, p-GSK3β^Ser9/GSK3β and p-ERK1/2/ERK1/2. In addition, Cd impaired mitochondrial function, which involved a reduction in ATP content and mitochondrial membrane potential (MMP), and an increase in the ratio of Bax/Bcl-2, cytoplasmic cytochrome c/mitochondrial cytochrome c, and Cleaved-Caspase 3/Pro-Caspase 3. Importantly, PAP alleviated Cd-induced MG53 reduction, activated the RISK pathway, and reduced mitochondrial damage. Interestingly, knockdown of MG53 or inhibition of the RISK pathway attenuated the protective effect of PAP in Cd-induced H9c2 cells. In sum, PAP reduces Cd-induced damage in H9c2 cells, which is mediated by increasing MG53 expression and activating the RISK pathway.

Dapagliflozin Guards Against Cadmium-Induced Cardiotoxicity via Modulation of IL6/STAT3 and TLR2/TNFα Signaling Pathways

Cadmium (Cd) is a common environmental pollutant that leads to severe cardiotoxic hazards. Several studies were carried out to protect the myocardium against Cd-induced cardiotoxicity. Up till now, no researches evaluated the protective effect of dapagliflozin (DAP) against Cd induced cardiotoxicity. Thus, we aimed to explore the role of DAP in such model with deep studying of the involved mechanisms. 40 male Wistar albino rats were included in current study. Cd (5 mg/kg/day) was administered orally for 7 days to induce cardiotoxicity with or without co-administration of DAP in three different doses (2.5, 5, 10 mg/kg/day) orally for 7 days. Our data revealed that Cd could induce cardiotoxicity with significant increase in serum cardiac enzymes, heart weight, tissue malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), nuclear factor kappa B (NFκB), toll like receptor2 (TLR2), interleukin 6 (IL6) and caspase3 immunoexpression with abnormal histopathological changes. In addition, Cd significantly decreased the level of heme oxygenase1 (HO1), nuclear factor erythroid 2-related factor 2 (Nrf2), signal transducer and activator of transcription (STAT3), reduced glutathione (GSH), glutathione peroxidase (GPx), and total antioxidant capacity (TAC). Co-administration of DAP could ameliorate Cd cardiotoxicity with significant improvement of the biochemical and histopathological changes. We found that DAP had protective properties against Cd induced cardiotoxicity and this may be due to its anti-oxidant, anti-inflammatory, anti-apoptotic properties and modulation of IL6/STAT3 and TLR2/TNFα-signaling pathways.

Simvastatin cardioprotection in cyclophosphamide-induced toxicity via the modulation of inflammasome/caspase1/interleukin1β pathway

Drug-induced cardiotoxicity is a serious adverse effect that occurs during the administration of chemotherapeutic agents such as cyclophosphamide (CYC). Therefore, there is a critical need to find cardioprotective agents to keep the heart healthy. The current study aimed to investigate the protective effect of simvastatin (SIM) against CYC-induced heart damage and evaluate different mechanisms involved in mediating this effect, including the inflammasome/caspase1/interleukin1β (IL1β) pathway and endothelial nitric oxide synthase (eNOS). 36 rats were randomly assigned to one of four groups: a control group that received only vehicles, a CYC group that received CYC (150 mg/kg/day) i.p. on the fourth and fifth days, a CYC+SIM group that received SIM (10 mg/kg/day) orally for 5 days and CYC (150 mg/kg/day) i.p. on the fourth and fifth days, and a CYC+SIM+ Nitro- ω-L-arginine (L-NNA) group that received L-NNA (25 mg/kg/day, SIM (10 mg/kg/day) orally for 5 days and CYC (150 mg/kg/day) i.p. on the 4th and 5th days. The CYC group revealed an obvious elevation in cardiac enzymes and heart weights with toxic histopathological changes. Moreover, there was an increase in malondialdehyde (MDA), tumor necrosis factor-alpha (TNFα) levels, and up-regulation of the NLRP3inflammasome/caspase1/IL1β pathway. In addition, total antioxidant capacity (TAC), eNOS, reduced glutathione (GSH), and superoxide dismutase (SOD) significantly decreased. CYC-induced cardiotoxicity was most properly reversed by SIM through its anti-oxidant, anti-inflammatory, and anti-apoptotic actions with the stimulation of eNOS. The co-administration of L-NNA diminished the protective effect of SIM, indicating the essential role of eNOS in mediating this effect. Therefore, SIM ameliorated CYC-induced cardiotoxicity.

Dose-Dependent Cardioprotective Effect of Hemin in Doxorubicin-Induced Cardiotoxicity Via Nrf-2/HO-1 and TLR-5/NF-κB/TNF-α Signaling Pathways

Doxorubicin (DOX) is one of the most widely used chemotherapeutic drugs, but its cardiotoxicity has been shown to be a dose-restricting factor during therapy. Finding new agents for reducing these complications is still in critical need. The current study aimed to evaluate the possible cardioprotective effect of hemin (HEM) in DOX-induced cardiotoxicity and exploring the role of toll like receptor-5/nuclear factor kappa-B/tumor necrosis factor-alpha (TLR-5/NF-κB/TNF-α) and nuclear factor erythroid 2-related factor-2/hemeoxygenase-1 (Nrf-2/HO-1) signaling pathways in mediating such effect. Wistar albino rats were randomly divided into five groups. They were administered DOX by interaperitoneal (i.p.) injection (15 mg/kg) on the 5th day of the experiment with or without HEM in different doses (2.5, 5, 10 mg/kg/day) i.p. for 7 days. Results showed that the DOX group had cardiotoxicity as manifested by a significant increase in cardiac enzymes, malondialdehyde (MDA), TLR-5, NF-κB, TNF-α, and cleaved caspase-3 levels with toxic histopathological changes. Based on these findings, HEM succeeded in reducing DOX-induced cardiotoxicity in a dose-dependent effect by stimulation of Nrf-2/HO-1 and inhibition of TLR-5/NF-κB/TNF-α pathways with subsequent antioxidant, anti-inflammatory, and anti-apoptotic effects.

Protective effects of bisoprolol against cadmium-induced myocardial toxicity through inhibition of oxidative stress and NF-κΒ signalling in rats

Introduction

The aim of the study was to investigate the mitigative effects of bisoprolol (BIS) in cadmium-induced myocardial toxicity on oxidative stress and its inhibitive effect on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) signalling in rats.

Material and Methods

Male albino Wistar rats were assigned to control, Cd, BIS 2 (2 mg/kg b.w.) and BIS 8 (8 mg/kg b.w.) groups with nine rats in each. Over four weeks, the control group was administered 1% gum acacia, all other groups received 3mg/kg b.w. CdCl2 dissolved in distilled water, and the BIS groups were additionally given bisoprolol in gum acacia. Blood samples were collected for biochemical estimations. Blood pressure and serum biomarker (lactate dehydrogenase, aspirate transaminase, alanine transferase and creatine kinase-MB, enzyme (superoxide dismutase, lipid hydroxy peroxidase, catalase and malondialdehyde), and tumour necrosis factor alpha (TNF-α) concentrations were measured. Western blot analysis was conducted for NF-κB and glutathione S-transferase (GST). After sacrificing the rats, cardiac tissue samples were examined histopathologically.

Results

Our findings pointed to a significant decrease (P < 0.05) in the studied serum biomarkers and levels of the relevant enzymes in the BIS 8 group compared to the Cd group. A significant decrease (P < 0.05) in NF-kB p65 expression and TNF-α levels was noted in the BIS 8 group relative to the BIS 2 and Cd groups, indicating a reduction at a higher dose. In microscopy, histopathological changes in the cardiac muscles of the BIS 8 group were evident compared to those of the Cd group.

Conclusion

BIS seemed to have protective effects against cardiac injury induced by cadmium and could be considered a novel therapeutic drug and prognostic biomarker in the pathology of the many cardiovascular diseases caused by heavy metal intake.

Neutrophil Gelatinase-Associated Lipocalin 2 Accelerates Hypoxia-Induced Endothelial Cell Injury via eNOS/NRF2 Signalling

Objective

Neutrophil gelatinase-associated lipocalin (NGAL), a lipocalin, is implicated in many cardiovascular diseases (CVD). The effect of NGAL on endothelial cells (ECs), particularly on ECs injured because of hypoxia, is unclear. In this study, we aim to explore the effect of NGAL in an EC injury in response to hypoxia.

Materials and Methods

In this experimental study, we isolated and cultured mouse heart ECs (MHECs). The EC injury model was established by exposure of the ECs to hypoxia for 24 hours. The ECs were treated with NGAL (30, 60, 120, 250 and 500 ng/ml). Cell inflammation and oxidative stress were detected by corresponding assays. Apoptotic cells were stained by the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay.

Results

NGAL increased the inflammatory response at the baseline level and further augmented the hypoxia-induced inflammation response. Reactive oxygen species (ROS) levels increased upon NGAL treatment, which caused antioxidase/oxidase imbalance. NGAL also exaggerated hypoxia-induced oxidative stress. The cell apoptosis rate also increased in both the NGAL-treated normoxic and hypoxic conditions. NGAL also reduced endothelial nitric oxide synthase (eNOS)-nitric oxide (NO) signalling, thus decreasing the expression and nuclear translocation of nuclear factor erythroid-2-related factor 2 (NRF2), which was confirmed by overexpression of NRF2.

Conclusion

NGAL exaggerates EC injury in both normoxic and hypoxic conditions by inhibiting the eNOS-NRF2 pathway.

Carvedilol induces biased β1 adrenergic receptor-nitric oxide synthase 3-cyclic guanylyl monophosphate signalling to promote cardiac contractility

AIMS

β-blockers are widely used in therapy for heart failure and hypertension. β-blockers are also known to evoke additional diversified pharmacological and physiological effects in patients. We aim to characterize the underlying molecular signalling and effects on cardiac inotropy induced by β-blockers in animal hearts.

METHODS AND RESULTS

Wild-type mice fed high-fat diet (HFD) were treated with carvedilol, metoprolol, or vehicle and echocardiogram analysis was performed. Heart tissues were used for biochemical and histological analyses. Cardiomyocytes were isolated from normal and HFD mice and rats for analysis of adrenergic signalling, calcium handling, contraction, and western blot. Biosensors were used to measure β-blocker-induced cyclic guanosine monophosphate (cGMP) signal and protein kinase A activity in myocytes. Acute stimulation of myocytes with carvedilol promotes β1 adrenergic receptor (β1AR)- and protein kinase G (PKG)-dependent inotropic cardiac contractility with minimal increases in calcium amplitude. Carvedilol acts as a biased ligand to promote β1AR coupling to a Gi-PI3K-Akt-nitric oxide synthase 3 (NOS3) cascade and induces robust β1AR-cGMP-PKG signal. Deletion of NOS3 selectively blocks carvedilol, but not isoproterenol-induced β1AR-dependent cGMP signal and inotropic contractility. Moreover, therapy with carvedilol restores inotropic contractility and sensitizes cardiac adrenergic reserves in diabetic mice with minimal impact in calcium signal, as well as reduced cell apoptosis and hypertrophy in diabetic hearts.

CONCLUSION

These observations present a novel β1AR-NOS3 signalling pathway to promote cardiac inotropy in the heart, indicating that this signalling paradigm may be targeted in therapy of heart diseases with reduced ejection fraction.

Enoxaparin prevents CXCL16/ADAM10-mediated cisplatin renal toxicity: Role of the coagulation system and the transcriptional factor NF-κB

BACKGROUND AND AIMS

C-X-C ligand 16 (CXCL16) is an exceptional chemokine that is expressed as transmembrane and soluble forms. Our aim is to shed lights on the role of CXCL16/ADAM10 (a disintegrin and metalloproteinase) in cisplatin (CP)-induced renal toxicity as well as possible protective effect of enoxaparin.

MAIN METHODS

Male albino mice were injected with CP (30 mg/kg, i.p.) in the presence or absence of enoxaparin (ENOX) (5 mg/kg, i.p.). Renal toxicity markers, serum level of cystatin-c, complete blood count (CBC), prothrombin time (Pt) and tissue expression of CXCL16, ADAM10, cluster of differentiation 3 (CD3), fibrinogen, tissue factor (TF), nuclear factor-κB (NF-κB) and tumour necrosis factor α (TNF-α) were measured. Besides, serum CXCL16 and histopathology were also analyzed.

KEY FINDINGS

CP increased renal toxicity markers, renal expression of CXCL16/ADAM10, fibrinogen, TF and CD3 tissue expression in a time-dependent manner, and elevated serum cystatin-c, CXCL16 and tissue TNF-α, NF-κB. Alternatively, ENOX restored the deteriorated parameters and reduced tissue level of NF-κB.

SIGNIFICANCE

This report, for the first time, showed that soluble CXCL16 resulting from ADAM10 cleavage may recruit T-cells to the renal glomeruli and tubules in CP toxicity. Furthermore, TF and fibrin, have similar expression and location pattern like CXCL16 and ADAM10 suggesting their possible interrelation. ENOX successfully restored the deteriorated parameters suggesting it may be an effective nephroprotective adjuvant therapy.

Endothelial Dysfunction Induced by Cadmium and Mercury and its Relationship to Hypertension

Hypertension is an important public health concern that affects millions globally, leading to a large number of morbidities and fatalities. The etiology of hypertension is complex and multifactorial, and it involves environmental factors, including heavy metals. Cadmium and mercury are toxic elements commonly found in the environment, contributing to hypertension. We aimed to assess the role of cadmium and mercury-induced endothelial dysfunction in the development of hypertension. A narrative review was carried out through database searches. In this review, we discussed the critical roles of cadmium and mercury in the etiology of hypertension and provided new insights into potential mechanisms of their effect, focusing primarily on endothelial dysfunction. Although the mechanisms by which cadmium and mercury induce hypertension have yet to be completely elucidated, evidence for both implicates impaired nitric oxide signaling in their hypertensive etiology.

Trehalose protects the endothelium from cadmium-induced dysfunction

The objective of the present study is to identify the possible regulatory role of trehalose (Tre) against cadmium chloride (CdCl₂ )-induced endothelial cell dysfunction. To screen the dose-dependent effect of both Tre and CdCl₂ , a methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay was performed. Interestingly, MTT assay results have shown that co-incubation of Tre (1 mM) with CdCl₂ significantly decreased the CdCl₂ (5 µM) cytotoxicity. Nitric oxide (NO) measurement using Griess assay and 4-amino-5-methylamino-2',7'-difluorofluorescein fluorescence probe results have shown that CdCl₂ decreases NO production in endothelial cells. Western blotting analysis results showed that CdCl₂ decreases endothelial nitric oxide synthase (eNOS) and phospho endothelial nitric oxide synthase (peNOS) expression. The present study results have also observed that CdCl₂ treatment increases reactive oxygen species (ROS) production. However, combination treatment (Tre + CdCl₂ ) could restore the NO production in CdCl₂ -treated cells. In addition, combination treatment could also restore eNOS and peNOS expression in endothelial cells. Moreover, Tre treatment was found to decrease CdCl₂ -induced ROS production. Collectively, the present study results demonstrate that Tre possesses a significant protective action against CdCl₂ -mediated endothelial dysfunction by increasing NO production, eNOS and peNOS expression, and by decreasing oxidative stress.

Back to Nucleus: Combating with Cadmium Toxicity Using Nrf2 Signaling Pathway as a Promising Therapeutic Target

There are concerns about the spread of heavy metals in the environment, and human activities are one of the most important factors in their spread. These agents have the high half-life resulting in their persistence in the environment. So, prevention of their spread is the first step. However, heavy metals are an inevitable part of modern and industrial life and they are applied in different fields. Cadmium is one of the heavy metals which has high carcinogenesis ability. Industrial waste, vehicle emissions, paints, and fertilizers are ways of exposing human to cadmium. This potentially toxic agent harmfully affects the various organs and systems of body such as the liver, kidney, brain, and cardiovascular system. Oxidative stress is one of the most important pathways of cadmium toxicity. So, improving the antioxidant defense system can be considered as a potential target. On the other hand, the Nrf2 signaling pathway involves improving the antioxidant capacity by promoting the activity of antioxidant enzymes such as catalase and superoxide dismutase. At the present review, we demonstrate how Nrf2 signaling pathway can be modulated to diminish the cadmium toxicity.

Ameliorative effect of 2-methoxyestradiol on radiation-induced lung injury

AIMS

Radiation-induced lung injury (RILI) is a serious complication of radiation therapy. Development of an effective drug that selectively protects normal lung tissues and sensitizes tumor cells to radiotherapy is an unmet need. 2-Methoxyestradiol (2ME2) possesses polypharmacological properties, which qualifies it as an effective radioprotector. Our aim is to explore the potential protective effects of 2ME2 against early and late stages of RILI and the underlying mechanisms.

MAIN METHODS

BALB/c mice were either treated with 2ME2 (50 mg/kg/day i.p., for 4 weeks); or received a single dose of 10 Gy ionizing radiation (IR) delivered to the lungs; or 10 Gy IR and 2ME2. Animal survival and pulmonary functions were evaluated. Immune-phenotyping of alveolar macrophages (AM) in the broncho-alveolar lavage fluids (BALF) was determined by flow cytometry. ELISA was used to evaluate the expression levels of TNF-α, TGF-β; and IL-10 in BALF. Lung tissues were used for histopathological examination or immunofluorescence staining for CD68 (pan-macrophage marker), Arginase-1 (Arg1, M2-specific marker), inducible nitric oxide synthase (iNOS, M1-specific marker) and HIF-1α. VEGF and γH2AX expression in lung tissues were detected by western blot.

KEY FINDINGS

The results demonstrated that 2ME2 improved the survival, lung functions and histopathological parameters of irradiated mice. Additionally, it attenuated the radiation-induced AM polarization and reduced the pneumonitis and fibrosis markers in lung tissues. Significant reduction of TNF-α and TGF-β with concomitant increase in IL-10 concentrations were observed. Moreover, the expression of HIF-1α, VEGF and γH2AX declined.

SIGNIFICANCE

2ME2 is a promising radioprotectant with fewer anticipated side effects.