Nitric oxide pathways and evidence-based perturbations in acute pancreatitis

The Prospective Ameliorative Role of Zinc Oxide Nanoparticles in STZ-Induced Diabetic Nephropathy in Rats: Mechanistic Targeting of Autophagy and Regulating Nrf2/TXNIP/NLRP3 Inflammasome Signaling

Diabetic nephropathy (DN) as one of the common microvascular complications of diabetes mellitus, is the main cause of end-stage renal disease. Zinc oxide nanoparticles (ZnO NPs) have been employed in several biomedical aspects. This study purposed to explore the mechanistic renoprotective effects of ZnO NPs in STZ-induced DN. Sixty male Wistar rats were allocated into four equal groups: control, ZnO NPs control, STZ, and STZ + ZnO NPs groups. At the end of the experiment, blood and urine biochemical parameters were assayed. Renal tissue level of advanced glycation end products (AGEs) was assayed spectrofluorometrically, moreover, nuclear factor erythroid 2-related factor 2 (Nrf2) DNA-binding activity and IL-1β levels were detected by ELISA. The gene expression levels of thioredoxin-interacting protein (TXNIP) and NOD-like receptor family pyrin domain containing 3 (NLRP3) were detected by quantitative real-time PCR. Oxidative stress markers were determined spectrophotometrically. Also, renal tissue histopathological and immunohistochemical analyses were determined. After 6 weeks of treatment, ZnO NPs markedly improved the biochemical, renal functions, and histopathological findings. Furthermore, ZnO NPs significantly increased Nrf2-DNA-binding activity and downregulated TXNIP gene expression leading to restoration of the redox status. Additionally, ZnO NPs ameliorated AGEs levels, enhanced autophagy activity, and attenuated inflammasome activation via downregulation of NLRP3 expression and reducing IL-1β levels. Based on our results, we concluded that ZnO NPs can be considered as a promising agent for slowing the progression of DN via interplay between autophagy and Nrf2/TXNIP/NLRP3 inflammasome signaling.

Identification and Validation of a Ferroptosis-Related Long Non-Coding RNA (FRlncRNA) Signature to Predict Survival Outcomes and the Immune Microenvironment in Patients With Clear Cell Renal Cell Carcinoma

Background: The incidence of clear cell renal cell carcinoma (ccRCC) is increasing worldwide, contributing to 70–85% of kidney cancer cases. Ferroptosis is a novel type of programmed cell death and could predict prognoses in cancers. Here, we developed a ferroptosis-related long non-coding RNA (FRlncRNA) signature to improve the prognostic prediction of ccRCC.

Methods: The transcriptome profiles of FRlncRNAs and clinical data of ccRCC were obtained from The Cancer Genome Atlas and ICGC databases. Patients were randomly assigned to training cohorts, testing cohorts, and overall cohorts. The FRlncRNA signature was constructed by Lasso regression and Cox regression analysis, and Kaplan–Meier (K-M) analysis was used to access the prognosis of each group. The accuracy of this signature was evaluated by the receiver operating characteristic (ROC) curve. The visualization of functional enrichment was carried out by the gene set enrichment analysis (GSEA). Internal and external datasets were performed to verify the FRlncRNA signature.

Results: A FRlncRNA signature comprising eight lncRNAs (AL590094.1, LINC00460, LINC00944, AC024060.1, HOXB-AS4, LINC01615, EPB41L4A-DT, and LINC01550) was identified. Patients were divided into low- and high-risk groups according to the median risk score, in which the high-risk group owned a dramatical shorter survival time than that of the low-risk group. Through ROC analysis, it was found that this signature had a greater predictive capability than traditional evaluation methods. The risk score was an independent risk factor for overall survival suggested by multivariate Cox analysis (HR = 1.065, 95%CI = 1.036–1.095, and p < 0.001). We constructed a clinically predictive nomogram based on this signature and its clinical features, which is of accurate prediction about the survival rate of patients. The GSEA showed that primary pathways were the P53 signaling pathway and tumor necrosis factor–mediated signaling pathway. The major FRlncRNAs (LINC00460, LINC00944, LINC01550, and EPB41L4A-DT) were verified with the prognosis of ccRCC in the GEPIA and K-M Plotter databases. Their major target genes (BNIP3, RRM2, and GOT1) were closely related to the stage, grade, and survival outcomes of ccRCC by the validation of multiple databases. Additionally, we found two groups had a significant distinct pattern of immune function, immune checkpoint, and immune infiltration, which may lead to different survival benefits.

Conclusions: The FRlncRNA signature was accurate and act as reliable tools for predicting clinical outcomes and the immune microenvironment of patients with ccRCC, which may be molecular biomarkers and therapeutic targets.

LINC01410 leads the migration, invasion and EMT of bladder cancer cells by modulating miR-4319 / Snail1

Background

Several previous studies have implied the significance of lncRNA1410 (LINC01410) in gastric cancer, rectal cancer, and cervical cancer. Nevertheless, the potential of LINC01410 in bladder cancer (BC) development has not been addressed.

Methods

The related mechanisms were explored by qRT-PCR analysis, CCK-8 assay, cell transfection assay, Transwell assay, Western Blot analysis, Luciferase reporter assay and RNA pull-down assay.

Results

In the following study, LINC01410, characterized as an oncogene, exhibited high levels of expression in BC tissues as compared to normal tissues and its expression leads to a reduced prognosis of BC. Functional characterization of LINC01410 showed that knocking down LINC01410 could markedly reduce the invasion and proliferation capacity of T24 and 5637 cells. Mechanistically, LINC01410 served as a sponge for miR-4319 and the findings were further attested through luciferase reporter assay. Analysis of miR-4319 demonstrated its low expression in BC tissues as compared to normal tissues and knocking down LINC01410 significantly increased miR-4319. Data obtained from rescue assay discovered that silencing of miR-4319 in T24 and 5637 cells restored the proliferation and invasion capacity of LINC01410.

Conclusions

Taken together, this study is the first report on the oncogenic potential of LINC01410 in BC development by upregulating Snail1 protein and downregulating miR-4319.

Trial registration Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02119-z.

Effect of Aggressive Fluid Therapy on Outcomes after Endoscopic Retrograde Cholangiopancreatography: A Randomized Controlled Clinical Trial

BACKGROUND Pancreatitis is a serious complication of endoscopic retrograde cholangiopancreatography (ERCP), which may lead to death. The purpose of this study was to evaluate the preventive effect of aggressive fluid therapy on the incidence of post-ERCP pancreatitis. METHODS In double-blind controlled condition, 240 patients were selected and divided into two groups. The treatment of the intervention group (n = 120) included a dose of 20 mL/kg of ringer lactate infusion within 90 minutes before ERCP and 3 mL/kg/h during ERCP followed by 3 mL/kg/h up to 8 hours. The treatment of the control group (n = 120) included a dose of 1.5 mL/kg of ringer lactate infusion during ERCP up to 8 hours later. Firstly, the patients were evaluated in terms of excessive fluid and serum amylase and pain level, and then they were re-evaluated 2, 8, and 24 hours after ERCP. RESULTS The mean age of the patients was 51.57 ± 13.5 years. Most of the patients were female (54.5%). Pancreatitis was developed in 26 patients including 5.83% of the patients in the intervention group and 15.83% of the patients in the control group (p = 0.013). Pancreatic pain was seen in 7.5% of the patients in the intervention group and in 27.5% of the control group (p < 0.005). Hyperamylasemia was seen in 20.83% of the patients in the intervention group and in 35% of the control group (p = 0.014). The mean days of hospital admission was 1.308 ± 0.807 in the intervention group and 1.425 ± 0.876 in the control group (p = 0.275). CONCLUSION Aggressive fluid therapy with ringer lactate solution before ERCP can effectively prevent postERCP pancreatitis, pancreatic pain, and hyperamylasemia.

How does cigarette smoking cause acute pancreatitis?

INTRODUCTION

Acute Pancreatitis (AP) is an emerging health problem world-wide and it is a major cause of admissions for gastrointestinal disease in many countries. Amongst the more common causes (alcohol and gallstones), recent evidence has emerged indicating that smoking is an independent risk factor for AP. However, the mechanisms involved in smoking-induced AP have not been completely elucidated. This review puts together all the published evidence in literature to present the clinical and laboratory evidence relating smoking to the causation of AP.

DISCUSSION

The two main metabolites from cigarette smoke, namely nicotine and NNK are able to induce functional and histological changes within the pancreas consistent with AP. The major mechanisms involved include their action on acinar cells and zymogen secretion through pathways involving CCK and the nicotinic preganglionic receptors. Effects on the pancreatic microvasculature may be mediated through the nitric oxide pathway. There is indirect evidence to suggest that nicotine and acrolein may lead to CFTR dysfunction thereby influencing ductal secretion. However, direct evidence for this effect is needed. The effect of cigarette smoke metabolites on stellate cells and the islets warrants further investigation in the context of pathogenesis of AP.

CONCLUSION

Using a step-wise approach, the review revisits the effects of the various metabolites of cigarette smoke on the constituents of the pancreas (exocrine, endocrine, neurohormonal, stellate cells, ductal system) and highlights their proven, and potential, mechanisms in triggering off an attack of AP.

Redox signaling in acute pancreatitis

Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF-VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis.

From nitric oxide to hyperbaric oxygen: invisible and subtle but nonnegligible gaseous signaling molecules in acute pancreatitis

Nitric oxide (NO), carbon monoxide, and hydrogen sulfide in addition to hydrogen are well established as gaseous signal molecules throughout the body. Although the role of gasotransmitters in acute pancreatitis (AP) has been explored for many years, many details remain to be elucidated. The physiologic effect of NO in AP mainly relies on induced NO synthase, which stimulates the production of cytokines in the blood. Carbon monoxide inhibits nuclear factor-κB activation, which leads to amelioration of the inflammatory response. Hydrogen sulfide displays a dual role in the mechanism of AP according to its concentration in the system. Hydrogen is a newly discovered gaseous signaling molecule, and currently, there is little evidence that it has any function in alleviating inflammation. We discovered that hyperbaric oxygen is a novel gasotransmitter that has potential use in the treatment of AP. The correlation among hyperbaric oxygen, hypoxia inducible factor 1α, and other signaling pathways should be further studied. We also discuss some prospects and issues that remain to be resolved in this review. In summary, the discovery of gaseous signal molecules has established a new platform for deep investigation of the mechanism of AP, and our knowledge of the role of gasotransmitters in AP will increase with further research.

Pathophysiology of acute pancreatitis: potential application from experimental models and human medicine to dogs

The cellular events leading to pancreatitis have been studied extensively in experimental models. Understanding the cellular events and inciting causes of the multisystem inflammatory cascades that are activated with this disease is of vital importance to advance diagnosis and treatment of this condition. Unfortunately, the pathophysiology of pancreatitis in dogs is not well understood, and extrapolation from experimental and human medicine is necessary. The interplay of the inflammatory cascades (kinin, complement, cytokine) is extremely complex in both initiating leukocyte migration and perpetuating disease. Recently, nitric oxide (NO) and altered microcirculation of the pancreas have been proposed as major initiators of inflammation. In addition, the role of the gut is becoming increasingly explored as a cause of oxidative stress and potentiation of systemic inflammation in pancreatitis.

Cardiocirculatory pathophysiological mechanisms in severe acute pancreatitis

Acute pancreatitis (AP) is a common and potentially lethal acute inflammatory process. Although the majority of patients have a mild episode of AP, 10%-20% develop a severe acute pancreatitis (SAP) and suffer systemic inflammatory response syndrome (SIRS) and/or pancreatic necrosis. The main aim of this article is to review the set of events, first localized in the pancreas, that lead to pancreatic inflammation and to the spread to other organs contributing to multiorganic shock. The early pathogenic mechanisms in SAP are not completely understood but both premature activation of enzymes inside the pancreas, related to an impaired cytosolic Ca²⁺ homeostasis, as well as release of pancreatic enzymes into the bloodstream are considered important events in the onset of pancreatitis disease. Moreover, afferent fibers within the pancreas release neurotransmitters in response to tissue damage. The vasodilator effects of these neurotransmitters and the activation of pro-inflammatory substances play a crucial role in amplifying the inflammatory response, which leads to systemic manifestation of AP. Damage extension to other organs leads to SIRS, which is usually associated with cardiocirculatory physiology impairment and a hypotensive state. Hypotension is a risk factor for death and is associated with a significant hyporesponsiveness to vasoconstrictors. This indicates that stabilization of the patient, once this pathological situation has been established, would be a very difficult task. Therefore, it seems particularly necessary to understand the pathological mechanisms involved in the first phases of AP to avoid damage beyond the pancreas. Moreover, efforts must also be directed to identify those patients who are at risk of developing SAP.

Effect of baicalin and octreotide on the expression levels of P-selectin protein in multiple organs of rats with severe acute pancreatitis

AIM

To investigate the effect of baicalin and octreotide on the expression levels of P-selectin protein in multiple organs of rats with severe acute pancreatitis and explore the underlying mechanism.

METHODS

Rats were randomly divided into sham-operated, model control, baicalin-treated and octreotide-treated groups. At 3, 6 and 12 h after operation, the mortality rates of rats, the contents of plasma endotoxin as well as serum NO and ET-1, the pathological changes in multiple organs, and the expression levels of P-selectin protein in each group were observed.

RESULTS

At 12 h after operation, the mortality rates of rats in treated groups were significantly lower than that in the model control group (P < 0.05), and the pathological severity scores in multiple organs in treated groups were also significantly lower than those in the model control group (P < 0.05). The contents of plasma endotoxin, serum PLA(2) (at 6 and 12 h after operation), ET-1 and NO (at 3 and 12 h after operation) in treated groups were significantly lower than those in the model control group (P < 0.05, P < 0.01 or P < 0.001). In the baicalin-treated group, the expression levels of P-selectin protein in liver (at 3 h after operation), kidney (at 3 and 6 h after operation), pancreas, lung and spleen were significantly lower than those in the model control group (P < 0.01). In the octreotide-treated group, the expression levels of this protein in lung, intestinal mucosa (at 6 and 12 h after operation), lymph nodes (at 3 and 6 h after operation), spleen and thymus were significantly lower than those in the model control group (P < 0.05). Additionally, the products of the staining intensity and positive rate of P-selectin protein in pancreas, spleen (at 3 h after operation), intestinal mucosa (at 6 h after operation), thymus (at 6 h after operation) and lung (at 6 h after operation) in treated groups were significantly lower than those in the model control group (P < 0.05).

CONCLUSION

Both baicalin and octreotide can exert some protective effects on multiple organs and the former is superior to the latter in protecting pancreas. Furthermore, decreasing the expression levels of P-selectin protein in these organs is one of the possible mechanisms.

Alcohol use and cigarette smoking as risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis

BACKGROUND & AIMS

Alcohol use and cigarette smoking are associated with various pancreatic diseases, but it is not known whether they associate with post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). We performed a retrospective case-control study to determine if these activities increase the risk of PEP.

METHODS

We identified 7638 patients who had undergone ERCP in the University of Michigan Health System and applied exclusion criteria to identify 123 with PEP. We randomly selected 308 age- and sex-stratified controls (2.5-fold case sample); after applying exclusion criteria 248 remained. In a masked fashion, we collected data for alcohol use, cigarette smoking, and 5 internal control variables: suspected sphincter of Oddi dysfunction (SOD), pancreatic sphincterotomy, moderate/difficult cannulation, 2 or more pancreatic injections, and pancreatic stent placement.

RESULTS

The univariate model showed an increased frequency of PEP in current drinkers (P < .001), former drinkers (P < .001), and former smokers (P < .001), as well as patients who were suspected of having SOD (P < .001), had undergone pancreatic sphincterotomy (P < .001), had a moderate/difficult cannulation (P = .001), and/or had 2 or more pancreatic injections (P = .007). The frequency of PEP was reduced in current smokers (P < .001). The multivariate model showed that the only independent significant predictors of PEP were current drinking (odds ratio [OR], 4.70; 95% confidence interval [CI], 2.60-8.50; P < .0001), former cigarette smoking (OR, 3.29; 95% CI, 1.28-8.44; P < .013), suspected SOD (OR, 3.69; 95% CI, 1.94-7.02; P < .001), and pancreatic sphincterotomy (OR, 5.91; 95% CI, 2.04-17.14; P = .001).

CONCLUSIONS

Current alcohol use and potentially former cigarette smoking are new risk factors for PEP. It is important to consider these variables in designing PEP prevention trials.

Expression of nitric oxide synthase isoforms and nitric oxide production in acute pancreatitis and associated lung injury

BACKGROUND/AIMS

The role of nitric oxide (NO) has been increasingly implicated in the pathophysiology of acute pancreatitis (AP). Studies have shown increased NO production in AP although not all are agreeable on whether NO is beneficial or detrimental in AP. This study aims to profile NO production and NO synthase (NOS) expression in the pancreas and lungs in the progression of AP in mice to gain insights to the role played by different NOS isoforms.

METHODS

AP was induced in mice by hourly administration of cerulein. NO production was determined by measuring the total nitrite and nitrate (NOx) content while NOS expression was measured by Western blot.

RESULTS

Pancreatic NO production increased sharply and was sustained throughout AP. iNOS expression was greatly increased while eNOS was downregulated at the later stages. In the lungs, there was an unexpected early increase in the constitutive NOS expression; however iNOS was also significantly overexpressed at the later time point along with a significant increase in NO. Acinar cells were found to overproduce NO in response to cerulein hyperstimulation with iNOS again being the major contributor.

CONCLUSION

These data show that NO production and NOS expression are differentially regulated temporally and in magnitude in the pancreas and lungs in response to cerulein hyperstimulation which suggests differing roles for each NOS isoform. and IAP.

Cardiovascular homeostasis in hypotension associated with initial stages of severe acute pancreatitis

OBJECTIVES

To identify the mechanisms underlying hypotension during the early phase of severe acute pancreatitis (SAP) by analyzing whether an impaired response to vasoactive substances occurs in this pathological process.

METHODS

Experimental SAP was induced by infusing 5% sodium taurocholate through the main pancreatic duct in rats. Once mean arterial pressure (MAP) in animals with pancreatitis was reduced, different vasoactive substances and inhibitors were administered.

RESULTS

Administration of the nonspecific nitric oxide synthase inhibitor N omega-nitro-L-arginine methyl ester caused a similar increase in MAP in rats with pancreatitis and control rats, whereas inducible nitric oxide synthase inhibition did not cause changes in MAP. Moreover, the hypertensive response to endothelin and angiotensin II was lower in pancreatitis. Inhibition of angiotensin II synthesis by the angiotensin-converting enzyme inhibitor perindopril in animals with pancreatitis caused severe hypotension, causing death in 40% of them. Finally, pressor hyporesponsiveness to angiotensin II in animals with pancreatitis was avoided by previous administration of perindopril and N omega-nitro-L-arginine methyl ester.

CONCLUSIONS

The SAP-induced hypotension is associated with a deficient pressor responsiveness to angiotensin II and endothelin-1. The renin-angiotensin system plays an important role in the control of MAP in animals with pancreatitis.