The role of ACE2 in RAS axis on microglia activation in Parkinson's disease.

BACKGROUND: The classic renin-angiotensin system (RAS) induces organ damage, while the ACE2/Ang-(1-7)/MasR axis opposes it. However, the role of ACE2 in the brain is unclear. We studied ACE2's role in the brain. METHOD: We used male C57BL/6J (WT) mice, ACE2 knockout (KO) mice, and MPTP-induced mice. Behavioral tests confirmed successful modeling. We assessed the impact of ACE2 KO on the RAS axis and PD index, including ACE, ACE2, AT1, AT2, MasR, TH, α-syn, and Iba1. We investigated ACE2 and MasR's involvement in microglial activation via western blot and immunofluorescence. GSE10867 and GSE26532 datasets were used to analyze the effects of AT1 antagonists and in vitro PD models on microglia. RESULT: Behavioral tests revealed that MPTP mice displayed motor deficits, depression, anxiety, and increased inflammatory markers in the SN and CPU, with reduced antioxidant capacity. ACE2 KO worsened these symptoms and exacerbated inflammation and oxidative stress. LPS-induced ACE2/MasR activation in BV2 cells demonstrated anti-inflammatory and neuroprotective effects by modulating microglial polarization. Antagonists inhibited microglial activation via inflammation and ROS processes. CONCLUSION: The RAS axis regulates inflammation and oxidative stress to maintain CNS function, suggesting potential targets for neurologic disease treatment. Understanding microglial RAS activation can offer new therapeutic strategies.

Current understanding of the link between angiotensin-converting enzyme and pain perception.

The renin-angiotensin system (RAS) is known to affect diverse physiological processes that affect the functioning of many key organs. Angiotensin-converting enzyme (ACE) modulates a variety of bioactive peptides associated with pain. ACE inhibitors (ACEis) have found applications in the treatment of cardiovascular, kidney, neurological and metabolic disorders. However, ACEis also tend to display undesirable effects, resulting in increased pain sensitization and mechanical allodynia. In this review, we provide comprehensive discussion of preclinical and clinical studies involving the evaluation of various clinically approved ACEis. With the emerging knowledge of additional factors involved in RAS signaling and the indistinct pharmacological role of ACE substrates in pain, extensive studies are still required to elucidate the mechanistic role of ACE in pain perception.

Progressive Kidney Failure by Angiotensinogen Inactivation in the Germline.

BACKGROUND: Autosomal recessive renal tubular dysgenesis is a rare, usually fatal inherited disorder of the REN (renin)-angiotensin system. Herein, we report an adolescent individual experiencing an unknown chronic kidney disease and aim to provide novel insights into disease mechanisms. METHODS: Exome sequencing for a gene panel associated with renal disease was performed. The REN-angiotensin system was assessed by comprehensive biochemical analysis in blood. REN expression was determined in primary tubular cells by quantitative polymerase chain reaction and in situ hybridization on kidney biopsy samples. Allele frequencies of heterozygous and biallelic deleterious variants were determined by analysis of the Genomics England 100,000 Genomes Project. RESULTS: The patient was delivered prematurely after oligohydramnios was detected during pregnancy. Postnatally, he recovered from third-degree acute kidney injury but developed chronic kidney disease stage G3b over time. Exome sequencing revealed a previously reported pathogenic homozygous missense variant, p.(Arg375Gln), in the AGT (angiotensinogen) gene. Blood AGT concentrations were low, but plasma REN concentration and gene expression in kidney biopsy, vascular, and tubular cells revealed strong upregulation of REN. Angiotensin II and aldosterone in blood were not abnormally elevated. CONCLUSIONS: Renal tubular dysgenesis may present as chronic kidney disease with a variable phenotype, necessitating broad genetic analysis for diagnosis. Functional analysis of the renin-angiotensin system in a patient with AGT mutation revealed novel insights regarding compensatory upregulation of REN in vascular and tubular cells of the kidney and in plasma in response to depletion of AGT substrate as a source of Ang II (similarly observed with hepatic AGT silencing for the treatment of hypertension).

Kidney outcomes with SGLT2is for type 2 diabetes patients: does background treatment with metformin or RASis matter?

Introduction: There is a lack of real-world evidence regarding the impact of concomitant metformin and renin-angiotensin system inhibitors (RASis) on sodium-glucose cotransporter-2 inhibitor (SGLT2i)-associated kidney outcomes. This study was aimed to investigate whether SGLT2i-associated kidney outcomes were modified by the concomitant use of metformin or RASis in patients with type 2 diabetes. Methods: SGLT2i users were identified from three electronic health record databases during May 2016 and December 2017 and categorized into those with and without concomitant use of metformin or RASis. Propensity score matching was performed to minimize baseline differences between groups. Study outcomes were mean estimated glomerular filtration rate (eGFR) change and time to 30%, 40%, and 50% eGFR reductions. A meta-analysis was performed to combine the estimates across databases. Results: After matching, there were 6,625 and 3,260 SGLT2i users with and without metformin, and 6,654 and 2,746 SGLT2i users with and without RASis, respectively. The eGFR dip was similar in SGLT2i users with and without metformin therapy, but was greater in SGLT2i users with RASis compared to those without RASis. Neither metformin nor RASi use had a significant effect on SGLT2i-associated eGFR reductions, as evidenced by the hazard ratios (95% CIs) of 30% eGFR reductions for SGLT2is with versus without metformin/RASis, namely 1.02 (0.87-1.20)/1.09 (0.92-1.31). Such findings were also observed in the outcomes of 40% and 50% eGFR reductions. Conclusion: Using metformin or RASis did not modify SGLT2i-associated kidney outcomes in type 2 diabetes.

Altered distribution and loss of ACE2 into the urine in acute kidney injury.

There are diverse pathophysiological mechanisms involved in acute kidney injury (AKI). Among them, overactivity of the renin angiotensin system (RAS) has been described. Angiotensin converting enzyme 2 (ACE2) is a tissue RAS enzyme expressed in the apical border of proximal tubules. Given the important role of ACE2 in the metabolism of Angiotensin II this study was aimed to characterize kidney and urinary ACE2 in amouse model of AKI. Ischemia reperfusion injury (IRI) was induced in C57BL/6 mice by clamping of the left renal artery followed by removal of the right kidney. In kidneys harvested 48 hours after IRI, immunostaining revealed a striking maldistribution of ACE2 including spillage into the tubular lumen and presence of ACE2 positive luminal casts in the medulla. In cortical membranes ACE2 protein and enzymatic activity were both markedly reduced (37±4 vs. 100±6 ACE2/ß-Actin, P=0.0004 and 96±14 vs. 152±6 RFU/µg protein/h P=0.006). In urine, the full-length membrane bound ACE2 protein (100kD) was markedly increased (1120±405 vs. 100±46 ACE2/µg Crea, P=0.04) and casts stained for ACE2 were recovered in the urine sediment. In AKI caused by IRI there is a marked loss of ACE2 from the apical tubular border with deposition of ACE2 positive material in the medulla and increased urinary excretion of the full length-membrane bound ACE2 protein. The deficiency of tubular ACE2 in AKI suggests that provision of this enzyme could have therapeutic applications and that its excretion in the urine may also serve as a diagnostic marker of severe proximal tubular injury.

[Renoprotective treatments : renin-angiotensin-aldosterone system blockade and beyond]. / Néphroprotection médicamenteuse : au-delà du blocage du système rénine-angiotensine.

RENOPROTECTIVE TREATMENTS: RENIN-ANGIOTENSINALDOSTERONE SYSTEM BLOCKADE AND BEYOND. Patients with chronic kidney disease (CKD) require both etiological and symptomatic treatments to slow renal function decline. Reductions of protein and salt intakes are required. Pharmacological treatments combines blockade of the renin-angiotensin system, sodium-glucose co-transporter type 2 inhibitors and mineralocorticoid receptor antagonists in most diabetic patients. The albumin creatinine ration (ACR) in morning spot urine samples is now a therapeutic target both in diabetic and non-diabetic CKD patients.

NÉPHROPROTECTION MÉDICAMENTEUSE : AU-DELÀ DU BLOCAGE DU SYSTÈME RÉNINE-ANGIOTENSINE. Au-delà du traitement étiologique éventuel d'une maladie rénale chronique (MRC), et du contrôle de l'ensemble des facteurs de risque vasculaire, un traitement symptomatique est nécessaire pour ralentir le déclin de la fonction rénale. La prise en charge diététique permet de limiter les apports en protéines et en sel. Le traitement pharmacologique comporte nécessairement une association d'un bloqueur du système rénine-angiotensine-aldostérone, le plus souvent un inhibiteur du co-transport sodiumglucose de type 2 (SGLT2i) et chez certains diabétiques un antagoniste des récepteurs des minéralocorticoïdes (ARM). Le rapport albuminurie/créatininurie (RAC) sur un échantillon d'urine devient une cible thérapeutique aussi bien chez les non-diabétiques que chez les diabétiques.

Aerobic training increases renal antioxidant defence and reduces angiotensin II levels, mitigating the high mortality in SHR-STZ model.

OBJECTVE: The purpose of the research was to investigate the effects of aerobic training on renal function, oxidative stress, intrarenal renin-angiotensin system, and mortality of hypertensive and diabetic (SHR-STZ) rats. MATERIALS AND METHODS: Blood pressure, creatinine, urea levels, urinary glucose, urine volume, and protein excretion were reduced in trained SHR-STZ rats. RESULTS: Aerobic training not only attenuated oxidative stress but also elevated the activity of antioxidant enzymes in the kid'ney of SHR-STZ rats. Training increased intrarenal levels of angiotensin-converting enzymes (ACE and ACE2) as well as the neprilysin (NEP) activity, along with decreased intrarenal angiotensin II (Ang II) levels. Aerobic training significantly improved the survival of STZ-SHR rats. CONCLUSION: The protective role of aerobic training was associated with improvements in the renal antioxidative capacity, reduced urinary protein excretion along with reduced intrarenal Ang II and increased NEP activity. These findings might reflect a better survival under the combined pathological conditions, hypertension, and diabetes.

Efficacy and safety of dual renin-angiotensin system (RAS) blockade for non-elderly diabetic kidney disease patients with preserved eGFR.

AIM: Although sodium glucose cotransporter2 inhibitor (SGLT-2I) is widely used in clinical practice, sufficient renin-angiotensin system (RAS) inhibition remains the cornerstone of diabetic kidney disease (DKD) treatment. The aim of this single-center study was to evaluate the efficacy and safety of dual RAS blockade compared with angiotensin-converting enzyme inhibitor (ACEI)/angiotensin II receptor blocker (ARB) monotherapy in non-elderly DKD patients with preserved eGFR (WHO Standard, < 60y). METHODS: This single-center study was registered in Chinese Clinical Trial Registry (ChiCTR1900024752), and approved by the ethical committee (KY201994). In this study, we recruited non-elderly type 2 diabetes volunteers with initial diagnosis of DKD to receive dual RAS blockade or monotherapy. 150 non-elderly DKD patients with preserved eGFR were recruited. The patients were randomly divided into dual RAS blockade group and monotherapy group. The dual RAS blockade group treatment regimen was an 80 mg valsartan plus a 4 mg perindopril tert-butylamine per day. At the same time, monotherapy group patients who received the 8 mg perindopril tert-butylamine or 160 mg valsartan monotherapy. The clinical data of the three groups were compared at baseline and collected during the follow-up period of 12 months. RESULTS: The baseline of patients who received dual RAS blockade was similar to that of monotherapy group. After 12 months of treatment, the median level of proteinuria in the dual RAS blockade group was significantly lower than that in the monotherapy group. There was no significant difference in the estimated glomerular filtration rate (eGFR) level, potassium, blood pressure and no serious adverse reactions. CONCLUSIONS: In non-elderly DKD patients with preserved eGFR, dual RAS blockade is superior to control proteinuria, and does not increase the probability of adverse reactions such as hyperkalemia, hypotension and acute kidney injury in 12 months.

Effects of Evodiamine on Behavior and Hippocampal Neurons through Inhibition of Angiotensin-Converting Enzyme and Modulation of the Renin Angiotensin Pathway in a Mouse Model of Post-Traumatic Stress Disorder.

Post-traumatic stress disorder (PTSD) is a persistent psychiatric condition that arises following exposure to traumatic events such as warfare, natural disasters, or other catastrophic incidents, typically characterized by heightened anxiety, depressive symptoms, and cognitive dysfunction. In this study, animals subjected to single prolonged stress (SPS) were administered evodiamine (EVO) and compared to a positive control group receiving sertraline. The animals were then assessed for alterations in anxiety, depression, and cognitive function. Histological analysis was conducted to examine neuronal changes in the hippocampus. In order to predict the core targets and related mechanisms of evodiamine intervention in PTSD, network pharmacology was used. The metabolic markers pre- and post-drug administration were identified using nontargeted serum metabolomics techniques, and the intersecting Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were screened. Finally, the core targets were validated through molecular docking, enzyme-linked immunosorbent assays, and immunofluorescence staining to confirm the anti-PTSD effects and mechanisms of these targets. As well as improving cognitive impairment, evodiamine reversed anxiety- and depression-like behaviors. It also inhibited the reduction in the number of hippocampal neuronal cells and Nissl bodies in SPS mice inhibited angiotensin converting enzyme (ACE) levels in the hippocampus of SPS mice, and modulated the renin angiotensin pathway and its associated serum metabolites in brain tissue. Evodiamine shows promise as a potential candidate for alleviating the symptoms of post-traumatic stress disorder.

Multimodal Blockade of the Renin-Angiotensin System in the Treatment of Cancer in Dogs Has Mild Adverse Effects in Some Dogs.

The renin-angiotensin system (RAS) is increasingly being recognized to play a role in the tumor microenvironment, promoting tumor growth. Studies blocking a single part of the RAS have shown mixed results, possibly due to the existence of different bypass pathways and redundancy within the RAS. As such, multimodal blockade of the RAS has been developed to exert more complete inhibition of the RAS. The aim of the present study was to assess the safety of multimodal RAS blockade in dogs. Five dogs (four with appendicular osteosarcoma, one with oral malignant melanoma) were treated with atenolol, benazepril, curcumin, meloxicam, and metformin. The dogs underwent clinical examination, blood pressure measurement, and hematology and serum biochemistry tests performed at 0, 1, 3, 6, 9, and 12 weeks, then every 3 months thereafter. End-of-life decisions were made by the owners. None of the dogs developed hypotension. One dog had intermittent vomiting during the 64 weeks it was on the trial. One dog had a one-off increase in serum SDMA(symmetrical dimethylarginine) concentration. Dogs were euthanized at weeks 3 (osteosarcoma), 10 (osteosarcoma), 17 (osteosarcoma), and 26 (oral malignant melanoma), and one dog was still alive at the end of the trial at 64 weeks (osteosarcoma). This is the first assessment of multimodal blockade of the RAS in dogs, and the results suggest it causes only mild adverse effects in some animals. The efficacy of the treatment was not assessed due to the small number of dogs. This pilot study allows for future larger studies assessing multimodal RAS blockade for the treatment of canine cancer.

Acupoint catgut embedding attenuates oxidative stress and cognitive impairment in chronic cerebral ischemia by inhibiting the Ang II/AT1R/NOX axis.

Chronic cerebral ischemia (CCI) is a common neurological disorder, characterized by progressive cognitive impairment. Acupoint catgut embedding (ACE) represents a modern acupuncture form that has shown neuroprotective effects; nevertheless, its effects on CCI and the mechanisms remain largely unknown. Here, we aimed to explore the therapeutic action of ACE in CCI-induced cognitive impairment and its mechanisms. The cognitive function of CCI rats was determined using Morris water maze test, and histopathological changes in the brain were assessed through hematoxylin-eosin (HE) staining. To further explore the molecular mechanisms, the expression levels of oxidative stress markers and the Ang II/AT1R/NOX axis-associated molecules in the hippocampus were evaluated using enzyme-linked immunosorbent assay (ELISA), western blotting, and immunohistochemistry. Here, we observed that ACE treatment alleviated cognitive dysfunction and histopathological injury in CCI rats. Intriguingly, candesartan (an AT1R blocker) enhanced the beneficial effects of ACE on ameliorating cognitive impairment in CCI rats. Mechanistically, ACE treatment blocked the Ang II/AT1R/NOX pathway and subsequently suppressed oxidative stress, thus mitigating cognitive impairment in CCI. Our findings first reveal that ACE treatment could suppress cognitive impairment in CCI, which might be partly due to the suppression of Ang II/AT1R/NOX axis.

Effect of exercise duration on toluene-induced locomotor sensitization in mice: a focus on the Renin Angiotensin System.

RATIONALE: Exercise attenuates addictive behavior; however, little is known about the contribution of exercise duration to this positive effect. The Renin Angiotensin System (RAS) has been implicated both in addictive responses and in the beneficial effects of exercise; though, its role in the advantageous effects of exercise on toluene-induced addictive responses has not been explored. OBJECTIVES: To evaluate the impact of different exercise regimens in mitigating the expression of toluene-induced locomotor sensitization and to analyze changes in RAS elements' expression at the mesocorticolimbic system after repeated toluene exposure and following voluntary wheel running in toluene-sensitized animals. METHODS: Toluene-induced addictive-like response was evaluated with a locomotor sensitization model in mice. Toluene-sensitized animals had access to running wheels 1, 2, 4 or 24 h/day for 4 weeks; thereafter, locomotor sensitization expression was evaluated after a toluene challenge. RAS elements (ACE and ACE2 enzymes; AT1, AT2 and Mas receptors) expression was determined by Western blot in the VTA, NAc and PFCx of toluene-sensitized mice with and without exercise. RESULTS: Individual differences in toluene-induced locomotor sensitization development were observed. Access to wheel running 1 and 2 h/day reduced but 4 and 24 h/day completely blocked locomotor sensitization expression. Repeated toluene exposure changed RAS elements' expression in the VTA, NAc and PFCx, while exercise mainly modified ACE and AT1 in air-exposed and toluene-sensitized mice. CONCLUSIONS: Inhalant-exposed animals show different sensitization phenotypes. Exercise duration determined its efficacy to attenuate the addictive-like response. Toluene exposure and exercise each modified RAS, the latter also modifying toluene-induced changes.

Modulation of ACE2/Ang1-7/Mas and ACE/AngII/AT1 axes affects anticancer properties of sertraline in MCF-7 breast cancer cells.

The renin-angiotensin system (RAS) is best known for playing a major role in maintaining the physiology of the cardiovascular system. Dysregulation of the RAS pathway has been proposed as a link to some malignancies and contributes to cancer metastasis. Breast cancer is considered as one of the leading causes of cancer death in women and its prevention remains yet a challenge. Elements of RAS are expressed in both normal breast tissue and cancerous cells, signifying the essential role of RAS in breast cancer pathology. Sertraline, a widely used antidepressant, has shown anti-proliferative properties on a variety of malignancies. This study aimed to investigate the effect of sertraline and its combination with agonists and antagonists of RAS (A779, Ang 1-7 and losartan) on viability of MCF-7 cells along with their effect on apoptosis and distribution of cell cycle. Our results indicated that sertraline, losartan and Ang 1-7 significantly decreased cell viability, induced apoptosis and cell cycle arrest. A779 blunted the effect of sertraline on cell viability, ROS generation and cell cycle arrest. Combination treatment of sertraline with losartan as well as Ang 1-7 caused a remarkable decline in cell viability. In conclusion, results of the present study support the anti-cancer properties of sertraline, losartan and Ang 1-7 via induction of apoptosis and cell cycle arrest.

New therapeutic targets in hypertension. / Nuevas dianas terapéuticas en hipertensión.

Even though a large number of antihypertensive drugs are suitable for hypertension treatment, some new therapeutic targets are recently under development. Most are focused in the treatment of resistant hypertension, added to the drugs currently available for treating such condition. Others have specific particularities in their duration of action, which allows their use once per month or every six months and could become alternatives to the current antihypertensive treatment. Most interesting therapeutic targets are the renin-angiotensin-aldosterone system, through interference with the RNA of the angiotensinogen, the inhibition of brain aminopeptidase III, the inhibition of aldosterone synthase, and new non-steroidal aldosterone receptor antagonists. In addition, dual endothelin receptor antagonists or agonists of the NPR1 receptor, the main effector of natriuretic peptides are other new interesting therapeutic possibilities. In this paper, we review clinical data on the development of the most interesting molecules acting through these new therapeutic targets.

Dietary supplementation with black cricket (Gryllus assimilis) reverses protein-energy malnutrition and modulates renin-angiotensin system expression in adipose tissue.

Edible insects are recognized as promising food sources due to their nutritional composition. Some species, such as Gryllus assimilis, contain proteins, lipids, and carbohydrates of high biological value, which regulate several metabolic functions, including the Renin-Angiotensin System (RAS). In this context, the present study aimed to assess the effects of dietary supplementation with whole Gryllus assimilis powder on the metabolism of malnourished mice. Thirty-two male Swiss mice were used and divided into four treatment groups. The groups were identified as (AIN93-M); AIN93-M + Gryllus assimilis diet (AIN93-M + GA); AIN93-M + Renutrition diet (AIN93-M + REN) and AIN93-M + Renutrition diet + Gryllus assimilis (AIN93-M + REN + GA). The results showed that whole Gryllus assimilis powder inclusion promotes recovery from protein-energy malnutrition, reduces adiposity, and improves glucose tolerance and insulin sensitivity. It also reduces total cholesterol, triglycerides, VLDL, and adipocyte area. We also observed a significant increase in the expression of RAS-related genes, such as ACE2 and MasR, followed by a reduction in Angiotensinogen and ACE. The main findings of the present study suggest the use of black cricket as a viable strategy for the prevention and treatment of protein-energy malnutrition, as well as the reduction of adiposity, and improvement of lipid and glycemic parameters, with antihypertensive potential.

The potential role of renin angiotensin system in acute leukemia: a narrative review.

Acute leukemias (ALs) are the most common cancers in pediatric population. There are two types of ALs: acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Some studies suggest that the Renin Angiotensin System (RAS) has a role in ALs. RAS signaling modulates, directly and indirectly, cellular activity in different cancers, affecting tumor cells and angiogenesis. Our review aimed to summarize the role of RAS in ALs and to explore future perspectives for the treatment of these hematological malignancies by modulating RAS molecules. The database including Pubmed, Scopus, Cochrane Library, and Scielo were searched to find articles about RAS molecules in ALL and in pediatric patients. The search terms were "RAS", "Acute Leukemia", "ALL", "Angiotensin-(1-7)", "Pediatric", "Cancer", "Angiotensin II", "AML". In the bone marrow, RAS has been found to play a key role in blood cell formation, affecting several processes including apoptosis, cell proliferation, mobilization, intracellular signaling, angiogenesis, fibrosis, and inflammation. Local tissue RAS modulates tumor growth and metastasis through autocrine and paracrine actions. RAS mainly acts via two molecules, Angiotensin II (Ang II) and Angiotensin (1-7) [Ang-(1-7)]. While Ang II promotes tumor cell growth and stimulates angiogenesis, Ang-(1-7) inhibits the proliferation of neoplastic cells and the angiogenesis, suggesting a potential therapeutic role of this molecule in ALL. The interaction between ALs and RAS reveals a complex network of molecules that can affect the hematopoiesis and the development of hematological cancers. Understanding these interactions could pave the way for innovative therapeutic approaches targeting RAS components.

The therapeutic potential of angiotensin-converting enzyme inhibitor enalapril to ameliorate muscle atrophy in a murine model.

Muscle atrophy due to limb immobilization and inactivity is a common consequence of many diseases and treatment processes. One of the systems activated in inflammatory conditions is the renin-angiotensin system (RAS). The present study was conducted with the aim of investigating the effects of one of the angiotensin-converting enzyme (ACE) inhibitors, enalapril, on improving muscle atrophy caused by immobility. The study was conducted in three groups: a control, an atrophy, and an atrophy group treated with enalapril on Balb/c mice. After tying a splint to cause atrophy in one of the legs, daily treatment with enalapril intraperitoneally (dissolved in DMSO) at a dose of 10 mg/kg/day was done for 7 days. On the eighth day, the splint was opened and half of the mice were evaluated. Then, in the recovery phase, treatment with enalapril was continued in the remaining mice for 10 days without a splint. At the end of each phase, the mice were examined for the muscle strength of the lower limb muscles, and histological and biochemical analyses were subsequently carried out. The tissue level of the oxidative stress index MDA was evaluated, which showed a significantly lower level in the enalapril group compared to the atrophy group (*P<0.1). Also, inflammatory factors in the enalapril group showed a decrease compared to the atrophy group. The strength of four limbs in the mice of the treatment group (-18.36 ± 1.70 %) was significantly higher than that of the atrophy group (-30.33 ± 3 %) at the end of the atrophy phase and also after 10 days of recovery. The results suggest that the use of enalapril that reduces the activation of angiotensin II-dependent pro-oxidant and pro-inflammatory pathways may improve the functional disorder and muscle necrosis in the murine model of muscle atrophy.

Inhibition of circulating dipeptidyl-peptidase 3 by procizumab in experimental septic shock reduces catecholamine exposure and myocardial injury.

BACKGROUND: Dipeptidyl peptidase 3 (DPP3) is a ubiquitous cytosolic enzyme released into the bloodstream after tissue injury, that can degrade angiotensin II. High concentrations of circulating DPP3 (cDPP3) have been associated with worse outcomes during sepsis. The aim of this study was to assess the effect of Procizumab (PCZ), a monoclonal antibody that neutralizes cDPP3, in an experimental model of septic shock. METHODS: In this randomized, open-label, controlled study, 16 anesthetized and mechanically ventilated pigs with peritonitis were randomized to receive PCZ or standard treatment when the mean arterial pressure (MAP) dropped below 50 mmHg. Resuscitation with fluids, antimicrobial therapy, peritoneal lavage, and norepinephrine was initiated one hour later to maintain MAP between 65-75 mmHg for 12 h. Hemodynamic variables, tissue oxygenation indices, and measures of organ failure and myocardial injury were collected. Organ blood flow was assessed using isotopic assessment (99mtechnetium albumin). cDPP3 activity, equilibrium analysis of the renin-angiotensin system and circulating catecholamines were measured. Tissue mRNA expression of interleukin-6 and downregulation of adrenergic and angiotensin receptors were assessed on vascular and myocardial samples. RESULTS: PCZ-treated animals had reduced cDPP3 levels and required less norepinephrine and fluid than septic control animals for similar organ perfusion and regional blood flow. PCZ-treated animals had less myocardial injury, and higher PaO2/FiO2 ratios. PCZ was associated with lower circulating catecholamine levels; higher circulating angiotensin II and higher angiotensin II receptor type 1 myocardial protein expression, and with lower myocardial and radial artery mRNA interleukin-6 expression. CONCLUSIONS: In an experimental model of septic shock, PCZ administration was associated with reduced fluid and catecholamine requirements, less myocardial injury and cardiovascular inflammation, along with preserved angiotensin II signaling.