Angiotensin-converting Enzyme Levels Research Articles

The Circulating Renin-Angiotensin System and Mortality among Patients Hospitalized for COVID-19: A Mechanistic Substudy of the ACTIV-4 Host Tissue Trials.

SARS-CoV-2 targets angiotensin converting enzyme-2 (ACE2), a key peptidase of the renin-angiotensin system (RAS), which regulates the balance of the vasoconstrictor/inflammatory peptide Ang II and the vasodilator/anti-inflammatory peptide Ang-(1-7). Few studies have quantified the circulating elements of the RAS longitudinally in SARS-CoV-2 infection and their association with COVID-19 outcomes. Thus, we evaluated the association of circulating RAS enzymes and peptides with mortality among patients with COVID-19. Blood samples were collected from 111 patients with COVID-19 and new-onset hypoxemia during the delta and omicron waves at 19 hospitals in the United States. Circulating RAS components were quantified via radioimmunoassay or ELISA at 0 (baseline), 1, 3, and 5 days after randomization. We used multivariable Cox regression to estimate the association of baseline and longitudinal RAS concentrations with 90-day mortality. Participants were aged 18-90 (mean [SD]: 55 [14]) years and 62% were male. There were 22 (20%) deaths over 90 days of follow-up. ACE2 levels above the sample median (≥4.9 pM; adjusted HR [95% CI]: 0.10 [0.02, 0.43]) and ACE2/ACE ratio (≥6.0×10-3; adjusted HR: 0.08 [0.02, 0.39]) were associated with significantly lower mortality. Similarly, when analyzed as continuous, log2-normalized, time-varying predictors from Day 0 to Day 5, two-fold increments of ACE2 and ACE2/ACE ratio over this period were associated with lower mortality (adjusted HR: 0.79 [0.65, 0.97] and 0.78 [0.63, 0.97], respectively). Circulating Ang II, Ang-(1-7), and ACE levels were not associated with mortality. These results suggest higher circulating ACE2 protein in hospitalized patients with COVID-19 is associated with reduced mortality.

P-15 DIAGNOSTIC PITFALL - A RARE CASE OF HYPERCALCEMIA

Abstract Introduction Infantile hypercalcaemia type 1 (IIH) is an autosomal recessive disorder characterized by homozygous mutations in the CYP24A1 gene that encodes the 24-hydroxylase enzyme used to inactivate 1,25-(OH)2-vitamin D. Clinical Case A 24-year-old male was referred to our department for the evaluation of hypertension and nephrolithiasis, in the context of hypercalcemia. The general physical examination and the endocrinological assessment revealed no abnormalities. The patient was initially evaluated in nephrology & urology departments, where computed tomography (CT) revealed renal nephrocalcinosis and a lower right renal cyst, with no findings at thoracic level. Laboratory results confirmed hypercalcemia (total calcium 12.6 mg/dL, Ca++ at 5.49 mg/dL), alongside low parathyroid hormone (PTH) at 3 pg/mL. Malignancy was ruled out by normal PTH-related peptide levels (<0.5 pmol/L) and normal 25-hydroxyvitamin D levels (46 ng/mL), though 1,25-dihydroxyvitamin D was slightly elevated (81.8 pg/mL; Ref: 19.9−79.3 pg/mL). Bone metabolism markers, including FGF-23, serum crosslaps, and osteocalcin, were normal, excluding metabolic bone disease. Urine/24h: low urinary calcium (0.27 g/24h) and normal urinary phosphate (0.87 g/24h). In the diagnostic algorithm, hypercalcemia can be PTH-mediated, non-PTH-mediated, medication-induced, and miscellaneous causes. The patient's low PTH and suppressed PTH-rp excluded primary hyperparathyroidism and malignancy-related hypercalcemia. Normal 25(OH) vitamin D and slightly elevated 1,25(OH) vitamin D levels raised the suspicion of extrarenal 1-alpha-hydroxylation of vitamin D, a mechanism seen in granulomatous diseases such as sarcoidosis or tuberculosis, or in lymphomas. However, granulomatous diseases were excluded based on negative chest X-ray and thoracic CT findings and normal angiotensin-converting enzyme (ACE) levels. Other possible malignancies were excluded: germ cell tumors, such as non-seminomatous germ cell tumors, testicular cancers, particularly seminomas or choriocarcinomas, Hodgkin's lymphoma and multiple myeloma. Additionally, through medical history, clinical examination, and laboratory tests, we have also excluded hyperthyroidism, acromegaly, pheochromocytoma, adrenal insufficiency, bed rest/immobilization, parenteral nutrition, and supplements. Consequently, a genetic cause of abnormal renal calcium metabolism was suspected. Genetic testing revealed a heterozygous pathogenic mutation in the CYP24A1 gene, which is linked to Infantile Hypercalcemia Type 1. The patient's diagnosis of IIH was confirmed by the detection of the CYP24A1 mutation. Management of his condition focuses on controlling calcium levels through dietary intake and diuresis to prevent kidney stones, as there is no specific treatment available. Conclusion This case report highlights the importance of determining the etiology of hypercalcemia and the significance of genetic testing in clinical management.

Increased angiotensin converting enzyme (ACE2) level is associated with the cardiovascular risk in diabetes

Objectives: Increased plasma angiotensin-converting enzyme 2 (ACE2) levels are associated with cardiovascular risk in diabetes and therapeutic targets. ACE2 is an endogenous regulator of the renin-angiotensin system and is important in various cardiovascular diseases (CVDs). This study aimed to investigate the association between increased ACE2 levels and cardiovascular risk in patients with type 2 diabetes mellitus (T2DM), particularly those with CVD. Materials and Methods: In this cross-sectional study, subjects were classified into 3 groups. Each Group has 87 individuals. Group I was considered as controls, Group II was considered as diabetes, and Group III was considered as diabetes with heart disease who attended the master health checkup, cardiology and general medicine OP in the tertiary care centre. The serum ACE, ACE2, oxidized-low-density lipoprotein (ox-LDL), and highly sensitive c-reactive were examined using the enzyme-linked immunosorbent assay technique, and the lipid levels were measured using the AU 480 (Auto analyser). Results: The study found that mean plasma ACE, ACE2, ACE/ACE2 ratio, ox-LDL, and high-sensitivity-C-reactive protein (hs-CRP) levels were significantly higher in group III than compared to group II and group I (P < 0.001). A significant correlation was observed between ACE2, ACE, ACE/ACE2 ratio, hs-CRP, and ox-LDL in patients with group III. Linear regression analysis showed a strong association of ACE2 with hs-CRP, ox-LDL and ACE. Conclusion: The study concludes that increased ACE2 levels may be associated with the risk of CVD in T2DM, especially in those with coronary heart disease. These findings suggest the possibility of independent risk assessment in diabetic patients.

Unveiling Pediatric Neurosarcoidosis Mimicking Central Nervous System Tuberculosis: Diagnostic Challenges.

Neurosarcoidosis is a rare chronic inflammatory disease affecting the nervous system. Owing to its varying manifestations that can mimic other central nervous system infectious or autoimmune diseases, and scarcity of literature, it proves to be a challenging diagnosis. We report two cases of possible neurosarcoidosis in the pediatric age group. Our first patient presented to us with seizures at the age of 13 years, whereas our second patient presented with headaches and vomiting at the age of 10 years. Both patients had elevated cerebrospinal fluid protein levels and leptomeningeal enhancement on magnetic resonance imaging (MRI); however, one patient also had a pituitary lesion. Tests for tuberculosis were negative for both. One of the 2 patients exhibited normal angiotensin-converting enzyme levels at the start of symptoms but later showed raised angiotensin-converting enzyme levels. His diagnosis was delayed as he was treated initially for central nervous system infections. His disease course showed frequent relapses with varying clinical symptoms. After trying steroids and different immunosuppressive agents, he was given a rituximab infusion, and he went into remission. Our cases contribute to the literature for addressing diagnostic and management challenges in children with neurosarcoidosis.

Unveiling a Diagnostic Enigma: A Rare Case Report of Abdominal Sarcoidosis

Sarcoidosis is an idiopathic inflammatory granulomatous disorder that primarily affects the lungs. Abdominal manifestations without pulmonary involvement are infrequent. We present an atypical case of sarcoidosis in an elderly lady who presented with symptomatic hypercalcemia with computed tomography (CT) revealing multiple hepatosplenic hypodense granulomatous lesions with raised angiotensin-converting enzyme (ACE) levels. She had a good response to immunosuppressants. There is a rare possibility of isolated organ involvement without any pulmonary manifestation. Hence, ruling out other differentials and starting appropriate immunosuppressive treatment is necessary.

Genetic determinants of COVID-19 severity and mortality: ACE1 Alu 287 bp polymorphism and ACE1, ACE2, TMPRSS2 expression in hospitalized patients.

The angiotensin-converting enzyme 2 (ACE2) and the transmembrane serine protease 2 (TMPRSS2) are central human molecules in the SARS-CoV-2 virus-host interaction. Evidence indicates that ACE1 may influence ACE2 expression. This study aims to determine whether ACE1, ACE2, and TMPRSS2 mRNA expression levels, along with the ACE1 Alu 287 bp polymorphism (rs4646994), contribute to the severity and mortality of COVID-19. Swabs were collected in two Brazilian cities in 2020: Belo Horizonte (n=134) and Rio de Janeiro (n=41). A swab of mild patients in Rio de Janeiro who were not hospitalized (n=172) was also collected. All analyzed biological material was obtained from residual diagnostic samples in 2020, prior to the emergence of SARS-CoV-2 variants of concern. ACE1, ACE2, TMPRSS2, and B2M (reference gene) expression levels were evaluated in 40 cycles of quantitative PCR. ACE1 Alu 287 bp polymorphism was genotyped using the FastStart Universal SYBR Green Master kit. The median age differed between clinical sites (p=0.016), but no difference in median days of hospitalization was observed (p=0.329). Age was associated with severity (p=0.014) and mortality (p=0.014) in the Belo Horizonte cohort. No alteration in ACE1, ACE2 and TMPRSS2 expression was associated with severity or mortality. ACE1 polymorphism rs4646994 did not influence the likelihood of either outcome. A meta-analysis including available data from the literature showed significant effects: the D-allele conferred risk (OR = 1.39; 95% CI [1.12-1.72]).

Blockade of PVN neuromedin B receptor alleviates inflammation via the RAS/ROS/NF-κB pathway in spontaneously hypertensive rats.

Neuromedin B (NMB) has potentially great impacts on the development of cardiovascular diseases by promoting hypertensive and sympatho-excitation effects. However, studies regarding the NMB function in paraventricular nucleus (PVN) are lacking. With selective neuromedin B receptor (NMBR) antagonist, BIM-23127, we aim to determine whether the blockade of NMB function in PVN could alleviate central inflammation and attenuate hypertensive responses. Spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were chronically infused with BIM-23127 in the PVN for 6 weeks. Mean arterial pressure (MAP) was assessed with tail cuff and electrophysiological acquisition systems. PVN tissues were collected to analyze expressions of Fra-LI, inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10, and IL-4), renin-angiotensin system (angiotensin-converting enzyme (ACE), ACE2, and AT1-reporter (AT1-R)) and oxidative stress (reactive oxygen species (ROS), superoxide dismutase (SOD)1, NADPH oxidase (NOX)2, and NOX4). ELISA was used to detect inflammation indices, norepinephrine (NE), and nuclear factor κB (NF-κB) p65 in plasma and PVN tissue homogenate. Compared to WKY, SHR exhibited higher mean arterial pressure (MAP), plasma NE, and pro-inflammatory cytokines (PICs). Higher PVN levels of Fra-LI, PICs, ACE, AT1-R, ROS, NOX2, NOX4, and NF-κB p65, while lower central levels of anti-inflammatory cytokines (AICs), ACE2, and SOD1 were observed in SHR. Administration of BIM-23127 in PVN reversed all these changes in SHR. In SHR, blockade of NMBR in the PVN inhibited sympatho-excitation and attenuated hypertensive response. The attenuation mechanism may involve reducing inflammation and the RAS/ROS/ NF-κB pathways in PVN.

Beyond the lungs: Multisystemic sarcoidosis as a rare infertility cause

Sarcoidosis is a systemic granulomatous disease of unknown origin, characterized by non- necrotizing granulomas that can affect various organs, notably the lungs, lymph nodes, skin, and eyes. Diagnosis relies on clinical presentation, histological evidence, and exclusion of other granulomatous diseases. This case report discusses a 49-year-old Moroccan man who was initially treated for pulmonary tuberculosis based on clinical, radiological, and histological findings. Despite treatment, his condition worsened, prompting further investigation. Symptoms included dyspnea, xerostomia, xerophthalmia, polyarthralgia, paresthesia, and recurrent oral ulcers, along with significant weight loss and infertility. Clinical examination revealed a range of symptoms, including neurological deficits and elevated angiotensin-converting enzyme (ACE) levels. Imaging studies showed diffuse interstitial lung involvement. A bronchial biopsy was suggestive of sarcoidosis, supporting the diagnosis. The patient also exhibited ocular, neurological, and urogenital manifestations, including azoospermia. This case highlights the complexity of diagnosing sarcoidosis, particularly when symptoms mimic other conditions, and underscores the importance of considering sarcoidosis in differential diagnoses to avoid misdiagnosis and ensure timely treatment.

Angiotensin-Converting Enzyme Insertion/Deletion Gene Polymorphism in Chronic Rhinosinusitis with Nasal Polyps.

Inflammatory processes play a role in the etiopathogenesis of chronic rhinosinusitis. Many gene polymorphisms have been associated with inflammation. In this study, we aimed to examine the relationship between angiotensin-converting enzyme insertion/deletion gene polymorphism and chronic rhinosinusitis. Fifty-two cases with nasal polyps and 139 control patients were included in the study. Angiotensin-converting enzyme insertion/deletion gene polymorphisms, genotype, and allele distributions were determined. Results were statistically compared between groups. Statistically significant differences were found between the chronic rhinosinusitis with nasal polyps group and the control group in terms of genotype and allele distribution (p=0.015, 0.003, respectively). There were no significant differences in genotype distribution in the chronic rhinosinusitis with nasal polyps group in terms of non-steroidal anti-inflammatory drug (NSAID) allergy, asthma, and NSAID-exacerbated respiratory disease (p=0.645, 0.660, 0.095, respectively). We observed that the risk of chronic rhinosinusitis is higher in individuals with the deletion-deletion genotype and D allele of the angiotensin-converting enzyme insertion/deletion gene polymorphism. We believe that these results could be related to the high angiotensin-converting enzyme levels in these patients.

Put Down the ACE: Low Clinical Utility for Angiotensin-Converting Enzyme Levels in Sarcoidosis: A Single-Center Retrospective Cohort Study.

Background/Objectives: ACE (angiotensin-converting enzyme) is considered a serological marker of sarcoidosis as elevated levels have been reported in 30-80% of patients. However, elevated ACE levels are also encountered in other medical conditions, and the clinical correlation between ACE levels and disease activity in sarcoidosis is disputable as well. To determine the significance of elevated ACE levels in the diagnosis and follow-up of sarcoidosis patients. Methods: All electronic patient records in which an ACE level was recorded in a large tertiary hospital were identified using a computerized algorithm. Medical diagnoses, ACE numerical values, and clinical data were also automatically extracted. Furthermore, all records with a diagnosis of sarcoidosis were manually reviewed for ascertainment of the diagnosis and searched for additional clinical manifestations and treatment responses. Results: A total of 1416 records with a documented ACE level were found in the database, and 146 of the records had a diagnosis of sarcoidosis in the medical record. However, the diagnosis was excluded in 27 of these cases after a manual review of the records. Elevated ACE levels were most commonly encountered among patients with sarcoidosis, non-Hodgkin's lymphoma, cirrhosis, and interstitial lung disease. Elevated ACE levels had a positive predictive value of 12.76% and a negative predictive value of 94.6% for the diagnosis of sarcoidosis in our cohort, with a sensitivity of 63.5% and a specificity of 59.5%. Among patients with sarcoidosis, ACE levels around the time of diagnosis were higher than ACE levels in remission. However, a paired analysis did not find a statistically significant difference in ACE levels between the two timepoints. A positive correlation between lack of cardiac involvement and elevated ACE levels was found on multivariate analysis. Conclusions: ACE levels are a non-specific serological marker with low specificity and sensitivity for sarcoidosis and a poor positive predictive value, but with a negative predictive value of 94.6%. Furthermore, elevated ACE levels correlated poorly with disease activity in our cohort.

Altered plasma levels of the SARS-CoV-2-related proteins ACE2 and TMPRSS2 in patients with Crohn’s disease

The SARS-CoV-2 coronavirus infects cells through the cellular receptor angiotensin-converting enzyme 2 (ACE2), and the protease TMPRSS2 for the priming of viral spike protein. Thus, changes in these key proteins due to chronic conditions can increase risk for SARS-CoV2 infection; but significance of changes may differ is these changes correspond to full-length species or proteolytic fragments. Here, we determined that full-length ACE2 decreased in the plasma of uninfected Crohn’s disease (CD) patients before treatment onset compared to controls. TMPRSS2 is mostly presented in plasma as full-length species and as an active peptidase fragment, but also as a prodomain fragment, which is the unique species remarkably decreased in plasma from CD patients. Patients treated with the anti-TNFα adalimumab showed recovery in ACE2 levels, while those treated with infliximab, or with the anti-IL-12/23 ustekinumab, still displayed a decrease in full-length species, as well as in cleaved fragments. Patients treated with azathioprine displayed similar ACE2 levels to that of controls, except a decrease in one of the ACE2 fragments. Uniquely, patients treated with azathioprine or with ustekinumab showed partial recovery in the reduction of the TMPRSS2-prodomain fragment characterized in treatment-naïve patients. Our data suggest that CD and common therapies are not related to increased susceptibility for SARS-CoV-2.

Potential blood pressure regulatory effect of low molecular weight α-chymotrypsin extract and its peptides from Stichopus japonicus: Peptide-ACE interaction study via in silico molecular docking

Hypertension is a significant risk factor for cardiovascular disease and heart damage. Stichopus japonicus (S. japonicus) is a red sea cucumber with antioxidant and anti-hypertensive activities. However, its anti-hypertensive mechanism remains unclear. In this study, we evaluated the inhibitory effects of angiotensin-converting enzyme (ACE) of α-chymotrypsin-assisted hydrolysate of S. japonicus (α-chy) and its ultrafiltrate fractions (>10 kDa [α-chy-I], 5–10 kDa [α-chy-II], and <5 kDa [α-chy-III]). Low molecular α-chy-III exerted excellent ACE inhibitory and anti-hypertensive activities in spontaneously hypertensive rats (SHR). Moreover, α-chy-III significantly reduced the systolic and diastolic blood pressure by modulating the serum angiotensin and ACE levels. Histological analysis revealed that α-chy-III markedly protected the aorta, heart, and kidney tissues of SHR from hypertension-induced tissue damage.Taken together, our findings highlight the potential of α-chy-III as a functional food ingredient for the treatment of hypertension and its comorbidities.

UBR1 Promotes Sex-Dependent ACE2 Ubiquitination in Hypertension.

Ang-II (angiotensin II) impairs the function of the antihypertensive enzyme ACE2 (angiotensin-converting enzyme 2) by promoting its internalization, ubiquitination, and degradation, thus contributing to hypertension. However, few ACE2 ubiquitination partners have been identified, and their role in hypertension remains unknown. Proteomics and bioinformatic analyses were used to identify ACE2 ubiquitination partners in the brain, heart, and kidney of hypertensive C57BL6/J mice of both sexes. The interaction between UBR1 (ubiquitin protein ligase E3 component N-recognin) and ACE2 was validated in cells. Central and peripheral UBR1 knockdown was then performed in male mice to investigate its role in the maintenance of hypertension. Proteomics analysis of the hypothalamus identified UBR1 as a potential E3 (ubiquitin protein ligase) ligase promoting ACE2 ubiquitination. Enhanced UBR1 expression, associated with ACE2 reduction, was confirmed in various tissues from hypertensive male mice and human samples. Treatment of endothelial and smooth muscle cells with testosterone, but not 17β-estradiol, confirmed a sex-specific regulation of UBR1. In vivo silencing of UBR1 using chronic administration of small interference RNA resulted in the restoration of ACE2 levels in hypertensive male mice. A transient decrease in blood pressure after intracerebroventricular, but not systemic, infusion was also observed. Interestingly, UBR1 knockdown increased brain activation of Nedd4-2 (neural precursor cell expressed developmentally downregulated protein 4), an E3 ligase promoting ACE2 ubiquitination, and reduced expression of serum and glucocorticoid-regulated kinase 1, the kinase that inactivates Nedd4-2. These data demonstrate that UBR1 is a novel E3 ubiquitin ligase targeting ACE2 in hypertension. UBR1 and Nedd4-2 appear to work synergistically to ubiquitinate ACE2. Targeting these ubiquitin ligases may represent a novel strategy to restore ACE2 compensatory activity in hypertension.

Clinical, biochemical, and genetic study of TACE/TNF-α/ACE signaling pathway in pediatric COVID-19 infection.

Pediatric patients infected with coronavirus disease 2019 (COVID-19) have unique clinical characteristics. Tumor necrosis factor (TNF) is a proinflammatory cytokine that greatly contributes to tumor pathogenesis. To describe the presenting characteristics of COVID-19 infection among pediatric patients, and investigate the possible role of the TNF-α signaling pathway. This prospective case-control study included 50 Egyptian pediatric patients with COVID-19 and 50 healthy controls. Clinical, laboratory, and radiological assessments were performed. Serum TNF-alpha (TNF-α), TNF-α-converting enzyme (TACE), and angiotensin-converting enzyme 2 (ACE2) were measured using enzyme-linked immunosorbent assay. ACE (I/D) (rs4646994), ACE2 rs2285666, and TNF-α-308G/A single nucleotide polymorphisms (SNPs) were performed using conventional polymerase chain reaction techniques with or without restriction fragment length polymorphism. The median age was 1 year (interquartile range [IQR], 0.31-2.50 years) in the case group and 1.45 years (IQR, 1.00-3.00) in the control group. The main presenting symptoms were fever (92%), dry cough (74%), and dyspnea (72%). The lymphocytic count was normal in 14 patients (28%), decreased in 16 patients (32%), and increased in 20 patients (40%) of the case group. Positive chest computed tomography finding of COVID-19 infection were demonstrated among 40% of patients using COVID-19 Reporting and Data System categories (ground-glass opacity with or without consolidations in the lungs). There were significant increased serum TACE and TNF-α with decreased ACE2 levels among cases versus controls (P< 0.001). The GG genotype and G allele of the TNF-α-308G/A SNP were significantly higher in patients than in controls (P<0.05 for both), with insignificant differences in genotype and allelic frequencies in the ACE (I/D) (rs4646994) and ACE2 rs2285666 SNPs. The TNF signaling pathway was significantly activated in pediatric COVID-19 infection. Only the TNF-α-308G/A SNP was significantly associated with pediatric COVID-19 infection.

Mathematical Modeling of Impacts of Patient Differences on Renin-Angiotensin System and Applications to COVID-19 Lung Fibrosis Outcomes.

Patient-specific premorbidity, age, and sex are significant heterogeneous factors that influence the severe manifestation of lung diseases, including COVID-19 fibrosis. The renin-angiotensin system (RAS) plays a prominent role in regulating the effects of these factors. Recent evidence shows patient-specific alterations of RAS homeostasis concentrations with premorbidity and the expression level of angiotensin-converting enzyme 2 (ACE2) during COVID-19. However, conflicting evidence suggests decreases, increases, or no changes in RAS peptides after SARS-CoV-2 infection. In addition, detailed mechanisms connecting the patient-specific conditions before infection to infection-induced RAS alterations are still unknown. Here, a multiscale computational model was developed to quantify the systemic contribution of heterogeneous factors of RAS during COVID-19. Three submodels were connected-an agent-based model for in-host COVID-19 response in the lung tissue, a RAS dynamics model, and a fibrosis dynamics model to investigate the effects of patient-group-specific factors in the systemic alteration of RAS and collagen deposition in the lung. The model results indicated cell death due to inflammatory response as a major contributor to the reduction of ACE and ACE2. In contrast, there were no significant changes in ACE2 dynamics due to viral-bound internalization of ACE2. The model explained possible mechanisms for conflicting evidence of patient-group-specific changes in RAS peptides in previously published studies. Simulated results were consistent with reported RAS peptide values for SARS-CoV-2-negative and SARS-CoV-2-positive patients. RAS peptides decreased for all virtual patient groups with aging in both sexes. In contrast, large variations in the magnitude of reduction were observed between male and female virtual patients in the older and middle-aged groups. The patient-specific variations in homeostasis RAS peptide concentrations of SARS-CoV-2-negative patients also affected the dynamics of RAS during infection. The model results also showed that feedback between RAS signaling and renin dynamics could restore ANGI homeostasis concentration but failed to restore homeostasis values of RAS peptides downstream of ANGI. In addition, the results showed that ACE2 variations with age and sex significantly altered the concentrations of RAS peptides and led to collagen deposition with slight variations depending on age and sex. This model may find further applications in patient-specific calibrations of tissue models for acute and chronic lung diseases to develop personalized treatments.

Optimization of Ultrasound Extraction of Total Anthocyanin From Berberis kaschgarica Rupr. by Response Surface Methodology and Its Antihypertensive Effect.

Berberis kaschgarica Rupr. is a berry fruit shrub found in the north-western region of China, locally its fruit is consumed as a tea ingredient a part of the daily diet, for treatment of different diseases like eczema, and for cardiovascular care as a traditional remedy. In the current study, an optimized ultrasound-assisted extraction (UAE) method is developed using response surface methodology (RSM) to extract anthocyanins from the fruit. The influence of the extraction conditions on the yield of anthocyanins was evaluated and discussed. Additionally, the antihypertensive activity of the extract was evaluated in rats. The negative control group comprised Wistar-Kyoto rats, while five experimental groups included spontaneously hypertensive rats: model group; captopril group; and three treatment groups receiving purified extract. Blood pressure was regularly monitored every 2 weeks during the 12-week treatment period. Post-treatment left ventricular cardiac function in rats was assessed, and serum level of renin (REN), angiotensin-converting enzyme (ACE), angiotensin II (Ang-II), angiotensin-(1-7) (Ang-(1-7)), endothelin-1 (ET-1) and nitric oxide (NO) were evaluated. The optimal UAE extraction condition determined by RSM was 56.5% ethanol volume, 1:19.74 solid-to-liquid ratio, 55 min extraction time, and 0.71% of HCL volume. The purified B. kaschgarica anthocyanin extract exhibited antihypertensive effects and significantly improved left ventricular cardiac functions in treated rats. Furthermore, serum levels of REN, ACE, Ang-II, ET-1, Ang-(1-7), and NO showed statistically significant changes in the treated groups. This study highlights the efficacy of the developed optimized UAE method for high-yield anthocyanin extraction from B. kaschgarica fruit and its potential as a therapeutic agent for hypertension.

SARS-CoV-2 Genomic Variants and Their Relationship with the Expressional and Genomic Profile of Angiotensin-Converting Enzyme 2 (ACE2) and Transmembrane Serine Protease 2 (TMPRSS2).

Over the past four years, angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) have been extensively studied, given their important role in SARS-CoV-2 replication; however, most studies have failed to compare their behavior in the face of different SARS-CoV-2 genomic variants. Therefore, this study evaluated the influence of different variants in ACE2/TMPRSS2 expressional and genomic profiles. To achieve this, 160 nasopharyngeal samples, previously detected with SARS-CoV-2 via RT-qPCR (June 2020-July 2022), were quantified for ACE2/TMPRSS2 expression levels, also using RT-qPCR; SARS-CoV-2 genomic variants, along with polymorphisms in the ACE2/TMPRSS2 coding genes, were identified using nanopore sequencing. In order of appearance, the B.1.1.28, Zeta, Gamma, and Omicron variants were identified in this study. The ACE2 levels were higher when B.1.1.28 was present, possibly due to the ACE2/spike binding affinity; the TMPRSS2 levels were also higher in the presence of B.1.1.28, probably attributable to inefficient usage of the TMPRSS2 pathway by the other variants, as well as to the decrease in protease transcription factors when in the presence of Omicron. The rs2285666 (ACE2) polymorphism was less frequent when B.1.1.28 was present, which is befitting, since rs2285666 increases ACE2/spike binding affinity. In conclusion, SARS-CoV-2 genomic variants appear to exhibit varying impacts in regards to ACE2/TMPRSS2 genomic and expressional behavior.

P12 Post-streptococcal reactive arthritis and panniculitis in pregnancy: a case report

Abstract Introduction Reactive arthritis is an inflammatory condition that can occur following an infection, commonly caused by bacterial pathogens such as Streptococcus. Pregnancy introduces unique challenges in managing autoimmune and inflammatory conditions due to the need to balance maternal and foetal health. This case report highlights the diagnosis and management of post-streptococcal reactive arthritis and panniculitis in a 16-week pregnant patient, focusing on the use of steroids and the resulting impact on her gestational diabetes Case description A 25-year-old woman, 16 weeks pregnant with no known comorbidities, presented with bilateral ankle pain and swelling for the last two weeks, preceded by an episode of tonsillitis. Initially, the pain was localised to her right ankle and left wrist, then involved her left ankle. She was treated with antibiotics for presumed cellulitis, and a doppler ultrasound ruled out deep vein thrombosis. Examination revealed swollen, inflamed ankles with limited range of motion due to pain. The rest of the examination was unremarkable. This was her second pregnancy and had no complications in her first pregnancy. Routine investigations were done; her C-reactive protein (CRP) was 126 and erythrocyte sedimentation rate (ESR) was 56, with a normal white cell count. Autoimmune workup, including rheumatoid factor (RF), antinuclear antibodies (ANA), and HLA-B27, was negative, but her anti-streptolysin O (ASO) titer was borderline positive. She was diagnosed with post-streptococcal reactive arthritis. After discussing the risks and benefits of NSAID use in the second trimester, we started her on prednisolone 20 mg with a tapering plan. The patient showed clinical improvement, but upon tapering the steroids to 5 mg daily, she developed well-demarcated erythema with desquamation and epidermal changes over both ankles. The left ankle was tender on the medial side, but the right was non-tender. Her angiotensin-converting enzyme (ACE) levels were negative, and calcium levels were normal. Her steroid dose was increased again to 20 mg with a slow tapering plan. She also developed gestational diabetes mellitus and was started on insulin by the diabetes team. Her foetal scan was reassuring and was under obstetrician. A dermatology team reviewed her and suggested the rash was likely panniculitis, which had improved significantly with steroids, so a biopsy was not performed. With careful management, her symptoms resolved, and she successfully discontinued steroid therapy as planned. Discussion This case highlights the complex nature of managing post-streptococcal reactive arthritis and panniculitis in a pregnant patient. The initial presentation with a sore throat and subsequent development of arthritis and panniculitis, along with raised inflammatory markers and a positive ASO titer, strongly suggested reactive arthritis triggered by a recent streptococcal infection. Given the foetal risk from NSAIDs, steroid therapy was chosen for its safety profile in pregnancy. While steroid therapy provided symptomatic relief, it led to gestational diabetes, requiring careful monitoring and adjustment of the patient’s diabetic management. The emergence of panniculitis during steroid tapering added another layer of complexity, necessitating collaboration with dermatology specialists for a revised approach. The dermatological team agreed with the recommendation of slow tapering of steroids, which were crucial in managing this complication. This case highlights the importance of a multidisciplinary approach and close monitoring to ensure optimal outcomes for both the mother and the developing foetus. Key learning points • The diagnosis of post-streptococcal reactive arthritis should be considered in pregnant patients presenting with joint inflammation and a recent history of infection. Prompt recognition and appropriate treatment are essential to prevent long-term joint damage. • Careful monitoring of glycaemic control is crucial when initiating steroid therapy in pregnant patients, as it may lead to uncontrolled diabetes and can cause foetal problems. Close collaboration between obstetric and endocrine specialists is necessary to optimise diabetes management while minimising foetal risks. • Collaboration with dermatology specialists can aid in the management of complications such as panniculitis during steroid tapering in pregnant patients. A multidisciplinary approach ensures comprehensive care and improves outcomes for both the mother and the developing foetus.

Predicting susceptibility to COVID-19 infection in patients on maintenance hemodialysis by cross-coupling soluble ACE2 concentration with lymphocyte count: an algorithmic approach.

Patients on maintenance hemodialysis (MHD) were more vulnerable to and had a higher mortality during the COVID-19 pandemic. As angiotensin converting enzyme 2 (ACE2) and transmembrane protease serine S1 member 2 (TMPRSS2) played crucial roles in viral entry into the human host cells, we therefore investigated in the MHD patients whether their plasma levels were associated with susceptibility to the COVID-19. Blood samples were collected from the patients in our then COVID-19 free center immediately upon lifting of the stringent quarantine measures in early December of 2022 and infection situation was observed within the following 2 weeks. Plasma levels of the soluble ACE2 (sACE2), ACE (sACE) and TMPRSS2 (sTMPRSS2) were measured with ELISA method. Data were stepwisely tested for independent effect, relevant role and synergistic action on the susceptibility by multiple logistic regression, receiver operating characteristic curve and multiple dimensionality reduction (MDR) method, respectively. Among the 174 eligible patients, 95 (54.6%) turned COVID-19 positive with a male to female ratio of 1.57 during the observation period. Comparing with the uninfected, the infected had significantly higher sACE2 and lower sTMPRSS2 levels upon comparable sACE concentration. Besides the sACE2, factors associated with susceptibility were vintage and individual session time of the hemodialysis, smoking and comorbidity of hepatitis, whereas lymphocyte counts showed a tendency (p = 0.052). Patients simultaneously manifesting higher sACE2 level and lower lymphocyte counts had an increased infection risk as confirmed by the MDR method. By sorting out the susceptible ones expeditiously, this algorithmic approach may help the otherwise vulnerable MHD patients weather over future wave of COVID-19 variants or outbreak of other viral diseases.

Apelin from Perivascular Adipose Tissue Is Involved in the Regulation of Vasorelaxation and Renal Function in Metabolic Syndrome

The perivascular adipose tissue (PVAT) regulates the arterial tone by releasing vasoactive molecules. PVAT dysfunction favoring the vasorelaxation response could contribute to the development of kidney disease in metabolic syndrome (MetS). Previously, we demonstrated that overactivation of angiotensin II signaling in the PVAT deteriorates the compensatory PVAT effects in rats with MetS (SHRSP.Z-Leprfa/IzmDmcr (SPZF) and SHR/NDmcr-cp (CP) rats). Apelin is an endogenous regulator of angiotensin II. Therefore, we investigated whether changes in apelin levels in the PVAT alter PVAT function and impair kidney function in MetS. Twenty-three-week-old male and female SPZF and CP rats were used. In the female CP rats, apelin mRNA levels in renal arterial PVAT, enhancing effects of the PVAT on acetylcholine-induced relaxation in renal arteries, and estimated glomerular filtration rate (eGFR) were the highest, and urine protein levels and homeostasis model assessment of insulin resistance (HOMA-IR) were the lowest. Apelin mRNA levels were positively correlated with the enhancing effects of the PVAT on vasorelaxation and eGFR but negatively correlated with urine protein levels and HOMA-IR. Moreover, apelin levels positively correlated with mRNA levels of angiotensin-converting enzyme 2 and angiotensin II type 1 receptor-associated protein, which are negative regulators of angiotensin II. This study suggests that a decline in apelin levels in the PVAT, probably owing to angiotensin II, is associated with PVAT dysfunction on vascular tone, resulting in impaired kidney function in MetS.