Peroxisome proliferator-activated receptor alpha is essential factor in enhanced macrophage immune function induced by angiotensin converting enzyme.

An upregulation of angiotensin-converting enzyme (ACE) expression strengthens the immune activity of myeloid lineage cells as a natural functional regulation mechanism in our immunity. ACE10/10 mice, possessing increased ACE expression in macrophages, exhibit enhanced anti-tumor immunity and anti-bactericidal effects compared to those of wild type (WT) mice, while the detailed molecular mechanism has not been elucidated yet. In this report, we demonstrate that peroxisome proliferator-activated receptor alpha (PPARα) is a key molecule in the functional upregulation of macrophages induced by ACE. The expression of PPARα, a transcription factor regulating fatty acid metabolism-associated gene expressions, was upregulated in ACE-overexpressing macrophages. To pinpoint the role of PPARα in the enhanced immune function of ACE-overexpressing macrophages, we established a line with myeloid lineage-selective PPARα depletion employing the Lysozyme 2 (LysM)-Cre system based on ACE 10/10 mice (named A10-PPARα-Cre). Interestingly, A10-PPARα-Cre mice exhibited larger B16-F10-originated tumors than original ACE 10/10 mice. PPARα depletion impaired cytokine production and antigen-presenting activity in ACE-overexpressing macrophages, resulting in reduced tumor antigen-specific CD8+ T cell activity. Additionally, the anti-bactericidal effect was also impaired in A10-PPARα-Cre mice, resulting in similar bacterial colonization to WT mice in Methicillin-Resistant Staphylococcus aureus (MRSA) infection. PPARα depletion downregulated phagocytic activity and bacteria killing in ACE-overexpressing macrophages. Moreover, THP-1-ACE-derived macrophages, as a human model, expressing upregulated PPARα exhibited enhanced cytotoxicity against B16-F10 cells and MRSA killing. These activities were further enhanced by the PPARα agonist, WY 14643, while abolished by the antagonist, GW6471, in THP-1-ACE cells. Thus, PPARα is an indispensable molecule in ACE-dependent functional upregulation of macrophages in both mice and humans.

Myeloid cell ACE shapes cellular metabolism and function in PCSK-9 induced atherosclerosis.

The pathogenesis of atherosclerosis is defined by impaired lipid handling by macrophages which increases intracellular lipid accumulation. This dysregulation of macrophages triggers the accumulation of apoptotic cells and chronic inflammation which contributes to disease progression. We previously reported that mice with increased macrophage-specific angiotensin-converting enzyme, termed ACE10/10 mice, resist atherosclerosis in an adeno-associated virus-proprotein convertase subtilisin/kexin type 9 (AAV-PCSK9)-induced model. This is due to increased lipid metabolism by macrophages which contributes to plaque resolution. However, the importance of ACE in peripheral blood monocytes, which are the primary precursors of lesional-infiltrating macrophages, is still unknown in atherosclerosis. Here, we show that the ACE-mediated metabolic phenotype is already triggered in peripheral blood circulating monocytes and that this functional modification is directly transferred to differentiated macrophages in ACE10/10 mice. We found that Ly-6Clo monocytes were increased in atherosclerotic ACE10/10 mice. The monocytes isolated from atherosclerotic ACE10/10 mice showed enhanced lipid metabolism, elevated mitochondrial activity, and increased adenosine triphosphate (ATP) levels which implies that ACE overexpression is already altered in atherosclerosis. Furthermore, we observed increased oxygen consumption (VO2), respiratory exchange ratio (RER), and spontaneous physical activity in ACE10/10 mice compared to WT mice in atherosclerotic conditions, indicating enhanced systemic energy consumption. Thus, ACE overexpression in myeloid lineage cells modifies the metabolic function of peripheral blood circulating monocytes which differentiate to macrophages and protect against atherosclerotic lesion progression due to better lipid metabolism.

Macrophage angiotensin-converting enzyme reduces atherosclerosis by increasing peroxisome proliferator-activated receptor α and fundamentally changing lipid metabolism.

AIMS: The metabolic failure of macrophages to adequately process lipid is central to the aetiology of atherosclerosis. Here, we examine the role of macrophage angiotensin-converting enzyme (ACE) in a mouse model of PCSK9-induced atherosclerosis. METHODS AND RESULTS: Atherosclerosis in mice was induced with AAV-PCSK9 and a high-fat diet. Animals with increased macrophage ACE (ACE 10/10 mice) have a marked reduction in atherosclerosis vs. WT mice. Macrophages from both the aorta and peritoneum of ACE 10/10 express increased PPARα and have a profoundly altered phenotype to process lipids characterized by higher levels of the surface scavenger receptor CD36, increased uptake of lipid, increased capacity to transport long chain fatty acids into mitochondria, higher oxidative metabolism and lipid ß-oxidation as determined using 13C isotope tracing, increased cell ATP, increased capacity for efferocytosis, increased concentrations of the lipid transporters ABCA1 and ABCG1, and increased cholesterol efflux. These effects are mostly independent of angiotensin II. Human THP-1 cells, when modified to express more ACE, increase expression of PPARα, increase cell ATP and acetyl-CoA, and increase cell efferocytosis. CONCLUSION: Increased macrophage ACE expression enhances macrophage lipid metabolism, cholesterol efflux, efferocytosis, and it reduces atherosclerosis. This has implications for the treatment of cardiovascular disease with angiotensin II receptor antagonists vs. ACE inhibitors.

miR766-3p and miR124-3p Dictate Drug Resistance and Clinical Outcome in HNSCC.

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive disease with poor prognosis, which is mainly due to drug resistance. The biology determining the response to chemo-radiotherapy in HNSCC is poorly understood. Using clinical samples, we found that miR124-3p and miR766-3p are overexpressed in chemo-radiotherapy-resistant (non-responder) HNSCC, as compared to responder tumors. Our study shows that inhibition of miR124-3p and miR766-3p enhances the sensitivity of HNSCC cell lines, CAL27 and FaDu, to 5-fluorouracil and cisplatin (FP) chemotherapy and radiotherapy. In contrast, overexpression of miR766-3p and miR124-3p confers a resistance phenotype in HNSCC cells. The upregulation of miR124-3p and miR766-3p is associated with increased HNSCC cell invasion and migration. In a xenograft mouse model, inhibition of miR124-3p and miR766-3p enhanced the efficacy of chemo-radiotherapy with reduced growth of resistant HNSCC. For the first time, we identified that miR124-3p and miR766-3p attenuate expression of CREBRF and NR3C2, respectively, in HNSCC, which promotes aggressive tumor behavior by inducing the signaling axes CREB3/ATG5 and ß-catenin/c-Myc. Since miR124-3p and miR766-3p affect complementary pathways, combined inhibition of these two miRNAs shows an additive effect on sensitizing cancer cells to chemo-radiotherapy. In conclusion, our study demonstrated a novel miR124-3p- and miR766-3p-based biological mechanism governing treatment-resistant HNSCC, which can be targeted to improve clinical outcomes in HNSCC.

The non-cardiovascular actions of ACE.

Angiotensin converting enzyme (ACE) is well known for its role producing the vasoconstrictor angiotensin II and ACE inhibitors are commonly used for treating hypertension and cardiovascular disease. However, ACE has many different substrates besides angiotensin I and plays a role in many different physiologic processes. Here, we discuss the role of ACE in the immune response. Several studies in mice indicate that increased expression of ACE by macrophages or neutrophils enhances the ability of these cells to respond to immune challenges such as infection, neoplasm, Alzheimer's disease, and atherosclerosis. Increased expression of ACE induces increased oxidative metabolism with an increase in cell content of ATP. In contrast, ACE inhibitors have the opposite effect, and in both humans and mice, administration of ACE inhibitors reduces the ability of neutrophils to kill bacteria. Understanding how ACE affects the immune response may provide a means to increase immunity in a variety of chronic conditions now not treated through immune manipulation.

ß-Galactosidase mediated synthesized nanosupport for the immobilization of same enzyme: Its stability and application in the hydrolysis of lactose.

ß-Galactosidase was immobilized on modified nanosilver reduced graphene oxide (Ag@rGO) nanocomposite prepared by in vitro synthesis using same enzyme. The effectiveness factor, η value of the immobilized enzyme was calculated to be 0.968, suggesting enhancement in enzyme activity after immobilization. The morphological structure of the crosslinked biopolymer was analyzed using electron microscopy and other characterization techniques. The kinetics displayed a decrease in Km value from 0.50 to 0.44 mmol L-1 while there was an increase in Vmax values from 0.031 to 0.039 µmol min-1 mL-1. The immobilized enzyme retained 85% activity after its 10th repeated use. Inhibition constant (Ki) value suggests galactose to be a more potent inhibitor of the enzyme. Despite the inhibitory potential of these hydrolysis products, the immobilized enzyme preparation retained 44.2% activity in the presence of both inhibitory sugars. The as-synthesized nanobiocatalyst was found quite effective in hydrolyzing 89% of lactose from whey. Hence, this nanobiocatalyst can be used in removing lactose from dairy waste, whey before releasing it into the water bodies. Also, the cytotoxicity and genotoxicity of Ag@rGO NC was assessed on human blood lymphocytes using flow cytometry and comet assay, respectively.

Severe acute respiratory syndrome coronavirus 2-induced acute aortic occlusion: a case report.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 infection can lead to a constellation of viral and immune symptoms called coronavirus disease 2019. Emerging literature increasingly supports the premise that severe acute respiratory syndrome coronavirus 2 promotes a prothrombotic milieu. However, to date there have been no reports of acute aortic occlusion, itself a rare phenomenon. We report a case of fatal acute aortic occlusion in a patient with coronavirus disease 2019. CASE REPORT: A 59-year-old Caucasian male with past medical history of peripheral vascular disease presented to the emergency department for evaluation of shortness of breath, fevers, and dry cough. His symptoms started 5-7 days prior to the emergency department visit, and he received antibiotics in the outpatient setting without any effect. He was found to be febrile, tachypneic, and hypoxemic. He was placed on supplemental oxygen via a non-rebreather mask. Chest X-ray showed multifocal opacifications. Intravenous antibiotics for possible pneumonia were initiated. Hydroxychloroquine was initiated to cover possible coronavirus disease 2019 pneumonia. During the hospitalization, the patient became progressively hypoxemic, for which he was placed on bilevel positive airway pressure. D-dimer, ferritin, lactate dehydrogenase, and C-reactive protein were all elevated. Severe acute respiratory syndrome coronavirus 2 reverse transcription polymerase chain reaction was positive. On day 3, the patient was upgraded to the intensive care unit. Soon after he was intubated, he developed a mottled appearance of skin, which extended from his bilateral feet up to the level of the subumbilical plane. Bedside ultrasound revealed an absence of flow from the mid-aorta to both common iliac arteries. The patient was evaluated emergently by vascular surgery. After a discussion with the family, it was decided to proceed with comfort-directed care, and the patient died later that day. DISCUSSION: Viral infections have been identified as a source of prothrombotic states due to direct injury of vascular tissue and inflammatory cascades. Severe acute respiratory syndrome coronavirus 2 appears to follow a similar pattern, with numerous institutions identifying elevated levels of thrombotic complications. We believe that healthcare providers should be aware of both venous and arterial thrombotic complications associated with coronavirus disease 2019, including possible fatal outcome.

Beta galactosidase mediated bio-enzymatically synthesized nano-gold with aggrandized cytotoxic potential against pathogenic bacteria and cancer cells.

The current investigation reports bactericidal and cytotoxicity evaluation of bio-enzymatically formulated nano­gold (AuNPs) using physiologically significant enzyme ß galactosidase. The AuNPs were characterized using spectroscopic and microscopic techniques. The anti-pathogenic efficacy of AuNPs as a potential drug was observed against five contagious bacterial strains of Escherichia coli, Staphylococcus aureus, group B Streptococcus, Acinetobacter baumannii and Klebsiella pneumonia. The estimation of minimum bactericidal concentration, minimum inhibitory concentration, scanning electron microscopy and fluorescence microscopy conclude enhanced bactericidal effects of green AuNPs. The cytotoxicity of AuNPs against human cervical (HeLa), breast (MCF-7) and liver (Hep 3B) cancer cells was evaluated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was adopted to analyze antitumor potential of AuNPs. Cell nuclear morphology associated with apoptosis after treatment with NPs was assessed against MCF-7 cells through 4,6-diamidino-2-phenylindole staining. Apoptotic activity of AuNPs was determined against HeLa cells using annexin V/ propidium iodide double staining by flow cytometric analysis. The AuNPs exhibited excellent efficacy against these cell lines and future prospects of usage as potential nano-drugs and drug delivery vehicles.

Protective effect of Nigella sativa oil on cisplatin induced nephrotoxicity and oxidative damage in rat kidney.

BACKGROUND: Nephrotoxicity is a severe complication in patients undergoing cisplatin (CP) chemotherapy. Previous studies in our lab have shown that administration of a single dose of CP results in decrease in the activities of brush border membrane (BBM) and free radical scavenging enzymes and induces oxidative stress in rat kidney. Nigella sativa, is one of the most revered medicinal plant known for its numerous health benefits. Nigella sativa seed/oil has been shown to improve kidney functions in animal models of acute kidney injury. OBJECTIVE: The present study was undertaken to investigate whether Nigella sativa oil (NSO) can prevent the CP-induced nephrotoxic effects. RESULTS: The effect of NSO was determined on CP induced alterations in various serum parameters and on enzymes of carbohydrate metabolism, BBM and antioxidant defense system in renal cortex and medulla. Administration of NSO (2ml/kg bwt. orally), prior to and following a single dose CP treatment (6mg/kg bwt. i.p), significantly attenuated the CP induced increase in serum creatinine (Scr) and blood urea nitrogen (BUN) and decrease in the activities of BBM enzymes in renal cortical and medullary homogenates as well as in isolated BBM vesicles (BBMV). NSO administration also precluded CP induced alterations in the activities of carbohydrate metabolism enzymes and in the enzymatic and non-enzymatic antioxidant parameters. Histopathological observations showed extensive kidney damage in CP treated animals and remarkably reduced renal injury in CP and NSO co-treated group. CONCLUSION: The biochemical and histological data suggest a protective effect of NSO against CP-induced acute kidney injury.

Primary renal aspergillosis and xanthogranulomatous pyelonephritis in an immuno-competent toddler.

Aspergillosis is primarily a pulmonary disease so that renal aspergillosis is usually secondary to hematogenous spread from lungs. Primary renal aspergillosis, though a rare entity, is still seen in immuno-compromised individuals. Renal aspergillosis may lead to formation of focal abscesses, fungal bezoars and may cause ureteric obstruction. Treatment involves stabilization of patient and removal of fungal bezoars along with administration of anti-fungal agents. This report describes the case of localized primary renal aspergillosis with fungal bezoar formation in 2 years old immuno-competent child who presented in sepsis and acute renal failure and was successfully managed by nephroscopic removal of fungal bezoar and intravenous voriconazole. The other kidney required nephrectomy for xanthogranulomatous pyelonephritis.

Correlation of early functional capacity with biventricular function and residual pulmonary artery hypertension following mitral valve replacement surgery.

PURPOSE: To evaluate the functional capacity following mitral valve replacement in the early postoperative period and to determine the correlation of biventricular function and residual pulmonary artery hypertension (PAH) to the functional capacity. METHODS: On the seventh postoperative day, 53 patients who underwent mitral valve replacement with preoperative diagnosis of PAH underwent a 2-dimensional echocardiographic and Doppler examination for the assessment of right ventricular systolic pressure, along with right ventricular (RV) and left ventricular (LV) myocardial performance indices (MPIs). These assessments were followed by a 6-Minute Walk Test. Five patients were eventually withdrawn from the study. RESULTS: The diminished functional capacity (51.6% ± 4.1% of predicted 6-Minute Walk Test distance for age, gender, weight, and height) significantly correlated with biventricular dysfunction evident from elevated RVMPI (0.35 ± 0.09) and LVMPI (0.52 ± 0.11) (for both Ps ≤ .001). Furthermore, the residual PAH, with mean right ventricular systolic pressure of 37 ± 11 mm Hg, showed negative correlation with the functional capacity (P ≤ .001). In addition, LVMPI had strong association with RVMPI (P ≤ .001). Linear regression analysis demonstrated that LVMPI and right ventricular systolic pressure were independent predictors of functional capacity. CONCLUSIONS: The RV and LV function, as quantified by MPI, and the degree of residual PAH are associated with functional capacity impairment after mitral valve replacement, with LVMPI and residual PAH as the independent predictorsqbetween RV and LV performance indices indicate that ventricular interactions contribute to the functional capacity impairment in these patients.

Comparison of effects of 3 and 7% hypertonic saline nebulization on lung function in children with cystic fibrosis: a double-blind randomized, controlled trial.

BACKGROUND: Beneficial effects of hypertonic saline on lung function in cystic fibrosis patients are well documented. However, the effects of various concentrations of hypertonic saline are not well studied. We, therefore, compared the effects of 3 and 7% hypertonic saline administered by nebulization on lung function in children with cystic fibrosis. METHOD: In a double-blind randomized controlled trial, 31 children with cystic fibrosis were randomized to receive either 3% saline or 7% saline nebulization twice daily for 28 days. Spirometry was performed and functional status was measured on Day 14 and 28. RESULTS: Of 31 children enrolled in the study, 30 completed the 28 days follow up (15 in each group). Percentage change in Forced Expiratory Volume during first second (FEV(1)) from baseline to Day 14 and on Day 28 was significantly higher in the group receiving 3% saline as compared with those receiving 7% saline inhalation. There was some decrease in FEV(1) (percentage predicted) immediately after 7% saline inhalation unlike 3% saline. The functional status remained comparable between the two groups. CONCLUSION: The results suggest that 3% hypertonic saline nebulization was better than 7% saline inhalation. There is a need for studies with larger sample size and longer duration to confirm our results.

Comparison of effects of manual versus ventilator hyperinflation on respiratory compliance and arterial blood gases in patients undergoing mitral valve replacement.

OBJECTIVE: To compare the effects of manual hyperinflation (MHI) and ventilator hyperinflation (VHI) delivered to completely sedated and paralyzed patients undergoing mitral valve replacement (MVR) while maintaining minute ventilation. METHODS: This was a randomized study with a 2-group, pre-test, post-test experimental design. Effects of hyperinflation were studied on static compliance (C(stat)), dynamic compliance (C(dyn)), oxygenation (Pao(2):Fio(2)), partial pressure of carbon dioxide in arterial blood (Paco(2)), and cologarithm of activity of dissolved hydrogen ions in arterial blood (pH). A sample of 30 patients in the immediate postoperative phase of MVR surgery were included in the study. RESULTS: No significant differences were found between the groups. Significant improvements were found in oxygenation at both 1minute and 20minutes after MHI, but only at 1minute after VHI (P < .05). VHI led to improved C(dyn) (P < .05). CONCLUSION: In the immediate postoperative phase of MVR, both techniques produced similar effects on respiratory compliance and oxygenation. MHI produced longer lasting improvements in oxygenation than VHI, whereas VHI produced better improvements in dynamic compliance. Paco(2) and pH were maintained by both.

Mayer Rokitansky Kuster Hauser syndrome with urogenital sinus anomaly.

Mayer Rokitansky Kuster Hauser (MRKH) syndrome is a rare disorder, characterized by the congenital absence of uterus and associated renal tract anomalies. The case presented with primary amenorrhea and primary infertility, despite development of normal female secondary sexual characteristics. CT scan revealed absent uterus, a solitary left sided pelvic kidney and a vesicovaginal communication that, on cystoscopy, revealed urogenital sinus anomaly manifesting as a common channel formed due to absent anterior wall of vagina and posterior wall of urethra. The urogenital sinus anomaly in MRKH syndrome has not been reported earlier.