Potential Alternative Receptors for SARS-CoV-2-Induced Kidney Damage: TLR-4, KIM-1/TIM-1, and CD147

Kidney damage in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can occur even in patients with no underlying kidney disease. Signs of kidney problems can progress to a state that demands dialysis and hampering recovery. Although not without controversy, emerging evidence implicates direct infectivity of SARS-CoV-2 in the kidney. At the early stage of the pandemic, consideration was mainly on the well-recognized angiotensin-converting enzyme 2 (ACE2) receptor as being the site for viral interaction and subsequent cellular internalization. Despite the abundance of ACE2 receptors in the kidneys, researchers have expanded beyond ACE2 and identified novel viral entry pathways that could be advantageously explored as therapeutic targets. This review presents the potential involvement of toll-like receptor 4 (TLR-4), kidney injury molecule-1/T cell immunoglobulin mucin domain 1 (KIM-1/TIM-1), and cluster of differentiation 147 (CD147) in SARS-CoV-2-associated renal damage. In this context, we address the unresolved issues surrounding SARS-CoV-2 renal infectivity.

Knockout of Matrix Metalloproteinase 2 Opposes Hypertension- and Diabetes-induced Nephropathy

ABSTRACT

The progression of chronic kidney disease results from the accumulation of extracellular matrix leading to end-stage renal disease. We previously demonstrated that a broad-spectrum matrix metalloproteinase (MMP) inhibitor reduced renal injury in rat models of hypertension and diabetes. However, the isoforms and mechanisms involved are unclear. This study examined the role of MMP2 during the development of proteinuria and renal injury after induction of hypertension or diabetes in Dahl salt-sensitive (SS) and MMP2 knockout (KO) rats. Mean arterial pressure rose from 115 ± 2 to 145 ± 2 mm Hg and 116 ± 1 to 152 ± 3 mm Hg in MMP2 KO and SS rats fed a high-salt (8% NaCl) diet for 3 weeks. The degree of proteinuria, glomerular injury, renal fibrosis, and podocyte loss was lower in MMP2 KO rats than in SS rats. Blood glucose and HbA1c levels, and mean arterial pressure rose to the same extent in streptozotocin-treated SS and MMP2 KO rats. However, the degree of proteinuria, glomerulosclerosis, renal fibrosis, renal hypertrophy, glomerular permeability to albumin, and the renal expression of MMP2 and TGFβ1 were significantly reduced in MMP2 KO rats. Glomerular filtration rate fell by 33% after 12 weeks of diabetes in streptozotocin-treated SS rats compared with time-control rats, but glomerular filtration rate only fell by 12% in MMP2 KO rats. These results indicate that activation of MMP2 plays an essential role in the pathogenesis of hypertensive and diabetic nephropathy and suggests that an MMP2 inhibitor might slow the progression of chronic kidney disease.

Nicotinamide Riboside Supplementation Restores Myocardial Nicotinamide Adenine Dinucleotide Levels, Improves Survival, and Promotes Protective Environment Post Myocardial Infarction

AIMS

Myocardial infarction (MI) is a major cause of death. Nicotinamide adenine dinucleotide (NAD+) is a coenzyme in oxidative phosphorylation and substrate of sirtuins and poly-ADP ribose polymerases, enzymes critical for cardiac remodeling post-MI. Decreased NAD+ is reported in several heart failure models with paradoxically an upregulation of nicotinamide riboside kinase 2, which uses nicotinamide riboside (NR) as substrate in an NAD+ biosynthetic pathway. We hypothesized that stimulating nicotinamide riboside kinase 2 pathway by NR supplementation exerts cardioprotective effects.

METHODS AND RESULTS

MI was induced by LAD ligation in 2-3-month-old male mice. NR was administered daily (1 µmole/g body weight) over 7 days. RT-PCR showed a 60-fold increase in nicotinamide riboside kinase 2 expression 4 days post-MI with a 60% drop in myocardial NAD+ and overall survival of 61%. NR restored NAD+ levels and improved survival to 92%. Assessment of respiration in cardiac fibers revealed mitochondrial dysfunction post-MI, and NR improved complexes II and IV activities and citrate synthase activity, a measure of mitochondrial content. Additionally, NR reduced elevated PARP1 levels and activated a type 2 cytokine milieu in the damaged heart, consistent with reduced early inflammatory and pro-fibrotic response.

CONCLUSION

Our data show that nicotinamide riboside could be useful for MI management.

Risk of thromboembolic events in non-hospitalized COVID-19 patients: A systematic review

The risk of thromboembolism in non-hospitalized COVID-19 patients remains uncertain and was assessed in this review to better weigh benefits vs. risks of prophylactic anticoagulation in this population. A search was performed through three databases: Medline, Embase, and Cochrane Library until 2022. Self-controlled case series, case-control and cohort studies were included, and findings summarized narratively. Meta-analyses for risk of thromboembolism including deep vein thrombosis (DVT), pulmonary embolism (PE), and myocardial infarction (MI) between COVID-19 and non-COVID-19 non-hospitalized patients were conducted. Frequency, incidence rate ratio (IRR), and risk ratio (RR) of stroke were used to assess risk in non-hospitalized COVID-19 patients considering the lack of studies to conduct a meta-analysis. Ten studies met inclusion criteria characterized by adult non-hospitalized COVID-19 patients. Risk of bias was relatively low. Risk of DVT (RR: 1.98 with 95% CI: 1.03-3.83) and PE (OR: 6.72 with 95% CI: 4.81-9.39 and RR: 4.44 with 95% CI: 1.98-9.99) increased in non-hospitalized COVID-19 patients compared to controls. Risk of MI (OR: 1.91 with 95% CI: 0.89-4.09) is possibly increased in non-hospitalized COVID-19 patients with moderate certainty when compared to controls. A trend in favor of stroke was documented in the first week following infection. Our meta-analyses support the increase in risk of DVT and PE, and likely increase of MI, in non-hospitalized COVID-19 patients. The risk of stroke appears significant in the first week following infection but drops to insignificance two weeks later. More studies are needed to establish evidence-based recommendations for prophylactic anticoagulation therapy in non-hospitalized COVID-19 patients.

Genomic, Proteomic, and Metabolic Comparisons of Small Animal Models of Heart Failure With Preserved Ejection Fraction: A Tale of Mice, Rats, and Cats

Heart failure with preserved ejection fraction (HFpEF) remains a medical anomaly that baffles researchers and physicians alike. The overall phenotypical changes of diastolic function and left ventricular hypertrophy observed in HFpEF are definable; however, the metabolic and molecular alterations that ultimately produce these changes are not well established. Comorbidities such as obesity, hypertension, and diabetes, as well as general aging, play crucial roles in its development and progression. Various animal models have recently been developed to better understand the pathophysiological and metabolic developments in HFpEF and to illuminate novel avenues for pharmacotherapy. These models include multi‐hit rodents and feline aortic constriction animals. Recently, genomic, proteomic, and metabolomic approaches have been used to define altered signaling pathways in the heart associated with HFpEF, including those involved in inflammation, cGMP‐related, Ca²⁺ handling, mitochondrial respiration, and the unfolded protein response in endoplasmic reticulum stress. This article aims to present an overview of what has been learnt by these studies, focusing mainly on the findings in common while highlighting unresolved issues. The knowledge gained from these research models will not simply be of benefit for treating HFpEF but will undoubtedly provide new insights into the mechanisms by which the heart deals with external stresses and how the processes involved can fail.

Abstract 15: The Cardio-renal Effects Of Il-33 Treatment In Myocardial Infarction-induced Kidney Damage

Introduction: Interleukin (IL)-33 is a nuclear alarmin released upon tissue damage and initiating a signaling cascade by binding to its cell membrane receptor ST2. Accumulating evidence shows that the IL-33/ST2 axis mediates both inflammatory and repair responses in different models of kidney diseases, suggesting a Janus-like effect that varies within disease context and progression. This study aimed to investigate the effect of IL-33 administration on acute kidney damage at 4 and 7 days post-MI in mice.

Methods: MI was induced by ligating the left anterior descending coronary artery, followed by IL-33 (1μg/day)/vehicle (PBS) treatment for 4 and 7 consecutive days. Cardiac systolic function was assessed, and kidneys were subjected to histological and molecular analysis.

Results: IL-33 had no significant effect on cardiac hemodynamic parameters at 4 days but significantly decreased the left ventricular ejection fraction (20 ± 1 vs 9.8 ± 2, P<0.01) at 7 days post-MI. In the kidneys, reduced glomerular retraction (0.57 ± 0.09 vs 0.24 ± 0.06, P < 0.05) was observed at day 4 post-MI only, along with a decrease in the protein expression of αSMA (2.89 ± 0.33 vs 0.43 ± 0.13, P < 0.001) and collagen 3 (1.96 ± 0.78 vs 0.34 ± 0.14, P < 0.05). Conversely, increased protein levels of αSMA (0.86 ± 0.42 vs 21.5 ± 2.53, P < 0.0001) and collagen 3 (0.33 ± 0.08 vs 1.71 ± 0.22, P<0.01) were observed at day 7 post-MI. Total renal fibrosis increased to levels comparable to the MI vehicle group at day 4 and 7 post-MI. The mRNA expression of the apoptotic BAX/BCL2 ratio (1.05 ± 0.09 vs 0.36 ± 0.23, P < 0.05) decreased only at day 4 post-MI, whereas an increase in the mRNA levels of the DNA repair enzyme PARP-1 (1.37 ± 0.06 vs 2.05 ± 0.4, P<0.05) was observed at day 7 post-MI. A marked increase in the mRNA expression of Sirtuin 3 (1.87 ± 0.57 vs 11.72 ± 4.24, P < 0.05) and in total renal NAD levels (386.75 ± 40.52 vs 706.36 ± 66.09, P < 0.05) was observed at day 4 post-MI.

Conclusion: Collectively, our findings suggest that although IL-33 treatment improves renal homeostasis 4 days post-MI, this protection is offset by day 7 post-MI through enhanced renal morphological and molecular alterations. The observed renal deterioration between day 4 and day 7 post-MI correlate with aggravated cardiac dysfunction.

Characterization of R-pyocin activity against Gram-positive pathogens for the first time with special focus on Staphylococcus aureus

AIM

This study is aimed at characterization of both antimicrobial and anti-biofilm activity of R-pyocin from clinical Pseudomonas aeruginosa against Gram-positive pathogens including Staphylococcus aureus.

METHODS AND RESULTS

Pyocinogenic P. aeruginosa was detected using reverse-side method, and pyocinogeny typing was confirmed using revised-spotting method. Transmission electron microscopy (TEM) was used for morphological characterization of R-pyocin and for detection of changes in membrane of R-pyocin-treated S. aureus. SDS-PAGE analysis was used for detection of the molecular weight of R-pyocin protein-subunits and Poisson-killing-distribution assay for burst-size calculation. Lipotechoic-acid (LTA) adsorption-assay was used to confirm whether LTA in Gram-positive bacteria served as R-pyocin receptor. Moreover, R-pyocin production at 10-60°C was assessed herein. Host-range of activity of R-pyocin was tested against antimicrobial resistant (AMR) pathogens. The anti-biofilm activity of R-pyocin was detected against sensitive bacterial strains. Chemical, enzymatic, pH and thermo-stability of R-pyocin were evaluated. TEM micrographs revealed a typical morphology of myotailocins indicating the production of R-pyocin designated as RPU15. TEM revealed pores formation in S. aureus membrane, and bacteriophage-like plaques were obvious on plates of R-pyocin-treated S. aureus. R-pyocin activity was neutralized by LTA of S. aureus and Listeria monocytogenes. Pseudomonas aeruginosa PU15 produced ~428 non-inducible R-pyocin particles. RPU15 sheath and tube protein-subunits exhibited a molecular weight of 38 and 23 kDa, respectively. RPU15 possessed activity against S. aureus, L. monocytogenes, Bacillus cereus and Candida albicans and reduced biofilm-biomasses of tested AMR strains.

CONCLUSION

Our results show the potential therapeutic use of R-pyocin due to its effectiveness on tested bacterial biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study that investigates antimicrobial and anti-biofilm activity of R-pyocin activity against S. aureus. R-pyocin shows new phenomenon of bacteriophage-like plaques. Our findings represent a future therapeutic agent targeting both methicillin-resistant and vancomycin-resistant S. aureus.

188 MicroRNA characterization in equine induced pluripotent stem cells

Cell reprogramming has been well described in mouse and human cells. The expression of specific microRNAs has demonstrated to be essential for pluripotent maintenance and cell differentiation, but not much information is available in domestic species. A single microRNA can regulate the expression of hundreds of mRNA targets, a property given by a short sequence (called “seed”) in positions 2 to 8 from the 5′ end that is complementary to the 3′ untranslated region (UTR) tail of specific mRNAs. We aimed to generate horse induced pluripotent stem cells (iPSC), characterise them, and evaluate the expression of different microRNAs (miR-302a, b, c, d, miR-205, miR-145, miR-9, miR-96, miR-125b, and miR-296) in pluripotency and differentiation. Both cell states were evaluated (pluripotency and differentiation) in order to understand more deeply the complex network of transcriptional regulation in different contexts but with the same genomic background. Two equine iPSC lines (named L2 and L3) were characterised after the reprogramming of equine fibroblasts with the 4 human Yamanaka factors (OCT-4, SOX-2, c-MYC, KLF4). The pluripotency of both lines was assessed by phosphatase alkaline activity, expression of OCT-4, NANOG, and REX1 by RT-PCR, and by immunofluorescence of OCT-4, SOX-2, and c-MYC. In vitro differentiation to embryo bodies (EB) showed the capacity of the iPSC to differentiate into ectodermal, endodermal, and mesodermal phenotypes. MicroRNA expression was analysed by quantitative RT-PCR and resulted in higher expression of the miR-302 family, miR-9, and miR-96 in L2 and L3v. fibroblasts (P ≤ 0.05), as previously shown in human pluripotent cells. Moreover, down-regulation of miR-145 and miR-205 was observed. After differentiation to EB, greater expression of miR-96 was observed in the EB compared with iPSC, and the expression of miR-205 was induced but only in the EB-L2. In addition, we performed in silico analysis of horse and human microRNAs. First, we compared the horse-miR-302/367 cluster with the human-miR-302/367 cluster and determined a 75% homology between them. Moreover, the seed region of the horse-miR-302 family resulted complementary to the 3′ UTR of horse cell cycle regulator genes CDK2, CYCLIN D1, and E2F1, and to the 3′ UTR of the RHOC gene, which is involved in the epithelial-mesenchymal transition. The miR-145 seed sequence was complementary to the 3′ UTR region of the OCT-4 and KLF-4 horse genes. With respect to miR-9 and miR-96, the seed sequence of these genes were complementary to the HES1 and PAX-6 genes. In all cases, the same gene targets were previously demonstrated in humans. In conclusion, we report the generation and characterization of equine iPSC and determined for the first time the expression of microRNAs in equine pluripotent cells. Moreover, several results led us to think that the horse microRNAs evaluated herein are highly conserved in sequence and function with respect to the human species. It will now be necessary to generate directed differentiations to derivatives of the 3 germ layers in order to strengthen our results. This is the first report to evaluate the expression and possible targets of microRNAs in pluripotent cells from domestic animals.

Influence of pH, Precursor Concentration, Growth Time, and Temperature on the Morphology of ZnO Nanostructures Grown by the Hydrothermal Method

We investigated the influence of the pH value, precursor concentration (C), growth time and temperature on the morphology of zinc oxide (ZnO) nanostructures. The pH of the starting solution was varied from 1.8 to 12.5. It was found that the final pH reaches an inherent value of 6.6 independently of the initial pH solution. Various ZnO structures of nanotetrapod-like, flower-like, and urchin-like morphology were obtained at alkaline pH (8 to 12.5) whereas for pH solution lower than 8 rod-like nanostructures occurred. Moreover, we observed the erosion of the nanorods for a pH value less than 4.6. By changing the concentrations the density and size were also varied. On going from a high (C>400 mM) to lower (C<25 mM)C, the resulted ZnO nanostructures change from a film to nanorods (NRs) and finally nanowires (NWs). It was also found that the length and diameter of ZnO NRs follow a linear relation with time up to 10 hours, above which no further increase was observed. Finally the effect of growth temperature was seen as an influence on the aspect ratio.

Stable White Light Electroluminescence from Highly Flexible Polymer/ZnO Nanorods Hybrid Heterojunction Grown at 50 degrees C

Stable intrinsic white light-emitting diodes were fabricated from c-axially oriented ZnO nanorods (NRs) grown at 50 degrees C via the chemical bath deposition on top of a multi-layered poly(9,9-dioctylfluorene-co-N-(4-butylpheneylamine)diphenylamine)/poly(9,9dioctyl-fluorene) deposited on PEDOT:PSS on highly flexible plastic substrate. The low growth temperature enables the use of a variety of flexible plastic substrates. The fabricated flexible white light-emitting diode (FWLED) demonstrated good electrical properties and a single broad white emission peak extending from 420 nm and up to 800 nm combining the blue light emission of the polyflourene (PFO) polymer layer with the deep level emission (DLEs) of ZnO NRs. The influence of the temperature variations on the FWLED white emissions characteristics was studied and the devices exhibited high operation stability. Our results are promising for the development of white lighting sources using existing lighting glass bulbs, tubes, and armature technologies.

Inhibitory effects of Sage extract on the growth of enteric bacteria

Antibacterial activity of Sage extract at concentrations of 0.1, 0.05, 0.025, 0.0125, 0.00625, 0.003125, 0.00156, 0.0005 and 0.00025 g dL(-1) against Salmonella typhi, Shigella sonnei, S. flexneri, Proteus vulgaris, Staphylococcus aureus, ETEC Escherichia coli and Pseudomonas aeruginosa was evaluated. Susceptibility testing of bacterial strains against 18 antibiotics was also performed for comparison. The results showed that P. aeruginosa and ETEC E. coli were completely resistant to Sage extract even at concentration of 0.1 g dL(-1). Its antibacterial activity (0.1 g dL(-1)) against P. vulgaris, S. flexneri and S. sonnei was the same as nitrofurantoin and ampicilline respectively. Sage extract (0.1 and 0.05 g dL(-1)) exhibited the same effects as ampicilline and streptomycin against S. typhi. Its antibacterial activity (0.1, 0.05 and 0.25 g dL(-1)) against S. aureus was the same as ceftazidim, chloramphenicol, gentamycin, neomycin and nitrofurantoin and was more significant compared to streptomycin and vancomycin. The results suggest Sage can be considered as an alternative herbal in the treatment of infections caused by the above-mentioned bacteria.

The prevelance and recognition of depression in primary care

In a two stage study of depression, 200 patients attending primary care were randomly investigated. All patients were screened using Beck Depression Inventory (BDI) (Beck & Beamesderfer, 1974) and were interviewed using Clinical Interview for Depression (CID) (Paykel, 1985). Sixty (30%) patients crossed BDI threshold for moderate or severe depression. On CID, forty two (21%) had depression. Being women, divorced or widowed and belonging to unitary families are associated with increased depression. Unemployment and lack of confiding relationship were related to depression The more common manifestations of depression viz. depressed mood, lack of energy and fatigue, decline in work and interest and anorexia had poor discriminatory power for the diagnosis of depression. The depressed patients did not have excess nicotine or alcohol dependence. The treating physicians missed diagnosis of depression in more than two third of patients. Implication of the study for the training of primary care physicians are discussed.

Chronic liver disease in the Alexandria governorate, Egypt: contribution of schistosomiasis and hepatitis virus infections

BACKGROUND/AIMS

In Egypt chronic liver disease is customarily attributed to Schistosoma mansoni infection. Anti-HCV antibodies are highly prevalent among Egyptian blood donors, yet little is known about the risk factors, pathogenicity and virological features of HCV and its association with schistosomiasis. We studied 135 adult patients with chronic liver disease living in the Alexandria governorate, mostly in rural areas of the Nile Delta.

METHODS

Evaluation included abdominal ultrasonography; detection of anti-HCV antibodies and markers of HBV and HDV infection; HCV-RNA assay by 5' untranslated region nested polymerase-chain-reaction and HCV genotyping by a line probe assay; serologic (anti-soluble egg antigen, anti-SEA) and parasitological examinations for Schistosoma mansoni infection; and liver biopsy, if not contraindicated.

RESULTS

Ninety-one (67%) patients had anti-HCV and 107 (85%) anti-SEA, 32 (30%) of whom excreted schistosomal eggs in stools. In addition, 21 (16%) patients had HBsAg, 86 (64%) anti-HBc and four (3%) anti-delta. Thus, many patients had evidence of multiple infections, double in 66% (anti-HCV and anti-SEA), triple in 33% (anti-HCV HBsAg and anti-SEA). Based on our diagnostic criteria, 25 (19%) patients had schistosomal portal fibrosis (anti-HCV positive in eight), 24 (18%) chronic hepatitis (anti-HCV positive in 19), 76 (56%) cirrhosis (anti-HCV positive in 58) and 10 hepatic tumors (anti-HCV positive in six). At multivariate analysis, the presence of anti-HCV was independently associated with previous parenteral anti-schistosomal therapy, a history of hematemesis and seropositivity for anti-HBc. Fifty (55%) of 91 anti-HCV positive sera had HCV-RNA, in 41 cases classified as genotype 4a. Detection of HCV-RNA was associated with a more severe liver disease and occurred less frequently in patients with a history of schistosomiasis.

CONCLUSIONS

HCV infection with genotype 4a is the main cause of severe chronic liver disease in Egypt, where it is highly associated with schistosomiasis.

Pharmacokinetics of an anti-human immunodeficiency virus antisense oligodeoxynucleotide phosphorothioate (GEM 91) in HIV-infected subjects

Human pharmacokinetics of an antisense oligodeoxynucleotide phosphorothioate (GEM 91) developed as an anti-human immunodeficiency virus (HIV) agent was carried out in this study. 35S-Labeled GEM 91 was administered to six HIV-infected individuals by means of 2-hour intravenous infusions at a dose of 0.1 mg/kg. Plasma disappearance curves for GEM 91-derived radioactivity could be described by the sum of two exponentials, with half-life values of 0.18 +/- 0.04 and 26.71 +/- 1.67 hours. The radioactivity in plasma was further evaluated by polyacrylamide gel electrophoresis, showing the presence of both intact GEM 91 and lower molecular weight metabolites. Urinary excretion represented the major pathway of elimination, with 49.15% +/- 6.80% of the administered dose excreted within 24 hours and 70.37% +/- 6.72% over 96 hours after dosing. The radioactivity in urine was associated with lower molecular weight metabolites. No drug-related toxicity was observed.