Gut microbiota dysbiosis in AKI to CKD transition

BACKGROUND AND AIM

The symptoms of acute kidney injury (AKI) include a sudden drop-in glomerular filtration rate (GFR), a rise in serum creatinine (sCr), blood urea nitrogen (BUN), and electrolytes, which leads to a rapid loss of kidney function. Chronic kidney disease progresses when AKI symptoms persist for over three months or 90 days. Numerous prevalent secondary risk factors, including diabetes, hypertension, obesity, and heart illness, are directly or indirectly linked to the development of AKI and the switch from AKI to CKD. Recently, the change of intestinal bacteria known as "gut dysbiosis" has been linked to distant organ dysfunction, including the heart, lungs, kidneys, and brain. Indirectly or directly, gut dysbiosis contributes to the progression of CKD and AKI. However, the effects of gut dysbiosis and the mechanism of action in the progression from AKI to CKD are unknown or need further investigation. The mechanism by which gut dysbiosis initiates AKI's progression to CKD should be explicitly concerned. The review primarily focuses on the action of gut dysbiosis in kidney disease, the effects of dysbiosis, the characterisation of dysbiosis and its pathogenic products, the various pathogenic routes and mechanism involved in expediting the transition from AKI to CKD.

CONCLUSION

We identified and briefly reviewed the impacts of dysbiosis in various situations such as hypoxia, mitochondrial induced reactive oxygen species (mtROS), aryl hydrocarbon receptor (AhR) activation and microbiota derived uremic toxemic substances profoundly to push AKI to CKD conditions.

Hyperbaric oxygen therapy and chemokine administration - a combination with potential therapeutic value for treating diabetic wounds

Non-healing wounds impart serious medical problems to people with diabetes. Amongst 15% of diabetic patients, the incidence of foot ulcer is the most prevailing, which confers a significant risk of limb amputation, mainly due to hypoxia and impairment in cell signaling. Alteration in the expression of chemokines and the related factors in diabetic conditions delays the recruitment of different cell types, including fibroblasts, keratinocytes, and immune cells such as macrophages to the site of injury, further impairing neovasculogenesis, re-epithelialization, and extracellular matrix formation. Thus, proper activation of effector cells through an accurate signal pathway is necessary for better therapeutic application. Hyperbaric oxygen therapy (HBOT) is the current treatment prescribed by medical practitioners, shown to have increased the wound healing rate by reducing the need for significant amputation among the diabetic population. However, the risk of morbidity associated with HBOT needs complete attention through rigorous research to avoid adverse outcomes. Altering the level of pro-angiogenic chemokines may regulate the inflammatory response, further promote vascularization, and enhance the complete healing of wounds in diabetic patients. Thus, a combination of better therapeutic approaches could pave the way for developing a successful treatment for diabetic foot and wound healing.

Oxalobacter formigenes: A new hope as a live biotherapeutic agent in the management of calcium oxalate renal stones

Recent advances in understanding the association of gut microbiota with the host have shown evidence of certain bacterial therapeutic potentiality in preventing and treating metabolic diseases. Hyperoxaluria is a severe challenge in nephrology and has led to the novel gut eubiosis as current therapy. The human gut commensal, obligate anaerobic, and intestinal oxalate-degrading strains of Oxalobacter formigenes have drawn a promising significant interest for the next-generation probiotics (NGPs). This nonpathogenic, potential probiotic, and specialist oxalotrophic properties of O. formigenes give a new hope as a live biotherapeutic agent for calcium oxalate renal therapy. Numerous satisfactory outcomes of in vitro and in vivo studies were achieved on evaluating O. formigenes functionality, but the commercial production of this bacterium is yet to be achieved. This bacterium finds diverse application in dietary and endogenous oxalate degradation and the improvement of gut health, on which we concentrated our attention in this review. The relationship between good anaerobic gut bacterial dysbiosis and renal complications is comprehensively discussed to address the need for the development probiotic formulation. However, the commercial production of this bacteria on a broad scale is complex, with numerous obstacles, mainly because they are oxygen-sensitive and difficult to culture. This review will coherently present the current and available methodologies in producing, stabilizing, and delivering these NGPs to treat calcium stones. Moreover, the study presents the extensive work and key milestones achieved in the research on O. formigenes from tale to the truth.

Combined effect of polyacrylic acid and vitamin E in preventing calcium oxalate crystal deposition in the kidneys of experimental hyperoxaluric rats

Our study explores the combined effect of polyacrylic acid and vitamin E as prophylactic and curative agent against ethylene glycol (EG) induced calcium oxalate stone formation in Wistar rats. Male Wistar rats (54) were divided into nine groups, including control. The experimental groups were equally segregated into two for preventive study (4) and curative study (4). Urolithiasis was induced with 0.75% (v/v) EG in drinking water. Polyacrylic acid (10 mg/kg) and vitamin E (300 IU/day) were supplemented from day 1 for preventive and day 30 for curative studies. Restoration of urinary lithogenic factors (calcium, oxalate, phosphate, citrate and magnesium) and renal function (urea and creatinine in serum) by intervening agents were accomplished compared to urolithic rats (P < .001). Abnormal localization and increased expression of Tamm-Horsfall Protein, osteopontin and transferrin were observed in the kidneys of urolithic rats (P < .001) from immunohistochemistry and immunoblotting analysis. Polyacrylic acid and vitamin E supplementation have regulated the expression of the urinary macromolecules. Pro-inflammatory cytokines in kidney were significantly reduced (P < .001) by the intervening agents compared to urolithic rats. Therefore, polyacrylic acid and vitamin E in combination could be a potential formulation for better management of urolithiasis.

Prevalence and Morphological Pattern of Haematopoietic Malignancy Involving Oral Cavity at a Tertiary Care Hospital, Chengalpattu District, Tamil Nadu, India

Introduction: Lymphomas, a cancer of lymphoid tissue (either B-or T-lymphocytes) are the second most common malignant tumour in the head and neck after squamous cell carcinoma. Extranodal Non-Hodgkin’s Lymphoma (NHL) in the oral cavity is thought to be rather uncommon. Aim: To study the prevalence and morphology of oral cavity-related haematopoietic malignancies. Materials and Methods: A descriptive cross-sectional study on 1089 cases of oral lesions at a Karpaga Vinayaga Institute of Medical Sciences and Research Centre, Chengalpattu, Tamil Nadu, India, was undertaken in the Pathology Department from July 2012 to July 2022. Demographic information including age, sex, clinical information, histopathological diagnosis, and investigational details were recorded. Morphology of oral cavity lesion was considered as primary outcome variable and the data was represented in frequency and percentage and the descriptive analysis was done using Statistical Package for Social Sciences (SPSS) version 22.0. Results: A total of 1089 patients, age distribution range from 10-70 years were analysed in this study. Majority were noted among 41-50 years 423 (38.8%), followed by 51-60 years 257 (23.5%). Buccal mucosa was the commonest site for lymphomas constituting 510 (46.8%), gingiva occupied 132 (12.2%). All Non-Hodgkins Lymphoma (NHL) (N=3) cases were reported as B cell lymphoma constituting 03 (100%). Conclusion: Non Hodgkins Lymphoma in oral cavity is very rare in occurrence and amongst them B-cell form of oral NHL was more frequent. It should always be considered in the differential diagnosis of intraoral malignant diseases.

High-quality whole-genome sequence analysis of Lactobacillus paragasseri UBLG-36 reveals oxalate-degrading potential of the strain

Lactobacillus paragasseri was identified as a novel sister taxon of L. gasseri in 2018. Since the reclassification of L. paragasseri, there has been hardly any report describing the probiotic properties of this species. In this study, an L. paragasseri strain UBLG-36 was sequenced and analyzed to determine the molecular basis that may confer the bacteria with probiotic potential. UBLG-36 was previously documented as an L. gasseri strain. Average nucleotide identity and phylogenomic analysis allowed accurate taxonomic identification of UBLG-36 as an L. paragasseri strain. Analysis of the draft genome (~1.94 Mb) showed that UBLG-36 contains 5 contigs with an average G+C content of 34.85%. Genes essential for the biosynthesis of bacteriocins, adhesion to host epithelium, stress resistance, host immunomodulation, defense, and carbohydrate metabolism were identified in the genome. Interestingly, L. paragasseri UBLG-36 also harbored genes that code for enzymes involved in oxalate catabolism, such as formyl coenzyme A transferase (frc) and oxalyl coenzyme A decarboxylase (oxc). In vitro oxalate degradation assay showed that UBLG-36 is highly effective in degrading oxalate (averaging more than 45% degradation), a feature that has not been reported before. As a recently identified bacterium, there are limited genomic reports on L. paragasseri, and our draft genome sequence analysis is the first to describe and emphasize the probiotic potential and oxalate degrading ability of this species. With results supporting the probiotic functionalities and oxalate catabolism of UBLG-36, we propose that this strain is likely to have immense biotechnological applications upon appropriate characterization.

Predisposition of Blood group Non-secretors to Urinary tract infection with Escherichia coli Anti-microbial Resistance and Acute Kidney Injury

Urinary tract infection (UTI) causes significant renal damage and disease severity is compounded by antimicrobial resistance (AMR) and other comorbidities in the patient. Blood group antigens secreted in body fluids (secretor status) are known to play a role in bacterial adhesion and we studied its influence on AMR in UTI. A total of 2758 patients with UTI were studied with urine culture, qualitative and semiquantitative urine microscopy, serum creatinine and secretor status in saliva samples by adsorption-inhibition method. Of these, AMR from 300 patients with E. coli infection were assessed as per CLSI 2019 guidelines and extended-spectrum beta-lactamase (ESBL) genes (bla TEM, bla CTX-M, bla SHV) and NDM1 genes were studied using TaqMan probes in Real-time polymerase chain reaction. Patients with UTI were followed up for two weeks. Female patients had higher predilection (57%) for E. coli infection while patients with diabetes or non-secretors had none. In our study, ESBL producers were seen in 62% of the E. coli isolates and fosfomycin had 100% susceptibility. Non-secretors were significantly associated with acute kidney injury (AKI), AMR and ESBL genes. Multidrug-resistance (MDR) was noted in 127/160 (79.4%) ESBL and 17/18 (94%) NDM1 gene encoding strains. Quantitative urine microscopy scoring predicted AKI both at presentation and at end of follow up. ESBL producers were common in our study population and non-secretors had a significant association with AMR genes. Urine microscopy scoring system may be a useful tool to predict AKI in patients with UTI.

Long noncoding RNAs in the regulation of p53-mediated apoptosis in human cancers

Long noncoding RNAs (lncRNAs) are widely known for their regulatory function in transcriptional and posttranscriptional processes. The involvement of such non-protein-coding RNAs in nuclear organization and chromatin remodeling is often associated with an increased risk of human malignancies. In cancer, lncRNAs either promote cell survival or may act as a growth suppressor, thus conferring a key regulatory function other than their established role in fundamental cellular processes. Interestingly, lncRNAs interfere with the stages of apoptosis and related pathways involving p53. Many of these molecules either regulate or are regulated by p53 while mounting oncogenic events. Consequently, they may confer both prosurvival or proapoptotic functions depending upon the tissue type. Since the mechanism of cell death is bypassed in many human cancers, it has emerged that the lncRNAs are either overexpressed or knocked down to sensitize cells to apoptotic stimuli. Nonetheless, the abundant expression of lncRNAs in tumor cells renders them suitable targets for anticancer therapies. Although the role of lncRNAs in the p53 network and apoptosis has been independently defined, their interplay in activating p53-target genes during cell cycle arrest remains unexplored. Thus, we have specifically reviewed the possible involvement of lncRNAs in the p53-mediated apoptosis of human cancer cells. In particular, we summarize the growing evidence from individual studies and analyze whether lncRNAs are essential to facilitate apoptosis in a p53-dependent manner. This may lead to the identification of p53-associated lncRNAs that are suitable therapeutic targets or diagnostic/prognostic markers.

Biofilm inhibition and antifouling evaluation of sol-gel coated silicone implants with prolonged release of eugenol against Pseudomonas aeruginosa

The incidence of biofilm-linked catheter-associated urinary tract infections (CAUTIs) is increasing across the world. However, there is no clinical evidence to support the modifications of biomaterials, such as antimicrobial agent-coated catheters, that are known to reduce the risk of bacterial colonization and resistance development. The present study developed and tested silicone segments coated with an antivirulence agent, eugenol. The parameters for sol-gel preparation and coating were tailored to achieve a prolonged release of eugenol (for >35 days) at predefined antivirulence doses from dip-coated thin films. The eugenol-coated segments could prevent biofilm formation by Pseudomonas aeruginosa PAO1 as well as bacterial adhesion. Significant repression in the expression of virulence and biofilm-associated genes were recorded, confirming the antivirulence and biofilm inhibition properties of silicone segments coated with eugenol. The drug release profiles, efficacy analysis, neutrophil-response studies, and in vitro toxicity profiling further supported the contention that the activity of the eugenol-coated sections was effective and safe.

Ferrotoxicity and Its Amelioration by Calcitriol in Cultured Renal Cells

Globally, acute kidney injury (AKI) is associated with significant mortality and an enormous economic burden. Whereas iron is essential for metabolically active renal cells, it has the potential to cause renal cytotoxicity by promoting Fenton chemistry-based oxidative stress involving lipid peroxidation. In addition, 1,25-dihydroxyvitamin D3 (calcitriol), the active form of vitamin D, is reported to have an antioxidative role. In this study, we intended to demonstrate the impact of vitamin D on iron-mediated oxidant stress and cytotoxicity of Vero cells exposed to iohexol, a low osmolar iodine-containing contrast media in vitro. Cultured Vero cells were pretreated with 1,25-dihydroxyvitamin D3 dissolved in absolute ethanol (0.05%, 2.0 mM) at a dose of 1 mM for 6 hours. Subsequently, iohexol was added at a concentration of 100 mg iodine per mL and incubated for 3 hours. Total cellular iron content was analysed by a flame atomic absorption spectrophotometer at 372 nm. Lipid peroxidation was determined by TBARS (thiobarbituric acid reactive species) assay. Antioxidants including total thiol content were assessed by Ellman’s method, catalase by colorimetric method, and superoxide dismutase (SOD) by nitroblue tetrazolium assay. The cells were stained with DAPI (4 ${}^{\prime }$ ,6-diamidino-2-phenylindole), and the cytotoxicity was evaluated by viability assay (MTT assay). The results indicated that iohexol exposure caused a significant increase of the total iron content in Vero cells. A concomitant increase of lipid peroxidation and decrease of total thiol protein levels, catalase, and superoxide dismutase activity were observed along with decreased cell viability in comparison with the controls. Furthermore, these changes were significantly reversed when the cells were pretreated with vitamin D prior to incubation with iohexol. Our findings of this in vitro model of iohexol-induced renotoxicity lend further support to the nephrotoxic potential of iron and underpin the possible clinical utility of vitamin D for the treatment and prevention of AKI.

High-quality whole-genome sequence analysis of Lactobacillus paragasseri UBLG-36 reveals oxalate-degrading potential of the strain

Lactobacillus paragasseri was identified as a novel sister taxon of L. gasseri in 2018. Since the reclassification of L. paragasseri, there has been hardly any report describing the probiotic properties of this species. In this study, an L. paragasseri strain UBLG-36 was sequenced and analyzed to determine the molecular basis that may confer the bacteria with probiotic potential. UBLG-36 was previously documented as an L. gasseri strain. Average nucleotide identity and phylogenomic analysis allowed accurate taxonomic identification of UBLG-36 as an L. paragasseri strain. Analysis of the draft genome (~1.94 Mb) showed that UBLG-36 contains 5 contigs with an average G+C content of 34.85%. Genes essential for the biosynthesis of bacteriocins, adhesion to host epithelium, stress resistance, host immunomodulation, defense, and carbohydrate metabolism were identified in the genome. Interestingly, L. paragasseri UBLG-36 also harbored genes that code for enzymes involved in oxalate catabolism, such as formyl coenzyme A transferase (frc) and oxalyl coenzyme A decarboxylase (oxc). In vitro oxalate degradation assay showed that UBLG-36 is highly effective in degrading oxalate (averaging more than 45% degradation), a feature that has not been reported before. As a recently identified bacterium, there are limited genomic reports on L. paragasseri, and our draft genome sequence analysis is the first to describe and emphasize the probiotic potential and oxalate degrading ability of this species. With results supporting the probiotic functionalities and oxalate catabolism of UBLG-36, we propose that this strain is likely to have immense biotechnological applications upon appropriate characterization.

Ferrotoxicity and Its Amelioration by Calcitriol in Cultured Renal Cells

Globally, acute kidney injury (AKI) is associated with significant mortality and an enormous economic burden. Whereas iron is essential for metabolically active renal cells, it has the potential to cause renal cytotoxicity by promoting Fenton chemistry-based oxidative stress involving lipid peroxidation. In addition, 1,25-dihydroxyvitamin D3 (calcitriol), the active form of vitamin D, is reported to have an antioxidative role. In this study, we intended to demonstrate the impact of vitamin D on iron-mediated oxidant stress and cytotoxicity of Vero cells exposed to iohexol, a low osmolar iodine-containing contrast media in vitro. Cultured Vero cells were pretreated with 1,25-dihydroxyvitamin D3 dissolved in absolute ethanol (0.05%, 2.0 mM) at a dose of 1 mM for 6 hours. Subsequently, iohexol was added at a concentration of 100 mg iodine per mL and incubated for 3 hours. Total cellular iron content was analysed by a flame atomic absorption spectrophotometer at 372 nm. Lipid peroxidation was determined by TBARS (thiobarbituric acid reactive species) assay. Antioxidants including total thiol content were assessed by Ellman's method, catalase by colorimetric method, and superoxide dismutase (SOD) by nitroblue tetrazolium assay. The cells were stained with DAPI (4',6-diamidino-2-phenylindole), and the cytotoxicity was evaluated by viability assay (MTT assay). The results indicated that iohexol exposure caused a significant increase of the total iron content in Vero cells. A concomitant increase of lipid peroxidation and decrease of total thiol protein levels, catalase, and superoxide dismutase activity were observed along with decreased cell viability in comparison with the controls. Furthermore, these changes were significantly reversed when the cells were pretreated with vitamin D prior to incubation with iohexol. Our findings of this in vitro model of iohexol-induced renotoxicity lend further support to the nephrotoxic potential of iron and underpin the possible clinical utility of vitamin D for the treatment and prevention of AKI.

Ferrotoxicity and its amelioration by endogenous vitamin D in experimental acute kidney injury

This work provides in-depth insights on catalytic iron-induced cytotoxicity and the resultant triggering of endogenous vitamin D synthesis in experimental acute kidney injury. Our results reveal significantly elevated levels of catalytic iron culminating in oxidant-mediated renal injury and a concomitant increase in 1,25-dihdyroxyvitamin D3 levels. Also, changes in other iron-related proteins including transferrin, ferritin, and hepcidin were observed both in the serum as well as in their mRNA expression. We consider all these findings vital since no connection between catalytic iron and vitamin D has been established so far. Furthermore, we believe that this work provides new and interesting results, with catalytic iron emerging as an important target in ameliorating renal cellular injury, possibly by timely administration of vitamin D. It also needs to be seen if these observations made in rats could be translated to humans by means of robust clinical trials.

Ferrotoxicity and its amelioration by endogenous vitamin D in experimental acute kidney injury

Acute kidney injury causes significant morbidity and mortality. This experimental animal study investigated the simultaneous impact of iron and vitamin D on acute kidney injury induced by iohexol, an iodinated, non-ionic monomeric radiocontrast agent in Wistar rats. Out of 36 healthy male Wistar rats, saline was injected into six control rats (group 1) and iohexol into the remaining 30 experimental rats (groups 2 to 6 comprising six rats each). Biochemical, renal histological changes, and gene expression of iron-regulating proteins and 1 α-hydroxylase were analyzed. Urinary neutrophil gelatinase-associated lipocalin (NGAL), serum creatinine, urine protein, serum and urine catalytic iron, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and tissue lipid peroxidation were assayed. Rats injected with iohexol showed elevated urinary NGAL (11.94 ± 6.79 ng/mL), serum creatinine (2.92 ± 0.91 mg/dL), and urinary protein levels (11.03 ± 9.68 mg/mg creatinine) together with histological evidence of tubular injury and iron accumulation. Gene expression of iron-regulating proteins and 1 α-hydroxylase was altered. Serum and urine catalytic iron levels were elevated (0.57 ± 0.17; 48.95 ± 29.13 µmol/L) compared to controls (0.49 ± 0.04; 20.7 ± 2.62 µmol/L, P < 0.001). Urine catalytic iron positively correlated with tissue peroxidation (r = 0.469, CI 0.122 to 0.667, P = 0.004) and urinary NGAL (r = 0.788, CI 0.620 to 0.887, P < 0.001). 25-hydroxyvitamin D3 (61.58 ± 9.60 ng/mL) and 1,25-dihydroxyvitamin D3 (50.44 ± 19.76 pg/mL) levels increased simultaneously. In a multivariate linear regression analysis, serum iron, urine catalytic iron, and tissue lipid peroxidation independently and positively predicted urinary NGAL, an acute kidney injury biomarker. This study highlights the nephrotoxic potential of catalytic iron besides demonstrating a concurrent induction of vitamin D endogenously for possible renoprotection in acute kidney injury.

Impact statement

This work provides in-depth insights on catalytic iron-induced cytotoxicity and the resultant triggering of endogenous vitamin D synthesis in experimental acute kidney injury. Our results reveal significantly elevated levels of catalytic iron culminating in oxidant-mediated renal injury and a concomitant increase in 1,25-dihdyroxyvitamin D3 levels. Also, changes in other iron-related proteins including transferrin, ferritin, and hepcidin were observed both in the serum as well as in their mRNA expression. We consider all these findings vital since no connection between catalytic iron and vitamin D has been established so far. Furthermore, we believe that this work provides new and interesting results, with catalytic iron emerging as an important target in ameliorating renal cellular injury, possibly by timely administration of vitamin D. It also needs to be seen if these observations made in rats could be translated to humans by means of robust clinical trials.

Kinetics and Computational Evaluation of Eugenol and Vanillic Acid on Inhibition of a Potential Enzyme of a Nosocomial Pathogen that Promotes Struvite Formation

Background:

Struvite/infection stone is one of the major clinical burdens in urinary tract infections that is caused by the ureolytic behavior of pathogenic bacteria.

Objective:

The current strategy for treating infective stones is mostly antibiotic therapy, which ends in promoting resistance to the organisms. Hence in the present study, we investigated two phytocompounds, eugenol (an allyl-substituted guaiacol) and vanillic acid (a phenolic acid) that are found to be effective in inhibiting the urease enzyme of a nosocomial pathogen Proteus mirabilis.

Methods:

The enzyme was purified to apparent homogeneity and the kinetic parameters were studied in the presence and in the absence of eugenol and vanillic acid. Molecular docking and simulation were done to understand the level of protein-ligand interactions and the interacting residues.

Results:

Kinetic parameters obtained from the Michaelis-Menten plot show that both eugenol and vanillic acid exhibit non-competitive inhibition of urease enzyme in a dose-dependent manner. In silico studies showed that eugenol and vanillic acid have almost similar binding affinities to the regulatory pocket of the modeled protein. Dynamics and simulation results indicate that the interaction of ligands with the ARG373 residue of the protein provides a stable bound conformation.

Conclusion:

Overall, our results suggest that both the phytocompounds eugenol and vanillic acid have a potential application as a new therapy for the inhibition of urease enzyme that could possibly replace the complexions related to struvite stone formation.

Potential application of nanoemulsified garlic oil blend in mitigating the progression of type 2 diabetes-mediated nephropathy in Wistar rats

The renoprotective potential of nanoemulsified garlic oil blend (GNE) in alleviating the progressive stages of hyperlipidemia-mediated diabetic nephropathy was examined. The study was carried out in high fat-fed, streptozotocin-induced type 2 diabetic Wistar rats for five months. The diabetic rats showed a significant increase of area under the curve in OGTT (p < 0.01) and IPITT (p < 0.01), increased urinary albumin (p < 0.01), urinary microprotein (p < 0.001), total cholesterol (p < 0.01), triglycerides (p < 0.001) and LDL cholesterol (p < 0.001), with decreased serum albumin (p < 0.01), serum protein (p < 0.001) and HDL-cholesterol levels (p < 0.05) than the control rats. The histopathological analysis evidenced mesangial expansion and hypercellularity at the end of the first and third month, and glomerulosclerosis and tubular atrophy at the end of the fifth month in diabetic rats. Moreover, on disease progression, increase in urinary podocalyxin, NGAL and CD36 was observed, and the renal mRNA and protein expression of podocalyxin decreased significantly with a concomitant increase in NGAL and CD36 expression from first till fifth month end. The treatment with GNE (20 mg/kg) significantly ameliorated the serum albumin (p < 0.001) and urine albumin (p < 0.01) from the end of the third month with significant attenuation in the lipid profile than GO (20 mg/kg) or Ator (8 mg/kg). Moreover, GNE reverted the histopathological alterations and attenuated the aberrant mRNA, protein expression and urinary excretion level of renal CD36, podocalyxin and NGAL in diabetic rats from an early stage of disease till the end of the study period. This study demonstrated the enhanced efficacy of GO in nanoemulsified form in mitigating the progression of nephropathy in type 2 diabetic rats.

Sulphated polysaccharide from Sargassum myriocystum confers protection against gentamicin-induced nephrotoxicity in adult zebrafish

The beneficial effect of purified fraction of sulphated polysaccharide extracted from Sargassum myriocystum (SMP) was examined on the gentamicin-induced nephrotoxicity in adult zebrafish. The major purified fractions (SMP1, SMP2 and SMP3) were obtained by anion-exchange and size-exclusion chromatography and characterized by FTIR, GCMS and NMR. The in vitro antioxidant activities of all purified SMP fractions were analysed. The SMP2 showed maximum carbohydrate, sulphate and fucose content with strong antioxidant activity than other fractions. Further, we evaluated the efficacy of SMP2 against gentamicin-induced nephrotoxicity in zebrafish model. The SMP2 administered group showed a significant attenuation in oxidative stress and histopathological alterations observed in renal tissues of gentamicin treated group. Moreover, the SMP2 supressed renal mRNA expression levels of KIM-1, NF-κB, TNF-α and IL-6 in dose-dependent manner. Thus, the present study suggests that the SMP2 is a potent antioxidant with anti-inflammatory and renoprotective properties that ameliorated the GEN induced nephrotoxicity in adult zebrafish.

Enhanced Therapeutic Potency of Nanoemulsified Garlic Oil Blend Towards Renal Abnormalities in Pre-diabetic Rats

The therapeutic potency of ultrasonic nanoemulsified garlic oil blend using a non-ionic surfactant (Tween 80) was assessed on pre-diabetic Wistar rats with microalbuminuria. The pre-diabetic condition was induced in male albino Wistar rats by supplementing high-fat diet. The prolonged period of the pre-diabetic state caused renal dysfunctioning, which was indicated by microalbuminuria. Treatment of pre-diabetic rats with nanoemulsified garlic oil blend significantly ameliorated the lipid profile (p < 0.001), urinary albumin (p < 0.01), microprotein (p < 0.001), urinary triglycerides (p < 0.01), serum triglycerides (p < 0.01), serum albumin (p < 0.05), and protein levels (p < 0.01) in comparison to treatment of pre-diabetic rats with garlic oil blend or atorvastatin. Similarly, histopathological investigations indicated a remarkable attenuation in the mesangial expansion and proliferation, glomerular and tubular basement membrane thickening, and the tubular lipid deposits on administering nanoemulsified garlic oil blend than garlic oil blend or atorvastatin. Moreover, nanoemulsified garlic oil blend significantly promoted renal podocin gene expression by 3.98-fold (p < 0.001) and attenuated increased urinary podocin level by 2.92-fold (p < 0.01). Thus, our study affirms that the efficacy of garlic oil blend was augmented upon nanoemulsification, which substantially ameliorated the renal abnormalities observed in the pre-diabetic condition than garlic oil blend or atorvastatin.

Anti-virulence potential of eugenol-rich fraction of Syzygium aromaticum against multidrug resistant uropathogens isolated from catheterized patients

Objective:

Considering the emergence of biofilm-associated pathogens with multidrug resistance, the objective(s) of the present study was to evaluate the anti-virulence property of Syzygium aromaticum extracts/fractions against 2 multidrug-resistant catheter isolates.

Materials and Methods:

Pulverized clove buds were subjected to bioactivity-guided isolation to identify the bioactive extract/fraction(s) with significant anti-virulence property. The clove bud powder was subjected to Soxhlet extraction and all these extracts were investigated in terms of anti-virulent efficacy using initial readout assays. Bioassay-guided partial purification was performed through column and size exclusion chromatography. Detailed testing of the anti-virulence and anti-biofilm activity of sub-minimum inhibitory concentration (sub-MIC) levels of the active fraction, was performed besides the cytotoxicity profiling in RAW 264.7 cells.

Results:

Gas chromatography-mass spectrometry (GC-MS) analysis of the clove bioactive fraction-2 (CBF-2), done after the bioassay-guided fractionation, revealed eugenol as the major bioactive ingredient present in CBF-2. Reduced mRNA levels of virulence factor genes after CBF-2 (700 μg/ml) treatment correlated well with the respective phenotypic assays (p<0.001). Similarly, CBF-2 (700 μg/ml) treatment exhibited significantly low mRNA levels of quorum sensing (QS) receptor genes compared to their cognate synthase genes (p<0.001). Crystal violet staining and scanning electron micrographs of CBF-2-treated biofilms showed lesser macrocolonies with remarkably simplified architecture. Cytotoxic evaluation of CBF-2 suggested a minute reduction in viability even at the highest tested concentration (1600 μg/ml, p<0.05).

Conclusion:

The present study indicated that eugenol-rich CBF-2 has potent anti-virulence and anti-biofilm activity against urinary catheter isolates and can be regarded as an alternative for treatment of catheter-associated urinary tract infections.

A random-matrix theory of the number sense

Number sense, a spontaneous ability to process approximate numbers, has been documented in human adults, infants and newborns, and many other animals. Species as distant as monkeys and crows exhibit very similar neurons tuned to specific numerosities. How number sense can emerge in the absence of learning or fine tuning is currently unknown. We introduce a random-matrix theory of self-organized neural states where numbers are coded by vectors of activation across multiple units, and where the vector codes for successive integers are obtained through multiplication by a fixed but random matrix. This cortical implementation of the 'von Mises' algorithm explains many otherwise disconnected observations ranging from neural tuning curves in monkeys to looking times in neonates and cortical numerotopy in adults. The theory clarifies the origin of Weber-Fechner's Law and yields a novel and empirically validated prediction of multi-peak number neurons. Random matrices constitute a novel mechanism for the emergence of brain states coding for quantity.This article is part of a discussion meeting issue 'The origins of numerical abilities'.

Methylation-Demethylation Dynamics: Implications of Changes in Acute Kidney Injury

Over the years, the epigenetic landscape has grown increasingly complex. Until recently, methylation of DNA and histones was considered one of the most important epigenetic modifications. However, with the discovery of enzymes involved in the demethylation process, several exciting prospects have emerged that focus on the dynamic regulation of methylation and its crucial role in development and disease. An interplay of the methylation-demethylation machinery controls the process of gene expression. Since acute kidney injury (AKI), a major risk factor for chronic kidney disease and death, is characterised by aberrant expression of genes, understanding the dynamics of methylation and demethylation will provide new insights into the intricacies of the disease. Research on epigenetics in AKI has only made its mark in the recent years but has provided compelling evidence that implicates the involvement of methylation and demethylation changes in its pathophysiology. In this review, we explore the role of methylation and demethylation machinery in cellular epigenetic control and further discuss the contribution of methylomic changes and histone modifications to the pathophysiology of AKI.

Proanthocyanidins-Will they effectively restrain conspicuous bacterial strains devolving on urinary tract infection?

Struvite or infection stones are one of the major clinical burdens among urinary tract infection, which occur due to the interaction between microbes and urine mineral components. Numerous urinary tract infection (UTI) causing microbes regulate through biofilm formation for survival from host defense, it is often found difficult in its eradication with simple anti-microbial agents and also the chance of recurrence and resistance development is significantly high. Cranberry consumption and maintenance of urinary tract health have been supported by clinical, epidemiological, and mechanistic studies. It predominantly contains proanthocyanidins that belong to the class of polyphenols with repeating catechin and epicatechin monomeric units. Numerous studies have correlated proanthocyanidin consumption and prevention of bacterial adhesion to uroepithelial cells. Quorum sensing (QS) is the prime mechanism that drives bacteria to coordinate biofilm development and virulence expression. Reports have shown that proanthocyanidins are effective in disrupting cell-cell communication by quenching signal molecules. Overall, this review assesses the merits of proanthocyanidins and its effective oppression on adherence, motility, QS, and biofilm formation of major UTI strains such as Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis by comparing and evaluating results from many significant findings.

Methylation-Demethylation Dynamics: Implications of Changes in Acute Kidney Injury

Over the years, the epigenetic landscape has grown increasingly complex. Until recently, methylation of DNA and histones was considered one of the most important epigenetic modifications. However, with the discovery of enzymes involved in the demethylation process, several exciting prospects have emerged that focus on the dynamic regulation of methylation and its crucial role in development and disease. An interplay of the methylation-demethylation machinery controls the process of gene expression. Since acute kidney injury (AKI), a major risk factor for chronic kidney disease and death, is characterised by aberrant expression of genes, understanding the dynamics of methylation and demethylation will provide new insights into the intricacies of the disease. Research on epigenetics in AKI has only made its mark in the recent years but has provided compelling evidence that implicates the involvement of methylation and demethylation changes in its pathophysiology. In this review, we explore the role of methylation and demethylation machinery in cellular epigenetic control and further discuss the contribution of methylomic changes and histone modifications to the pathophysiology of AKI.

Eugenol exhibits anti-virulence properties by competitively binding to quorum sensing receptors

The primary objective of this study was to ascertain the anti-biofilm and anti-virulence properties of sub-minimum inhibitory concentration (MIC) levels of eugenol against the standard strain PAO1 and two multi-drug resistant P. aeruginosa clinical isolates utilizing quorum sensing inhibition (QSI). Eugenol at 400 μM significantly reduced biofilm formation on urinary catheters and the virulence factors (VF) including extracellular polysaccharides, rhamnolipid, elastase, protease, pyocyanin, and pyoverdine (p < 0.001). Further, eugenol exhibited a marked effect on the production of QS signals (AIs) (p < 0.001) without affecting their chemical integrity. In silico docking studies demonstrated a stable molecular binding between eugenol and QS receptor(s) in comparison with respective AIs. Investigation on reporter strains confirmed the competitive binding of eugenol to a QS receptor (LasR) as the possible QSI mechanism leading to significant repression of QS associated genes besides the VF genes (p < 0.001). This study provides insights, for the first time, into the mechanism of the anti-virulence properties of eugenol.

Evaluation of garlic oil in nano-emulsified form: Optimization and its efficacy in high-fat diet induced dyslipidemia in Wistar rats

Garlic oil nanoemulsion was formulated using ultrasonic emulsification and the optimized garlic oil nanoemulsion ratio (1:2) of oil: surfactant showed spherical, with tiny droplet size 24.9 ± 1.11 nm. It was observed that the prepared nanoemulsion has the zeta potential of -42.63 ± 1.58 mV and a low polydispersity index of 0.2 ± 0.09 with excellent stability. The formulation was subjected to in vivo acute and sub-acute toxicity. In acute toxicity study, single oral administration of 18.63 ml of garlic oil nanoemulsion/kg resulted in immediate mortality. However, garlic oil nanoemulsion (0.46 ml/kg) and tween 80 (0.5 ml/kg) administered rats did not exhibit any toxicity and showed no changes in hematological and histological parameters. Further, both preventive and curative studies of garlic oil nanoemulsion were evaluated in high-fat diet fed dyslipidemic Wistar rats. Garlic oil nanoemulsion administered groups showed a significant effect in reducing the levels of lipid profiles (p < 0.001) compared to atorvastatin and garlic oil. Evaluation of lipid deposits in hepatic tissues was analyzed by Oil Red O staining, which revealed that garlic oil nanoemulsion administered rats markedly reduced the fat depots. Our findings suggest that garlic oil nano-emulsified form reduced toxicity and improved efficacy in preventing and treating dyslipidemia.

Seaweed Polysaccharides - New Therapeutic Insights Against the Inflammatory Response in Diabetic Nephropathy

BACKGROUND

The higher risk of diabetic nephropathy (DN) leads to end stage renal diseases worldwide, which is associated with chronic inflammation. Currently, the available treatments are limited, lack of efficacy and safety. Therefore, we are in need of novel targets and advanced treatments to reduce the necessity for the renal replacement therapy and burden of this disease management. Object/Methods: In this review, we performed through an inflammatory mechanism that contribute to DN, will provide a key point to the finding off novel therapeutic agents. In addition, we discuss the current anti-inflammatory drugs, an alternative approach of seaweed polysaccharides and also exploring the future perspective of anti-inflammatory natural seaweed compounds. Currently, seaweeds are taking majority of attention from scientists for targeting the various diseases. This will become a more significant part of the pipeline and alternate medicines for anti-inflammatory and chronic diseases.

CONCLUSION

The potential benefits of natural seaweed novel compounds in inhibiting inflammatory pathways would be useful for the prevention of diabetic nephropathy. Thus, this therapy manifests the clinical benefits of these compounds in the near future.

Procedures for risk-stratification of lung cancer using buccal nanocytology

Lung cancer is the leading cause of cancer deaths in the U.S. with survival dramatically depending on stage at diagnosis. We had earlier reported that nanocytology of buccal cells can accurately risk-stratify smokers for the presence of early and late-stage lung cancer. To translate the technique into clinical practice, standardization of operating procedures is necessary to consistently yield precise and repeatable results. Here, we develop and validate simple, robust, and easily implementable procedures for specimen collection, processing, etc. in addition to a commercially-viable instrument prototype. Results of this work enable translation of the technology from academic lab to physicians' office.

Regulation of urinary crystal inhibiting proteins and inflammatory genes by lemon peel extract and formulated citrus bioflavonoids on ethylene glycol induced urolithic rats

The objective of this study is to check the regulation of crystal matrix proteins and inflammatory mediators by citrus bioflavonoids (CB) and Lemon peel (LP) extract in hyperoxaluric rats. The animals were divided into six groups with 6 animals each. Group 1: Control, Group 2: Urolithic (Ethylene glycol (EG)-0.75%); Group 3 & 5: Preventive study (EG + CB (20 mg/kg body weight) and LP (100 mg/kg body weight) extract administration from 0th-7th week) respectively; Group 4 & 6: Curative study (EG + CB and LP extract administration from 4th-7th week) respectively by oral administration. Urinary lithogenic factors (Calcium, oxalate, phosphate and citrate) were normalized in CB & LP supplemented rats, while serum parameters revealed the nephroprotective nature of the intervening agents compared to urolithic rats (p < 0.001). Immunoblotting studies showed significantly increased expression of THP, osteopontin and transferrin in kidneys of urolithic rats (p < 0.001), while preventive and curative study showed near normal expression of these proteins. Expression of NF-κB, TNF-α and IL-6 were raised significantly (p < 0.001), while a very minimal increase in MCP-1 expression was observed in urolithic rats compared to control. Hence, supplementation of CB and LP reduced the crystal promoting factors and provides protection from crystal induced renal damage.

Differential elastic responses to barrier-altering agonists in two types of human lung endothelium

Vascular integrity is primarily determined by endothelial cell (EC) cytoskeletal structure that is differentially regulated by various stimuli. In this study, atomic force microscopy (AFM) was used to characterize structural and mechanical properties in the cytoskeleton of cultured human pulmonary artery EC (HPAEC) and human lung microvascular EC (HLMVEC) by determining elastic properties (Young's modulus) in response to endogenous barrier protective agents sphingosine 1-phosphate (S1P) and hepatocyte growth factor (HGF), or the barrier disruptive molecule thrombin. Initial studies in unstimulated cells indicate higher baseline peripheral elastic modulus values in HPAEC (mean 2.9 KPa) than in HLMVEC (1.8 KPa). After 30 min of stimulation, S1P induced the highest Young's modulus increase (6.1 KPa) compared to the other barrier enhancing stimuli, HGF (5.8 KPa) and the pharmaceutical agent and S1P analog FTY720 (4.1 KPa). In contrast, the barrier disruptive agent thrombin decreased values from 2.5 KPa to 0.7 KPa depending on the cell type and treatment time. AFM topographical imaging supports these quantitative biophysical data regarding differential peripheral elastic properties in EC. Overall, these AFM studies provide novel insights into the biomechanical properties of human lung EC that regulate vascular barrier function and have potential applicability to pathophysiologic vascular leak syndromes such as acute lung injury.

Polyacrylic acid attenuates ethylene glycol induced hyperoxaluric damage and prevents crystal aggregation in vitro and in vivo

The study explores calcium oxalate crystal inhibiting characteristic of polyacrylic acid (pAA), an anionic polymer in in vitro and in vivo. Animals were divided into 5 groups where group 1 served as control, group 2 were made hyperoxaluric by supplementing with Ethylene glycol (EG) 0.75% (v/v) for 30 days. Group 3, 4 & 5 were also given with EG and treated simultaneously with 2.5, 5 & 10 mg of pAA/kg of body weight, respectively. Urine, serum and tissue analyses along with histological studies were performed at the end of the 30 days study. In vitro crystallization was significantly inhibited by pAA and further it was supported by particle size analyses, XRD and FT-IR studies. Toxicological analyses showed that pAA was safe to use in animals at concentrations below 100 mg/kg BW. In vivo anti-urolithic study showed significant improvement in urinary lithogenic factors (calcium, oxalate, phosphate, citrate & magnesium) and renal function parameters (creatinine, urea and protein). Tissue analyses on anti-oxidant enzyme activity and lipid peroxides showed maintenance of tissue antioxidant status in the pAA supplemented rats and histological studies demonstrated the nephroprotection offered by pAA and were concurrent to the biochemical analyses. Supplementation of pAA not only reduces the crystal aggregation but also regulates the expression and localization of crystal inhibiting proteins and gene expression of inflammatory cytokines in experimental animals. In summary, pAA is a potent anti-urolithic agent in rats and we can propose that 10 mg/kg body weight is the effective dosage of pAA and this concentration can be used for further studies.

Beneficial effect of Citrus limon peel aqueous methanol extract on experimentally induced urolithic rats

CONTEXT

Citrus limon (L.) Burm.f. (Rutaceace) is a commonly available fruit variety with high medicinal and industrial values.

OBJECTIVE

Lemon peel (LP) extract was studied as a potent preventive and curative agent for experimentally induced hyperoxaluric rats.

MATERIALS AND METHODS

Gas chromatography-mass spectrometry (GC-MS) analyses and toxicity study were performed for aqueous methanol LP extract. Twenty-four Wistar rats were segregated into four groups. Group 1: Control; Group 2: Urolithic (ethylene glycol (EG) - 0.75%); Group 3: Preventive study (EG + LP extract administration from 0th to 7th week); Group 4: Curative study (EG + LP extract administration from 4th to 7th week). Animals received LP extract daily by oral administration (100 mg/kg body weight) for 7 weeks.

RESULTS AND DISCUSSION

GC-MS analyses revealed that compound 6 was abundant in the LP extract (32%) followed by compound 1 (∼21%). The LD50 value of LP extract was found to be >5000 mg/kg of body weight. Urolithic rats showed significantly higher urinary calcium and oxalate (4.47 ± 0.44 and 18.86 ± 0.55 mg/24 h, respectively) excretion compared with control and experimental rats. Renal function parameters like urea (84 ± 8.5 and 96.1 ± 3.6 mg/dL), creatinine (1.92 ± 0.27 and 1.52 ± 0.22 mg/dL), and urinary protein (2.03 ± 0.02 and 2.13 ± 0.16 mg/24 h) were also reduced by LP extract (p < 0.001) and corroborated with tissue analyses (SOD, catalase, and MDA levels) and histological studies in normal and experimental animals. Immunohistochemical staining of THP and NF-κB in urolithic animals showed elevated expression than the control, while LP extract suppressed the expression of these proteins.

CONCLUSION

In conclusion, lemon peel is effective in curing kidney stone disease and also can be used to prevent the disease and its recurrence.

Citrus Bioflavonoids Ameliorate Hyperoxaluria Induced Renal Injury and Calcium Oxalate Crystal Deposition in Wistar Rats

PURPOSE

Citrus is considered as a medically important plant from ancient times and the bioflavonoids of different variety of citrus fruits were well explored for their biological activities. The study aim was to explore the effect of citrus bioflavonoids (CB) to prevent and cure hyperoxaluria induced urolithiasis.

METHODS

Twenty four Wistar rats were segregated into 4 Groups. Group 1: Control; Group 2: Urolithic (EG-0.75%); Group 3: Preventive study (EG+CB, day 1-50); Group 4: Curative study (EG+CB, day 30-50). Animals received CB orally (20mg/kg body weight) after performing a toxicity study.

RESULTS

Urinary risk factors and serum renal function parameters were significantly reduced by CB administration in both preventive and curative study (p<0.001). Hematoxylin & Eosin and von Kossa staining demonstrated that renal protection was offered by CB against EG insult. Immunohistochemical analyses revealed over expression and abnormal localization of THP and NF-κB in urolithic rats, while it was effectively regulated by CB supplementation.

CONCLUSION

CB prevented and significantly controlled lithogenic factors and CaOx deposition in rats. We propose CB as a potential therapy in management of urolithiasis.

Soluble CD36 in plasma and urine: a plausible prognostic marker for diabetic nephropathy

AIMS

This study was designed to analyze the level of soluble CD36 (sCD36) in both plasma and urine of type 2 diabetic patients with and without microalbuminuria/macroalbuminuria.

METHODS

Study subjects (n=20 each) comprised of those with normal glucose tolerance, type 2 diabetes (T2DM) with normoalbuminiria, T2DM with microalbuminuria and T2DM with macroalbuminuria. The biochemical parameters were analyzed using auto-analyzer, and the level of sCD36 was estimated using an in-house Sandwich ELISA.

RESULTS

The presence of sCD36 has been identified for the first time in the urine sample. Significant increase in the level of sCD36 was observed in both plasma and urine of diabetic patients with microalbuminuria (P<0.01) and macroalbuminuria (P<0.001). Positive correlation of sCD36 with the kidney markers such as urea, creatinine and eGFR confirmed the association of sCD36 with kidney damage in diabetic patients. Microalbuminuria, which is clinically used as a biomarker for nephropathy showed a strong positive correlation with urine sCD36 (r=0.642; P<0.001) and plasma sCD36 (r=0.498; P<0.001) in Pearson correlation analysis, which was further substantiated in stepwise multiple regression analysis.

CONCLUSIONS

Our study implies a plausible prognostic/adjuvant biomarker role of soluble CD36 for diabetic nephropathy.