Simran Tandon

Kidney stone matrix proteins ameliorate calcium oxalate monohydrate induced apoptotic injury to renal epithelial cells.

AIMS Kidney stone formation is a highly prevalent disease, affecting 8-10% of the human population worldwide. Proteins are the major constituents of human kidney stones organic matrix and considered to play critical role in the pathogenesis of disease but their mechanism of modulation still needs to be explicated. Therefore, in this study we investigated the effect of human kidney stone matrix proteins on the calcium oxalate monohydrate (COM) mediated cellular injury. MAIN METHODS The renal epithelial cells (MDCK) were exposed to 200μg/ml COM crystals to induce injury. The effect of proteins isolated from human kidney stone was studied on COM injured cells. The alterations in cell-crystal interactions were examined by phase contrast, polarizing, fluorescence and scanning electron microscopy. Moreover, its effect on the extent of COM induced cell injury, was quantified by flow cytometric analysis. KEY FINDINGS Our study indicated the antilithiatic potential of human kidney stone proteins on COM injured MDCK cells. Flow cytometric analysis and fluorescence imaging ascertained that matrix proteins decreased the extent of apoptotic injury caused by COM crystals on MDCK cells. Moreover, the electron microscopic studies of MDCK cells revealed that matrix proteins caused significant dissolution of COM crystals, indicating cytoprotection against the impact of calcium oxalate injury. SIGNIFICANCE The present study gives insights into the mechanism implied by urinary proteins to restrain the pathogenesis of kidney stone disease. This will provide a better understanding of the formation of kidney stones which can be useful for the proper management of the disease.

In vitro studies reveal antiurolithic effect of Terminalia arjuna using quantitative morphological information from computerized microscopy

ABSTRACT Purpose: For most cases, urolithiasis is a condition where excessive oxalate is present in the urine. Many reports have documented free radical generation followed by hyperoxaluria as a consequence of which calcium oxalate (CaOx) deposition occurs in the kidney tissue. The present study is aimed to exam the antilithiatic potency of the aqueous extract (AE) of Terminalia arjuna (T. arjuna). Materials and Methods: The antilithiatic activity of Terminalia arjuna was investigated in vitro nucleation, aggregation and growth of the CaOx crystals as well as the morphology of CaOx crystals using the inbuilt software ‘Image-Pro Plus 7.0’ of Olympus upright microscope (BX53). Antioxidant activity of AE of Terminalia arjuna bark was also determined in vitro. Results: Terminalia arjuna extract exhibited a concentration dependent inhibition of nucleation and aggregation of CaOx crystals. The AE of Terminalia arjuna bark also inhibited the growth of CaOx crystals. At the same time, the AE also modified the morphology of CaOx crystals from hexagonal to spherical shape with increasing concentrations of AE and reduced the dimensions such as area, perimeter, length and width of CaOx crystals in a dose dependent manner. Also, the Terminalia arjuna AE scavenged the DPPH (2, 2-diphenyl-1-picrylhydrazyl) radicals with an IC50 at 13.1µg/mL. Conclusions: The study suggests that Terminalia arjuna bark has the potential to scavenge DPPH radicals and inhibit CaOx crystallization in vitro. In the light of these studies, Terminalia arjuna can be regarded as a promising candidate from natural plant sources of antilithiatic and antioxidant activity with high value.

Profiling of Virulence Determinants in Cronobacter sakazakii Isolates from Different Plant and Environmental Commodities

Cronobacter sakazakii is an emerging pathogen causing meningitis, sepsis and necrotizing enterocolitis in neonates and immune-compromised adults. The present study describes the profiling of different virulence factors associated with C. sakazakii isolates derived from plant-based materials and environmental samples (soil, water, and vacuum dust). All the isolates exhibited β-hemolysis and chitinase activity, and were able to utilize inositol. Among the nine virulence-associated genes, hly gene coding for hemolysin was detected in all the isolates followed by ompA (outer membrane protein); however, plasmid-borne genes were detected at a level of 60% for both cpa (cronobacter plasminogen activator) and eitA (Ferric ion transporter protein) gene, respectively. Furthermore, the isolate C. sakazakii N81 showed cytotoxicity for Caco-2 cells. The presence of the virulence determinants investigated in this study indicates the pathogenic potential of C. sakazakii with their plausible connection with clinical manifestations.

Mechanistic Insights into the Antilithiatic Proteins from Terminalia arjuna: A Proteomic Approach in Urolithiasis

Kidney stone formation during hyperoxaluric condition is inherently dependent on the interaction between renal epithelial cells and calcium oxalate (CaOx) crystals. Although modern medicine has progressed in terms of removal of these stones, recurrence and persistent side effects restricts their use. Strategies involving plant based agents which could be used as adjunct therapy is an area which needs to be explored. Plant proteins having antilithiatic activity is a hitherto unexplored area and therefore, we conducted a detailed identification and characterization of antilithiatic proteins from Terminalia arjuna (T. arjuna). Proteins were isolated from the dried bark of T. arjuna and those having molecular weights > 3 kDa were subjected to anion exchange chromatography followed by gel filtration chromatography. Four proteins were identified exhibiting inhibitory activity against CaOx crystallization and crystal growth kinetics The cytoprotective and anti-apoptotic efficacy of these purified proteins was further investigated on oxalate injured renal epithelial cells (MDCK and NRK-52E) wherein, injury due to oxalate was significantly attenuated and led to a dose dependent increase in viability of these cells. These proteins also prevented the interaction of the CaOx crystals to the cell surface and reduced the number of apoptotic cells. Identification of these 4 anionic proteins from the bark of T. arjuna was carried out by Matrix-assisted laser desorption/ionization-time of flight Mass spectrometry (MALDI-TOF MS). This was followed by database search with the MASCOT server and sequence similarity was found with Nuclear pore anchor, DEAD Box ATP-dependent RNA helicase 45, Lon protease homolog 1 and Heat shock protein 90–3. These novel proteins isolated from T. arjuna have the potential to inhibit CaOx crystallization and promote cell survival and therefore, offer novel avenues which need to be explored further for the medical management of urolithiasis.

Impact of homeopathic remedies on the expression of lineage differentiation genes: an in vitro approach using embryonic stem cells

BACKGROUND Well-documented studies of the potential effects and safety of homeopathic medicines in pregnancy are required. In this study, specific genes were studied which could serve as biomarkers for specification of three lineages to predict the safety of homeopathic remedies using mouse embryonic stem (ES) cells. Thus, the present work was to study the effects of homeopathic remedies taken during pregnancy using ES cells as the model. METHODS Mouse ES cells were exposed to 30C potency of Nux Vomica and Sepia, which are homeopathic medicines prescribed for the management of pregnancy related symptoms. Cytotoxicity studies were done using a modified Embryonic Stem cell test (EST). The expression levels of key genes and proteins were analyzed using real time polymerase chain reaction and immunocytochemistry, respectively. RESULTS Homeopathic treatment led to modulations in the expression of certain lineage specific genes but this difference was not significant with respect to solvent control and showed normal differentiation as demonstrated by the expression of α/β MHC and α-actinin proteins in the differentiated ES cells. CONCLUSIONS Our study for the first time has shown the feasibility of using ES cells in the developmental toxicity testing of remedies. The results suggest that they are not associated with developmental toxicity.

Human kidney stone matrix: Latent potential to restrain COM induced cytotoxicity and inflammatory response

Kidney stone disease is a multi-factorial disorder resulting from the interplay of various risk factors including lifestyle, environment and genetics along with metabolic activities inside the body. However, it is difficult to determine how these factors converge to promote stone disease. Extensive investigations of kidney stone composition at the molecular level have been carried out however; its impact on the complex mechanism of stone formation is still obscure. Hence, an in vitro study was designed to investigate the attenuation of calcium oxalate toxicity by human kidney stone matrix proteins on NRK-52E cells using flowcytometry, Western blotting, RT-PCR and immunofluorescence assays. Morphological alterations in cell-crystal interaction were assessed using scanning electron microscopy. Microscopic studies showed profound impairment of COM crystal structure as a consequence of protein-crystal interactions. RT-PCR analysis and immunocytochemistry of NRK-52E cells revealed the up-regulation of inflammatory and stress biomarkers OPN and HSP-70, respectively, in response to COM toxicity; which diminished significantly in the presence of kidney stone matrix proteins. The results of present study propose that the mechanism undertaken by matrix proteins to attenuate COM induced cytotoxicity could be attributed to the modulation of crystal structure, which subsequently restraint the inflammatory response and apoptotic cell death. The inference drawn through this study could provide better understanding of the intricate process of kidney stone formation.

Mitochondrial pathway mediated apoptosis and cell cycle arrest triggered by aqueous extract of wheatgrass in colon cancer colo-205 cells

Four different extracts of wheatgrass i.e. hexane, chloroform, methanol and aqueous were used to evaluate the anti-cancer potential on COLO-205 cells. Aqueous extract demonstrated maximum anti-cancer activities with significant inhibition on growth of COLO-205 cells. Anti-proliferative capabilities were also enhanced, as observed from clonogenic survival and in vitro wound scratch assay. Increased apoptotic hallmarks were evidenced in aqueous extract treated cells such as, DNA fragmentation, nuclear condensation and membrane blebbing. Increased expression of caspase-9, caspase-3 and Bax genes, along with down-regulation of Bcl-2 gene was also seen. Arrest of cells at G0/G1 phase by flow cytometric analysis could be attributed to up-regulated expression of inhibitors of cell cycle progression i.e. p16, p21 and p27 in aqueous extract treated cells. GC analysis revealed the presence of various chemicals possessing medicinal properties which could be responsible for the effects seen on the cancer cells. Our findings, for the first time suggest that the aqueous extract of wheatgrass represents a potential plant based anti-cancer agent.