Seasonal Variation in Arsenic Concentration and its Bioremediation Potential of Marine Bacteria Isolated from Alang-Sosiya Ship-Scrapping Yard, Gujarat, India

This work investigates seasonal variations in arsenic concentration at Alang-Sosiya, world’s largest ship-scrapping yard situated on the Gulf of Khambhat. Annually, hundreds of ships have been dismantled, which lead to discharge large amounts of detrimental and persistent pollutants at this location. In all seasons, the arsenic concentration was significantly elevated in sediments and seawaters in the intertidal zone of Alang-Sosiya ship-scrapping yard as compared to the reference station at Ghogha, 42 km away towards the northeast. The highest arsenic concentrations in seawater and sediment samples were observed during the Winter season and Summer season respectively. The marine environment affected by ship-scrapping activity and contaminated with arsenic is the potential location to get arsenic hyper-tolerant bacterial isolates. Out of 16 isolated bacterial strains, KKDK-1 and KKDK-2 sustained 600 mM and 500 mM arsenate respectively. The 16S rRNA ribotyping identified strains KKDK-1 and KKDK-2 as Halomonas species. The strain KKDK-1 showed the maximum arsenic accumulation of 21.7±3.3 mg g-1 cell dry weight at exponential phase (60 h), followed by sudden extrusion of arsenic during stationary phase (84 h) of bacterial growth. Whereas, strain KKDK-2 accumulated 6.8±1.12 mg Arsenic g-1 cell dry weight during exponential phase (72 h), which remains almost invariable during stationary phase (96-144 h) of bacterial growth. These results indicate the hypertolerance of arsenic by KKDK-1 and KKDK-2 with its higher accumulation capacity, signifying them as potential candidates for arsenic detoxification of arsenic contaminated sites

Site-Specifically Labeled Immunoconjugates for Molecular Imaging—Part 1: Cysteine Residues and Glycans

Due to their remarkable selectivity and specificity for cancer biomarkers, immunoconjugates have emerged as extremely promising vectors for the delivery of diagnostic radioisotopes and fluorophores to malignant tissues. Paradoxically, however, these tools for precision medicine are synthesized in a remarkably imprecise way. Indeed, the vast majority of immunoconjugates are created via the random conjugation of bifunctional probes (e.g., DOTA-NCS) to amino acids within the antibody (e.g., lysines). Yet antibodies have multiple copies of these residues throughout their macromolecular structure, making control over the location of the conjugation reaction impossible. This lack of site specificity can lead to the formation of poorly defined, heterogeneous immunoconjugates with suboptimal in vivo behavior. Over the past decade, interest in the synthesis and development of site-specifically labeled immunoconjugates—both antibody-drug conjugates as well as constructs for in vivo imaging—has increased dramatically, and a number of reports have suggested that these better defined, more homogeneous constructs exhibit improved performance in vivo compared to their randomly modified cousins. In this two-part review, we seek to provide an overview of the various methods that have been developed to create site-specifically modified immunoconjugates for positron emission tomography, single photon emission computed tomography, and fluorescence imaging. We will begin with an introduction to the structure of antibodies and antibody fragments. This is followed by the core of the work: sections detailing the four different approaches to site-specific modification strategies based on cysteine residues, glycans, peptide tags, and unnatural amino acids. These discussions will be divided into two installments: cysteine residues and glycans will be detailed in Part 1 of the review, while peptide tags and unnatural amino acids will be addressed in Part 2. Ultimately, we sincerely hope that this review fosters interest and enthusiasm for site-specific immunoconjugates within the nuclear medicine and molecular imaging communities

Sub-chronic arsenic exposure aggravates nephrotoxicity in experimental diabetic rats

762-768The present experiment was planned to study nephrotoxicity in experimental diabetic rats under sub-chronic exposure to arsenic. Alloxan induced diabetic and control rats were exposed to sodium arsenite (0 and 5.5 mg/kg, orally) for 30 days. More pronounced nephrotoxic effects were noted in arsenic exposed diabetic group as evidenced by increased blood urea nitrogen, serum creatinine and relative kidney weight and decreased level of reduced glutathione and glutathione peroxidase activity compared to non arsenic exposed diabetic group. Increased level of lipid peroxidation, protein oxidation, superoxide dismutase and catalase activities under diabetic condition remained unchanged in arsenic exposed diabetic group compared to unexposed diabetic group

Correction: miR29b regulates aberrant methylation in In-Vitro diabetic nephropathy model of renal proximal tubular cells.

[This corrects the article DOI: 10.1371/journal.pone.0208044.]

miR29b regulates aberrant methylation in In-Vitro diabetic nephropathy model of renal proximal tubular cells.

The role of DNA methylation has not been enough explored in pathophysiology of diabetic nephropathy (DN). However, according to recent reports it has been inferred that hypermethylation could be one of the principle cause associated with the enhancement of DN. An interrelationship between miR29b and DNA methylation has been studied via in-silico analysis. We have validated that miR29b prominently targets DNA methyl transferase (DNMT), specifically DNMT1, DNMT3A and DNMT3B. We have developed in vitro DN model using renal proximal tubule epithelial cells (RPTECs), contributed to a significant alleviation in RNA and protein expression levels of DNMT3A, DNMT3B and DNMT1. The developed model has also demonstrated downregulation in expression of miR29b. Our studies have also suggested that miR29b targets DNMT1 via targeting its transcription factor SP1. In addition to this, downregulation of a specific biomarker for kidney injury, tubular kidney injury molecule-1 (KIM-1) and fibrosis causing glycoprotein i.e. fibronectin, was also demonstrated. Hence, the developed model revealed that hypermethylation is a key factor incorporated in DN, and miR29b could effectively ameliorate defensive actions in DN pathogenesis

Polymeric micelle nanocarriers for targeted epidermal delivery of the hedgehog pathway inhibitor vismodegib: formulation development and cutaneous biodistribution in human skin

Background: The aim was to investigate cutaneous delivery and biodistribution of the hedgehog pathway inhibitor, vismodegib (VSD), indicated for basal cell carcinoma (BCC), from polymeric micelle formulations under infinite/finite dose conditions. Methods: VSD-loaded micelles were characterized for drug content, particle size, and shape; a micelle gel was characterized for its rheological behavior. Cutaneous deposition and biodistribution of VSD were determined using porcine and human skin in vitro with quantification by UHPLC-MS/MS. Results: The optimal micelle solution (Zav 20-30 nm) increased the aqueous solubility of VSD by >8000-fold; drug content was stable after 4 weeks at 4°C. Application of micelle solution and micelle gel (0.086% w/v) to human skin for 12 h under infinite dose conditions resulted in statistically equivalent VSD deposition (0.62 ± 0.11 and 0.67 ± 0.14 μg/cm2, respectively). Cutaneous biodistribution in human skin under infinite (micelle solution and gel) and finite (micelle gel) dose conditions showed that the VSD concentrations obtained in the basal epidermis, at depths of 120-200 μm, were ˃3800- and ˃2300-fold greater than the IC50 reported for hedgehog signaling pathway inhibition in vitro. Conclusion: Cutaneous delivery of VSD from micelle-based formulations might enable targeted, topical treatment of superficial BCC with minimal risk of systemic exposure

Piezoelectric smart biomaterials for bone and cartilage tissue engineering

Abstract Tissues like bone and cartilage are remodeled dynamically for their functional requirements by signaling pathways. The signals are controlled by the cells and extracellular matrix and transmitted through an electrical and chemical synapse. Scaffold-based tissue engineering therapies largely disturb the natural signaling pathways, due to their rigidity towards signal conduction, despite their therapeutic advantages. Thus, there is a high need of smart biomaterials, which can conveniently generate and transfer the bioelectric signals analogous to native tissues for appropriate physiological functions. Piezoelectric materials can generate electrical signals in response to the applied stress. Furthermore, they can stimulate the signaling pathways and thereby enhance the tissue regeneration at the impaired site. The piezoelectric scaffolds can act as sensitive mechanoelectrical transduction systems. Hence, it is applicable to the regions, where mechanical loads are predominant. The present review is mainly concentrated on the mechanism related to the electrical stimulation in a biological system and the different piezoelectric materials suitable for bone and cartilage tissue engineering