Differential expression of zinc transporters in functionally contrasting tissues involved in zinc homeostasis

Abstract

Zinc homeostasis is maintained by 24 tissue-specific zinc transporters which include ZnTs (ZnT1-10), ZIPs (ZIP1-14), in addition to metallothionein (MT). Current study aimed the role of zinc transporters in maintaining the basal levels of zinc in functionally contrasting tissue specific THP-1 (monocyte), RD (muscle), and Saos-2 (bone) cells. Zinc transporters expression was assessed by qRT-PCR. The mRNA levels of ZnTs (ZnT5-7 & ZnT9), ZIPs (ZIP6-10, ZIP13-14), and MT were significantly (p?<?0.05) higher in Saos-2 compared to THP-1 and RD. The present study suggests that distinct expression pattern of zinc transporters and metallothionein might be responsible for the differential zinc assimilation.     

Cryopreservation of Cymbidium eburneum Lindl. and C. hookerianum Rchb. f., two threatened and vulnerable orchids via encapsulation–dehydration

A successful cryopreservation protocol for the long-term conservation of protocorms of two threatened and vulnerable orchids, Cymbidium eburneum Lindl. and Cymbidium hookerianum Rchb. f., was developed using encapsulation–dehydration. Protocorms were osmoprotected in liquid Murashige and Skoog medium (MS) containing 0.7 M sucrose for 20 h at 25?±?2°C on a rotary shaker, and incorporated into an encapsulation matrix [consisting of 3% (w/v) sodium alginate and 100 mM CaCl₂]. The encapsulated protocorms, which were desiccated in a laminar airflow cabinet for 6 h, were able to withstand cryostorage in liquid nitrogen. Maximum regeneration into complete plantlets (72% for C. eburneum and 70% for C. hookerianum) of the cryostored, encapsulated protocorms was obtained using MS medium containing 3% sucrose and 0.8% agar. Using this protocol of cryopreservation, long-term preservation for ex situ conservation of these two threatened orchids can be accomplished.     

Gaussian curvature analysis allows for automatic block placement in multi-block hexahedral meshing

Musculoskeletal finite element analysis (FEA) has been essential to research in orthopaedic biomechanics. The generation of a volumetric mesh is often the most challenging step in a FEA. Hexahedral meshing tools that are based on a multi-block approach rely on the manual placement of building blocks for their mesh generation scheme. We hypothesise that Gaussian curvature analysis could be used to automatically develop a building block structure for multi-block hexahedral mesh generation. The Automated Building Block Algorithm incorporates principles from differential geometry, combinatorics, statistical analysis and computer science to automatically generate a building block structure to represent a given surface without prior information. We have applied this algorithm to 29 bones of varying geometries and successfully generated a usable mesh in all cases. This work represents a significant advancement in automating the definition of building blocks.     

Bioremoval of Cyanide and Phenol from Industrial Wastewater: An Update

In nature, phenols and cyanides are produced by certain microbes and plants. Phenols are antioxidants found in almost all plants, and cyanides are important components of lima beans, almonds, and cassava. Their presence in small amounts may not upset the environment, but their large-scale production, wide applicability, and unrestricted release by the industries makes them widespread and important pollutants. Phenols and cyanides can be recovered/removed from wastewater streams using various physicochemical techniques practiced commercially. Lack of complete mineralization, cost-effectiveness, and release of secondary by-products are amongst a few of the major considerations that limit the installation of such processes. Biological removal of such pollutants from industrial waste has gained momentum in recent years, as they promise to surpass the major drawbacks laid by the physicochemical methods and can be practically carried out in all conditions. Presence of either cyanide or phenol is highly dangerous, and in the presence of both, the effect is compounded. The present review illustrates the various industries involved in the release of phenols, cyanides, or both; it summarizes the available technologies for their treatment and emphasizes recent advances and advantages of biological abatement of these pollutants.     

Myeloid related protein induces muscle derived inflammatory mediators in juvenile dermatomyositis

Introduction

The aetiopathogenesis of juvenile dermatomyositis (JDM) remains poorly understood. In particular the contribution of monocytes or macrophages, which are frequently observed to be an infiltrate within muscle tissue very early in the disease process, is unknown. We hypothesised that these cells secrete the pro-inflammatory myeloid related protein (MRP) 8/14 which may then contribute to muscle pathology in JDM.

Methods

In this study of 56 JDM patients, serum MRP8/14 levels were compared with clinical measures of disease activity. Muscle biopsies taken early in disease were assessed by immunohistochemistry to determine the frequency and identity of MRP-expressing cells. The effects of MRP stimulation and endoplasmic reticulum (ER) stress on muscle were tested in vitro. Serum or supernatant levels of cytokines were analyzed by multiplex immunoassay.

Results

Serum MRP8/14 correlated with physician’s global assessment of disease activity in JDM (R = 0.65, p = 0.0003) and muscle strength/endurance, childhood myositis assessment score (CMAS, R = −0.55, p = 0.004). MRP8/14 was widely expressed by CD68+ macrophages in JDM muscle tissue. When cultured with human myoblasts, MRP8 led to the secretion of MCP-1 and IL-6, which was enhanced by ER stress. Both inflammatory mediators were detected in significantly higher levels in the serum of JDM patients compared to healthy controls.

Conclusions

This study is the first to identify serum MRP8/14 as a potential biomarker for disease activity in JDM. We propose that tissue infiltrating macrophages secreting MRP8/14 may contribute to myositis, by driving the local production of cytokines directly from muscle.     

Correction for Irrelevant Absorption in Multicomponent Spectrophotometric Assay of Riboflavin, Formylmethylflavin, and Degradation Products: Kinetic Applications

In the spectrophotometric assay of multicomponent systems involved in drug degradation studies, some minor or unknown degradation products may be present. These products may interfere in the assay and thus invalidate the results due to their absorption in the range of analytical wavelengths. This interference may be eliminated by the application of an appropriate correction procedure to obtain reliable data for kinetic treatment. The present study is based on the application of linear and non-linear irrelevant absorption corrections in the multicomponent spectrophotometric assay of riboflavin and formylmethylflavin during the photolysis and hydrolysis studies. The correction procedures take into account the interference caused by minor or unknown products and have shown considerable improvement in the assay data in terms of the molar balance. The treatment of the corrected data has led to more accurate kinetic results in degradation studies.     

Nature of KaiB-KaiC binding in the cyanobacterial circadian oscillator

In the cyanobacteria Synechococcus elongatus and Thermosynechococcus elongatus, the KaiA, KaiB and KaiC proteins in the presence of ATP generate a post-translational oscillator (PTO) that can be reconstituted in vitro. KaiC is the result of a gene duplication and resembles a double doughnut with N-terminal CI and C-terminal CII hexameric rings. Six ATPs are bound between subunits in both the CI and CII ring. CI harbors ATPase activity, and CII catalyzes phosphorylation and dephosphorylation at T432 and S431 with a ca. 24-h period. KaiA stimulates KaiC phosphorylation, and KaiB promotes KaiC subunit exchange and sequesters KaiA on the KaiB-KaiC interface in the final stage of the clock cycle. Studies of the PTO protein-protein interactions are convergent in terms of KaiA binding to CII but have led to two opposing models of the KaiB-KaiC interaction. Electron microscopy (EM) and small angle X-ray scattering (SAXS), together with native PAGE using full-length proteins and separate CI and CII rings, are consistent with binding of KaiB to CII. Conversely, NMR together with gel filtration chromatography and denatured PAGE using monomeric CI and CII domains support KaiB binding to CI. To resolve the existing controversy, we studied complexes between KaiB and gold-labeled, full-length KaiC with negative stain EM. The EM data clearly demonstrate that KaiB contacts the CII ring. Together with the outcomes of previous analyses, our work establishes that only CII participates in interactions with KaiA and KaiB as well as with the His kinase SasA involved in the clock output pathway.     

Tracking 20 Years of Compound-to-Target Output from Literature and Patents

The statistics of drug development output and declining yield of approved medicines has been the subject of many recent reviews. However, assessing research productivity that feeds development is more difficult. Here we utilise an extensive database of structure-activity relationships extracted from papers and patents. We have used this database to analyse published compounds cumulatively linked to nearly 4000 protein target identifiers from multiple species over the last 20 years. The compound output increases up to 2005 followed by a decline that parallels a fall in pharmaceutical patenting. Counts of protein targets have plateaued but not fallen. We extended these results by exploring compounds and targets for one large pharmaceutical company. In addition, we examined collective time course data for six individual protease targets, including average molecular weight of the compounds. We also tracked the PubMed profile of these targets to detect signals related to changes in compound output. Our results show that research compound output had decreased 35% by 2012. The major causative factor is likely to be a contraction in the global research base due to mergers and acquisitions across the pharmaceutical industry. However, this does not rule out an increasing stringency of compound quality filtration and/or patenting cost control. The number of proteins mapped to compounds on a yearly basis shows less decline, indicating the cumulative published target capacity of global research is being sustained in the region of 300 proteins for large companies. The tracking of six individual targets shows uniquely detailed patterns not discernible from cumulative snapshots. These are interpretable in terms of events related to validation and de-risking of targets that produce detectable follow-on surges in patenting. Further analysis of the type we present here can provide unique insights into the process of drug discovery based on the data it actually generates.