Design and synthesis of thiazolidine-2,4-diones hybrids with 1,2-dihydroquinolones and 2-oxindoles as potential VEGFR-2 inhibitors: in-vitro anticancer evaluation and in-silico studies

A thiazolidine-2,4-dione nucleus was molecularly hybridised with the effective antitumor moieties; 2-oxo-1,2-dihydroquinoline and 2-oxoindoline to obtain new hybrids with potential activity against VEGFR-2. The cytotoxic effects of the synthesised derivatives against Caco-2, HepG-2, and MDA-MB-231 cell lines were investigated. Compound 12a was found to be the most potent candidate against the investigated cell lines with IC₅₀ values of 2, 10, and 40 µM, respectively. Furthermore, the synthesised derivatives were tested in vitro for their VEGFR-2 inhibitory activity showing strong inhibition. Moreover, an in vitro viability study against Vero non-cancerous cell line was investigated and the results reflected a high safety profile of all tested compounds. Compound 12a was further investigated for its apoptotic behaviour by assessing the gene expression of four genes (Bcl2, Bcl-xl, TGF, and Survivin). Molecular dynamic simulations authenticated the high affinity, accurate binding, and perfect dynamics of compound 12a against VEGFR-2.     

PKC regulation of ion channels: The involvement of PIP2

Ion channels are integral membrane proteins whose gating has been increasingly shown to depend on the presence of the low-abundance membrane phospholipid, phosphatidylinositol (4,5) bisphosphate. The expression and function of ion channels is tightly regulated via protein phosphorylation by specific kinases, including various PKC isoforms. Several channels have further been shown to be regulated by PKC through altered surface expression, probability of channel opening, shifts in voltage dependence of their activation, or changes in inactivation or desensitization. In this review, we survey the impact of phosphorylation of various ion channels by PKC isoforms and examine the dependence of phosphorylated ion channels on phosphatidylinositol (4,5) bisphosphate as a mechanistic endpoint to control channel gating.     

Human C1orf27 protein interacts with α2A-adrenergic receptor and regulates its anterograde transport

The molecular mechanisms underlying the anterograde surface transport of G protein–coupled receptors (GPCRs) after their synthesis in the endoplasmic reticulum (ER) are not well defined. In C. elegans, odorant response abnormal 4 has been implicated in the delivery of olfactory GPCRs to the cilia of chemosensory neurons. However, the function and regulation of its human homolog, C1orf27, in GPCR transport or in general membrane trafficking remain unknown. Here, we demonstrate that siRNA-mediated knockdown of C1orf27 markedly impedes the ER-to-Golgi export kinetics of newly synthesized α_2A-adrenergic receptor (α_2A-AR), a prototypic GPCR, with the half-time being prolonged by more than 65%, in mammalian cells in retention using the selective hooks assays. Using modified bioluminescence resonance energy transfer assays and ELISAs, we also show that C1orf27 knockdown significantly inhibits the surface transport of α_2A-AR. Similarly, C1orf27 knockout by CRISPR-Cas9 markedly suppresses the ER–Golgi-surface transport of α_2A-AR. In addition, we demonstrate that C1orf27 depletion attenuates the export of β₂-AR and dopamine D2 receptor but not of epidermal growth factor receptor. We further show that C1orf27 physically associates with α_2A-AR, specifically via its third intracellular loop and C terminus. Taken together, these data demonstrate an important role of C1orf27 in the trafficking of nascent GPCRs from the ER to the cell surface through the Golgi and provide novel insights into the regulation of the biosynthesis and anterograde transport of the GPCR family members.     

G4-quadruplex-binding proteins: review and insights into selectivity

There are over 700,000 putative G4-quadruplexes (G4Qs) in the human genome, found largely in promoter regions, telomeres, and other regions of high regulation. Growing evidence links their presence to functionality in various cellular processes, where cellular proteins interact with them, either stabilizing and/or anchoring upon them, or unwinding them to allow a process to proceed. Interest in understanding and manipulating the plethora of processes regulated by these G4Qs has spawned a new area of small-molecule binder development, with attempts to mimic and block the associated G4-binding protein (G4BP). Despite the growing interest and focus on these G4Qs, there is limited data (in particular, high-resolution structural information), on the nature of these G4Q-G4BP interactions and what makes a G4BP selective to certain G4Qs, if in fact they are at all. This review summarizes the current literature on G4BPs with regards to their interactions with G4Qs, providing groupings for binding mode, drawing conclusions around commonalities and highlighting information on specific interactions where available.     

Biotechnological challenges of bioartificial kidney engineering

With the world-wide increase of patients with renal failure, the development of functional renal replacement therapies have gained significant interest and novel technologies are rapidly evolving. Currently used renal replacement therapies insufficiently remove accumulating waste products, resulting in the uremic syndrome. A more preferred treatment option is kidney transplantation, but the shortage of donor organs and the increasing number of patients waiting for a transplant warrant the development of novel technologies. The bioartificial kidney (BAK) is such promising biotechnological approach to replace essential renal functions together with the active secretion of waste products. The development of the BAK requires a multidisciplinary approach and evolves at the intersection of regenerative medicine and renal replacement therapy. Here we provide a concise review embracing a compact historical overview of bioartificial kidney development and highlighting the current state-of-the-art, including implementation of living-membranes and the relevance of extracellular matrices. We focus further on the choice of relevant renal epithelial cell lines versus the use of stem cells and co-cultures that need to be implemented in a suitable device. Moreover, the future of the BAK in regenerative nephrology is discussed.     

Structure-activity relationships of pyrazole-4-carbodithioates as antibacterials against methicillin–resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of serious hospital-acquired infections and is responsible for significant morbidity and mortality in residential care facilities. New agents against MRSA are needed to combat rising resistance to current antibiotics. We recently reported 5-hydroxy-3-methyl-1-phenyl-1H-pyrazole-4-carbodithioate (HMPC) as a new bacteriostatic agent against MRSA that appears to act via a novel mechanism. Here, twenty nine analogs of HMPC were synthesized, their anti-MRSA structure-activity relationships evaluated and selectivity versus human HKC-8 cells determined. Minimum inhibitory concentrations (MIC) ranged from 0.5 to 64?μg/mL and up to 16-fold selectivity was achieved. The 4-carbodithioate function was found to be essential for activity but non-specific reactivity was ruled out as a contributor to antibacterial action. The study supports further work aimed at elucidating the molecular targets of this interesting new class of anti-MRSA agents.     

A Simple Novel Agar Diffusion Method for Isolation of Indigenous Microalgae Chlamydomonas sp. CRP7 and Chlorella sp. CB4 from Operational Swampy Top Soil

A simple agar diffusion method is developed where pure colony of Chlamydomonas sp. CRP7 was isolated from Chlorella sp. CB4 mixtures by passing through agar migration with a light exposure of 6,000 lux for 7 h. The main concept behind it is that Chlamydomonas has flagella and the rhodopsin pigment is attracted towards light. Thus the above two microalgae species can be separated from the mixtures as eye spot serves as a navigator and flagella serves as a propeller for Chlamydomonas spp. Further the genomic DNA was isolated and purified from the above mentioned two species after the separation from the mixtures. PCR amplification was carried out for ITS1, 5.8S and ITS2 regions. The amplified products were sequenced and the sequence analysis confirmed that they belong to Chlamydomonas sp. and Chlorella sp. This is an important augmentation for isolation and separation of microalgae.     

DEAGGREGATION OF eIF4E INDUCED BY mRNA 5′ CAP BINDING

All eukaryotic mRNAs contain a 5′ terminal cap structure, which consists of 7-methylguanosine linked by a 5′-5′ triphosphate bridge to the first transcribed nucleoside (m⁷GpppN). Specific recognition of the cap by the eukaryotic initiation factor eIF4E plays a key role in regulation of translation initiation as a rate-limiting step. Using dynamic light scattering (DLS), the apo-form of murine eIF4E (33–217) was shown to aggregate. After addition of m⁷GTP, progressive deaggregation with the time of incubation in the presence of the cap analogue has been observed.     

Circulating soluble CD4 directly prevents host resistance and delayed-type hypersensitivity response to Cryptococcus neoformans in mice

In the present study, we examined the effect of soluble CD4 (sCD4) on host resistance and delayed-type hypersensitivity (DTH) response to Cryptococcus neoformans using a novel mutant mouse that exhibits a defect in the expression of membrane-bound CD4 but secretes high levels of sCD4 in the serum. In these mice, host resistance to this pathogen was impaired as indicated by an increased number of live pathogens in the lung. To elucidate the mechanism of immunodeficiency, three different sets of experiments were conducted. First, administration of anti-CD4 mAb restored the attenuated host defense. Second, in CD4 gene-disrupted (CD4KO) mice, host resistance was not attenuated compared to control mice. Third, implantation of sCD4 gene-transfected myeloma cells rendered the CD4KO mice susceptible to this infection, while similar treatment with mock-transfected cells did not show such an effect. These results indicated that immunodeficiency in the mutant mice was attributed to the circulating sCD4 rather than to the lack of CD4+ T cells. In addition, DTH response to C. neoformans evaluated by footpad swelling was reduced in the mutant mice compared to that in the control, and the reduced response was restored by the administration of anti-CD4 mAb. Finally, serum levels of IFN-gamma, IL-12 and IL-18 in the mutant mice were significantly reduced, while there was no difference in Th2 cytokines, such as IL-4 and IL-10. Considered collectively, our results demonstrated that sCD4 could directly prevent host resistance and DTH response to C. neoformans through interference with the production of Th1-type cytokines.     

The promoter of rbcS in a C3 plant (rice) directs organ-specific,light-dependent expression in a C4 plant (maize), but does not confer bundle sheath cell-specific expression

The small subunit of ribulose-bisphosphate carboxylase (Rubisco), encoded by rbcS, is essential for photosynthesis in both C3 and C4 plants, even though the cell specificity of rbcS expression is different between C3 and C4 plants. The C3 rbcS is specifically expressed in mesophyll cells, while the C4 rbcS is expressed in bundle sheath cells, and not mesophyll cells. Two chimeric genes were constructed consisting of the structural gene encoding -glucuronidase (GUS) controlled by the two promoters from maize (C4) and rice (C3) rbcS genes. These constructs were introduced into a C4 plant, maize. Both chimeric genes were specifically expressed in photosynthetic organs, such as leaf blade, but not in non-photosynthetic organs. The expressions of the genes were also regulated by light. However, the rice promoter drove the GUS activity mainly in mesophyll cells and relatively low in bundle sheath cells, while the maize rbcS promoter induced the activity specifically in bundle sheath cells. These results suggest that the rice promoter contains some cis-acting elements responding in an organ-pecific and light-inducible regulation manner in maize but does not contain element(s) for bundle sheath cell-specific expression, while the maize promoter does contain such element(s). Based on this result, we discuss the similarities and differences between the rice (C3) and maize (C4) rbcS promoter in terms of the evolution of the C4 photosynthetic gene.