Immunophenotypic and Functional Characterization of Eosinophil and Migratory Dendritic Cell Subsets during Filarial Manifestation of Tropical Pulmonary Eosinophilia.

The role of eosinophil and migratory dendritic cell (migDC) subsets during tropical pulmonary eosinophilia (TPE), a potentially fatal complication of lymphatic filariasis, has not been explored. We show that the onset of TPE is characterized by the accumulation of ROS and anaphylatoxins and a rapid influx of morphologically distinct Siglec-Fint resident eosinophils (rEos) and Siglec-Fhi inflammatory eosinophils (iEos) in the lungs, BAL fluid, and blood of TPE mice. While rEos display regulatory behavior, iEos are highly inflammatory cells, as evident in upregulated expression of activation markers CD69 and CD101, anaphylatoxin receptor C5AR1, alarmins s100a8 and s100a9, components of NADPH oxidase, and copious secretion of TNF-α, IFN-γ, IL-6, IL-1ß, IL-4, IL-10, IL-12, and TGF-ß. Importantly, iEos exhibited heightened ROS generation, higher phagocytic and increased antigen presentation capacity, elevated Ca2+ influx, and increased F-actin polymerization but downregulated negative regulators of the immune response, i.e., Cd300a, Anaxa1, Runx3, Lilrb3, and Serpinb1a, underlining their essential role in promoting lung damage during TPE. Interestingly, TPE mice also showed significant expansion of CD24+CD11b+ migDCs, which showed upregulated expression of maturation and costimulatory markers CD40, CD80, CD83, CD86, and MHCII, increased antigen presentation capacity, and higher migratory potential as evidenced by increased expression of cytokine receptors CCR4, CCR5, CXCR4, and CXCR5. CD24+CD11b+ migDCs also upregulated the expression of immunoregulators PD-L1 and PD-L2 and secreted proinflammatory cytokines, suggesting their significant involvement during TPE. Taken together, we document important morphological, immunophenotypic, and functional characteristics of eosinophil and migDC subsets in the lungs of TPE mice and suggest that they contribute to worsening lung histopathological conditions during TPE.

Synthesis of N-substituted indole derivatives as potential antimicrobial and antileishmanial agents.

Leishmaniasis and microbial infections are two of the major contributors to global mortality and morbidity rates. Hence, development of novel, effective and safer antileishmanial and antimicrobial agents having reduced side effects are major priority for researchers. Two series of N-substituted indole derivatives i.e. N-substituted indole based chalcones (12a-g) and N-substituted indole based hydrazide-hydrazones (18a-g, 19a-f, 21 a-g) were synthesized. The synthesized compounds were characterized by 1H NMR, 13C NMR, Mass and FT-IR spectral data. Further these derivatives were evaluated for their antimicrobial potential against Escherichia coli, Bacillus subtilis, Pseudomonas putida and Candida viswanathii, and antileishmanial potential against promastigotes of Leishmania donovani. Compounds 18b, 18d and 19d exhibited significant activity with an IC50 of 0.19 ± 0.03 µM, 0.14 ± 0.02 µM and 0.16 ± 0.06 µM against B. subtilis which was comparable to chloramphenicol (IC50 of 0.25 ± 0.03 µM). Compounds 12b and 12c exhibited an IC50 of 24.2 ± 3.5 µM and 21.5 ± 2.1 µM in the antileishmanial assay. Binding interactions of indole based hydrazide-hydrazones were studied with nitric oxide synthase in silico in order to understand the structural features responsible for activity.

Investigation of anti-cancer and migrastatic properties of novel curcumin derivatives on breast and ovarian cancer cell lines.

BACKGROUND: Curcumin is known for its multitude of medicinal properties, including anti-cancer and migrastatic activity. Efforts to overcome poor bioavailability, stability, and side effects associated with the higher dose of curcumin has led to the development of newer derivatives of curcumin. Thus, the focus of this study is to screen novel curcumin derivatives, namely ST03 and ST08, which have not been reported before, for their cytotoxicity and migrastatic property on cancer cells. METHODS: Anti-cancer activity of ST03 and ST08 was carried out using standard cytotoxicity assays viz., LDH, MTT, and Trypan blue on both solid and liquid cancer types. Flow cytometric assays and western blotting was used to investigate the cell death mechanisms. Transwell migration assay was carried out to check for migrastatic properties of the compounds. RESULTS: Both the compounds, ST03 and ST08, showed ~ 100 fold higher potency on liquid and solid tumour cell lines compared to its parent compound curcumin. They induced cytotoxicity by activating the intrinsic pathway of apoptosis in the breast (MDA-MB-231) and ovarian cancer cell lines (PA-1) bearing metastatic and stem cell properties, respectively. Moreover, ST08 also showed inhibition on breast cancer cell migration by inhibiting MMP1 (matrix metalloproteinase 1). CONCLUSION: Both ST03 and ST08 exhibit anti-cancer activity at nanomolar concentration. They induce cell death by activating the intrinsic pathway of apoptosis. Also, they inhibit migration of the cancer cells by inhibiting MMP1 in breast cancer cells.

Real-time monitoring of redox changes in the mammalian endoplasmic reticulum.

Redox-sensitive GFPs with engineered disulphide bonds have been used previously to monitor redox status in the cytosol and mitochondria of living cells. The usefulness of these redox probes depends on the reduction potential of the disulphide, with low values suiting the cytosol and mitochondrion, and higher values suiting the more oxidising environment of the endoplasmic reticulum (ER). Here, we targeted a modified redox-sensitive GFP (roGFP1-iL), with a relatively high reduction potential, to the ER of mammalian cells. We showed that the disulphide is partially oxidised, allowing roGFP1-iL to monitor changes in ER redox status. When cells were treated with puromycin, the redox balance became more reducing, suggesting that the release of nascent chains from ribosomes alters the ER redox balance. In addition, downregulating Ero1α prevented normal rapid recovery from dithiothreitol (DTT), whereas downregulating peroxiredoxin IV had no such effect. This result illustrates the contribution of the Ero1α oxidative pathway to ER redox balance. This first report of the use of roGFP to study the ER of mammalian cells demonstrates that roGFP1-iL can be used to monitor real-time changes to the redox status in individual living cells.

Divalent cations regulate the folding and activation status of integrins during their intracellular trafficking.

Integrins are divalent cation-dependent, αß heterodimeric adhesion receptors that control many fundamental aspects of cell behaviour by bi-directional signalling between the extracellular matrix and intracellular cytoskeleton. The activation state of cell surface integrins is tightly regulated by divalent cation occupancy of the ligand-binding pocket and by interaction with cytoplasmic adaptor proteins, such as talin. These agents elicit gross conformational changes across the entire molecule, which specify the activation state. Much less is known about the activation state of newly synthesised integrins or the role of cations during the early folding and trafficking of integrins. Here we use a number of well-characterised, conformation-specific antibodies to demonstrate that ß1-integrins adopt the bent, inactive conformation after assembly with α-integrins in the endoplasmic reticulum. Folding and assembly are totally dependent on the binding of Ca(2+) ions. In addition, Ca(2+) binding prevents integrin activation before its arrival at the cell surface. Activation at the cell surface occurs only following displacement of Ca(2+) with Mg(2+) or Mn(2+). These results demonstrate the essential roles played by divalent cations to facilitate folding of the ß-integrin subunit, to prevent inappropriate intracellular integrin signalling, and to activate ligand binding and signalling at the cell surface.

A study of thyroid status in hyperemesis gravidarum.

Study was undertaken to assess thyroid status in hyperemesis gravidarum. 150 women pregnant with <20 weeks of gestation were selected randomly and out of these 100 women presenting with hyperemesis formed study group while 50 normal pregnant women served as controls. 53% of hyperemetic pregnant women were primigravidae and 82% of pregnant women presented with vomiting at less than 12 weeks of gestation. Statistically significant, 22% of hyperemetic women had increased serum T(3) levels while T(4) levels were increased in 67% of women in study group as compared to 8% and 16% respectively in control group. TSH levels were decreased in 18% of hyperemetic women as compared to 8% in control group with decrease in mean TSH level statistically significant. 22% of hyperemetic women had electrolyte disturbances and 7% were ketonuric. In clinically euthyroid women, biochemically altered thyroid function can attribute to vomiting and its prolongation to second trimester.