A role for the eIF4E-binding protein 4E-T in P-body formation and mRNA decay

4E-transporter (4E-T) is one of several proteins that bind the mRNA 5'cap-binding protein, eukaryotic initiation factor 4E (eIF4E), through a conserved binding motif. We previously showed that 4E-T is a nucleocytoplasmic shuttling protein, which mediates the import of eIF4E into the nucleus. At steady state, 4E-T is predominantly cytoplasmic and is concentrated in bodies that conspicuously resemble the recently described processing bodies (P-bodies), which are believed to be sites of mRNA decay. In this paper, we demonstrate that 4E-T colocalizes with mRNA decapping factors in bona fide P-bodies. Moreover, 4E-T controls mRNA half-life, because its depletion from cells using short interfering RNA increases mRNA stability. The 4E-T binding partner, eIF4E, also is localized in P-bodies. 4E-T interaction with eIF4E represses translation, which is believed to be a prerequisite for targeting of mRNAs to P-bodies. Collectively, these data suggest that 4E-T interaction with eIF4E is a priming event in inducing messenger ribonucleoprotein rearrangement and transition from translation to decay.     

Germline deletion of Igh 3' regulatory region elements hs 5, 6, 7 (hs5-7) affects B cell-specific regulation, rearrangement, and insulation of the Igh locus

Regulatory elements located within an ～28-kb region 3' of the Igh gene cluster (3' regulatory region) are required for class switch recombination and for high levels of IgH expression in plasma cells. We previously defined novel DNase I hypersensitive sites (hs) 5, 6, 7 immediately downstream of this region. The hs 5-7 region (hs5-7) contains a high density of binding sites for CCCTC-binding factor (CTCF), a zinc finger protein associated with mammalian insulator activity, and is an anchor for interactions with CTCF sites flanking the D(H) region. To test the function of hs5-7, we generated mice with an 8-kb deletion encompassing all three hs elements. B cells from hs5-7 knockout (KO) (hs5-7KO) mice showed a modest increase in expression of the nearest downstream gene. In addition, Igh alleles in hs5-7KO mice were in a less contracted configuration compared with wild-type Igh alleles and showed a 2-fold increase in the usage of proximal V(H)7183 gene families. Hs5-7KO mice were essentially indistinguishable from wild-type mice in B cell development, allelic regulation, class switch recombination, and chromosomal looping. We conclude that hs5-7, a high-density CTCF-binding region at the 3' end of the Igh locus, impacts usage of V(H) regions as far as 500 kb away.     

SWIFT: A deep learning approach to prediction of hypoxemic events in critically-Ill patients using SpO2 waveform prediction

Hypoxemia is a significant driver of mortality and poor clinical outcomes in conditions such as brain injury and cardiac arrest in critically ill patients, including COVID-19 patients. Given the host of negative clinical outcomes attributed to hypoxemia, identifying patients likely to experience hypoxemia would offer valuable opportunities for early and thus more effective intervention. We present SWIFT (SpO₂ Waveform ICU Forecasting Technique), a deep learning model that predicts blood oxygen saturation (SpO₂) waveforms 5 and 30 minutes in the future using only prior SpO₂ values as inputs. When tested on novel data, SWIFT predicts more than 80% and 60% of hypoxemic events in critically ill and COVID-19 patients, respectively. SWIFT also predicts SpO₂ waveforms with average MSE below .0007. SWIFT predicts both occurrence and magnitude of potential hypoxemic events 30 minutes in the future, allowing it to be used to inform clinical interventions, patient triaging, and optimal resource allocation. SWIFT may be used in clinical decision support systems to inform the management of critically ill patients during the COVID-19 pandemic and beyond.     

Qualitative and Quantitative Evaluation of Gall Induced by <Emphasis Type="Italic">Pseudophacopteron alstonium</Emphasis> Yang et Li 1983 (Hemiptera: Psyllidae: Phacopteronidae) as Plant Parasite,in <Emphasis Type="Italic">Alstonia scholaris</Emphasis> Leaves

Alstonia scholaris (Dr C. Alston, 1685–1760) (Family Apocynaceae) (Chattim tree), commonly known as devil tree, is an evergreen tropical tree. The tree is native to India and also found in Sri Lanka, Southern China, throughout Malaysia to northern Australia. This plant is seriously damaged by formation of tumor like galls across the Kolkata city,West Bengal which affects its ornamental and medicinal value. Gall is formed by ovipositing adults of Pseudophacopteron alstonium Yang et Li 1983 (Hemiptera: Psyllidae: Phacopteronidae) and results in destruction of host plant. The nymphal stage undergoes moulting through first instar to third instar to reach the adult within galls. It is observed that highly infested leaves can bear 60–80 galls. The gallmaker Pseudophacopteron sp. stresses the host organ, and the host counters it with physiological activities supplemented by newly differentiated tissues. In infested leaves, chlorophyll and carbohydrate contents decreased sequentially with the age of the gall. There were no significant changes in protein and total amino acid content in gall tissue. But total lipid content was highest in mature galled leaves. Increased phenolic content after psylloid herbivory, which exerted oxidative stress on the host plants, was observed in gall infested leaves as compared to fresh ungalled leaves of Alstonia scholaris. Moisture content was highest in ungalled healthy leaves than the young galled, mature galled and perforated galled leaves.     

An unusual pro-inflammatory role of interleukin-10 induced by arabinosylated lipoarabinomannan in murine peritoneal macrophages

Various species of Mycobacteria produce a major cell wall-associated lipoglycan, called Lipoarabinomannan (LAM), which is involved in the virulence of Mycobacterial species. In this study, we tried to establish the role of the increased IL-10 secretion under Arabinosylated-LAM (Ara-LAM) treatment, the LAM that induces apoptosis in host macrophages or PBMC. We have studied the survival and apoptotic factors by western blotting, and estimated nitrite generation by Griess reaction, quantified iNOS mRNA by semi-quantitative RT-PCR, and ultimately the fate of the cells were studied by Flow Cytometric Analysis of AnnexinV-FITC binding. As per our observations, neutralization of released IL-10 in C57BL/6 peritoneal macrophages prior to Ara-LAM treatment, as well as macrophages from IL-10 knockout (KO) mice treated with Ara-LAM, showed significant down regulation of pro-apoptotic factors and up regulation of survival factors. These effects were strikingly similar to those when peritoneal macrophages were subjected to TNF-α and IL-12 neutralization followed by Ara-LAM-treatment. However, under similar conditions virulent Mannosylated-LAM (from Mycobacterium tuberculosis) treatment of macrophages clearly depicts the importance of IL-10 in the maintenance of pathogenesis, proving its usual immunosuppressive role. Thus, from our detailed investigations we point out an unusual pro-inflammatory action of IL-10 in Ara-LAM treated macrophages, where it behaves in a similar manner as the known Th1 cytokines TNF- α and IL-12. This work is financed by the Council of Scientific and Industrial Research (CSIR), Govt. of India.     

Analysis of long-term culture properties and pluripotent character of two sibling human embryonic stem cell lines derived from discarded embryos

We had earlier reported the derivation and characterization of two new sibling human embryonic stem cell lines BJNhem19 and BJNhem20, from discarded grade III embryos of Indian origin. We report here the characteristics of the two sibling cell lines after long-term continuous culture for over 2 yr during which they have been passaged over 200 times. We show that both cell lines adapt well to culture on various mouse and human feeders as well as in feeder-free conditions. The cells show normal diploid karyotype and continue to express all pluripotency markers. Both cell lines differentiate to derivatives of all three germ layers in vitro. However as reported earlier, BJNhem19 is unable to generate teratomas in nude or SCID mice or differentiate to beating cardiomyocytes when tested over several passages during long-term stable culture. On the other hand, the cardiac differentiation capacity of BJNhem20 is greatly increased, and it can generate beating cardiomyocytes that proliferate when isolated and cultured further. In conclusion, the two cell lines have maintained a stable phenotype for over 2 yr and are indeed immortal. Their derivation from grade III embryos does not seem to have any adverse effect on their long-term phenotype. The cells can be obtained for research purposes from the UK Stem Cell Bank and from the authors.     

The Glycemic Elemental Profile of <Emphasis Type=Italic>Trichosanthes dioica</Emphasis>: A LIBS-Based Study

The scientific evaluation of the antidiabetic efficacy of aqueous extract of Trichosanthes dioica fruits on streptozotocin-induced diabetic rats is being presented. The graded doses of the extract, viz., 500, 750, 1,000, and 1,250 mg/kg body weight (bw), were administered orally, and it was observed that the blood glucose concentration decreased in a dose-dependent manner. The dose of 1,000 mg/kg bw showed the maximum fall of 23.8% and 19.1% in blood glucose level (BGL) during fasting BGL and glucose tolerance test (GTT) studies, respectively, of nondiabetic rats. Whereas in the case of subdiabetic and mild diabetic models, the same dose showed reduction in BGL of 22.0% and 31.4% during GTT. The study also involves the first use of laser-induced breakdown spectroscopy as a sensitive analytical tool to detect the elemental profile responsible for the antidiabetic activity of aqueous extract of T. dioica fruits that exhibits the antidiabetic activity. High intensities of Ca, Mg, and Fe indicate large concentrations of these elements in the extract, since according to Boltzmann’s distribution law, intensities are directly proportional to concentrations. The higher concentrations of these glycemic elements, viz. Ca, Mg, and Fe, are responsible for the antidiabetic potential of T. dioica as well as other plant already reported by our research group.