Cripto regulates hematopoietic stem cells as a hypoxic-niche-related factor through cell surface receptor GRP78

Hematopoietic stem cells (HSCs) are maintained in hypoxic niches in endosteal regions of bones. Here we demonstrate that Cripto and its receptor GRP78 are important regulators of HSCs in the niche. Flow cytometry analyses revealed two distinct subpopulations of CD34(-)KSL cells based on the expression of GRP78, and these populations showed different reconstitution potential in transplantation assays. GRP78(+)HSCs mainly reside in the endosteal area, are more hypoxic, and exhibit a lower mitochondrial potential, and their HSC capacity was maintained in?vitro by Cripto through induction of higher glycolytic activity. Additionally, HIF-1α KO mice have decreased numbers of GRP78(+)HSCs and reduced expression of Cripto in the endosteal niche. Furthermore, blocking GRP78 induced a movement of HSCs from the endosteal to the central marrow area. These data suggest that Cripto/GRP78 signaling is an important pathway that regulates HSC quiescence and maintains HSCs in hypoxia as an intermediary of HIF-1α.     

In search of an uncultured human-associated TM7 bacterium in the environment

We have identified an environmental bacterium in the Candidate Division TM7 with ≥98.5% 16S rDNA gene homology to a group of TM7 bacteria associated with the human oral cavity and skin. The environmental TM7 bacterium (referred to as TM7a-like) was readily detectable in wastewater with molecular techniques over two years of sampling. We present the first images of TM7a-like cells through FISH technique and the first images of any TM7 as viable cells through the STARFISH technique. In situ quantification showed TM7 concentration in wastewater up to five times greater than in human oral sites. We speculate that upon further characterization of the physiology and genetics of the TM7a-like bacterium from environmental sources and confirmation of its genomic identity to human-associated counterparts it will serve as model organisms to better understand its role in human health. The approach proposed circumvents difficulties imposed by sampling humans, provides an alternative strategy to characterizing some diseases of unknown etiology, and renders a much needed understanding of the ecophysiological role hundreds of unique Bacteria and Archaea strains play in mixed microbial communities.     

Propyl-2-(8-(3,4-Difluorobenzyl)-2′,5′-Dioxo-8-Azaspiro[Bicyclo[3.2.1] Octane-3,4′-Imidazolidine]-1′-yl) Acetate Induces Apoptosis in Human Leukemia Cells through Mitochondrial Pathway following Cell Cycle Arrest

Background

Due to the functional defects in apoptosis signaling molecules or deficient activation of apoptosis pathways, leukemia has become an aggressive disease with poor prognosis. Although the majority of leukemia patients initially respond to chemotherapy, relapse is still the leading cause of death. Hence targeting apoptosis pathway would be a promising strategy for the improved treatment of leukemia. Hydantoin derivatives possess a wide range of important biological and pharmacological properties including anticancer properties. Here we investigated the antileukemic activity and mechanism of action of one of the potent azaspiro hydantoin derivative, (ASHD).

Materials and Methods

To investigate the antileukemic efficacy of ASHD, we have used MTT assay, cell cycle analysis by FACS, tritiated thymidine incorporation assay, Annexin V staining, JC1 staining and western blot analysis.

Results

Results showed that ASHD was approximately 3-fold more potent than the parent compounds in inducing cytotoxicity. Tritiated thymidine assay in conjunction with cell cycle analysis suggests that ASHD inhibited the growth of leukemic cells. The limited effect of ASHD on cell viability of normal cells indicated that it may be specifically directed to cancer cells. Translocation of phosphatidyl serine, activation of caspase 3, caspase 9, PARP, alteration in the ratio of BCL2/BAD protein expression as well as the loss of mitochondrial membrane potential suggests activation of the intrinsic pathway of apoptosis.

Conclusion

These results could facilitate the future development of novel hydantoin derivatives as chemotherapeutic agents for leukemia.     

Acute promyelocytic leukemia with unusual karyotype

Acute myeloid leukemia (AML-M3) is associated with the translocation t(15;17)(q22;q12-21) which disrupts the retinoic acid receptor alpha (RARA) gene on chromosome 17 and the PML gene on chromosome 15. We report a two-year-old patient with AML-M3 without the usual translocation t(15;17). Cytogenetic studies demonstrated normal appearance of chromosome 15 while the abnormal 17 homologue was apparently a derivative 17, der(17)(17qter-cen-q21:), the rearrangement distinctly shows deletion at 17q21 band and the morphology corresponding to an iso chromosome i(17q-). This case report is a rare cytogenetic presentation of acute promyelocytic leukemia (APML).     

Mercury(II)-methylene blue interactions: Complexation and metallate formation

Reactions of HgX₂ (X = Cl, Br, I) with methylene blue (MB) chloride dihydrate and the reaction of HgCl₂ with MB nitrate dihydrate have been undertaken in an attempt to prepare metal derivatives of MB. The products were characterized by elemental analysis, UV-Vis, IR, ¹H NMR spectroscopy and X-ray crystallography. The reaction of HgCl₂ with MB chloride dihydrate and subsequent crystallization in a DMF/H₂O mixture yielded the products (1 and 2) with different crystal morphologies. The structure of complex 1 represents the first structural report of a complex of MB with any metal ion. The efficacy of MB to act as a ligand in spite of its cationic nature is thus demonstrated. The structure of 1 comprises a distorted tetrahedral geometry around Hg(II); the coordination valencies being provided by three chloride ions and a MB cation. The structure of 2 is a salt consisting of an anion and two MB cations. The reaction of HgI₂ and HgBr₂ with MB chloride dihydrate yielded salts 3 and 4 with (X = Br or I) anions and MB cations. A mixed salt 5, whose anions comprise mercury(II), chloride and nitrate species resulted from the reaction between HgCl₂ with MB nitrate dihydrate. The reaction of Hg₂F₂ with MB chloride dihydrate and the crystallization of the resulting product 6 in aqueous DMF yielded crystals of (MB)₂HgCl₄ · H₂O.     

Pre‐Clinical Testing of Microwave Radiometer and a Pilot Study on the Screening Inflammation of Knee Joints

This article presents the pre‐clinical evaluation of our custom‐built, single‐band microwave radiometer centered at 1.3 GHz for deep tissue thermometry, and a pilot study on volunteers for passive detection of inflammation in knee joints. The electromagnetic (EM) compatibility of the battery‐operated radiometer for clinical use was assessed as per International Special Committee on Radio Interference (CISPR) 22 standard. The ability to detect inflammation in knee joints was assessed using a substrate integrated waveguide antenna connected to the radiometer. EM compatibility tests carried out in the laboratory indicated device immunity to intentional radiated interference up to ?20 dBm injected power in the global system for mobile communication frequency band, and pre‐compliance to CISPR 22 standard. Radiometer temperature measurements recorded at the lateral and medial aspects of both knees of 41 volunteers indicated mean temperature greater than 33°C for the diseased sites compared with the mean temperature of 28°C measured for the healthy sites. One‐way analysis of variance statistics indicated significantly (P < 0.005) higher radiometer temperature at the diseased sites unlike the healthy sites. Thus, the EM pre‐compliance of the device and the potential to measure deep tissue inflammation were demonstrated. Bioelectromagnetics. 2019;40:402–411. © 2019 Bioelectromagnetics Society.