4-Deoxyraputindole C induces cell death and cell cycle arrest in tumor cell lines

Several molecules extracted from natural products exhibit different biological activities, such as ion channel modulation, activation of signaling pathways, and anti-inflammatory or antitumor activity. In this study, we tested the antitumor ability of natural compounds extracted from the Raputia praetermissa plant. Among the compounds tested, an alkaloid, here called compound S4 (4-Deoxyraputindole C), showed antitumor effects against human tumor lineages. Compound S4 was the most active against Raji, a lymphoma lineage, promoting cell death with characteristics that including membrane permeabilization, dissipation of the mitochondrial potential, increased superoxide production, and lysosomal membrane permeabilization. The use of cell death inhibitors such as Z-VAD-FMK (caspase inhibitor), necrostatin-1 (receptor-interacting serine/threonine-protein kinase 1 inhibitor), E-64 (cysteine peptidases inhibitor), and N-acetyl- L -cysteine (antioxidant) did not decrease compound S4-dependent cell death. Additionally, we tested the effect of cellular activity on adherent human tumor cells. The highest reduction of cellular activity was observed in A549 cells, a lung carcinoma lineage. In this lineage, the effect on the reduction of the cellular activity was due to cell cycle arrest, without plasma membrane permeabilization, loss of the mitochondrial potential or lysosomal membrane permeabilization. Compound S4 was able to inhibit cathepsin B and L by a nonlinear competitive (negative co-operativity) and simple-linear competitive inhibitions, respectively. The potency of inhibition was higher against cathepsin L. Compound S4 promoted cell cycle arrest at G ₀ and G ₂ phase, and increase the expression of p16 and p21 proteins. In conclusion, compound S4 is an interesting molecule against cancer, promoting cell death in the human lymphoma lineage Raji and cell cycle arrest in the human lung carcinoma lineage A549.     

Effects of 2,6-dichlorobenzonitrile on differentiation to tracheary elements of isolated mesophyll cells of Zinnia elegans and formation of secondary cell walls

Seeds of Caesulia axillaris Roxb. displayed an absolute light requirement for germination throughout the period of dry storage at 28°C. The seeds were found to show a gradual increase in percent germination with storage time - reaching a maximum value between 8-14 months and then a sharp decline. Percent water uptake and photosensitivity were at maximum after a 5-day imbibition period in the dark in both seedlots studied. Seedlot I, which was only marginally responsive to far-red light, showed a nearly complete red-far-red reversal effect in contrast to seedlot II. The latter also displayed a considerable promotion of germination in far-red light. Interestingly, a noticeable degree of heterogeneity, besides the one observed in both seedlots with reference to red light, was found to exist in seedlot II for far-red light. Exogenous application of nitrate and ammonium, at the levels occurring in soil during seed germination/seedling emergence phase of the plant in nature, promoted a considerable proportion of high Ø-requiring seeds to germinate under irradiation conditions establishing low Ø-value. The probable ecological implication of this reponse has been discussed. Little correlation was found between the requirement for an exogenous supply of nitrate and the endogenous nitrate level in the seeds in their response to far-red light.     

Current knowledge of vector-borne zoonotic pathogens in Zambia: A clarion call to scaling-up “One Health” research in the wake of emerging and re-emerging infectious diseases

BackgroundAlthough vector-borne zoonotic diseases are a major public health threat globally, they are usually neglected, especially among resource-constrained countries, including those in sub-Saharan Africa. This scoping review examined the current knowledge and identified research gaps of vector-borne zoonotic pathogens in Zambia.Methods and findingsMajor scientific databases (Web of Science, PubMed, Scopus, Google Scholar, CABI, Scientific Information Database (SID)) were searched for articles describing vector-borne (mosquitoes, ticks, fleas and tsetse flies) zoonotic pathogens in Zambia. Several mosquito-borne arboviruses have been reported including Yellow fever, Ntaya, Mayaro, Dengue, Zika, West Nile, Chikungunya, Sindbis, and Rift Valley fever viruses. Flea-borne zoonotic pathogens reported include Yersinia pestis and Rickettsia felis. Trypanosoma sp. was the only tsetse fly-borne pathogen identified. Further, tick-borne zoonotic pathogens reported included Crimean-Congo Haemorrhagic fever virus, Rickettsia sp., Anaplasma sp., Ehrlichia sp., Borrelia sp., and Coxiella burnetii.ConclusionsThis study revealed the presence of many vector-borne zoonotic pathogens circulating in vectors and animals in Zambia. Though reports of human clinical cases were limited, several serological studies provided considerable evidence of zoonotic transmission of vector-borne pathogens in humans. However, the disease burden in humans attributable to vector-borne zoonotic infections could not be ascertained from the available reports and this precludes the formulation of national policies that could help in the control and mitigation of the impact of these diseases in Zambia. Therefore, there is an urgent need to scale-up “One Health” research in emerging and re-emerging infectious diseases to enable the country to prepare for future epidemics, including pandemics.     

Effect of the presence and location of corpus luteum on competence of bovine cumulus-oocyte complexes

This study aimed to determine the effect of presence of the corpus luteum (CL) and its influence on cumulus–oocyte complexes (COCs) obtained from the ipsilateral or contralateral ovary in bovine on the recovery and capacity of the oocytes to sustain mono-spermic fertilization, undergo preimplantation development, and develop to the blastocyst stage. Ovaries were collected at a local slaughterhouse and kept in pairs corresponding to the same animal. In the first experiment the variables evaluated were compared between cows with (CCL⁺) and without (CCL^-) CL, and for the second experiment, comparisons were made between ovaries with an ipsilateral (CL⁺), contralateral (CL⁻), and no (NCL). The recovery rate of COCs was higher in ovaries from CCL⁻ cows, and a higher proportion of grade 1 COCs were recovered from this group. A higher proportion of metaphase I oocytes at 7 h of maturation, and a higher rate of cleavage were observed in the CCL⁺ group; however, a higher proportion of embryos were obtained from the CCL⁻ group. Besides, COCs from the CL⁺ group had a lower proportion of grades 1 and 2 morphological qualities, lower rate of metaphase II oocytes at 22 h of maturation, and lower rate of formation of two pronuclei, whereas a higher proportion of unfertilized oocytes after in vitro fertilization. On the other hand, the COCs from the CL⁻ group displayed a lower proportion of oocytes with more than two pronuclei, higher cleavage rate, and higher final blastocyst production were obtained when compared to CL+. Thus, the effects of CL on the competence of bovine COCs are different depending on the anatomical proximity of their location in the animal, negatively affecting the quality of COCs located in the same ovary, but not having negative effects on the competence of COCs in the ovaries contralateral to their location.     

The interstitial nuclei of the human anterior hypothalamus: an investigation of variation with sex, sexual orientation, and HIV status

The interstitial nuclei of the human anterior hypothalamus (INAH1-4) have been considered candidates for homology with the sexually dimorphic nucleus of the preoptic area of the rat. Volumetric sexual dimorphism has been described for three of these nuclei (INAH1-3), and INAH3 has been reported to be smaller in homosexual than heterosexual men. The current study measured the INAH in Nissl-stained coronal sections in autopsy material from 34 presumed heterosexual men (24 HIV- and 10 HIV+), 34 presumed heterosexual women (25 HIV- and 9 HIV+), and 14 HIV+ homosexual men. HIV status significantly influenced the volume of INAH1 (8% larger in HIV+ heterosexual men and women relative to HIV- individuals), but no other INAH. INAH3 contained significantly more neurons and occupied a greater volume in presumed heterosexual males than females. No sex difference in volume was detected for any other INAH. No sexual variation in neuronal size or density was observed in any INAH. Although there was a trend for INAH3 to occupy a smaller volume in homosexual men than in heterosexual men, there was no difference in the number of neurons within the nucleus based on sexual orientation.     

The viral CC chemokine-binding protein vCCI inhibits monocyte chemoattractant protein-1 activity by masking its CCR2B-binding site

Monocyte chemoattractant protein-1 (MCP-1) is a chemotactic cytokine mainly acting on monocytes and T cells that elicits its biological effects by interacting with the seven-transmembrane helix receptor CCR2B. The vaccinia virus strain Lister and many other poxviruses express soluble proteins (vCCI) that bind MCP-1 and other CC chemokines and inhibit their function. In order to define the interaction site of MCP-1 with vCCI from vaccinia, surface exposed residues of MCP-1 were identified and mutated to alanine. The MCP-1 variants were expressed, purified, and their interaction with vCCI was characterized. The site on MCP-1 for vCCI binding is dominated by arginine 18 with important additional contributions from tyrosine 13 and arginine 24. These residues define a binding site that largely overlaps with the CCR2B receptor interaction site. The viral chemokine-binding protein vCCI thus inhibits the biological function of MCP-1 by directly masking its CCR2B receptor-binding site.     

Ascorbic acid increases the yield of dopaminergic neurons derived from basic fibroblast growth factor expanded mesencephalic precursors

CNS precursors derived from E12 rat mesencephalon proliferate in the presence of basic fibroblast growth factor and differentiate in vitro into functional dopaminergic neurons, which upon transplantation alleviate behavioral symptoms in a rat model of Parkinson's disease. Here we show that the efficiency of dopaminergic differentiation decreases in the mesencephalic precursors that were proliferated or passaged for extended periods in vitro. Ascorbic acid treatment restored dopaminergic differentiation in these precursors and led to a greater than 10-fold increase in dopamine neuron yield compared with untreated cultures. The effect of ascorbic acid was stereospecific and could not be mimicked by any other antioxidants. The expression of sodium-dependent vitamin C transporter, a recently identified stereospecific ascorbic acid transporter, was maintained in mesencephalic precursors for extended in vitro periods. Pre-treatment of in vitro expanded mesencephalic precursors with ascorbic acid might facilitate the large-scale generation of dopaminergic neurons for clinical transplantation.     

Matrilin-2, a large, oligomeric matrix protein, is expressed by a great variety of cells and forms fibrillar networks

Matrilin-2 is a member of the protein superfamily with von Willebrand factor type A-like modules. Mouse matrilin-2 cDNA fragments were expressed in 293-EBNA cells, and the protein was purified, characterized, and used to immunize rabbits. The affinity-purified antiserum detects matrilin-2 in dense and loose connective tissue structures, subepithelial connective tissue of the skin and digestive tract, specialized cartilages, and blood vessel walls. In situ hybridization of 35S-labeled riboprobes localizes the matrilin-2 mRNA to fibroblasts of dermis, tendon, ligaments, perichondrium, and periosteum; connective tissue elements in the heart; smooth muscle cells; and epithelia and loose connective tissue cells of the alimentary canal and respiratory tract. RNA blot hybridization and immunoblotting revealed both matrilin-2 mRNA and protein in cultures of a variety of cell types, confirming the tissue distribution. Alternative splicing affects a module unique for matrilin-2 in all of the above RNA sources. SDS-polyacrylamide gel electrophoresis and electron microscopy reveals matrilin-2 from tissue extracts and cell line cultures as a mixture of mono-, di-, tri-, and tetramers. Matrilin-2 is substituted with N-linked oligosaccharides but not with glycosaminoglycans. Because of other, yet unidentified, cell-type dependent posttranslational modifications, the monomer is heterogeneous in size. Immunofluorescence showed that matrilin-2 functions by forming an extracellular, filamentous network.