Antioxidant and Hypoglycemic Potential of Phytogenic Selenium Nanoparticle- and Light Regime-Mediated In Vitro Caralluma tuberculata Callus Culture Extract.

In vitro plant cultures have emerged as a viable source, holding auspicious reservoirs for medicinal applications. This study aims to delineate the antioxidant and hypoglycemic potential of phytosynthesized selenium nanoparticle (SeNP)- and light stress-mediated in vitro callus cultures of Caralluma tuberculata extract. The morphophysicochemical characteristics of biogenic SeNPs were assessed through a combination of analytical techniques, including UV-visible spectrophotometry, scanning electron microscopy, energy-dispersive X-rays, Fourier transform infrared spectrometry, and zeta potential spectroscopy. The antioxidative potential of the callus extract 200 and 800 µg/mL concentrations was assessed through various tests and exhibited pronounced scavenging potential in reducing power (26.29%), ABTS + scavenging (42.51%), hydrogen peroxide inhibition (37.26%), hydroxyl radical scavenging (40.23%), and phosphomolybdate (71.66%), respectively. To inspect the hypoglycemic capacity of the callus extract, various assays consistently demonstrated a dosage-dependent relationship, with higher concentrations of the callus extract exerting a potent inhibitory impact on the catalytic sites of the alpha-amylase (78.24%), alpha-glucosidase (71.55%), antisucrase (59.24%), and antilipase (74.26%) enzyme activities, glucose uptake by yeast cells at 5, 10, and 25 mmol/L glucose solution (72.18, 60.58 and 69.33%), and glucose adsorption capacity at 5, 10, and 25 mmol/L glucose solution (74.37, 83.55, and 86.49%), respectively. The findings of this study propose selenium NPs and light-stress-mediated in vitro callus cultures of C. tuberculata potentially operating as competitive inhibitors. The outcomes of the study were exceptional and hold promising implications for future medicinal applications.

Exposure of Caralluma tuberculata to biogenic selenium nanoparticles as in vitro rooting agent: Stimulates morpho-physiological and antioxidant defense system.

The commercial-scale production of Caralluma tuberculata faces significant challenges due to lower seed viability and sluggish rate of root growth in natural conditions. To overcome these obstacles, using phyto-mediated selenium nanomaterials as an in vitro rooting agent in plant in vitro cultures is a promising approach to facilitate rapid propagation and enhance the production of valuable therapeutic compounds. This study aimed to investigate the impact of phytosynthesized selenium nanoparticles (SeNPs) on the morphological growth attributes, physiological status, and secondary metabolite fabrication in in vitro propagated Caralluma tuberculata. The results demonstrated that a lower dose of SeNPs (100 µg/L) along with plant growth regulators (IBA 1 mg/L) had an affirmative effect on growth parameters and promoted earliest root initiation (4.6±0.98 days), highest rooting frequency (68.21±5.12%), number of roots (6.3±1.8), maximum fresh weight (710±6.01 mg) and dry weight (549.89±6.77 mg). However, higher levels of SeNPs (200 and 400 µg/L) in the growth media proved detrimental to growth and development. Further, stress caused by SeNPs at 100 µg/L along with PGRs (IBA 1 mg/L) produced a higher level of total chlorophyll contents (32.66± 4.36 µg/ml), while cultures exposed to 200 µg/L SeNPs alone exhibited the maximum amount of proline contents (10.5± 1.32 µg/ml). Interestingly, exposure to 400 µg/L SeNPs induced a stress response in the cultures, leading to increased levels of total phenolic content (3.4 ± 0.052), total flavonoid content (1.8 ± 0.034), and antioxidant activity 82 ± 4.8%). Furthermore, the combination of 100 µg/L SeNPs and plant growth regulators (1 mg/L IBA) led to accelerated enzymatic antioxidant activities, including superoxide dismutase (SOD = 4.4 ± 0.067 U/mg), peroxidase dismutase (POD = 3.3 ± 0.043 U/mg), catalase (CAT = 2.8 ± 0.048 U/mg), and ascorbate peroxidase (APx = 1.6 ± 0.082 U/mg). This is the first report that highlights the efficacy of SeNPs in culture media and presents a promising approach for the commercial propagation of C. tuberculata with a strong antioxidant defense system in vitro.

Exposure to zinc oxide nanoparticles induced reproductive toxicities in male Sprague Dawley rats.

BACKGROUND: This research delves into the reproductive toxicology of zinc oxide nanoparticles (ZnO-NPs) in male Sprague Dawley rats. It specifically examines the repercussions of Zn accumulation in the testes, alterations in testosterone levels, and histopathological changes in the gonadal tissues. AIMS: The primary objective of this study is to elucidate the extent of reproductive toxicity induced by ZnO-NPs in male Sprague Dawley rats. The investigation aims to contribute to a deeper understanding of the potential endocrine and reproductive disruptions caused by ZnO-NPs exposure. METHODS: Characterization techniques including SEM-EDX and XRD affirmed the characteristic nature of ZnO-NPs. Twenty-five healthy post weaning rats (200-250 g) were intraperitoneally exposed to different concentrations of ZnO-NPs @ 10 or 20 or 30 mg/kg BW for 28 days on alternate days. RESULTS: Results showed significant dose dependent decline in the body weight and testicular somatic index of rats. It also showed significant dose dependent accumulation of Zn in testis with increasing dose of ZnO-NPs. Conversely, serum testosterone level and sperm count were reduced with increasing dose of ZnO-NPs. Histological results showed dose dependent abnormalities i.e., vacuolization, edema, hemorrhage, destruction of seminiferous tubules, loss of germ cells and necrosis in rat testis. CONCLUSION: The findings of this study clearly indicate that high doses of zinc oxide nanoparticles (ZnO-NPs) can adversely affect the structural integrity and functional efficacy of the male reproductive system. Given these results, it becomes crucial to implement stringent precautionary measures in the utilization of ZnO-NPs, particularly in cosmetics and other relevant sectors. Such measures are imperative to mitigate the toxicological impact of ZnO-NPs on the male reproductive system and potentially on other related physiological functions. This study underscores the need for regulatory vigilance and safety assessments in the application of nanotechnology to safeguard human health.

Evaluation of Brown and red seaweeds-extracts as a novel larvicidal agent against the deadly human diseases-vectors, Anopheles stephensi, Aedes aegypti and Culex quinquefasciatus.

Infectious diseases such as malaria, dengue, and yellow fever are predominantly transmitted by insect vectors like Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus in tropical regions like India and Africa. In this study, we assessed the larvicidal activity of commonly found seaweeds, including Padina gymnospora, P. pavonica, Gracilaria crassa, Amphiroa fragilissima, and Spatoglossum marginatum, against these mosquito vectors. Our findings indicate that extracts from P. gymnospora Ethyl Acetate (PgEA), P. pavonica Hexane (PpH), and A. fragilissima Ethyl Acetate (AfEA) displayed the highest larval mortality rates for A. stephensi, with LC50 values of 10.51, 12.43, and 6.43 µg/mL, respectively. Additionally, the PgEA extract from P. gymnospora exhibited the highest mortality rate for A. aegypti, with an LC50 of 27.0 µg/mL, while the PgH extract from the same seaweed showed the highest mortality rate for C. quinquefasciatus, with an LC50 of 9.26 µg/mL. Phytochemical analysis of the seaweed extracts revealed the presence of 71 compounds in the solvent extracts. Fourier-transform infrared spectra of the selected seaweeds indicated the presence of functional groups such as alkanes, alcohols, and phenols. Gas chromatography-mass spectrometry analysis of the seaweeds identified major compounds, including hexadecanoic acid in PgEA, tetradecene (e)- in PpEA, octadecanoic acid in GcEA, and 7-hexadecene, (z)-, and trans-7-pentadecene in SmEA.

Participation of the TBP-associated factors (TAFs) in cell differentiation.

The understanding of the mechanisms that regulate gene expression to establish differentiation programs and determine cell lineages, is one of the major challenges in Developmental Biology. Besides the participation of tissue-specific transcription factors and epigenetic processes, the role of general transcription factors has been ignored. Only in recent years, there have been scarce studies that address this issue. Here, we review the studies on the biological activity of some TATA-box binding protein (TBP)-associated factors (TAFs) during the proliferation of stem/progenitor cells and their involvement in cell differentiation. Particularly, the accumulated evidence suggests that TAF4, TAF4b, TAF7L, TAF8, TAF9, and TAF10, among others, participate in nervous system development, adipogenesis, myogenesis, and epidermal differentiation; while TAF1, TAF7, TAF15 may be involved in the regulation of stem cell proliferative abilities and cell cycle progression. On the other hand, evidence suggests that TBP variants such as TBPL1 and TBPL2 might be regulating some developmental processes such as germ cell maturation and differentiation, myogenesis, or ventral specification during development. Our analysis shows that it is necessary to study in greater depth the biological function of these factors and its participation in the assembly of specific transcription complexes that contribute to the differential gene expression that gives rise to the great diversity of cell types existing in an organism. The understanding of TAFs' regulation might lead to the development of new therapies for patients which suffer from mutations, alterations, and dysregulation of these essential elements of the transcriptional machinery.

Exploring the Therapeutic Potential of Traditional Antimalarial and Antidengue Plants: A Mechanistic Perspective.

Malaria, a highly perilous infectious disease, impacted approximately 230 million individuals globally in 2019. Mosquitoes, vectors of over 10% of worldwide diseases, pose a significant public health menace. The pressing need for novel antimalarial drugs arises due to the imminent threat faced by nearly 40% of the global population and the escalating resistance of parasites to current treatments. This study comprehensively addresses prevalent parasitic and viral illnesses transmitted by mosquitoes, leading to the annual symptomatic infections of 400 million individuals, placing 100 million at constant risk of contracting these diseases. Extensive investigations underscore the pivotal role of traditional plants as rich sources for pioneering pharmaceuticals. The latter half of this century witnessed the ascent of bioactive compounds within traditional medicine, laying the foundation for modern therapeutic breakthroughs. Herbal medicine, notably influential in underdeveloped or developing nations, remains an essential healthcare resource. Traditional Indian medical systems such as Ayurveda, Siddha, and Unani, with a history of successful outcomes, highlight the potential of these methodologies. Current scrutiny of Indian medicinal herbs reveals their promise as cutting-edge drug reservoirs. The propensity of plant-derived compounds to interact with biological receptors positions them as prime candidates for drug development. Yet, a comprehensive perspective is crucial. While this study underscores the promise of plant-based compounds as therapeutic agents against malaria and dengue fever, acknowledging the intricate complexities of drug development and the challenges therein are imperative. The journey from traditional remedies to contemporary medical applications is multifaceted and warrants prudent consideration. This research aspires to offer invaluable insights into the management of malaria and dengue fever. By unveiling plant-based compounds with potential antimalarial and antiviral properties, this study aims to contribute to disease control. In pursuit of this goal, a thorough understanding of the mechanistic foundations of traditional antimalarial and antidengue plants opens doors to novel therapeutic avenues.

Phytomediated selenium nanoparticles and light regimes elicited in vitro callus cultures for biomass accumulation and secondary metabolite production in Caralluma tuberculata.

Introduction: Caralluma tuberculata holds significant importance as a medicinal plant due to its abundance of bioactive metabolites, which offer a wide range of therapeutic potentials. However, the sustainable production of this plant is challenged by overexploitation, changes in natural conditions, slow growth rate, and inadequate biosynthesis of bioactive compounds in wild populations. Therefore, the current study was conducted to establish an in vitro based elicitation strategy (nano elicitors and light regimes) for the enhancement of biomass and production of secondary metabolites. Methods: Garlic clove extract was employed as a stabilizing, reducing, or capping agent in the green formulation of Selenium nanoparticles (SeNPs) and various physicochemical characterization analyses such as UV visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-Ray (EDX) Spectroscopy, fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were performed. Furthermore, the effects of phytosynthesized SeNPs at various concentrations (0, 50, 100, 200, and 400 µg/L on callus proliferation and biosynthesis of medicinal metabolites under different light regimes were investigated. Results and discussion: Cultures grown on Murashige and Skoog (MS) media containing SeNPs (100 µg/L), in a dark environment for two weeks, and then transferred into normal light, accumulated maximum fresh weight (4,750 mg/L FW), phenolic contents (TPC: 3.91 mg/g DW), flavonoid content (TFC: 2.04 mg/g DW) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity (85%). Maximum superoxide dismutase (SOD: 4.36 U/mg) and peroxide dismutase activity (POD: 3.85 U/mg) were determined in those cultures exposed to SeNPs (100 µg/L) under complete dark conditions. While the callus cultures proliferate on media augmented with SeNPs (200 µg/L) and kept under dark conditions for two weeks and then shifted to normal light conditions exhibited the highest catalase (CAT: 3.25 U/mg) and ascorbate peroxidase (APx: 1.93 U/mg) activities. Furthermore, LC-ESI-MS/MS analysis confirmed the effects of SeNPs and light conditions that elicited the antidiabetic metabolites (cumarins, gallic acid, caffeic acid, ferulic acid, catechin, querctin and rutin). This protocol can be scaled up for the industrial production of plant biomass and pharmacologically potent metabolites using in vitro callus cultures of C. tuberculata.

Candida albicans the main opportunistic pathogenic fungus in humans / Candida albicans el principal hongo patógeno oportunista en humanos

Abstract Candida albicans is a commensal of the mammalian microbiome and the primarypathogenic fungus of humans. It becomes a severe health problem in immunocompromisedpatients and can cause a wide variety of mucosal and systemic infections. The interactionbetween C. albicans and host cells is characterized by the expression of virulence factors suchas adhesins and invasins, the secretion of hydrolytic enzymes, a transition from yeast to fil-amentous hyphae form, and the ability to form biofilms; these features collectively result in cell adhesion, invasion, and damage. This review describes complex commensal interactions of C. albicans with host cells and the cellular events that it triggers in a pathogenic environment. We also review the host immune response induced by C. albicans antigens and the mechanisms developed by this fungus to avoid the action of antifungal agents.

Resumen Candida albicans es un comensal del microbioma de mamíferos y el principal hongopatógeno de humanos. En pacientes inmunocomprometidos se convierte en un grave problemade salud por causar una amplia variedad de infecciones en mucosas y sistémicas. La interacciónentre C. albicans y las células del huésped lleva a la expresión de factores de virulencia, comoadhesinas e invasinas, a la secreción de enzimas hidrolíticas y a la transición de levadura a hifa filamentosa, capaz de para formar biopelículas, lo que genera adherencia, invasión y dano celular. En esta revisión describimos la compleja interacción comensal de C. albicans con la célula huésped y los eventos celulares que ejecuta en un ambiente patogénico. También se revisa la respuesta inmunitaria del huésped inducida por antígenos de C. albicans y los mecanismos desarrollados por este hongo para evitar la acción de agentes antifúngicos.

Clinical and Virological Features of SARS-CoV-2 Variants during the Four Waves of the Pandemic in the Mexican Southeast.

We conducted a retrospective study using a population of patients who were hospitalized at Dr. Juan Graham Casasus Hospital in Villahermosa (Tabasco, Mexico) and had a positive RT-PCR test for SARS-CoV-2 between June 2020 and January 2022. We analyzed all medical records, including demographic data, SARS-CoV-2 exposure history, underlying comorbidities, symptoms, signs at admission, laboratory findings during the hospital stay, outcome, and whole-genome sequencing data. Finally, the data were analyzed in different sub-groups according to distribution during waves of the COVID-19 pandemic regarding Mexican reports from June 2020 to January 2022. Of the 200 patients who tested positive via PCR for SARS-CoV-2, only 197 had samples that could be sequenced. Of the samples, 58.9% (n = 116) were males and 41.1% (n = 81) females, with a median age of 61.7 ± 17.0 years. Comparisons between the waves of the pandemic revealed there were significant differences in the fourth wave: the age of patients was higher (p = 0.002); comorbidities such as obesity were lower (p = 0.000), while CKD was higher (p = 0.011); and hospital stays were shorter (p = 0.003). The SARS-CoV-2 sequences revealed the presence of 11 clades in the study population. Overall, we found that adult patients admitted to a third-level Mexican hospital had a wide range of clinical presentations. The current study provides evidence for the simultaneous circulation of SARS-CoV-2 variants during the four pandemic waves.

Candida albicans the main opportunistic pathogenic fungus in humans.

Candida albicans is a commensal of the mammalian microbiome and the primary pathogenic fungus of humans. It becomes a severe health problem in immunocompromised patients and can cause a wide variety of mucosal and systemic infections. The interaction between C. albicans and host cells is characterized by the expression of virulence factors such as adhesins and invasins, the secretion of hydrolytic enzymes, a transition from yeast to filamentous hyphae form, and the ability to form biofilms; these features collectively result in cell adhesion, invasion, and damage. This review describes complex commensal interactions of C. albicans with host cells and the cellular events that it triggers in a pathogenic environment. We also review the host immune response induced by C. albicans antigens and the mechanisms developed by this fungus to avoid the action of antifungal agents.

High baseline expression of IL-6 and IL-10 decreased CCR7 B cells in individuals with previous SARS-CoV-2 infection during BNT162b2 vaccination.

The current pandemic generated by SARS-CoV-2 has led to mass vaccination with different biologics that have shown wide variations among human populations according to the origin and formulation of the vaccine. Studies evaluating the response in individuals with a natural infection before vaccination have been limited to antibody titer analysis and evaluating a few humoral and cellular response markers, showing a more rapid and intense humoral response than individuals without prior infection. However, the basis of these differences has not been explored in depth. In the present work, we analyzed a group of pro and anti-inflammatory cytokines, antibody titers, and cell populations in peripheral blood of individuals with previous SARS-CoV-2 infection using BNT162b2 biologic. Our results suggest that higher antibody concentration in individuals with an earlier disease could be generated by higher production of plasma cells to the detriment of the presence of memory B cells in the bloodstream, which could be related to the high baseline expression of cytokines (IL-6 and IL-10) before vaccination.

Role of the TATA-box binding protein (TBP) and associated family members in transcription regulation.

The assembly of transcription complexes on eukaryotic promoters involves a series of steps, including chromatin remodeling, recruitment of TATA-binding protein (TBP)-containing complexes, the RNA polymerase II holoenzyme, and additional basal transcription factors. This review describes the transcriptional regulation by TBP and its corresponding homologs that constitute the TBP family and their interactions with promoter DNA. The C-terminal core domain of TBP is highly conserved and contains two structural repeats that fold into a saddle-like structure, essential for the interaction with the TATA-box on DNA. Based on the TBP C-terminal core domain similarity, three TBP-related factors (TRFs) or TBP-like factors (TBPLs) have been discovered in metazoans, TRF1, TBPL1, and TBPL2. TBP is autoregulated, and once bound to DNA, repressors such as Mot1 induce TBP to dissociate, while other factors such as NC2 and the NOT complex convert the active TBP/DNA complex into inactive, negatively regulating TBP. TFIIA antagonizes the TBP repressors but may be effective only in conjunction with the RNA polymerase II holoenzyme recruitment to the promoter by promoter-bound activators. TRF1 has been discovered inDrosophila melanogasterandAnophelesbut found absent in vertebrates and yeast. TBPL1 cannot bind to the TATA-box; instead, TBPL1 prefers binding to TATA-less promoters. However, TBPL1 shows a stronger association with TFIIA than TBP. The TCT core promoter element is present in most ribosomal protein genes inDrosophilaand humans, and TBPL1 is required for the transcription of these genes. TBP directly participates in the DNA repair mechanism, and TBPL1 mediates cell cycle arrest and apoptosis. TBPL2 is closely related to its TBP paralog, showing 95% sequence similarity with the TBP core domain. Like TBP, TBPL2 also binds to the TATA-box and shows interactions with TFIIA, TFIIB, and other basal transcription factors. Despite these advances, much remains to be explored in this family of transcription factors.

MDR1 protein (ABC-C1) Over Expression in Giardia Intestinalis Incubated with Albendazole and Nitazoxanide.

BACKGROUND: Giardia intestinalis is a worldwide parasite. Drugs used for the treatment of giardiasis are metronidazole, albendazole and nitazoxanide. The development of drug resistance is an obstacle to the effective treatment. Resistance mechanisms in some parasites involve the participation of ATP-binding cassette (ABC) transporter superfamily. PURPOSE: To find if the ATP-binding cassette genes are overexpressed in trophozoites treated with albendazole or nitazoxanide. METHODS: A search for ATP-binding cassette genes in Giardia sequence database (GiardiaDB) was done and six genes were selected. Trophozoites treated with albendazole or nitazoxanide and the expression of these six ABC genes was quantitated by real-time RT-PCR. The ABC-C1 gene was selected, and a fragment cloned. The ABC-C1 protein was expressed, and polyclonal antibodies were elicited in mice to detect the protein in treated trophozoites, finally a docking analysis was performed for ABC-C1 and tizoxanide interaction. RESULTS: Bioinformatics analysis showed that the ATP-binding cassette (ABC) topology is present in the six proteins. The qRT-PCR revealed that the ABC-C1 gene was overexpressed in cells incubated with nitazoxanide or albendazole. Confocal analysis showed that ABC-C1 protein levels increased in trophozoites with both treatments but was higher with nitazoxanide. The mark was detected heavily in the periphery of the cells. Using a docking analysis, it was found that the nitazoxanide metabolite, tizoxanide was docked close to the ATP-binding region as well as in the exit tunnel, located in the transmembrane region. CONCLUSION: These findings in Giardia intestinalis, support the possible role of ABC-C1 in drug efflux.

Apoptosis Induced by (-)-Epicatechin in Human Breast Cancer Cells is Mediated by Reactive Oxygen Species.

(-)-Epicatechin is a phenolic compound with antioxidant activity that is present in natural food and drinks, such as cocoa and red wine. Evidence suggests that (-)-epicatechin exhibits anticancer activity; however, its mechanism of action is poorly understood. Here, we investigated the anticancer effects of (-)-epicatechin and its mechanism of action in breast cancer cells. We assessed the anticancer activity by cell proliferation assays, apoptosis by DNA fragmentation and flow cytometry. The expression of proteins associated with apoptosis was analyzed by the human apoptosis array. MitoSOXTM Red and biomarkers of oxidative damage were used to measure the effect of (-)-epicatechin on mitochondrial reactive oxygen species (ROS) and cellular damage, respectively. (-)-Epicatechin treatment caused a decreasing in the viability of MDA-MB-231 and MCF-7 cells. This cell death was associated with DNA fragmentation and an apoptotic proteomic profile. Further, (-)-epicatechin in MDA-MB-231 cells upregulated death receptor (DR4/DR5), increased the ROS production, and modulated pro-apoptotic proteins. In MCF-7 cells, (-)-epicatechin did not involve death receptor; however, an increase in ROS and the upregulation of pro-apoptotic proteins (Bad and Bax) were observed. These changes were associated with the apoptosis activation through the intrinsic pathway. In conclusion, this study shows that (-)-epicatechin has anticancer activity in breast cancer cells and provides novel insight into the molecular mechanism of (-)-epicatechin to induce apoptosis.

Identification of the gene encoding the TATA box-binding protein-associated factor 1 (TAF1) and its putative role in the heat shock response in the protozoan parasite Entamoeba histolytica.

Transcription factor IID (TFIID) is a cornerstone in the transcription initiation in eukaryotes. It is composed of TBP and approximately 14 different subunits named TBP-associated factors (TAFs). TFIID has a key role in transcription of many genes involved in cell proliferation, cell growth, cell cycle, cell cycle checkpoint, and various other processes as well. Entamoeba histolytica, the protozoan parasite responsible for human amoebiasis, represents a major global health concern. Our research group has previously reported the genes coding the TATA box-binding protein (EhTBP) and TBP-related factor 1 (EhTRF1), which displayed different mRNA levels in trophozoites under different stress conditions. In this work, we identified the TBP-associated factor 1 (Ehtaf1) gene in the E. histolytica genome, which possess a well-conserved DUF domain and a Bromo domain located in the middle and C-terminus of the protein, respectively. The EhTAF1-DUF domain tertiary structure is similar to the corresponding HsTAF1 DUF domain. RT-qPCR experiments with RNA isolated from trophozoites harvested at different time points of the growth curve and under different stress conditions revealed that the Ehtaf1 gene was found slightly upregulated in the death phase of growth curve, but under heat shock stress, it was found upregulated 10 times, suggesting that Ehtaf1 might have an important role in the heat shock stress response. We also found that EhTAF1 is expressed in the nucleus and cytoplasm at 37 °C, but under heat shock stress, it is overexpressed in both the nucleus and cytoplasm, and partially colocalized with EhHSP70 in cytoplasm.

The Entamoeba histolytica TBP and TRF1 transcription factors are GAAC-box binding proteins, which display differential gene expression under different stress stimuli and during the interaction with mammalian cells.

BACKGROUND: Entamoeba histolytica is the protozoan parasite responsible for human amebiasis. It causes up to 100,000 deaths worldwide each year. This parasite has two closely related basal transcription factors, the TATA-box binding protein (EhTBP) and the TBP-related factor 1 (EhTRF1). TBP binds to the canonical TATTTAAA-box, as well as to different TATA variants. TRF1 also binds to the TATTTAAA-box. However, their binding capacity to diverse core promoter elements, including the GAAC-element, and their role in gene regulation in this parasite remains unknown. METHODS: EMSA experiments were performed to determine the binding capacity of recombinant TBP and TRF1 to TATA variants, GAAC and GAAC-like boxes. For the functional analysis under different stress stimuli (e.g. growth curve, serum depletion, heat-shock, and UV-irradiation) and during the interaction with mammalian cells (erythrocytes, MDCK cell monolayers, and hepatocytes of hamsters), RT-qPCR, and gene knockdown were performed. RESULTS: Both transcription factors bound to the different TATA variants tested, as well as to the GAAC-boxes, suggesting that they are GAAC-box-binding proteins. The K D values determined for TBP and TRF1 for the different TATA variants and GAAC-box were in the range of 10-12 M to 10-11 M. During the death phase of growth or in serum depletion, Ehtbp mRNA levels significantly increased, whereas the mRNA level of Ehtrf1 did not change under these conditions. Ehtrf1 gene expression was negatively regulated by UV-irradiation and heat-shock stress, with no changes in Ehtbp gene expression. Moreover, Ehtrf1 gene also showed a negative regulation during erythrophagocytosis, liver abscess formation, and a transient expression level increase at the initial phase of MDCK cell destruction. Finally, the Ehtbp gene knockdown displayed a drastic decrease in the efficiency of erythrophagocytosis in G3 trophozoites. CONCLUSIONS: To our knowledge, this study reveals that these basal transcription factors are able to bind multiple core promoter elements. However, their immediate change in gene expression level in response to different stimuli, as well as during the interaction with mammalian cells, and the diminishing of erythrophagocytosis by silencing the Ehtbp gene indicate the different physiological roles of these transcription factors in E. histolytica.

The Candida albicans ENO1 gene encodes a transglutaminase involved in growth, cell division, morphogenesis, and osmotic protection.

Candida albicans is an opportunistic fungus that is part of the normal microflora commonly found in the human digestive tract and the normal mucosa or skin of healthy individuals. However, in immunocompromised individuals, it becomes a serious health concern and a threat to their lives and is ranked as the leading fungal infection in humans worldwide. As existing treatments for this infection are non-specific or under threat of developing resistance, there is a dire necessity to find new targets for designing specific drugs to defeat this fungus. Some authors reported the presence of the transglutaminase activity in Candida and Saccharomyces, but its identity remains unknown. We report here the phenotypic effects produced by the inhibition of transglutaminase enzymatic activity with cystamine, including growth inhibition of yeast cells, induction of autophagy in response to damage caused by cystamine, alteration of the normal yeast division pattern, changes in cell wall, and inhibition of the yeast-to-mycelium transition. The latter phenomenon was also observed in the C. albicans ATCC 26555 strain. Growth inhibition by cystamine was also determined in other Candida strains, demonstrating the importance of transglutaminase in these species. Finally, we identified enolase 1 as the cell wall protein responsible for TGase activity. After studying the inhibition of enzymatic activities with anti-CaEno1 antibodies and through bioinformatics studies, we suggest that the enolase and transglutaminase catalytic sites are localized in different domains of the protein. The aforementioned data indicate that TGase/Eno1 is a putative target for designing new drugs to control C. albicans infection.

Antibody-coupled hydroxyapatite nanoparticles as efficient tools for labeling intracellular proteins.

Smart biomaterials for active targeting are a novel way for biosensing, gene and drug delivery, and bioimaging. The functional additives are chosen according to the material carrier characteristics, i.e. the functional mercapto acids of different lengths. In order to identify the target tissue, cell, organ or molecule, the biomaterial must be equipped with a recognizing molecule on its surface. In most cases, semiconductor o metal materials are employed in bioimaging and biosensing applications; in gene and drug delivery area, it is useful to employ porous nanoparticles as carriers. Hydroxyapatite nanoparticles have been proved efficiently in drug delivery. In this work we established a new protocol to obtain smart hydroxyapatite nanoparticles with 3-mercaptopropionic acid and anti-Actin molecules in order to localize actin molecules in cells.

Bioinformatics Tools for Proteomics Data Interpretation.

Biological systems function via intricate cellular processes and networks in which RNAs, metabolites, proteins and other cellular compounds have a precise role and are exquisitely regulated (Kumar and Mann, FEBS Lett 583(11):1703-1712, 2009). The development of high-throughput technologies, such as the Next Generation DNA Sequencing (NGS) and DNA microarrays for sequencing genomes or metagenomes, have triggered a dramatic increase in the last few years in the amount of information stored in the GenBank and UniProt Knowledgebase (UniProtKB). GenBank release 210, reported in October 2015, contains 202,237,081,559 nucleotides corresponding to 188,372,017 sequences, whilst there are only 1,222,635,267,498 nucleotides corresponding to 309,198,943 sequences from Whole Genome Shotgun (WGS) projects. In the case of UniProKB/Swiss-Prot, release 2015_12 (December 9, 2015) contains 196,219,159 amino acids that correspond to 550,116 entries. Meanwhile, UniProtKB/TrEMBL (release 2015_12 of December 9 2015) contains 1,838,851,8871 amino acids corresponding to 555,270,679 entries. Proteomics has also improved our knowledge of proteins that are being expressed in cells at a certain time of the cell cycle. It has also allowed the identification of molecules forming part of multiprotein complexes and an increasing number of posttranslational modifications (PTMs) that are present in proteins, as well as the variants of proteins expressed.

Data set of interactomes and metabolic pathways of proteins differentially expressed in brains with Alzheimer׳s disease.

Alzheimer׳s disease is one of the main causes of dementia in the elderly and its frequency is on the rise worldwide. It is considered the result of complex interactions between genetic and environmental factors, being many of them unknown. Therefore, there is a dire necessity for the identification of novel molecular players for the understanding of this disease. In this data article we determined the protein expression profiles of whole protein extracts from cortex regions of brains from patients with Alzheimer׳s disease in comparison to a normal brain. We identified 721 iTRAQ-labeled polypeptides with more than 95% in confidence. We analyzed all proteins that changed in their expression level and located them in the KEGG metabolic pathways, as well as in the mitochondrial complexes of the electron transport chain and ATP synthase. In addition, we analyzed the over- and sub-expressed polypeptides through IPA software, specifically Core I and Biomarkers I modules. Data in this article is related to the research article "Identification of proteins that are differentially expressed in brains with Alzheimer's disease using iTRAQ labeling and tandem mass spectrometry" (Minjarez et al., 2016) [1].