Genome-wide identification and characterization of protein phosphatase 2C (PP2C) gene family in sunflower (Helianthus annuus L.) and their expression profiles in response to multiple abiotic stresses.

Plant protein phosphatase 2C (PP2C) plays vital roles in responding to various stresses, stimulating growth factors, phytohormones, and metabolic activities in many important plant species. However, the PP2C gene family has not been investigated in the economically valuable plant species sunflower (Helianthus annuus L.). This study used comprehensive bioinformatics tools to identify and characterize the PP2C gene family members in the sunflower genome (H. annuus r1.2). Additionally, we analyzed the expression profiles of these genes using RNA-seq data under four different stress conditions in both leaf and root tissues. A total of 121 PP2C genes were identified in the sunflower genome distributed unevenly across the 17 chromosomes, all containing the Type-2C phosphatase domain. HanPP2C genes are divided into 15 subgroups (A-L) based on phylogenetic tree analysis. Analyses of conserved domains, gene structures, and motifs revealed higher structural and functional similarities within various subgroups. Gene duplication and collinearity analysis showed that among the 53 HanPP2C gene pairs, 48 demonstrated segmental duplications under strong purifying selection pressure, with only five gene pairs showing tandem duplications. The abundant segmental duplication was observed compared to tandem duplication, which was the major factor underlying the dispersion of the PP2C gene family in sunflowers. Most HanPP2C proteins were localized in the nucleus, cytoplasm, and chloroplast. Among the 121 HanPP2C genes, we identified 71 miRNAs targeting 86 HanPP2C genes involved in plant developmental processes and response to abiotic stresses. By analyzing cis-elements, we identified 63 cis-regulatory elements in the promoter regions of HanPP2C genes associated with light responsiveness, tissue-specificity, phytohormone, and stress responses. Based on RNA-seq data from two sunflower tissues (leaf and root), 47 HanPP2C genes exhibited varying expression levels in leaf tissue, while 49 HanPP2C genes showed differential expression patterns in root tissue across all stress conditions. Transcriptome profiling revealed that nine HanPP2C genes (HanPP2C12, HanPP2C36, HanPP2C38, HanPP2C47, HanPP2C48, HanPP2C53, HanPP2C54, HanPP2C59, and HanPP2C73) exhibited higher expression in leaf tissue, and five HanPP2C genes (HanPP2C13, HanPP2C47, HanPP2C48, HanPP2C54, and HanPP2C95) showed enhanced expression in root tissue in response to the four stress treatments, compared to the control conditions. These results suggest that these HanPP2C genes may be potential candidates for conferring tolerance to multiple stresses and further detailed characterization to elucidate their functions. From these candidates, 3D structures were predicted for six HanPP2C proteins (HanPP2C47, HanPP2C48, HanPP2C53, HanPP2C54, HanPP2C59, and HanPP2C73), which provided satisfactory models. Our findings provide valuable insights into the PP2C gene family in the sunflower genome, which could play a crucial role in responding to various stresses. This information can be exploited in sunflower breeding programs to develop improved cultivars with increased abiotic stress tolerance.

Mechanistic insight of Staphylococcus aureus associated skin cancer in humans by Santalum album derived phytochemicals: an extensive computational and experimental approaches.

An excessive amount of multidrug-resistant Staphylococcus aureus is commonly associated with actinic keratosis (AK) and squamous cell carcinoma (SCC) by secreted virulence products that induced the chronic inflammation leading to skin cancer which is regulated by staphylococcal accessory regulator (SarA). It is worth noting that there is currently no existing published study that reports on the inhibitory activity of phytochemicals derived from Santalum album on the SarA protein through in silico approach. Therefore, our study has been designed to find the potential inhibitors of S. aureus SarA protein from S. album-derived phytochemicals. The molecular docking study was performed targeting the SarA protein of S. aureus, and CID:5280441, CID:162350, and CID: 5281675 compounds showed the highest binding energy with -9.4 kcal/mol, -9.0 kcal/mol, and -8.6 kcal/mol respectively. Further, molecular dynamics simulation revealed that the docked complexes were relatively stable during the 100 ns simulation period whereas the MMPBSA binding free energy proposed that the ligands were sustained with their binding site. All three complexes were found to be similar in distribution with the apoprotein through PCA analysis indicating conformational stability throughout the MD simulation. Moreover, all three compounds' ADMET profiles revealed positive results, and the AMES test did not show any toxicity whereas the pharmacophore study also indicates a closer match between the pharmacophore model and the compounds. After comprehensive in silico studies we evolved three best compounds, namely, Vitexin, Isovitexin, and Orientin, which were conducted in vitro assay for further confirmation of their inhibitory activity and results exhibited all of these compounds showed strong inhibitory activity against S. aureus. The overall result suggests that these compounds could be used as a natural lead to inhibit the pathogenesis of S. aureus and antibiotic therapy for S. aureus-associated skin cancer in humans as well.

Induction of premature senescence and a less-fibrogenic phenotype by programmed cell death 4 knockdown in the human hepatic stellate cell line Lieming Xu-2.

Although programmed cell death 4 (PDCD4) was initially reported as a tumor suppressor and has been shown to inhibit cancer cell growth and metastasis, recent studies have demonstrated that loss of PDCD4 expression also induces growth inhibition by inducing apoptosis and/or cellular senescence. At present, the roles of PDCD4 in the activation and profibrogenic properties of myofibroblasts, which are critically involved in organ fibrosis, such as that in the liver, are unclear. We, therefore, investigated the roles of PDCD4 in myofibroblasts using human hepatic stellate cell line Lieming Xu-2 (LX-2). PDCD4 knockdown inhibited LX-2 proliferation and induced a senescent phenotype with increased ß-galactosidase staining and p21 expression in a p53-independent manner together with downregulation of the notch signaling mediator RBJ-κ/CSL. During PDCD4 knockdown, alpha smooth muscle actin (α-SMA; an activation marker of myofibroblasts), matrix metalloproteinases MMP-1 and MMP-9, and collagen IV were upregulated, but the expression of collagen1α1 and collagen III was markedly downregulated without any marked change in the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1). These results demonstrated that knockdown of PDCD4 induced the cellular senescence phenotype and activated myofibroblasts while suppressing the profibrogenic phenotype, suggesting roles of PDCD4 in cellular senescence and fibrogenesis in the liver.

Determination of aflatoxin M1 and deoxynivalenol biomarkers in infants and children urines from Bangladesh.

The mycotoxins aflatoxin B1 (AFB1) and deoxynivalenol (DON) are found worldwide in crops and dietary staples. The prevalence and levels of these contaminants can vary greatly, and data in Bangladeshi food commodities are scarce. To characterize human exposure, we have conducted biomonitoring, analyzing AFM1 (a metabolite of AFB1) and DON levels in urines of adult cohorts in Bangladesh. Yet, AFM1 and DON occurrence has not been studied in the very young population of this country. Thus, the same methods, HPLC-FD for AFM1 and LC-MS/MS for DON analysis, were now applied to determine these biomarkers in urines of infants (n = 49) and young children (n = 105) in Rajshahi and Dhaka district. Overall, AFM1 and DON detection frequency was 43.5% and 33.4%, with 34.7% and 11.5% in infant and 47.6% and 39.4% in children urines, respectively. The mean AFM1 levels in all infants (9.1 ± 14.3, max 55.6 pg/mL) and children (8.8 ± 12.9, max 75.3 pg/mL) were not significantly different. The AFM1 mean level was slightly higher in Dhaka (9.4 ± 12.4) compared to Rajshahi (8.5 ± 13.9 pg/mL) district. The average DON level was about 2-fold higher in infant (3.8 ± 2.9, max 6.8 ng/mL) than children urines (1.6 ± 1.8, max 8.6 ng/mL), and higher in Rajshahi (2.1 ± 2.3 ng/mL) than Dhaka (1.4 ± 1.6 ng/mL) district. The biomarker-based estimated average daily DON intake (29.6 ± 108.3 ng/kg bw in infants and 36.4 ± 81.8 ng/kg bw in children) or the maximum exposure (560 ng/kg bw) do not exceed the current maximum provisional tolerable daily intake value of 1 µg/kg bw for DON, although DON exposure in infants and children is higher than that of Bangladeshi adults. The AFM1 urine levels in young children are somewhat lower than those found previously in adult cohorts in Bangladesh, but the frequent detection of this biomarker for AFB1 exposure raises further concerns, also for this vulnerable part of the population. Therefore, continuous surveillance for aflatoxins in Bangladeshi food commodities is clearly required, first to identify major sources of intake and then to reduce exposure.

Degradation of the Tumor Suppressor PDCD4 Is Impaired by the Suppression of p62/SQSTM1 and Autophagy.

PDCD4 (programmed cell death 4) is a tumor suppressor that plays a crucial role in multiple cellular functions, such as the control of protein synthesis and transcriptional control of some genes, the inhibition of cancer invasion and metastasis. The expression of this protein is controlled by synthesis, such as via transcription and translation, and degradation by the ubiquitin-proteasome system. The mitogens, known as tumor promotors, EGF (epidermal growth factor) and TPA (12-O-tetradecanoylphorbol-13-acetate) stimulate the degradation of PDCD4 protein. However, the whole picture of PDCD4 degradation mechanisms is still unclear, we therefore investigated the relationship between PDCD4 and autophagy. The proteasome inhibitor MG132 and the autophagy inhibitor bafilomycin A1 were found to upregulate the PDCD4 levels. PDCD4 protein levels increased synergistically in the presence of both inhibitors. Knockdown of p62/SQSTM1 (sequestosome-1), a polyubiquitin binding partner, also upregulated the PDCD4 levels. P62 and LC3 (microtubule-associated protein 1A/1B-light chain 3)-II were co-immunoprecipitated by an anti-PDCD4 antibody. Colocalization particles of PDCD4, p62 and the autophagosome marker LC3 were observed and the colocalization areas increased in the presence of autophagy and/or proteasome inhibitor(s) in Huh7 cells. In ATG (autophagy related) 5-deficient Huh7 cells in which autophagy was impaired, the PDCD4 levels were increased at the basal levels and upregulated in the presence of autophagy inhibitors. Based on the above findings, we concluded that after phosphorylation in the degron and ubiquitination, PDCD4 is degraded by both the proteasome and autophagy systems.

Control Mechanisms of the Tumor Suppressor PDCD4: Expression and Functions.

PDCD4 is a novel tumor suppressor to show multi-functions inhibiting cell growth, tumor invasion, metastasis, and inducing apoptosis. PDCD4 protein binds to the translation initiation factor eIF4A, some transcription factors, and many other factors and modulates the function of the binding partners. PDCD4 downregulation stimulates and PDCD4 upregulation inhibits the TPA-induced transformation of cells. However, PDCD4 gene mutations have not been found in tumor cells but gene expression was post transcriptionally downregulated by micro environmental factors such as growth factors and interleukins. In this review, we focus on the suppression mechanisms of PDCD4 protein that is induced by the tumor promotors EGF and TPA, and in the inflammatory conditions. PDCD4-protein is phosphorylated at 2 serines in the SCFßTRCP ubiquitin ligase binding sequences via EGF and/or TPA induced signaling pathway, ubiquitinated, by the ubiquitin ligase and degraded in the proteasome system. The PDCD4 protein synthesis is inhibited by microRNAs including miR21.

Hypertension prevalence and influence of basal metabolic rate on blood pressure among adult students in Bangladesh.

BACKGROUND: Hypertension is a global health issue and is currently increasing at rapid pace in South Asian countries including Bangladesh. Although, some studies on hypertension have been conducted in Bangladesh, there is a lack of scientific evidence in the adult student population that was missing from the previous and recent national cross-sectional studies. Moreover, the specific risk factors of hypertension in the Bangladeshi adults still need to be investigated. This study was conducted to estimate hypertension prevalence among adult students in Bangladesh and to test the hypothesis of Luke et al. (Hypertension 43:555-560, 2004) that basal metabolic rate (BMR) and blood pressure are positively associated independent of body size. METHOD: The data was collected on 184 adult university students (118 female and 66 male) in Dhaka, Bangladesh. Anthropometric, BMR details and an average of at least two blood pressure measurements were obtained. Hypertension was defined by a systolic blood pressure (SBP) ≥ 140 mmHg and/or, diastolic blood pressure (DBP) ≥ 90 mmHg. RESULTS: Overall, 6.5% of participants had hypertension with significantly (p < 0.001) higher prevalence in male (12.1%) than in the female (3.4%) students. Age and BMI showed positive and significant correlation with hypertension among the students. When adjusted for body mass index (BMI), as well as other potentially confounding variables such as age, sex, smoking status and degree of urbanization, BMR was positively correlated with SBP and DBP (p < 0.001). Thus, higher BMR is associated with SBP and DBP; this is opposite the well documented inverse relationship between physical activity and blood pressure. If the influence of BMR on blood pressure is confirmed, the systematically elevated BMR might be an important predictor that can explain relatively high blood pressure and hypertension in humans. CONCLUSION: This study reports the prevalence and associated risk factors of hypertension in the Bangladeshi adult students. The study also showed a positive association between BMR and blood pressure among the participants. A large scale longitudinal study across the country is needed to find out the underlying causes of hypertension in the Bangladeshi adults. In addition, comprehensive and integrated intervention programs focusing on modifiable risk factors are recommended to make awareness and prevent hypertension.

Vitamin D and Parathyroid Hormone Status in Female Garment Workers: A Case-Control Study in Bangladesh.

Despite the abundant sunlight, vitamin D deficiency is prevalent in South Asian countries including Bangladesh. Information on vitamin D level is insufficient in adults particularly in female garment workers in Bangladesh. This study was designed to evaluate the status of vitamin D, parathormone (PTH), calcium, and alkaline phosphatase (ALP) among the female garment workers in Bangladesh. Blood samples were collected from female garment workers (n = 40, case group) and general female workers (n = 40, control group) in Dhaka. Serum vitamin D, PTH, calcium, and ALP were measured by chemiluminescence microparticle immunoassay. The mean level of vitamin D was significantly (p < 0.001) lower in case (14.2 ± 2.6 ng/mL) than in the control (22.4 ± 2.4 ng/mL) group. No significant difference was found at mean of PTH and calcium between case (33.9 ± 17.2 pg/mL; 9.1 ± 0.6 mg/dL, resp.) and control (35.9 ± 16.3 pg/mL; 9.3 ± 0.6 mg/dL, resp.) group. The mean ALP in case (117.2 ± 14.4 U/L) group was significantly (p < 0.001) higher than the control group (80.5 ± 30.6 U/L). Overall, PTH level did not show significant correlation with vitamin D. However, calcium and ALP levels showed a significant positive (p < 0.05) and negative (p < 0.001) correlation with vitamin D, respectively. This study indicates a high prevalence of vitamin D deficiency in the female garment workers in Bangladesh.

Biomonitoring of concurrent exposure to ochratoxin A and citrinin in pregnant women in Bangladesh.

Ochratoxin A (OTA) and citrinin (CIT) are both nephrotoxic and teratogenic in animals, and the occurrence of these mycotoxins in food may cause adverse health effects in humans. Data on the combined exposure to these food contaminants are still scarce, especially in pregnancy. Therefore, a biomonitoring study was conducted to determine the presence of urinary biomarkers of exposure to OTA and CIT in pregnant women in Bangladesh. In total, 54 spot urine samples were collected from residents of a rural and a suburban area of the Savar region in Dhaka district for analysis of OTA and CIT urinary biomarkers by previously validated HPLC-FD and LC-MS/MS methods. Most urines were positive for OTA and CIT biomarkers, with OTA being detected in 93 % (range 0.01-0.84 ng/mL) and CIT biomarkers in 87 % (range 0.02-6.93 ng/mL) of all samples. The mean levels of OTA were different between the rural (0.06 ± 0.07 ng/mL) and suburban (0.15 ± 0.19 ng/mL) study participants. CIT and its metabolite dihydrocitrinone (HO-CIT) were more than twofold higher in the rural (0.42 ± 1.20 and 0.55 ± 1.04 ng/mL, respectively) than the suburban (CIT 0.15 ± 0.13 ng/mL; HO-CIT 0.23 ± 0.18 ng/mL) participants. When a provisional daily intake for CIT was calculated, it exceeded the preliminary tolerable value set by European Food Safety Authority (0.2 µg/kg/day) in 9 % of the rural participants but in none of the urban participants. Urinary biomarker levels for OTA and CIT did not show significant association with intake of certain types of food consumed by the pregnant women, although total CIT biomarker levels were considerably higher among participants who consumed more rice in a day. Overall, this study indicates a frequent co-exposure to OTA and CIT among pregnant women in Bangladesh, at levels similar to those determined recently in the general population of this country.

Biomonitoring of ochratoxin A in blood plasma and exposure assessment of adult students in Bangladesh.

SCOPE: Ochratoxin A (OTA), a mycotoxin known for its nephrotoxic, immunotoxic, and carcinogenic effects in animals, deserves attention due to its widespread occurrence as food and feed contaminant. Studies in many countries report the presence of OTA in human blood plasma or serum at variable levels. However, no biomonitoring study has been carried out in so far, and also food analysis data are insufficient to assess OTA exposure. METHODS AND RESULTS: Therefore, 64 blood samples were collected from healthy university students (32 female, 32 male) in Bangladesh for biomarker analysis. OTA and its metabolite ochratoxin alpha were determined in the plasma samples by a validated method using HPLC-fluorescence analysis. After liquid-liquid extraction, OTA was detected in all plasma samples (100%) at a range of 0.20-6.63 ng/mL and ochratoxin alpha was detected in 95% of the samples at 0.10-0.79 ng/mL. The OTA mean level in plasma of males (0.92 ± 1.09 ng/mL) and females (0.78 ± 1.02) were not significantly different. Statistical analysis of food consumption data for the participants, provided in a food frequency questionnaire, did not reveal a significant association between OTA level in plasma and their intake of typical staple foods (rice, wheat, maize, and lentil). CONCLUSION: The dietary intake of OTA (mean 11.7, max 91.7 ng/kg b.w./wk) calculated on the basis of plasma concentration in Bangladeshi students was lower than the tolerable weekly OTA intake (120 ng/kg b.w./wk) set by EFSA. Nonetheless, further biomonitoring is recommended in cohorts from other parts of the country that may have higher mycotoxin exposure than the present group.