Non-Coding RNAs in HIV Infection, NeuroHIV, and Related Comorbidities.

NeuroHIV affects approximately 30-60% of people living with HIV-1 (PLWH) and is characterized by varying degrees of cognitive impairments, presenting a multifaceted challenge, the underlying cause of which is chronic, low-level neuroinflammation. Such smoldering neuroinflammation is likely an outcome of lifelong reliance on antiretrovirals coupled with residual virus replication in the brains of PLWH. Despite advancements in antiretroviral therapeutics, our understanding of the molecular mechanism(s) driving inflammatory processes in the brain remains limited. Recent times have seen the emergence of non-coding RNAs (ncRNAs) as critical regulators of gene expression, underlying the neuroinflammatory processes in HIV infection, NeuroHIV, and their associated comorbidities. This review explores the role of various classes of ncRNAs and their regulatory functions implicated in HIV infection, neuropathogenesis, and related conditions. The dysregulated expression of ncRNAs is known to exacerbate the neuroinflammatory responses, thus contributing to neurocognitive impairments in PLWH. This review also discusses the diagnostic and therapeutic potential of ncRNAs in HIV infection and its comorbidities, suggesting their utility as non-invasive biomarkers and targets for modulating neuroinflammatory pathways. Understanding these regulatory roles could pave the way for novel diagnostic strategies and therapeutic interventions in the context of HIV and its comorbidities.

Neuropathogenic role of astrocyte-derived extracellular vesicles in HIV-associated neurocognitive disorders.

Our previous findings demonstrated that astrocytic HIF-1α plays a major role in HIV-1 Tat-mediated amyloidosis which can lead to Alzheimer's-like pathology-a comorbidity of HIV-Associated Neurocognitive Disorders (HAND). These amyloids can be shuttled in extracellular vesicles, and we sought to assess whether HIV-1 Tat stimulated astrocyte-derived EVs (ADEVs) containing the toxic amyloids could result in neuronal injury in vitro and in vivo. We thus hypothesized that blocking HIF-1α could likely mitigate HIV-1 Tat-ADEV-mediated neuronal injury. Rat hippocampal neurons when exposed to HIV-1 Tat-ADEVs carrying the toxic amyloids exhibited amyloid accumulation and synaptodendritic injury, leading to functional loss as evidenced by alterations in miniature excitatory post synaptic currents. The silencing of astrocytic HIF-1α not only reduced the biogenesis of ADEVs, as well as amyloid cargos, but also ameliorated neuronal synaptodegeneration. Next, we determined the effect of HIV-1 Tat-ADEVs carrying amyloids in the hippocampus of naive mice brains. Naive mice receiving the HIV-1 Tat-ADEVs, exhibited behavioural changes, and Alzheimer's 's-like pathology accompanied by synaptodegeneration. This impairment(s) was not observed in mice injected with HIF-1α silenced ADEVs. This is the first report demonstrating the role of amyloid-carrying ADEVs in mediating synaptodegeneration leading to behavioural changes associated with HAND and highlights the protective role of HIF-1α.

Characterization of myo-inositol oxygenase from rice (OsMIOX): influence of salinity stress in different indica rice cultivars.

Myo-inositol oxygenase (MIOX), the only catabolic enzyme of the inositol pathway, catalyzes conversion of myo-inositol to D-GlcA (glucuronic acid). The present study encompasses bioinformatic analysis of MIOX gene across phylogenetically related plant lineages and representative animal groups. Comparative motif analysis of the MIOX gene(s) across various plant groups suggested existence of abiotic- stress related cis-acting elements such as, DRE, MYB, MYC, STRE, MeJa among others. A detailed analysis revealed a single isoform of MIOX gene, located in chromosome 6 of indica rice (Oryza sativa) with an open reading frame of 938 bp coding for 308 amino acids producing a protein of ~ 35 kD. Secondary structure prediction of the protein gave the predicted number of 144 alpha helices and 154 random coils. The three-dimensional structure suggested it to be a monomeric protein with a single domain. Bacterial overexpression of the protein, purification and enzyme assay showed optimal catalytic activity at pH 7.5-8 at an optimal temperature of 37 °C with Michaelis constant of 40.92 mM. The range of Km was determined as 22.74-28.7 mM and the range of Vmax was calculated as 3.51-3.6 µM/min, respectively. Four salt-tolerant and salt-sensitive rice cultivars displayed differential gene expression of OsMIOX at different time points in different tissues under salinity and drought stress as observed from qRT-PCR data, microarray results and protein expression profile in immunoblot analysis. Gel volumetric analysis confirmed a very high expression of MIOX in roots and leaves on 7th day following germination. Microarray data showed high expression of MIOX at all developmental stages including seedling growth and reproduction. These data suggest that OsMIOX might have a role to play in rice abiotic stress responses mediated through the myo-inositol oxidation pathway. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01340-6.

Opioid abuse and SIV infection in non-human primates.

Human immunodeficiency virus (HIV) and drug abuse are intertwined epidemics, leading to compromised adherence to combined antiretroviral therapy (cART) and exacerbation of NeuroHIV. As opioid abuse causes increased viral replication and load, leading to a further compromised immune system in people living with HIV (PLWH), it is paramount to address this comorbidity to reduce the NeuroHIV pathogenesis. Non-human primates are well-suited models to study mechanisms involved in HIV neuropathogenesis and provide a better understanding of the underlying mechanisms involved in the comorbidity of HIV and drug abuse, leading to the development of more effective treatments for PLWH. Additionally, using broader behavioral tests in these models can mimic mild NeuroHIV and aid in studying other neurocognitive diseases without encephalitis. The simian immunodeficiency virus (SIV)-infected rhesus macaque model is instrumental in studying the effects of opioid abuse on PLWH due to its similarity to HIV infection. The review highlights the importance of using non-human primate models to study the comorbidity of opioid abuse and HIV infection. It also emphasizes the need to consider modifiable risk factors such as gut homeostasis and pulmonary pathogenesis associated with SIV infection and opioid abuse in this model. Moreover, the review suggests that these non-human primate models can also be used in developing effective treatment strategies for NeuroHIV and opioid addiction. Therefore, non-human primate models can significantly contribute to understanding the complex interplay between HIV infection, opioid abuse, and associated comorbidities.

Comparative Cytogenetics and Fluorescent Chromosome Banding in Five Indian Species of Dipcadi Medik.

The genus Dipcadi Medik. (Subfamily: Scilloideae) has a narrow distribution in India and several overlapping morphological traits make the genus taxonomically challenging at the species level. Cytogenetic characterization can provide additional taxonomic data and can be used to evaluate genetic diversity at the species level. We have accomplished comparative karyotype analysis and fluorescence banding patterns using 4'-6-Diamidino-2-phenylindole (DAPI) and Chromomycin A3 (CMA) in five Indian species for the first time. The karyotypes of D. concanense and D. goaense exhibited similar fluorochrome banding profiles. However, D. montanum, D. ursulae and D. erythraeum differ distinctly in their karyotypes. In all taxa, CMA+ve/DAPI-ve or DAPI0 (GC-rich) constitutive heterochromatin was located at the constriction region or terminal satellite of the nucleolar chromosome. DAPI+ve/CMA-ve or CMA0 (AT-rich) heterochromatin dominates in D. montanum, D. ursulae and D. erythraeum. However, D. erythraeum shows a distinct variation in fluorochrome banding pattern from all other species. The distribution of CMA and DAPI bands is a reflection of heterochromatin composition and variations acquired by different species. This characterization can be used to assess phylogenetic relationships in the understudied genus Dipcadi and may serve as a basis for other genomic analyses and evolutionary studies.

Designed and synthesizedde novoANTPABA-PDI nanomaterial as an acceptor in inverted solar cell at ambient atmosphere.

In this work, a novel soluble and air-stable electron acceptor containing perylenediimide moiety named ANTPABA-PDI was designed and synthesized with band gap 1.78eV and that was used as non-fullerene acceptor material. ANTPABA-PDI possess not only good solubility but also much lower LUMO (lowest unoccupied molecular orbital) energy level. Furthermore, its excellent electron acceptor capability also supported by density functional theory calculation which validates the experimental observations. Inverted organic solar cell has been fabricated using ANTPABA-PDI along with P3HT as standard donor material in ambient atmosphere. The device, after characterization in open air, exhibited a power conversion efficiency of 1.70%. This is the first ever PDI based organic solar cell that has been fabricated completely in ambient atmosphere. The characterizations of the device have also been performed in ambient atmosphere. This kind of stable organic material can easily be used in fabricating organic solar cell and therefore it can be used as the best alternative as non-fullerene acceptor materials.

The C-terminal stretch of glycine-rich proline-rich protein (SbGPRP1) from Sorghum bicolor serves as an antimicrobial peptide by targeting the bacterial outer membrane protein.

KEY MESSAGE: The C-terminal stretch in SbGPRP1 (Sorghum glycine-rich proline-rich protein) acts as an antimicrobial peptide in the host innate defense mechanism. Cationic antimicrobial proteins or peptides can either bind to the bacterial membrane or target a specific protein on the bacterial membrane thus leading to membrane perturbation. The 197 amino acid polypeptide of SbGPRP1 showed disordered structure at the N-terminal end and ordered conformation at the C-terminal end. In the present study, the expression of N-SbGPRP1, C-SbGPRP1, and ∆SbGPRP1 followed by antimicrobial assays showed potential antimicrobial property of the C-terminal peptide against gram-positive bacteria Bacillus subtilis and phytopathogen Rhodococcus fascians. The SbGPRP1 protein loses its antimicrobial property when the 23 amino acid sequence (GHGGHGVFGGGYGHGGYGHGYGG) from position 136 to 158 is deleted from the protein. Thus, it can be concluded that the 23 amino acid sequence is vital for the said antimicrobial property. NPN assay, SEM analysis, and electrolyte leakage assays showed potent antimicrobial activity for C-SbGPRP1. Overexpression of the C-SbGPRP1 mutant protein in tobacco followed by infection with Rhodococcus fascians inhibited bacterial growth as shown by SEM analysis. To determine if C-SbGPRP1 might target any protein on the bacterial membrane we isolated the bacterial membrane protein from both Bacillus subtilis and Rhodococcus fascians. Bacterial membrane protein that interacted with the column-bound C-SbGPRP1 was eluted and subjected to LC-MS/MS. LC-MS/MS data analysis showed peptide hit with membrane protein YszA from Bacillus subtilis and a membrane protein from Rhodococcus fascians. Isolated bacterial membrane protein from Bacillus subtilis or Rhodococcus fascians was able to reduce the antimicrobial activity of C-SbGPRP1. Furthermore, BiFC experiments showed interactions between C-SbGPRP1 and YszA protein from Bacillus subtilis leading to the conclusion that bacterial membrane protein was targeted in such membrane perturbation leading to antimicrobial activity.

Role of the gut-brain axis in HIV and drug abuse-mediated neuroinflammation.

Drug abuse and related disorders are a global public health crisis affecting millions, but to date, limited treatment options are available. Abused drugs include but are not limited to opioids, cocaine, nicotine, methamphetamine, and alcohol. Drug abuse and human immunodeficiency virus-1/acquired immune deficiency syndrome (HIV-1/AIDS) are inextricably linked. Extensive research has been done to understand the effect of prolonged drug use on neuronal signaling networks and gut microbiota. Recently, there has been rising interest in exploring the interactions between the central nervous system and the gut microbiome. This review summarizes the existing research that points toward the potential role of the gut microbiome in the pathogenesis of HIV-1-linked drug abuse and subsequent neuroinflammation and neurodegenerative disorders. Preclinical data about gut dysbiosis as a consequence of drug abuse in the context of HIV-1 has been discussed in detail, along with its implications in various neurodegenerative disorders. Understanding this interplay will help elucidate the etiology and progression of drug abuse-induced neurodegenerative disorders. This will consequently be beneficial in developing possible interventions and therapeutic options for these drug abuse-related disorders.

Chloroplastic RecA protein from Physcomitrium patens is able to repair chloroplastic DNA damage by homologous recombination but unable to repair nuclear DNA damage.

Plants are unavoidably exposed to a range of environmental stress factors throughout their life. In addition to the external environmental factors, the production of reactive oxygen species as a product of the cellular metabolic process often causes DNA damage and thus affects genome stability. Homologous recombination (HR) is an essential mechanism used for DNA damage repair that helps to maintain genome integrity. Here we report that the recombinase, PpRecA2, a bacterial RecA homolog from moss Physcomitrium patens can partially complement the function of Escherichia coli RecA in the bacterial system. Transcript analysis showed induced expression of PpRecA2 upon experiencing DNA damaging stressors indicating its involvement in DNA damage sensing and repair mechanism. Over-expressing the chloroplast localizing PpRecA2 confers protection to the chloroplast genome against DNA damage by enhancing the chloroplastic HR frequency in transgenic tobacco plants. Although it fails to protect against nuclear DNA damage when engineered for nuclear localization due to the non-availability of interacting partners. Our results indicate that the chloroplastic HR repair mechanism differs from the nucleus, where chloroplastic HR involves RecA as a key player that resembles the bacterial system. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01264-7.

NBS1 protein from Physcomitrium patens confers protection against oxidative damage by limiting the accumulation of cellular reactive oxygen species.

Nijmegen breakage syndrome 1 (NBS1) protein is a core member of the MRE11-RAD50-NBS1 (MRN) complex that plays a crucial role in DNA damage sensing and repair in plants. Here we report that NBS1 from moss Physcomitrium patens reduces oxidative damage by lowering the cellular ROS in addition to its known role in oxidative DNA damage recovery. Real-time transcript analysis showed up-regulation of the PpNBS1 transcript under different stress conditions. Bacterial cells showed better cell survivability upon over-expressing PpNBS1 protein as compared to untransformed cells. Likewise, overexpression of PpNBS1 in tobacco plants provides improved protection against oxidative damage and exhibited a lesser amount of ROS upon exposure to oxidative stress. Moreover, PpNBS1 contributes to the antioxidant defense mechanism by positively regulating the expression of the antioxidant genes under stress conditions in transgenic tobacco plants. PpNBS1 expressing transgenic tobacco plants resulted in lesser membrane damage, lower lipid peroxidation level, and higher chlorophyll content under stress conditions. Taken together, we conclude in addition to its known role as DNA damage sensor, PpNBS1 also plays a definite role in oxidative stress mitigation by minimizing ROS accumulation in the cell.

A rice R2R3-MYB (OsC1) transcriptional regulator improves oxidative stress tolerance by modulating anthocyanin biosynthesis.

The R2R3 type MYB transcription factors participate in controlling flavonoid production in plants, including anthocyanin and proanthocyanin. Black rice with high anthocyanin content is an important candidate for understanding R2R3-MYB-based regulation of the anthocyanin biosynthesis pathway (ABP). This study was undertaken to draw the functional relationship of an R2R3-MYB protein with anthocyanin biosynthesis and oxidative stress tolerance in plants. The expression levels of the late ABP genes in the panicle stage of black rice were in good agreement with the accumulation of anthocyanin, especially cyanidin 3-glucoside. Among all MYB genes present in rice, an R2R3 type (C1) regulates anthocyanin biosynthesis and was studied further. The positive correlation between the expression of ABP genes and OsC1 along with the nuclear localization of OsC1 are in line with its possible involvement as a transcriptional regulator of ABP genes. Interestingly, OsC1 overexpressed in white rice plants triggered anthocyanin production through augmentation of the transcript level of late ABP genes. Moreover, OsC1-transformed plants exhibited a lower amount of reactive oxygen species upon exposure to oxidative stress. The increased anthocyanin content in white rice seedlings resulted in higher photosynthetic efficiency, less membrane damage and consequently lower oxidative stress. The OsC1 transcriptional regulator helps to ameliorate oxidative stresses in plants owing to its anthocyanin modulating ability.

Multiple copies of a novel amphipathic α-helix forming segment in Physcomitrella patens dehydrin play a key role in abiotic stress mitigation.

Plants use a diverse set of proteins to mitigate various abiotic stresses. The intrinsically disordered protein dehydrin is an important member of this repertoire of proteins, characterized by a canonical amphipathic K-segment. It can also contain other stress-mitigating noncanonical segments-a likely reflection of the extremely diverse nature of abiotic stress encountered by plants. Among plants, the poikilohydric mosses have no inbuilt mechanism to prevent desiccation and therefore are likely to contain unique noncanonical stress-responsive motifs in their dehydrins. Here we report the recurring occurrence of a novel amphipathic helix-forming segment (D-segment: EGφφD(R/K)AKDAφ, where φ represents a hydrophobic residue) in Physcomitrella patens dehydrin (PpDHNA), a poikilohydric moss. NMR and CD spectroscopic experiments demonstrated the helix-forming tendency of the D-segment, with the shuffled D-segment as control. PpDHNA activity was shown to be size as well as D-segment dependent from in vitro, in vivo, and in planta studies using PpDHNA and various deletion mutants. Bimolecular fluorescence complementation studies showed that D-segment-mediated PpDHNA self-association is a requirement for stress abatement. The D-segment was also found to occur in two rehydrin proteins from Syntrichia ruralis, another poikilohydric plant like P. patens. Multiple occurrences of the D-segment in poikilohydric plant dehydrins/rehydrins, along with the experimental demonstration of the role of D-segment in stress abatement, implies that the D-segment mediates unique resurrection strategies, which may be employed by plant dehydrins that are capable of mitigating extreme stress.

Exposure to chewing tobacco promotes primary oral squamous cell carcinoma and regional lymph node metastasis by alterations of SDF1α/CXCR4 axis.

A high incidence of oral squamous cell carcinoma (OSCC) is observed in South-East Asian countries due to addictions such as chewing tobacco. Local invasion and distant metastases are primary causes of poor prognosis in OSCC. This study aimed to understand the alterations in metastasis biomarkers, such as stromal cell-derived factor-1α (SDF-1 or SDF1α) and its receptor C-X-C chemokine receptor type 4 (CXCR4), in OSCC patient samples that were stratified based on the history of addiction to chewing tobacco. Targeted immunohistochemical staining and Western blotting were performed on primary tumour and metastatic lymph node (LN) tissues in parallel. Overexpression of hepatocyte growth factor (HGF), activated form of its cognate receptor tyrosine kinase, c-Met (p-Met), GRB2-associated-binding protein 1 (Gab1), phospho-protein kinase B (pAkt), nuclear factor kappa B (NF-κB) and cyclooxygenase-2 (COX-2) were observed in primary tumour and metastatic lymph nodes in both chewer and non-chewer cohorts. Variance analysis showed significant positive correlation between them (P < .0001) indicating upregulation of these biomarkers upon ligand-induced activation of c-Met in both tobacco chewers and non-chewers. Significantly higher expressions of SDF1α and CXCR4 were observed in both primary tumours and metastatic lymph nodes of tobacco chewers (P < .0001) and coincided with overexpressed HGF. In contrast, no significant correlation was observed between expression of HGF and that of SDF1α and CXCR4 in non-chewers. Together, our findings provide important insights into the association of HGF/c-Met and the SDF1α/CXCR4 axis in lymph node metastasis and to an aetiological link with the habit of chewing tobacco.

Chewing tobacco may act as a risk factor for dysplastic transformation of squamous cells in Oral leukoplakia- A cytochemistry based approach.

The use of chewing tobacco is a severe risk factor for oral mucosa related diseases including cancer in India as well as USA, although its relationship with Oral Leukoplakia (OL) or related carcinogenicity is still not clear. This work chose two oncogenic pathway proteins- the Epidermal Growth Factor Receptor and the WNT pathway among leukoplakia patients and established their correlation with the individuals' tobacco chewing habit. 89 fresh patients with OL were selected for the work. The samples were classified based on the individual's tobacco chewing habit. The divided samples were then immunostained with antibodies for both of the EGFR as well as WNT pathway proteins. The samples were further classified based on their proliferation status and the expression of these oncoproteins was also observed. In order to compare the cytological data with histological data, 30 OL patients undergoing biopsy were chosen and immunohistological analysis was performed for the same pathways. Results showed overexpressing EGFR and WNT pathway proteins in all OL samples. Structurally atypic cells had a tendency to overexpress these oncoproteins. However the immunocytochemistry data could not confirm any positive effect of chewing tobacco on the OL's proliferative state. Statistical data from the immunfluorescence finally revealed the overexpression of both EGFR and WNT pathway proteins on the proliferative population establishing chewing tobacco as a positive risk factor for the onset of OL. Data from biopsy samples followed the same trend of protein expression seen in the cytological samples. Dysplastic zones showed huge overexpression of EGFR and WNT pathway proteins among tobacco chewers. In conclusion, this is the first time report showing the effect of chewing tobacco on the EGFR and WNT pathway in OL and its possible role as a potential risk factor for its proliferative type.

Glycine rich proline rich protein from Sorghum bicolor serves as an antimicrobial protein implicated in plant defense response.

KEY MESSAGE: Sorghum glycine rich proline rich protein (SbGPRP1) exhibit antimicrobial properties and play a crucial role during biotic stress condition. Several proteins in plants build up the innate immune response system in plants which get triggered during the occurrence of biotic stress. Here we report the functional characterization of a glycine-rich proline-rich protein (SbGPRP1) from Sorghum which was previously demonstrated to be involved in abiotic stresses. Expression studies carried out with SbGPRP1 showed induced expression upon application of phytohormones like salicylic acid which might be the key in fine-tuning the expression level. Upon challenging the Sorghum plants with a compatible pathogen the SbGprp1 transcript was found to be upregulated. SbGPRP1 encodes a 197 amino acid polypeptide which was bacterially-expressed and purified for in vitro assays. Gram-positive bacteria like Bacillus and phytopathogen Rhodococcus fascians showed inhibited growth in the presence of the protein. The NPN assay, electrolytic leakage and SEM analysis showed membrane damage in bacterial cells. Ectopic expression of SbGPRP1 in tobacco plants led to enhanced tolerance towards infection caused by R. fascians. Though the N-terminal part of the protein showed disorderness the C-terminal end was quite capable of forming several α-helices which was correlated with CD spectroscopic analysis. Here, we have tried to determine the structural model for the protein and predicted the association of antimicrobial activity with the C-terminal region of the protein.

Selective manipulation of the inositol metabolic pathway for induction of salt-tolerance in indica rice variety.

Halophytes are rich sources of salt stress tolerance genes which have often been utilized for introduction of salt-tolerance character in salt-sensitive plants. In the present study, we overexpressed PcINO1 and PcIMT1 gene(s), earlier characterized in this laboratory from wild halophytic rice Porteresia coarctata, into IR64 indica rice either singly or in combination and assessed their role in conferring salt-tolerance. Homozygous T3/T4 transgenic plants revealed that PcINO1 transformed transgenic rice lines exhibit significantly higher tolerance upto 200 mM or higher salt concentration with negligible compromise in their growth or other physiological parameters compared to the untransformed system grown without stress. The PcIMT1-lines or the double transgenic lines (DC1) having PcINO1 and PcIMT1 introgressed together, were less efficient in such respect. Comparison of inositol and/or pinitol pool in three types of transgenic plants suggests that plants whose inositol production remains uninterrupted under stress by the functional PcINO1 protein, showed normal growth as in the wild-type plants without stress. It is conceivable that inositol itself acts as a stress-ameliorator and/or as a switch for a number of other pathways important for imparting salt-tolerance. Such selective manipulation of the inositol metabolic pathway may be one of the ways to combat salt stress in plants.

Reversing effect of Lupeol on vasculogenic mimicry in murine melanoma progression.

Vasculogenic mimicry, an endothelia-independent tumor microcirculation has been found in various cancers and is thought to be achieved by cancer stem like cells. Dacarbazine resistance is one of the most common features of melanoma and recent studies suggest that the mode of resistance is closely related to the formation of vasculogenic mimicry. In our work, we examined the anticancer effect of Lupeol, a novel phytochemical with Dacarbazine in vivo and in vitro. Results demonstrated adequate cytotoxicity followed by down regulation of CD 133 expression in Lupeol treated B16-F10 cell line. In solid tumor model the drug also inhibited vasculogenic mimicry along with angiogenesis by altering both the cancer stem cell as well as the endothelial progenitor cell population. Lupeol hindered the maturation of bone marrow derived endothelial progenitors and thus, retarded the formation of rudimentary tumor microvessels. Notably, Dacarbazine treatment demonstrated unresponsiveness to B16-F10 cells in both in vivo and in vitro model via upregulation of CD 133 expression and increased formation of vasculogenic mimicry tubes. Together, these data indicate that Lupeol alone can become a proficient agent in treating melanoma, inhibiting vasculogenic mimicry and might play a significant role in subduing Dacarbazine induced drug resistance.

Madhuca indica Inhibits Breast Cancer Cell Proliferation by Modulating COX-2 Expression.

BACKGROUND: Madhuca indica belongs to the family sapotaceae, commonly known as Mahua. It is primarily known for alcoholic beverage production and is reported to have anti-inflammatory, analgesic and antipyretic properties. Madhuca indica has also been reported to be effective in several diseases. OBJECTIVE: This study was undertaken to check the anticancer efficacy and chemopreventive effect of methanolic extract of Mahua flower (ME) on human breast cancer cell lines MCF-7 and MDA-MB-468. METHOD: The cytotoxic and anti-proliferative effects on MCF-7 and MDA-MB-468 cells were studied by MTT, hexosaminidase and colony formation assay. Expression of caspase 3/7 was assessed by flow cytometry and western blot analysis. Expression of COX-2 was evaluated by western blot analysis, luciferase assay and mRNA analysis. RESULTS: ME inhibited the proliferation of breast cancer cells by inducing apoptosis through up-regulating the expression of Caspase 3/7 (P < 0.0001). Our results showed a decrease in the expression of COX-2 mRNA and COX-2 protein in both MCF-7 and MDA-MB-468 cells with an increase in ME concentration. Furthermore synergistic effect of ME and chemotherapeutic drug paclitaxel was also studied in MCF-7 and MDA-MB- 468 cells which were found to be more effective (P < 0.0001) than treatment of either ME or paclitaxel alone. Results were analyzed by ANOVA and Pearson correlation analysis. CONCLUSION: All these experiments suggest that ME inhibits breast cancer cell proliferation and apoptosis by inhibiting the expression of COX-2 in MCF-7 and MDAMB- 468 cells. This work further highlighted that ME may enhance the potentiality of paclitaxel in breast cancer treatment.

Functional characterization of two myo-inositol-1-phosphate synthase (MIPS) gene promoters from the halophytic wild rice (Porteresia coarctata).

MAIN CONCLUSION: The promoter deletion mutants from second isoform of INO1 (gene-encoding MIPS) from Porteresia coarctata of 932 bp (pPcINO1.2.932) and 793 bp (pPcINO1.2.793) prove to be very efficient as salt/drought stress-inducible promoters, while pPcINO1.2.932 is found to be responsive to cold stress as well. The promoters of the two identified myo-inositol-1-phosphate synthase (INO1) isoforms from salt-tolerant wild rice, Porteresia coarctata (PcINO1.1 and PcINO1.2) have been compared bioinformatically with their counterparts present in the salt-sensitive rice, Oryza sativa. PcINO1.2 promoter was found to be enriched with many abiotic stress-responsive elements, like abscisic acid-responsive elements, MYC-responsive elements, MYB-binding sites, low-temperature stress-responsive elements, and heat-shock elements similar to the ones found in the conserved motifs of the promoters of salt/drought stress-inducible INO1 promoters across Kingdom Planta. To have detailed analysis on the arrangement of cis-acting regulatory elements present in PcINO1 promoters, 5' deletion mutational studies were performed in dicot model plants. Both transient as well as stable transformation methods were used to check the influence of PcINO1 promoter deletion mutants under salt and physiologically drought conditions using ß-glucuronidase as the reporter gene. The deletion mutant from the promoter of PcINO1.2 of length 932 bp (pPcINO1.2.932) was found to be significantly upregulated under drought stress and also in cold stress, while another deletion mutant, pPcINO1.2.793 (of 793 bp), was significantly upregulated under salt stress. P. coarctata being a halophytic species, the high inducibility of pPcINO1.2.932 upon exposure to low-temperature stress was an unexpected result.

Dehydrins Impart Protection against Oxidative Stress in Transgenic Tobacco Plants.

Environmental stresses generate reactive oxygen species (ROS) which might be detrimental to the plants when produced in an uncontrolled way. However, the plants ameliorate such stresses by synthesizing antioxidants and enzymes responsible for the dismutation of ROS. Additionally, the dehydrins were also able to protect the inactivation of the enzyme lactate dehydrogenase against hydroxyl radicals (OH⋅) generated during Fenton's reaction. SbDhn1 and SbDhn2 overexpressing transgenic tobacco plants were able to protect against oxidative damage. Transgenic tobacco lines showed better photosynthetic efficiency along with high chlorophyll content, soluble sugar and proline. However, the malonyl dialdehyde (MDA) content was significantly lower in transgenic lines. Experimental evidence demonstrates the protective effect of dehydrins on electron transport chain in isolated chloroplast upon methyl viologen (MV) treatment. The transgenic tobacco plants showed significantly lower superoxide radical generation () upon MV treatment. The accumulation of the H2O2 was also lower in the transgenic plants. Furthermore, in the transgenic plants the expression of ROS scavenging enzymes was higher compared to non-transformed (NT) or vector transformed (VT) plants. Taken together these data, during oxidative stress dehydrins function by scavenging the () directly and also by rendering protection to the enzymes responsible for the dismutation of () thereby significantly reducing the amount of hydrogen peroxides formed. Increase in proline content along with other antioxidants might also play a significant role in stress amelioration. Dehydrins thus function co-operatively with other protective mechanisms under oxidative stress conditions rendering protection in stress environment.