Halotolerant Citrobacter sp. remediates salinity stress and promotes the growth of Vigna radiata (L) by secreting extracellular polymeric substances (EPS) and biofilm formation: a novel active cell for microbial desalination cell (MDC).

To address soil salinization and its impact on crop production, microbial desalination cells (MDCs) offer a promising solution. These bioelectrochemical systems integrate desalination and wastewater treatment through microbial activity. A halotolerant beneficial bacterial strain called Citrobacter sp. strain KUT (CKUT) was isolated from India's salt desert Run of Kutch, Gujrat, highlighting its potential application in combating soil salinization. CKUT exhibits high salt tolerance and has the ability to produce extracellular polymeric substances (EPS) at a concentration of 0.04 mg/ml. It forms biofilm that enable it to withstand up to 10% NaCl concentration. Additionally, CKUT shows promise in remediating salinity levels, reducing it from 4.5 to 2.7 gL-1. These characteristics are driven by biofilm formation and EPS production. In an experiment where V. radiata L. seedlings were inoculated with CKUT, the treated plants exhibited enhanced chlorophyll content, growth, and overall plant characteristics compared to seedlings treated with sodium chloride (NaCl). These improvements included increased shoot length (150 mm), root length (40 mm), and biomass. This indicates that CKUT treatment has the potential to enhance the suitability of V. radiata and other crops for cultivation in saline lands, effectively addressing the issue of soil salinization. Furthermore, integrating CKUT into microbial desalination cells (MDCs) offers an opportunity for freshwater production from seawater, contributing to sustainable agriculture by promoting improved crop growth and increased yield in areas prone to salinity. HIGHLIGHTS : • Soil salinization reduces crop yield, including Vigna radiata L. • Citrobacter sp. strain KUT (CKUT) is a halotolerant bacterium isolated from the salt desert Run of Kutch, Gujarat, which can tolerate high salt concentrations. • CKUT mitigates salinity by producing extracellular polymeric substances (EPS) and forming biofilms. • CKUT treatment demonstrated increased plant growth, biomass, and chlorophyll content under salinity stress, showcasing its potential in microbial desalination cell (MDC) for enhancing crop yield in salinized soils.

Alleviation of heavy metals chromium, cadmium and lead and plant growth promotion in Vigna radiata L. plant using isolated Pseudomonas geniculata.

Plants exposed to heavy metals (HMs) stress negatively affect their development and production capacity. Chromium (Cr), Cadmium (Cd), and Lead (Pb) are the most common hazardous trace metals in agriculture. The physiological, biochemical, and molecular characteristics of crops are being affected. Phytoremediation is a method to alleviate heavy metals from the contaminated soil. The study aims to evaluate the phytoremediation ability of Vigna radiata L. (mung bean) in the absence and the presence of multi-metal tolerant and plant growth promoting Pseudomonas geniculata strain TIU16A3 isolated from soil of tannery industrial estate, Kolkata, West Bengal, India. The strain was further assessed with increasing concentrations of Cr, Cd, and Pb (10, 20, 40, and 80 µg/mL) when the mung bean plant was a test crop. The strain significantly increased plant growth, chlorophyll content, increased level of antioxidant enzymes such as superoxide dismutase, peroxidase, and catalase, and decreased oxidative stress indicators like H2O2 and electrolyte leakage in the presence of Cr, Cd, and Pb as compared to plants grown in the absence of Pseudomonas geniculata strain. Shoot length responsive gene (Aux/IAA) in the presence of heavy metal alone and Pseudomonas geniculata treated Cd and Cr showed higher relative expression of (Aux/IAA) compared to Pb. Due to these intrinsic abilities, Pseudomonas geniculata strain TIU16A3 can be a plant growth promoter and thus can help in the remediation of heavy metal (Cr, Cd, and Pb) contaminated soil.

Understanding crosstalk of organ tropism, tumor microenvironment and noncoding RNAs in breast cancer metastasis.

Cancer metastasis is one of the major clinical challenges worldwide due to limited existing effective treatments. Metastasis roots from the host organ of origin and gradually migrates to different regional and distant organs. In different breast cancer subtypes, different organs like bones, liver, lungs and brain are targeted by the metastatic tumor cells. Cancer renders mortality to their respective metastasizing sites like bones, brain, liver, and lungs. Metastatic breast cancers are best treated and managed if detected at an early stage. Metastasis is regulated by various molecular activators and suppressors. The conventional theory of 'seed and soil' states that metastatic tumor cells move to tumor microenvironment that has favorable conditions like blood flow for them to grow just like seeds grows when planted in fertile land. Additionally, different coding as well as non-coding RNAs play a very significant role in the process of metastasis by modulating their expression levels leading to a crosstalk of various tumorigenic cascades. Treatments for metastasis is also very critical in controlling this lethal process. Detecting breast cancer metastasis at an early stage is crucial for managing and predicting metastatic progression. In this review, we have compiled several factors that can be targeted to manage the onset and gradual stages of breast cancer metastasis.

Pathogenic Mechanisms in Acute Myeloid Leukemia.

OPINION STATEMENT: Acute myeloid leukemia (AML) is the most common form of leukemia in adults, leading to the highest number of annual leukemia-associated deaths in the USA. Although most AML patients initially enter remission following induction therapy, most eventually relapse, underscoring the unmet need for more effective therapies. In recent years, novel high-throughput sequencing techniques, and mouse and human models of disease have increased our understanding of the molecular mechanisms that lead to AML. Leukemogenic mechanisms can be broadly classified into two types-cell-intrinsic and cell-extrinsic. Cell-intrinsic mechanisms include an array of genetic and epigenetic alterations that lead to dysregulated gene expression and function in hematopoietic stem/progenitor cells, leading to their increased fitness and ultimately, malignant transformation. Extrinsic mechanisms include both hematopoietic and non-hematopoietic stromal components of the leukemic microenvironment that interact with pre-leukemic and leukemic clones to promote their survival, self-renewal, and/or resistance to therapy. Through the individual and concerted action of these factors, pre-leukemic clones acquire the changes necessary for leukemic transformation. In addition, following therapy, specific leukemic clones are selected for that eventually re-initiate disease. Improving our understanding of these cell-intrinsic and cell-extrinsic mechanisms will provide novel opportunities to treat AML as well as prevent the development of disease.

Activating transcription factor 3 modulates the macrophage immune response to Mycobacterium tuberculosis infection via reciprocal regulation of inflammatory genes and lipid body formation.

Infection of macrophages by Mycobacterium tuberculosis elicits an immune response that clears the bacterium. However, the bacterium is able to subvert the innate immune response. Differential expression of transcription factors (TFs) is central to the dynamic balance of this interaction. Among other functions, TFs regulate the production of antibacterial agents such as nitric oxide, pro-inflammatory cytokines and neutral lipids which are stored in lipid bodies (LBs) and favour bacterial survival. Here, we demonstrate that the TF activating transcription factor 3 (ATF3) is upregulated early during infection of macrophages or mice. Depletion of ATF3 enhances mycobacterial survival in macrophages suggesting its host-protective role. ATF3 interacts with chromatin remodelling protein brahma-related gene 1 and both associate with the promoters of interleukin-12p40, interleukin-6 and nitric oxide synthase 2, to activate expression of these genes. Strikingly, ATF3 downregulates LB formation by associating at the promoters of positive regulators of LB formation such as cholesterol 25 hydroxylase and the microRNA-33 locus. ATF3 represses the association of the activating mark, acetyl histone H4 lysine 8 at the promoter of cholesterol 25 hydroxylase. Our study suggests opposing roles of ATF3 in regulation of distinct sets of macrophage genes during infection, converging on a host-protective immune response.

Encouraging Outcomes of Alternate Donor Hematopoietic Stem Cell Transplant in Pediatric High-risk/Relapsed Leukemias: A Single Center Experience.

Outcomes of high-risk and relapsed pediatric acute leukemias continue to be suboptimal. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative modality. However, <30% of patients have matched sibling donors available. Hence, alternate donors (matched unrelated and haploidentical) are being used to improve outcomes. We retrospectively analyzed our data of all children with high-risk/relapsed acute leukemias who underwent alternate donor HSCT at our center from April 2015 to July 2020. A total of 15 patients were included-3 underwent matched unrelated and 12 underwent haploidentical HSCT. Before HSCT, all patients were in complete remission (CR): CR1-1, CR2-11, and CR3-3. All patients engrafted except one. Median time to neutrophil and platelet engraftment was 15 and 16 days, respectively. There were 3 transplant related mortalities. One patient was lost to follow-up. Remaining 11 patients remain in remission and are alive. The cumulative incidence of acute graft versus host disease was 57.1% and of chronic graft versus host disease was 21.4%. Overall survival was 80% and the event-free survival was 73.3%. The median follow-up of alive patients was 775 days (range: 333 to 2077 d). Our experience shows encouraging outcomes using alternate donor HSCT for these patients from developing world.

Allogeneic Hematopoietic Stem Cell Transplant Offer Good Outcomes in Pediatric Aplastic Anemia: Experience From Developing World.

Between 2014 and 2020, 31 patients with severe aplastic anemia (SAA) underwent full match allogeneic hematopoietic stem cell transplantation at our center. Of the 31 patients with SAA, 19 had acquired aplastic anemia, 2 had Diamond Blackfan anemia and 10 had Fanconi anemia. Donors were either matched sibling (n=29), related donors (n=2), or unrelated donors (n=3). Peripheral blood stem cells were the graft source in all the cases except 1. Fludarabine-based reduced intensity conditioning was used in all except for patients with a diagnosis of Diamond Blackfan anemia. All patients except 1 achieved hematologic recovery in the form of neutrophil engraftment at 13 days (range, 9 to 17), whereas platelet engraftment occurred at 14 days (range, 10 to 18). Graft versus host disease (GvHD) prophylaxis consisted of cyclosporine and methotrexate ±antithymocyte globulin (horse/rabbit). Acute GvHD developed in 12.9% patients, whereas no patients developed chronic GvHD till the time of last follow-up. The 2-year overall survival for the entire cohort was 93.21±4.6%. In patients with SAA, allogeneic stem cell transplant using fludarabine-based conditioning regimens are very well tolerated and have excellent outcomes in a full match setting.

Haploidentical Stem Cell Transplant With Post-transplant Cyclophosphamide for Chediak-Higashi Syndrome: A Very Rare Case Report.

Chediak-Higashi syndrome is a rare immunodeficiency disorder for which hematopoietic stem cell transplant (HSCT) is the only curative treatment option. HSCT only corrects the hematologic and immunologic manifestations of the disease but neurologic complications may still progress after transplant. Haploidentical HSCT (haplo-HSCT) has evolved as a feasible alternative for patients with primary immunodeficiency. More recently, there has been use of haplo-HSCT with post-transplant cyclophosphamide. However, only 4 cases of Chediak-Higashi syndrome have been reported using this approach. Here, the authors describe a case of a 17-month-old boy who was successfully treated by haplo-HSCT with reduced-toxicity conditioning (fludarabine/treosulfan/melphalan) and post-transplant cyclophosphamide.

Elucidating the gene regulatory networks modulating cancer stem cells and non-stem cancer cells in high grade serous ovarian cancer.

The origin and pathogenesis of epithelial ovarian cancer have perplexed investigators for decades. The most prevalent type of it is the high-grade serous ovarian carcinoma (HGSOv) which is a highly aggressive disease with high relapse rates and insurgence of chemo-resistance at later stages of treatment. These are driven by a rare population of stem cell like cancer cells called cancer stem cells (CSCs). We have taken up a systems approach to find out the common gene interaction paths between non-CSC tumor cells (CCs) and CSCs in HGSOv. Detailed investigation reveals a set of 17 Transcription Factors (named as pivot-TFs) which can govern changes in the mode of gene regulation along these paths. Overall, this work highlights a divergent road map of functional information relayed by these common key players in the two cell states, which might aid towards designing novel therapeutic measures to target the CSCs for ovarian cancer therapy.

A systemic insight into astrocytoma biology across different grades.

Astrocytomas are the most common type of brain tumors, which originate from glial cells, and are classified into specific grades based on their histopathological behavior. To develop precise therapeutic strategies for the disease, it is important to identify the molecular signatures specific to each grade as well as the key factors responsible for the transition from one grade to the next. In this study, we have taken a systems approach to investigate the gene expression profiles of each grades of the disease by mapping shortest paths of gene interaction in each grade and also between one grade and the next. Module core genes govern the topology of these networks and serve as important functional players in each grade as well as help in grade transition events. Shortlisted among these module core genes are well-characterized players of glioma as well as novel molecules (32 grade-specific genes and 15 grade transition-specific genes), which influence important prooncogenic functions but have not been linked to glioma biology yet. These module core genes provide interesting insight into the biology of astrocytic tumors and are potential therapeutic targets for astrocytoma.

MicroRNA 26a (miR-26a)/KLF4 and CREB-C/EBPß regulate innate immune signaling, the polarization of macrophages and the trafficking of Mycobacterium tuberculosis to lysosomes during infection.

For efficient clearance of Mycobacterium tuberculosis (Mtb), macrophages tilt towards M1 polarization leading to the activation of transcription factors associated with the production of antibacterial effector molecules such as nitric oxide (NO) and proinflammatory cytokines such as interleukin 1 ß (IL-1ß) and tumor necrosis factor α (TNF-α). At the same time, resolution of inflammation is associated with M2 polarization with increased production of arginase and cytokines such as IL-10. The transcriptional and post-transcriptional mechanisms that govern the balance between M1 and M2 polarization, and bacteria-containing processes such as autophagy and trafficking of Mtb to lysosomes, are incompletely understood. Here we report for the first time, that the transcription factor KLF4 is targeted by microRNA-26a (miR-26a). During Mtb infection, downregulation of miR-26a (observed both ex vivo and in vivo) facilitates upregulation of KLF4 which in turn favors increased arginase and decreased iNOS activity. We further demonstrate that KLF4 prevents trafficking of Mtb to lysosomes. The CREB-C/EBPß signaling axis also favors M2 polarization. Downregulation of miR-26a and upregulation of C/ebpbeta were observed both in infected macrophages as well as in infected mice. Knockdown of C/ebpbeta repressed the expression of selected M2 markers such as Il10 and Irf4 in infected macrophages. The importance of these pathways is substantiated by observations that expression of miR-26a mimic or knockdown of Klf4 or Creb or C/ebpbeta, attenuated the survival of Mtb in macrophages. Taken together, our results attribute crucial roles for the miR-26a/KLF4 and CREB-C/EBPßsignaling pathways in regulating the survival of Mtb in macrophages. These studies expand our understanding of how Mtb hijacks host signaling pathways to survive in macrophages, and open up new exploratory avenues for host-targeted interventions.

Genome-wide mRNA-miRNA profiling uncovers a role of the microRNA miR-29b-1-5p/PHLPP1 signalling pathway in Helicobacter pylori-driven matrix metalloproteinase production in gastric epithelial cells.

Aberrant expression of microRNAs (miRNAs) is associated with tumour progression, extracellular matrix remodelling, and cell proliferation. miRNAs modulate host gene expression during infection by pathogens such as Helicobacter pylori, which is associated with varying degrees of gastric pathology. In order to gain insight into the regulation of gene expression by miRNAs during H. pylori infection of gastric epithelial cells and its likely downstream consequences, we analysed the transcriptomes and miRnomes of AGS cells infected with H. pylori. In silico analysis of miRNA-mRNA interactions suggested that miR-29b-1-5p was a likely regulator of pathways associated with gastric epithelial cell pathology. We validated PH domain leucine rich phosphatase 1 (PHLPP1), a negative regulator of the Akt signalling pathway, as a target of miR-29b-1-5p. In an in vivo mouse model, we observed that infection with H. pylori was associated with upregulation of miR-29b-1-5p and downregulation of PHLPP1. Transfection with either a mimic or an inhibitor of miR-29b-1-5p confirmed that downregulation of PHLPP1 upregulates Akt-dependent NF-κB signalling leading to activation of matrix metalloproteinases 2 and 9, players in the degradation of extracellular matrix during H. pylori infection. The secreted antigen HP0175 was associated with upregulation of miR-29b-1-5p, regulation of metalloproteinase activity, and migration of AGS cells. Our study suggests that targeting the miR-29b-1-5p/PHLPP1 signalling axis could be a potential host-directed approach for regulating the outcome of H. pylori infection.

Ganglioside GM2 mediates migration of tumor cells by interacting with integrin and modulating the downstream signaling pathway.

The definitive role of ganglioside GM2 in mediating tumor-induced growth and progression is still unknown. Here we report a novel role of ganglioside GM2 in mediating tumor cell migration and uncovered its mechanism. Data shows differential expression levels of GM2-synthase as well as GM2 in different human cancer cells. siRNA mediated knockdown of GM2-synthase in CCF52, A549 and SK-RC-26B cells resulted in significant inhibition of tumor cell migration as well as invasion in vitro without affecting cellular proliferation. Over-expression of GM2-synthase in low-GM2 expressing SK-RC-45 cells resulted in a consequent increase in migration thus confirming the potential role GM2 and its downstream partners play in tumor cell migration and motility. Further, treatment of SK-RC-45 cells with exogenous GM2 resulted in a dramatic increase in migratory and invasive capacity with no change in proliferative capacity, thereby confirming the role of GM2 in tumorigenesis specifically by mediating tumor migration and invasion. Gene expression profiling of GM2-synthase silenced cells revealed altered expression of several genes involved in cell migration primarily those controlling the integrin mediated signaling. GM2-synthase knockdown resulted in decreased phosphorylation of FAK, Src as well as Erk, while over-expression and/or exogenous GM2 treatment caused increased FAK and Erk phosphorylation respectively. Again, GM2 mediated invasion and Erk phosphorylation is blocked in integrin knockdown SK-RC-45 cells, thus confirming that GM2 mediated migration and phosphorylation of Erk is integrin dependent. Finally, confocal microscopy suggested co-localization while co-immunoprecipitation and surface plasmon resonance (SPR) confirmed direct interaction of membrane bound ganglioside, GM2 with the integrin receptor.

Gene expression profiling of Mycobacterium tuberculosis Lipoarabinomannan-treated macrophages: A role of the Bcl-2 family member A1 in inhibition of apoptosis in mycobacteria-infected macrophages.

Macrophages play an important role in the establishment of infection by intracellular pathogens. Mycobacterium tuberculosis is known to inhibit apoptosis and to downregulate immune responses of host cells using various strategies, including activation of peroxisome proliferator-activated receptor (PPAR)γ. Mannose-capped lipoarabinomannan (ManLAM) is one of the known bacterial effectors that plays a role in subversion of host immunity and activation of PPARγ. Here, we have used an unbiased global gene expression profiling approach to understand (a) how ManLAM regulates host cell immune responses and (b) the role of PPARγ in modulating ManLAM-induced host cell signaling. We have demonstrated that ManLAM-dependent inhibition of macrophage apoptosis is mediated by the upregulation of the antiapoptotic B-cell CLL/lymphoma 2 (Bcl2) family member A1. Our in silico analyses suggested that ManLAM-mediated PPARγ signaling is linked to important functions such as phagocytosis, cytoskeleton remodeling, cell survival, and autophagy. We have validated that ManLAM upregulates signal transducer and activator of transcription (STAT5)α, an important transcriptional regulator of cell survival in a PPARγ-dependent manner.