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1.
Am J Physiol Gastrointest Liver Physiol ; 324(1): G24-G37, 2023 01 01.
Article in English | MEDLINE | ID: mdl-36410023

ABSTRACT

Single immunoglobulin interleukin-1-related receptor (SIGIRR), toll-interacting protein (TOLLIP), and A20 are major inhibitors of toll-like receptor (TLR) signaling induced postnatally in the neonatal intestine. Short-chain fatty acids (SCFAs), fermentation products of indigestible carbohydrates produced by symbiotic bacteria, inhibit intestinal inflammation. Herein, we investigated the mechanisms by which SCFAs regulate SIGIRR, A20, and TOLLIP expression and mitigate experimental necrotizing enterocolitis (NEC). Butyrate induced NOTCH activation by repressing sirtuin 1 (SIRT1)-mediated deacetylation of the Notch intracellular domain (NICD) in human intestinal epithelial cells (HIECs). Overexpression of NICD induced SIGIRR, A20, and TOLLIP expression. Chromatin immunoprecipitation revealed that butyrate-induced NICD binds to the SIGIRR, A20, and TOLLIP gene promoters. Notch1-shRNA suppressed butyrate-induced SIGIRR/A20 upregulation in mouse enteroids and HIEC. Flagellin (TLR5 agonist)-induced inflammation in HIEC was inhibited by butyrate in a SIGIRR-dependent manner. Neonatal mice fed butyrate had increased NICD, A20, SIGIRR, and TOLLIP expression in the ileal epithelium. Butyrate inhibited experimental NEC-induced intestinal apoptosis, cytokine expression, and histological injury. Our data suggest that SCFAs can regulate the expression of the major negative regulators of TLR signaling in the neonatal intestine through Notch1 and ameliorate experimental NEC. Enteral SCFAs supplementation in preterm infants provides a promising bacteria-free, therapeutic option for NEC.NEW & NOTEWORTHY Short-chain fatty acids (SCFAs), such as propionate and butyrate, metabolites produced by symbiotic gut bacteria are known to be anti-inflammatory, but the mechanisms by which they protect against NEC are not fully understood. In this study, we reveal that SCFAs regulate intestinal inflammation by inducing the key TLR and IL1R inhibitors, SIGIRR and A20, through activation of the pluripotent transcriptional factor NOTCH1. Butyrate-mediated SIGIRR and A20 induction represses experimental NEC in the neonatal intestine.


Subject(s)
Enterocolitis, Necrotizing , Infant, Newborn , Animals , Mice , Humans , Enterocolitis, Necrotizing/drug therapy , Enterocolitis, Necrotizing/prevention & control , Enterocolitis, Necrotizing/genetics , Receptors, Interleukin-1/genetics , Receptors, Interleukin-1/metabolism , Infant, Premature , Inflammation/metabolism , Intestinal Mucosa/metabolism , Fatty Acids, Volatile/pharmacology , Fatty Acids, Volatile/metabolism , Butyrates/metabolism , Immunoglobulins/metabolism , Interleukin-1/metabolism , Receptor, Notch1/metabolism , Intracellular Signaling Peptides and Proteins/metabolism
2.
Mol Carcinog ; 62(2): 145-159, 2023 02.
Article in English | MEDLINE | ID: mdl-36218231

ABSTRACT

Doublecortin like kinase 1 (DCLK1) plays a crucial role in several cancers including colon and pancreatic adenocarcinomas. However, its role in squamous cell carcinoma (SCC) remains unknown. To this end, we examined DCLK1 expression in head and neck SCC (HNSCC) and anal SCC (ASCC). We found that DCLK1 is elevated in patient SCC tissue, which correlated with cancer progression and poorer overall survival. Furthermore, DCLK1 expression is significantly elevated in human papilloma virus negative HNSCC, which are typically aggressive with poor responses to therapy. To understand the role of DCLK1 in tumorigenesis, we used specific shRNA to suppress DCLK1 expression. This significantly reduced tumor growth, spheroid formation, and migration of HNSCC cancer cells. To further the translational relevance of our studies, we sought to identify a selective DCLK1 inhibitor. Current attempts to target DCLK1 using pharmacologic approaches have relied on nonspecific suppression of DCLK1 kinase activity. Here, we demonstrate that DiFiD (3,5-bis [2,4-difluorobenzylidene]-4-piperidone) binds to DCLK1 with high selectivity. Moreover, DiFiD mediated suppression of DCLK1 led to G2/M arrest and apoptosis and significantly suppressed tumor growth of HNSCC xenografts and ASCC patient derived xenografts, supporting that DCLK1 is critical for SCC growth.


Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Humans , Apoptosis , Carcinoma, Squamous Cell/drug therapy , Carcinoma, Squamous Cell/genetics , Cell Line, Tumor , Doublecortin-Like Kinases , G2 Phase Cell Cycle Checkpoints , Intracellular Signaling Peptides and Proteins/genetics , Protein Serine-Threonine Kinases/metabolism , Squamous Cell Carcinoma of Head and Neck/genetics , Animals
3.
Physiol Plant ; 175(6): e14092, 2023.
Article in English | MEDLINE | ID: mdl-38148187

ABSTRACT

Salt stress is an alarming abiotic stress that reduces mustard growth and yield. To attenuate salt toxicity effects, plant growth-promoting rhizobacteria (PGPR) offers a sustainable approach. Among the various PGPR, Pseudomonas fluorescens (P. fluorescens NAIMCC-B-00340) was chosen for its salt tolerance (at 100 mM NaCl) and for exhibiting various growth-promoting activities. Notably, P. fluorescens can produce auxin, which plays a role in melatonin (MT) synthesis. Melatonin is a pleiotropic molecule that acts as an antioxidant to scavenge reactive oxygen species (ROS), resulting in stress reduction. Owing to the individual role of PGPR and MT in salt tolerance, and their casual nexus, their domino effect was investigated in Indian mustard under salt stress. The synergistic action of P. fluorescens and MT under salt stress conditions was found to enhance the activity of antioxidative enzymes and proline content as well as  promote the production of secondary metabolites. This led to reduced oxidative stress following effective ROS scavenging, maintained photosynthesis, and improved growth. In mustard plants treated with MT and P. fluorescens under salt stress, eight flavonoids showed significant increase. Kaempferol and cyanidin showed the highest concentrations and are reported to act as antioxidants with protective functions under stress. Thus, we can anticipate that strategies involved in their enhancement could provide a better adaptive solution to salt toxicity in mustard plants. In conclusion, the combination of P. fluorescens and MT affected antioxidant metabolism and flavonoid profile that could be used to mitigate salt-induced stress and bolster plant resilience.


Subject(s)
Melatonin , Pseudomonas fluorescens , Antioxidants/metabolism , Melatonin/pharmacology , Mustard Plant/metabolism , Pseudomonas fluorescens/metabolism , Reactive Oxygen Species/metabolism , Flavonoids/metabolism
4.
Int J Mol Sci ; 24(4)2023 Feb 04.
Article in English | MEDLINE | ID: mdl-36834525

ABSTRACT

Bacterial infections are common in the etiology of human diseases owing to the ubiquity of bacteria. Such infections promote the development of periodontal disease, bacterial pneumonia, typhoid, acute gastroenteritis, and diarrhea in susceptible hosts. These diseases may be resolved using antibiotics/antimicrobial therapy in some hosts. However, other hosts may be unable to eliminate the bacteria, allowing them to persist for long durations and significantly increasing the carrier's risk of developing cancer over time. Indeed, infectious pathogens are modifiable cancer risk factors, and through this comprehensive review, we highlight the complex relationship between bacterial infections and the development of several cancer types. For this review, searches were performed on the PubMed, Embase, and Web of Science databases encompassing the entirety of 2022. Based on our investigation, we found several critical associations, of which some are causative: Porphyromonas gingivalis and Fusobacterium nucleatum are associated with periodontal disease, Salmonella spp., Clostridium perfringens, Escherichia coli, Campylobacter spp., and Shigella are associated with gastroenteritis. Helicobacter pylori infection is implicated in the etiology of gastric cancer, and persistent Chlamydia infections present a risk factor for the development of cervical carcinoma, especially in patients with the human papillomavirus (HPV) coinfection. Salmonella typhi infections are linked with gallbladder cancer, and Chlamydia pneumoniae infection is implicated in lung cancer, etc. This knowledge helps identify the adaptation strategies used by bacteria to evade antibiotic/antimicrobial therapy. The article also sheds light on the role of antibiotics in cancer treatment, the consequences of their use, and strategies for limiting antibiotic resistance. Finally, the dual role of bacteria in cancer development as well as in cancer therapy is briefly discussed, as this is an area that may help to facilitate the development of novel microbe-based therapeutics as a means of securing improved outcomes.


Subject(s)
Anti-Infective Agents , Bacterial Infections , Escherichia coli Proteins , Gastroenteritis , Helicobacter Infections , Helicobacter pylori , Neoplasms , Typhoid Fever , Humans , Bacterial Infections/microbiology , Anti-Bacterial Agents , Gastroenteritis/microbiology , Escherichia coli , Carrier Proteins
5.
Int J Cancer ; 150(9): 1497-1503, 2022 05 01.
Article in English | MEDLINE | ID: mdl-34927724

ABSTRACT

COVID-19 disruptions severely impacted access to health services for noncommunicable diseases, including cancer, but few studies have examined patient perspectives of COVID-19-induced barriers to care in low/middle-income countries. Data come from a survey completed online, over the phone or in person of 284 adult people with cancer in Kenya. One-third (36%) of participants had primary or no education and 34% had some or complete secondary education. Half of the participants (49%) were aged 40 to 59, 21% were 18 to 39 and 23% were 60 or older. Two-thirds were female (65%) and most visited a national referral hospital in Nairobi to receive care (84%). Mean travel time to Nairobi from the respondent county of residence was 2.47 hours (±2.73). Most participants reported decreased household income (88%) and were worried about their ability to afford cancer treatment due to COVID-19 (79%). After covariate adjustment, participants who lost access to hospitals due to COVID-19 travel restrictions were 15 times more likely to experience a cancer care delay (OR = 14.90, 95% CI: 7.44-29.85) compared to those with continued access to hospitals. Every additional hour of travel time to Nairobi from their county of residence resulted in a 20% increase in the odds of a cancer care delay (OR = 1.20, 95% CI: 1.06-1.36). Transportation needs and uninterrupted access to cancer care and medicines should be accounted for in COVID-19 mitigation strategies. These strategies include permits for cancer patients and caregivers to travel past curfew time or through block posts to receive care during lockdowns, cash assistance and involving patient navigators to improve patient communication.


Subject(s)
COVID-19/epidemiology , Health Services Accessibility , Neoplasms/therapy , Adolescent , Adult , COVID-19/economics , COVID-19/prevention & control , Female , Humans , Kenya/epidemiology , Male , Middle Aged , Neoplasms/diagnosis , Neoplasms/economics , Neoplasms/epidemiology , SARS-CoV-2 , Time-to-Treatment , Travel , Young Adult
6.
Molecules ; 27(4)2022 Feb 19.
Article in English | MEDLINE | ID: mdl-35209196

ABSTRACT

Traditionally, medicinal plants have long been used as a natural therapy. Plant-derived extracts or phytochemicals have been exploited as food additives and for curing many health-related ailments. The secondary metabolites produced by many plants have become an integral part of human health and have strengthened the value of plant extracts as herbal medicines. To fulfil the demand of health care systems, food and pharmaceutical industries, interest in the cultivation of precious medicinal plants to harvest bio-active compounds has increased considerably worldwide. To achieve maximum biomass and yield, growers generally apply chemical fertilizers which have detrimental impacts on the growth, development and phytoconstituents of such therapeutically important plants. Application of beneficial rhizosphere microbiota is an alternative strategy to enhance the production of valuable medicinal plants under both conventional and stressed conditions due to its low cost, environmentally friendly behaviour and non-destructive impact on fertility of soil, plants and human health. The microbiological approach improves plant growth by various direct and indirect mechanisms involving the abatement of various abiotic stresses. Given the negative impacts of fertilizers and multiple benefits of microbiological resources, the role of plant growth promoting rhizobacteria (PGPR) in the production of biomass and their impact on the quality of bio-active compounds (phytochemicals) and mitigation of abiotic stress to herbal plants have been described in this review. The PGPR based enhancement in the herbal products has potential for use as a low cost phytomedicine which can be used to improve health care systems.


Subject(s)
Bacteria/growth & development , Bioprospecting , Crops, Agricultural , Phytochemicals , Plants, Medicinal , Rhizosphere , Soil Microbiology , Crops, Agricultural/chemistry , Crops, Agricultural/growth & development , Crops, Agricultural/microbiology , Humans , Phytochemicals/chemistry , Phytochemicals/therapeutic use , Plants, Medicinal/chemistry , Plants, Medicinal/growth & development , Plants, Medicinal/microbiology
7.
J Biol Chem ; 295(4): 1021-1035, 2020 01 24.
Article in English | MEDLINE | ID: mdl-31836665

ABSTRACT

Wnt signaling regulates immunomodulatory functions during infection and inflammation. Employing NCCIT and HCT116 cells, having high endogenous Wnt signaling, we observed elevated levels of low-density lipoprotein receptor-related protein 5/6 (LRP5/6) and Frizzled class receptor 10 (FZD10) and increases in ß-catenin, doublecortin-like kinase 1 (DCLK1), CD44 molecule (CD44), and aldehyde dehydrogenase 1 family member A1 (ALDH1A1). siRNA-induced knockdown of these receptors antagonized TOPflash reporter activity and spheroid growth in vitro and elevated Wnt-inhibitory factor 1 (WIF1) activity. Elevated mRNA and protein levels of LRP5/6 and FZD10 paralleled expression of WNT2b and WNT4 in colonic crypts at days 6 and 12 post-infection with Citrobacter rodentium (CR) and tended to decline at days 20-34. The CR mutant escV or the tankyrase inhibitor XAV939 attenuated these responses. A three-dimensional organoid assay in colonic crypts isolated from CR-infected mice revealed elevated levels of LRP5/6 and FZD10 and ß-catenin co-localization with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). Co-immunoprecipitation in the membrane fraction revealed that axin associates with LRP5/6 in CR-infected crypts, and this association was correlated with increased ß-catenin. Colon tumors from either CR-infected ApcPMin/+ or azoxymethane/dextran sodium sulfate (AOM/DSS)-treated mice had high LRP5/6 or FZD10 levels, and chronic Notch blockade through the γ-secretase inhibitor dibenzazepine down-regulated LRP5/6 and FZD10 expression. In CR-responsive CT-26 cells, siRNA-induced LRP5/6 or FZD10 knockdown antagonized TOPflash reporter activity. Elevated miR-153-3p levels correlated with LRP5/6 and FZD10, and miR-153-3p sequestration via a plasmid-based miR inhibitor system attenuated Wnt signaling. We conclude that infection-induced signals from the plasma membrane epigenetically regulate Wnt signaling.


Subject(s)
Cell Membrane/metabolism , Citrobacter rodentium/physiology , Enterobacteriaceae Infections/genetics , Epigenesis, Genetic , Wnt Signaling Pathway/genetics , Frizzled Receptors/genetics , Frizzled Receptors/metabolism , HCT116 Cells , HEK293 Cells , Humans , Ligands , Low Density Lipoprotein Receptor-Related Protein-5/genetics , Low Density Lipoprotein Receptor-Related Protein-5/metabolism , Low Density Lipoprotein Receptor-Related Protein-6/genetics , Low Density Lipoprotein Receptor-Related Protein-6/metabolism , Male , MicroRNAs/genetics , MicroRNAs/metabolism , Organoids/pathology , Receptors, Notch/metabolism
8.
Am J Physiol Gastrointest Liver Physiol ; 320(4): G411-G419, 2021 04 01.
Article in English | MEDLINE | ID: mdl-33439103

ABSTRACT

Advances in metagenomics have allowed a detailed study of the gut microbiome, and its role in human health and disease. Infants born prematurely possess a fragile gut microbial ecosystem that is vulnerable to perturbation. Alterations in the developing gut microbiome in preterm infants are linked to life-threatening diseases such as necrotizing enterocolitis (NEC) and late-onset sepsis; and may impact future risk of asthma, atopy, obesity, and psychosocial disease. In this mini-review, we summarize recent literature on the origins and patterns of development of the preterm gut microbiome in the perinatal period. The host-microbiome-environmental factors that portend development of dysbiotic intestinal microbial patterns associated with NEC and sepsis are reviewed. Strategies to manipulate the microbiome and mitigate dysbiosis, including the use of probiotics and prebiotics will also be discussed. Finally, we explore the challenges and future directions of gut microbiome research in preterm infants.


Subject(s)
Bacteria/growth & development , Enterocolitis, Necrotizing/microbiology , Gastrointestinal Microbiome , Infant, Premature , Intestines/microbiology , Neonatal Sepsis/microbiology , Animals , Dysbiosis , Enterocolitis, Necrotizing/therapy , Fecal Microbiota Transplantation , Gestational Age , Host-Pathogen Interactions , Humans , Infant, Newborn , Neonatal Sepsis/therapy , Prebiotics , Probiotics/therapeutic use , Prognosis , Risk Factors
9.
Gastroenterology ; 158(5): 1433-1449.e27, 2020 04.
Article in English | MEDLINE | ID: mdl-31786131

ABSTRACT

BACKGROUND & AIMS: Prolactin (PRL) signaling is up-regulated in hormone-responsive cancers. The PRL receptor (PRLR) is a class I cytokine receptor that signals via the Janus kinase (JAK)-signal transducer and activator of transcription and mitogen-activated protein kinase pathways to regulate cell proliferation, migration, stem cell features, and apoptosis. Patients with pancreatic ductal adenocarcinoma (PDAC) have high plasma levels of PRL. We investigated whether PRLR signaling contributes to the growth of pancreatic tumors in mice. METHODS: We used immunohistochemical analyses to compare levels of PRL and PRLR in multitumor tissue microarrays. We used structure-based virtual screening and fragment-based drug discovery to identify compounds likely to bind PRLR and interfere with its signaling. Human pancreatic cell lines (AsPC-1, BxPC-3, Panc-1, and MiaPaCa-2), with or without knockdown of PRLR (clustered regularly interspaced short palindromic repeats or small hairpin RNA), were incubated with PRL or penfluridol and analyzed in proliferation and spheroid formation. C57BL/6 mice were given injections of UNKC-6141 cells, with or without knockdown of PRLR, into pancreas, and tumor development was monitored for 4 weeks, with some mice receiving penfluridol treatment for 21 days. Human pancreatic tumor tissues were implanted into interscapular fat pads of NSG mice, and mice were given injections of penfluridol daily for 28 days. Nude mice were given injections of Panc-1 cells, xenograft tumors were grown for 2 weeks, and mice were then given intraperitoneal penfluridol for 35 days. Tumors were collected from mice and analyzed by histology, immunohistochemistry, and immunoblots. RESULTS: Levels of PRLR were increased in PDAC compared with nontumor pancreatic tissues. Incubation of pancreatic cell lines with PRL activated signaling via JAK2-signal transducer and activator of transcription 3 and extracellular signal-regulated kinase, as well as formation of pancospheres and cell migration; these activities were not observed in cells with PRLR knockdown. Pancreatic cancer cells with PRLR knockdown formed significantly smaller tumors in mice. We identified several diphenylbutylpiperidine-class antipsychotic drugs as agents that decreased PRL-induced JAK2 signaling; incubation of pancreatic cancer cells with these compounds reduced their proliferation and formation of panco spheres. Injections of 1 of these compounds, penfluridol, slowed the growth of xenograft tumors in the different mouse models, reducing proliferation and inducing autophagy of the tumor cells. CONCLUSIONS: Levels of PRLR are increased in PDAC, and exposure to PRL increases proliferation and migration of pancreatic cancer cells. Antipsychotic drugs, such as penfluridol, block PRL signaling in pancreatic cancer cells to reduce their proliferation, induce autophagy, and slow the growth of xenograft tumors in mice. These drugs might be tested in patients with PDAC.


Subject(s)
Antipsychotic Agents/pharmacology , Carcinoma, Pancreatic Ductal/drug therapy , Pancreatic Neoplasms/drug therapy , Penfluridol/pharmacology , Prolactin/metabolism , Receptors, Prolactin/antagonists & inhibitors , Animals , Antipsychotic Agents/therapeutic use , Autophagy/drug effects , Carcinoma, Pancreatic Ductal/blood , Carcinoma, Pancreatic Ductal/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Discovery , Gene Knockdown Techniques , Humans , Injections, Intraperitoneal , Janus Kinase 2/metabolism , Male , Mice , Pancreas/pathology , Pancreatic Neoplasms/blood , Pancreatic Neoplasms/pathology , Penfluridol/therapeutic use , Prolactin/blood , Receptors, Prolactin/genetics , Receptors, Prolactin/metabolism , STAT3 Transcription Factor/metabolism , Signal Transduction/drug effects , Spheroids, Cellular , Tissue Array Analysis , Xenograft Model Antitumor Assays
10.
Plant Cell Rep ; 40(8): 1429-1450, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33909122

ABSTRACT

Heat stress adversely affects plants growth potential. Global warming is reported to increase in the intensity, frequency, and duration of heatwaves, eventually affecting ecology, agriculture and economy. With an expected increase in average temperature by 2-3 °C over the next 30-50 years, crop production is facing a severe threat to sub-optimum growth conditions. Abscisic acid (ABA) and nitric oxide (NO) are growth regulators that are involved in the adaptation to heat stress by affecting each other and changing the adaptation process. The interaction between these molecules has been discussed in various studies in general or under stress conditions; however, regarding high temperature, their interaction has little been worked out. In the present review, the focus is shifted on the role of these molecules under heat stress emphasizing the different possible interactions between ABA and NO as both regulate stomatal closure and other molecules including hydrogen peroxide (H2O2), hydrogen sulfide (H2S), antioxidants, proline, glycine betaine, calcium (Ca2+) and heat shock protein (HSP). Exploring the crosstalk between ABA and NO with other molecules under heat stress will provide us with a comprehensive knowledge of plants mechanism of heat tolerance which could be useful to develop heat stress-resistant varieties.


Subject(s)
Abscisic Acid/metabolism , Heat-Shock Response/physiology , Nitric Oxide/metabolism , Plant Physiological Phenomena , Plant Proteins/metabolism , Adaptation, Physiological , Antioxidants/metabolism , Betaine/metabolism , Enzymes/metabolism , Hydrogen Peroxide/metabolism , Hydrogen Sulfide/metabolism , Proline/metabolism , Signal Transduction
11.
Int J Mol Sci ; 23(1)2021 Dec 29.
Article in English | MEDLINE | ID: mdl-35008767

ABSTRACT

Decreases in short-chain-fatty-acids (SCFAs) are linked to inflammatory bowel disease (IBD). Yet, the mechanisms through which SCFAs promote wound healing, orchestrated by intestinal stem cells, are poorly understood. We discovered that, in mice with Citrobacter rodentium (CR)-induced infectious colitis, treatment with Pectin and Tributyrin diets reduced the severity of colitis by restoring Firmicutes and Bacteroidetes and by increasing mucus production. RNA-seq in young adult mouse colon (YAMC) cells identified higher expression of Lgr4, Lgr6, DCLK1, Muc2, and SIGGIR after Butyrate treatment. Lineage tracing in CR-infected Lgr5-EGFP-IRES-CreERT2/ROSA26-LacZ (Lgr5-R) mice also revealed an expansion of LacZ-labeled Lgr5(+) stem cells in the colons of both Pectin and Tributyrin-treated mice compared to control. Interestingly, gut microbiota was required for Pectin but not Tributyrin-induced Lgr5(+) stem cell expansion. YAMC cells treated with sodium butyrate exhibited increased Lgr5 promoter reporter activity due to direct Butyrate binding with Lgr5 at -4.0 Kcal/mol, leading to thermal stabilization. Upon ChIP-seq, H3K4me3 increased near Lgr5 transcription start site that contained the consensus binding motif for a transcriptional activator of Lgr5 (SPIB). Thus, a multitude of effects on gut microbiome, differential gene expression, and/or expansion of Lgr5(+) stem cells seem to underlie amelioration of colitis following dietary intervention.


Subject(s)
Colitis/microbiology , Colitis/pathology , Diet , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae Infections/pathology , Microbiota , Stem Cells/pathology , Animals , Biodiversity , Butyrates/pharmacology , Cell Proliferation/drug effects , Cell Proliferation/genetics , Citrobacter rodentium/physiology , Epithelium/pathology , Fermentation , Gene Expression Profiling , Gene Expression Regulation/drug effects , HEK293 Cells , Humans , Mice, Inbred C57BL , Mucin-2/metabolism , Pectins/pharmacology , Promoter Regions, Genetic/genetics , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Regeneration/drug effects , Transcription, Genetic/drug effects , Triglycerides/pharmacology
12.
Am J Physiol Renal Physiol ; 318(1): F35-F42, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31682174

ABSTRACT

Studies in rodents with reduced nephron mass have suggested a strong positive correlation between dietary phosphate consumption and CKD progression. Prior work by our group demonstrated that dietary phosphate restriction can prevent tubular injury and microcyst formation in rodents with glomerulonephritis. Tubular injury and cystic dilation of tubules are key contributors to kidney function decline in polycystic kidney disease (PKD). Here, we determined whether dietary phosphate restriction slows renal cyst growth and fibrosis in a mouse model of PKD. Pcy/pcy mice received a normal phosphate (0.54%) or a phosphate-restricted (0.02%) diet (n = 10/group) from 7 to 20 wk of age. All of the other major dietary constituents, including protein source and content, were comparable between the two diets. At 20 wk, body weight, kidney weight-to-body weight ratio (KW/BW), cystic area, cyst number, and kidney fibrosis were quantified. Pcy/pcy mice fed a phosphate-restricted diet had lower serum phosphate, fibroblast growth factor 23, and parathyroid hormone levels, along with elevated serum calcium levels and increased kidney Klotho gene expression compared with mice that consumed the control diet. Dietary phosphate restriction resulted in a 25% lower KW/BW ratio and reduced the cyst number, cystic index, and gene expression for the tubular injury markers neutrophil gelatinase-associated lipocalin and interleukin-18. Mice fed the phosphate-restricted diet exhibited lower kidney expression for pathways involved in collagen deposition and myofibroblast activation (collagen type I-α1, phosphorylated SMAD3, and α-smooth muscle actin); however, histological differences in kidney fibrosis were not appreciated. Dietary phosphate restriction slows cystogenesis and inhibits the activation of key pathways in the generation of kidney fibrosis in PKD mice.


Subject(s)
Kidney/metabolism , Phosphates , Polycystic Kidney Diseases/diet therapy , Animals , Disease Models, Animal , Disease Progression , Female , Kidney/pathology , Kinesins/genetics , Kinesins/metabolism , Male , Mice , Mice, Knockout , Polycystic Kidney Diseases/metabolism , Polycystic Kidney Diseases/pathology
13.
Pediatr Res ; 88(4): 546-555, 2020 10.
Article in English | MEDLINE | ID: mdl-32053825

ABSTRACT

BACKGROUND: Exaggerated Toll-like receptor (TLR) signaling and intestinal dysbiosis are key contributors to necrotizing enterocolitis (NEC). Lactobacillus rhamnosus GG (LGG) decreases NEC in preterm infants, but underlying mechanisms of protection remain poorly understood. We hypothesized that LGG alleviates dysbiosis and upregulates TLR inhibitors to protect against TLR-mediated gut injury. METHODS: Effects of LGG (low- and high-dose) on intestinal pro-inflammatory TLR signaling and injury in neonatal mice subjected to formula feeding (FF) and NEC were determined. 16S sequencing of stool and expression of anti-TLR mediators SIGIRR (single immunoglobulin interleukin-1-related receptor) and A20 were analyzed. RESULTS: FF induced mild intestinal injury with increased expression of interleukin-1ß (IL-1ß) and Kupffer cell (KC) (mouse homolog of IL-8) compared to controls. LGG decreased IL-1ß and KC in association with attenuated TLR signaling and increased SIGIRR and A20 expression in a dose-dependent manner. Low- and high-dose LGG had varying effects on gut microbiome despite both doses providing gut protection. Subsequent experiments of LGG on NEC revealed that pro-inflammatory TLR signaling and intestinal injury were also decreased, and SIGIRR and A20 expression increased, in a dose-dependent manner with LGG pre-treatment. CONCLUSIONS: LGG protects against intestinal TLR-mediated injury by upregulating TLR inhibitors without major changes in gut microbiome composition.


Subject(s)
Enterocolitis, Necrotizing/metabolism , Intestines/injuries , Lacticaseibacillus rhamnosus/metabolism , Receptors, Interleukin-1/metabolism , Toll-Like Receptors/metabolism , Tumor Necrosis Factor alpha-Induced Protein 3/metabolism , Animals , Animals, Newborn , Apoptosis , Cytokines/metabolism , Dietary Supplements , Gastrointestinal Microbiome , Ileum/pathology , Infant Formula , Inflammation , Intestinal Mucosa/metabolism , Kupffer Cells/cytology , Mice , Mice, Inbred C57BL , Probiotics , RNA, Ribosomal, 16S/metabolism , Signal Transduction
14.
Mol Carcinog ; 58(8): 1400-1409, 2019 08.
Article in English | MEDLINE | ID: mdl-31020708

ABSTRACT

We previously reported that ionizing radiation (IR) mediates cell death through the induction of CUGBP elav-like family member 2 (CELF2), a tumor suppressor. CELF2 is an RNA binding protein that modulates mRNA stability and translation. Since IR induces autophagy, we hypothesized that CELF2 regulates autophagy-mediated colorectal cancer (CRC) cell death. For clinical relevance, we determined CELF2 levels in The Cancer Genome Atlas (TCGA). Role of CELF2 in radiation response was carried out in CRC cell lines by immunoblotting, immunofluorescence, autophagic vacuole analyses, RNA stability assay, quantitative polymerase chain reaction and electron microscopy. In vivo studies were performed in a xenograft tumor model. TCGA analyses demonstrated that compared to normal tissue, CELF2 is expressed at significantly lower levels in CRC, and is associated with better overall 5-year survival in patients receiving radiation. Mechanistically, CELF2 increased levels of critical components of the autophagy cascade including Beclin-1, ATG5, and ATG12 by modulating mRNA stability. CELF2 also increased autophagic flux in CRC. IR significantly induced autophagy in CRC which correlates with increased levels of CELF2 and autophagy associated proteins. Silencing CELF2 with siRNA, mitigated IR induced autophagy. Moreover, knockdown of CELF2 in vivo conferred tumor resistance to IR. These studies elucidate an unrecognized role for CELF2 in inducing autophagy and potentiating the effects of radiotherapy in CRC.


Subject(s)
Autophagy/physiology , CELF Proteins/metabolism , Cell Survival/radiation effects , Colorectal Neoplasms/pathology , Colorectal Neoplasms/radiotherapy , Nerve Tissue Proteins/metabolism , Animals , Autophagy-Related Protein 12/metabolism , Autophagy-Related Protein 5/metabolism , Beclin-1/metabolism , CELF Proteins/genetics , Cell Line, Tumor , Cell Survival/genetics , HCT116 Cells , Humans , Male , Mice , Neoplasm Transplantation , Nerve Tissue Proteins/genetics , Prognosis , RNA Interference , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Radiation, Ionizing , Transplantation, Heterologous
15.
Int J Mol Sci ; 20(5)2019 Mar 11.
Article in English | MEDLINE | ID: mdl-30862015

ABSTRACT

Secondary bile acids (BAs) and short chain fatty acids (SCFAs), two major types of bacterial metabolites in the colon, cause opposing effects on colonic inflammation at chronically high physiological levels. Primary BAs play critical roles in cholesterol metabolism, lipid digestion, and host⁻microbe interaction. Although BAs are reabsorbed via enterohepatic circulation, primary BAs serve as substrates for bacterial biotransformation to secondary BAs in the colon. High-fat diets increase secondary BAs, such as deoxycholic acid (DCA) and lithocholic acid (LCA), which are risk factors for colonic inflammation and cancer. In contrast, increased dietary fiber intake is associated with anti-inflammatory and anticancer effects. These effects may be due to the increased production of the SCFAs acetate, propionate, and butyrate during dietary fiber fermentation in the colon. Elucidation of the molecular events by which secondary BAs and SCFAs regulate colonic cell proliferation and inflammation will lead to a better understanding of the anticancer potential of dietary fiber in the context of high-fat diet-related colon cancer. This article reviews the current knowledge concerning the effects of secondary BAs and SCFAs on the proliferation of colon epithelial cells, inflammation, cancer, and the associated microbiome.


Subject(s)
Bile Acids and Salts/metabolism , Colon/metabolism , Fatty Acids, Volatile/metabolism , Lipid Metabolism , Animals , Butyrates/metabolism , Cell Proliferation , Colitis/etiology , Colitis/metabolism , Colitis/pathology , Colon/microbiology , Colonic Neoplasms/etiology , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Disease Susceptibility , Gastrointestinal Microbiome , Humans , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology
16.
J Food Sci Technol ; 56(4): 1757-1765, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30996411

ABSTRACT

This study examined the role of seed ageing in the control of anti-nutritional factors in cowpea (Vigna unguiculata L.). In differently aged seeds of three cultivars of V. unguiculata (V240, V78 and V585), germination ability and vigour were studied. Effort was also made to assay trypsin inhibitor, phenol and phytic acid, perform protein profiling in these seeds. High vigour lots (V240 and V585) registered maximum increases in germination of aged seeds. The contents of nutritional factors such as total protein and carbohydrate declined with decrease in seed vigour lots. Anti-nutritional factors such as phytic acid, phenolic content and trypsin inhibitor activity decreased and varied in low and high vigour seed lots. Polypeptide banding pattern significantly varied in the high, medium and low vigour seeds. Notably, proteins with the highest relative mobility of 0.98 and lowest molecular weight of 11.5 kDa and lowest relative mobility of 0.17 and highest molecular weight of 102.0 kDa were observed in all the vigour lots. Results implied the decline in vigour of V. unguiculata seeds under conditions of controlled ageing can be related to the decline in content of major nutritional factors (total carbohydrates and proteins) required for the growing embryo during seed germination. Additionally, decreases in the contents of anti-nutritional factors phytic acid and phenols, and the activity of trypsin inhibitor in particular are connected with the decrease in seed vigour irrespective of V. unguiculata cultivars. The use of short duration controlled ageing technique can, at least partially, reduce the negative effects of anti-nutritional factors, and eventually improve the nutritional quality of V. unguiculata seeds.

17.
Pediatr Res ; 83(1-1): 164-174, 2018 01.
Article in English | MEDLINE | ID: mdl-28846670

ABSTRACT

BackgroundThe mechanisms underlying aberrant activation of intestinal Toll-like receptor 4 (TLR4) signaling in necrotizing enterocolitis (NEC) remain unclear. In this study, we examined the role of single-immunoglobulin interleukin-1 receptor-related molecule (SIGIRR), an inhibitor of TLR signaling, in modulating experimental NEC vulnerability in mice.MethodsExperimental NEC was induced in neonatal wild-type and SIGIRR-/- mice using hypoxia, formula-feeding, and lipopolysaccharide administration. Intestinal TLR canonical signaling, inflammation, apoptosis, and severity of experimental NEC were examined at baseline and after NEC induction in mice.ResultsSIGIRR is developmentally regulated in the neonatal intestine with a restricted expression after birth and a gradual increase by day 8. At baseline, breast-fed SIGIRR-/- mouse pups exhibited low-grade inflammation and TLR pathway activation compared with SIGIRR+/+ pups. With experimental NEC, SIGIRR-/- mice had significantly more intestinal interleukin (IL)-1ß, KC (mouse homolog to IL-8), intercellular adhesion molecule-1 (ICAM-1), and interferon-beta (IFN-ß) expression in association with the amplified TLR pathway activation. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining, cleaved caspase 3, and severity of intestinal injury with NEC were worse in SIGIRR-/- mice in comparison with SIGIRR+/+ mice.ConclusionSIGIRR is a negative regulator of TLR4 signaling in the developing intestine, and its insufficiency results in native intestinal TLR hyper-responsiveness conducive to the development of severe experimental NEC in mice.


Subject(s)
Enterocolitis, Necrotizing/metabolism , Receptors, Interleukin-1/metabolism , Toll-Like Receptor 4/metabolism , Animals , Animals, Newborn , Apoptosis , Cytokines/metabolism , Disease Models, Animal , Hypoxia , Immunity, Innate , Inflammation , Lipopolysaccharides , Mice , Mice, Inbred C57BL , Mice, Transgenic , Mutation , Phosphorylation , Signal Transduction
18.
Carcinogenesis ; 37(4): 385-96, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26785732

ABSTRACT

Phytochemicals modulate key cellular signaling pathways and have proven anticancer effects. Alcea rosea(AR; Hollyhock) is an ornamental plant with known anti-inflammatory properties. This study explored its role as an anticancer agent. The AR seed extract (AR extract) inhibited proliferation and colony formation in a dose- and time-dependent manner and promoted apoptosis as was evidenced by cleavage of PARP and increased expression of Bax accompanying reduced levels of BCL-xl protein in HCT116 and SW480 cells, respectively. In addition, AR extract-arrested cells at Go/G1 phase of cell cycle and exhibited decreases in Cyclin D1. AR extract-treated cells exhibited reduced number and size of colonospheres in a dose-dependent manner concomitant with decreases in cancer stem cell (CSC) markers ALDH1A1 and Dclk1. Relative levels of ß-catenin, Notch-ICD, Hes1 and EZH2 were also attenuated by AR extract. TOP-flash reporter activity, a measure of Wnt signaling, decreased significantly in response to treatment while overexpression of wild type but not mutant EZH2, reversed the inhibitory effects. Moreover, WIF1 (a Wnt antagonist) promoter activity increased dramatically following treatment with AR extract which phenocopied increases in WIF1 reporter activity following EZH2 knockdown.In vivo, AR extract attenuated tumor growth due probably to reduced levels of EZH2, ß-catenin, CyclinD1 and Ki-67 along with reduced levels of CSC markers. Since partial purification via HPLC yielded a prominent peak, efforts are underway to identify the active ingredient(s). Taken together, the results clearly suggest that AR extract/active component(s) can be an effective preventative/therapeutic agent to target colon cancer.


Subject(s)
Colonic Neoplasms/pathology , Epigenesis, Genetic , Neoplastic Stem Cells/pathology , Plants , Signal Transduction , Humans
19.
Mol Carcinog ; 55(11): 1503-1516, 2016 Nov.
Article in English | MEDLINE | ID: mdl-26331352

ABSTRACT

Colorectal cancer (CRC) is the second leading cause of cancer deaths in the United States. It arises from loss of intestinal epithelial homeostasis and hyperproliferation of the crypt epithelium. In order to further understand the pathogenesis of CRC it is important to further understand the factors regulating intestinal epithelial proliferation and more specifically, regulation of the intestinal epithelial stem cell compartment. Here, we investigated the role of the RNA binding protein RBM3 in stem cell homeostasis in colorectal cancers. Using a doxycycline (Dox) inducible RBM3 overexpressing cell lines HCT 116 and DLD-1, we measured changes in side population (SP) cells that have high xenobiotic efflux capacity and increased capacity for self-renewal. In both cell lines, RBM3 induction showed significant increases in the percentage of side population cells. Additionally, we observed increases in spheroid formation and in cells expressing DCLK1, LGR5 and CD44Hi . As the Wnt/ß-catenin signaling pathway is important for both physiologic and cancer stem cells, we next investigated the effects of RBM3 overexpression on ß-catenin activity. RBM3 overexpression increased levels of nuclear ß-catenin as well as TCF/LEF transcriptional activity. In addition, there was inactivation of GSK3ß leading to decreased ß-catenin phosphorylation. Pharmacologic inhibition of GSK3ß using (2'Z,3'E)-6-Bromoindirubin-3'-oxime (BIO) also recapitulates the RBM3 induced ß-catenin activity. In conclusion, we see that RNA binding protein RBM3 induces stemness in colorectal cancer cells through a mechanism involving suppression of GSK3ß activity thereby enhancing ß-catenin signaling. © 2015 Wiley Periodicals, Inc.


Subject(s)
Colorectal Neoplasms/pathology , Neoplastic Stem Cells/cytology , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , beta Catenin/metabolism , Cell Line, Tumor , Cell Proliferation , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Doxycycline/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Glycogen Synthase Kinase 3 beta/metabolism , HCT116 Cells , Humans , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Phosphorylation , Wnt Proteins/metabolism , Wnt Signaling Pathway
20.
Lab Invest ; 95(11): 1222-33, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26280221

ABSTRACT

In recent years, increasing threats of radiation exposure and nuclear disasters have become a significant concern for the United States and countries worldwide. Exposure to high doses of radiation triggers a number of potentially lethal effects. Among the most severe is the gastrointestinal (GI) toxicity syndrome caused by the destruction of the intestinal barrier, resulting in bacterial translocation, systemic bacteremia, sepsis, and death. The lack of effective radioprotective agents capable of mitigating radiation-induced damage has prompted a search for novel countermeasures that can mitigate the effects of radiation post exposure, accelerate tissue repair in radiation-exposed individuals, and prevent mortality. We report that a single injection of regenerative peptide TP508 (rusalatide acetate, Chrysalin) 24 h after lethal radiation exposure (9 Gy, LD100/15) appears to significantly increase survival and delay mortality by mitigating radiation-induced intestinal and colonic toxicity. TP508 treatment post exposure prevents the disintegration of GI crypts, stimulates the expression of adherens junction protein E-cadherin, activates crypt cell proliferation, and decreases apoptosis. TP508 post-exposure treatment also upregulates the expression of DCLK1 and LGR5 markers of stem cells that have been shown to be responsible for maintaining and regenerating intestinal crypts. Thus, TP508 appears to mitigate the effects of GI toxicity by activating radioresistant stem cells and increasing the stemness potential of crypts to maintain and restore intestinal integrity. These results suggest that TP508 may be an effective emergency nuclear countermeasure that could be delivered within 24 h post exposure to increase survival and delay mortality, giving victims time to reach clinical sites for advanced medical treatment.


Subject(s)
Gastrointestinal Tract/radiation effects , Peptide Fragments/pharmacology , Stem Cells/drug effects , Thrombin/pharmacology , Adherens Junctions/drug effects , Adherens Junctions/metabolism , Animals , Cell Proliferation/drug effects , Gastrointestinal Tract/pathology , Male , Mice , Mice, Inbred ICR , Stem Cells/cytology , Survival Analysis
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