1
|
Singh RD, Wager JL, Scheidl TB, Connors LT, Easson S, Callaghan MA, Alatorre-Hinojosa S, Swift LH, Colarusso P, Jadli A, Shutt TE, Patel V, Thompson JA. Potentiation of Adipogenesis by Reactive Oxygen Species Is a Unifying Mechanism in the Proadipogenic Properties of Bisphenol A and Its New Structural Analogues. Antioxid Redox Signal 2024; 40:1-15. [PMID: 37154733 DOI: 10.1089/ars.2022.0150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Aims: Structural analogues of bisphenol A (BPA), including bisphenol S (BPS) and bisphenol F (BPF), are emerging environmental toxicants as their presence in the environment is rising since new regulatory restrictions were placed on BPA-containing infant products. The adipogenesis-enhancing effect of bisphenols may explain the link between human exposure and metabolic disease; however, underlying molecular pathways remain unresolved. Results: Exposure to BPS, BPF, BPA, or reactive oxygen species (ROS) generators enhanced lipid droplet formation and expression of adipogenic markers after induction of differentiation in adipose-derived progenitors isolated from mice. RNAseq analysis in BPS-exposed progenitors revealed modulation in pathways regulating adipogenesis and responses to oxidative stress. ROS were higher in bisphenol-exposed cells, while cotreatment with antioxidants attenuated adipogenesis and abolished the effect of BPS. There was a loss of mitochondrial membrane potential in BPS-exposed cells and mitochondria-derived ROS contributed to the potentiation of adipogenesis by BPS and its analogues. Male mice exposed to BPS during gestation had higher whole-body adiposity, as measured by time domain nuclear magnetic resonance, while postnatal exposure had no impact on adiposity in either sex. Innovation: These findings support existing evidence showing a role for ROS in regulating adipocyte differentiation and are the first to highlight ROS as a unifying mechanism that explains the proadipogenic properties of BPA and its structural analogues. Conclusion: ROS act as signaling molecules in the regulation of adipocyte differentiation and mediate bisphenol-induced potentiation of adipogenesis. Antioxid. Redox Signal. 40, 1-15.
Collapse
Affiliation(s)
- Radha D Singh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| | - Jessica L Wager
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| | - Taylor B Scheidl
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| | - Liam T Connors
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| | - Sarah Easson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| | - Mikyla A Callaghan
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| | | | - Lucy H Swift
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Canada
| | - Pina Colarusso
- Cumming School of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Canada
| | - Anshul Jadli
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
| | - Timothy E Shutt
- Cumming School of Medicine, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
- Department of Medical Genetics and University of Calgary, Calgary, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
| | - Vaibhav Patel
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
| | - Jennifer A Thompson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada
| |
Collapse
|
2
|
Connors LT, Zhu HL, Gill M, Walsh E, Singh RD, Easson S, Ahmed SB, Habibi HR, Cole WC, Thompson JA. Prenatal exposure to a low dose of BPS causes sex-dependent alterations to vascular endothelial function in adult offspring. Front Toxicol 2022; 4:933572. [PMID: 36310694 PMCID: PMC9606655 DOI: 10.3389/ftox.2022.933572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 09/28/2022] [Indexed: 11/07/2022] Open
Abstract
Background: Bisphenol S (BPS) is among the most commonly used substitutes for Bisphenol A (BPA), an endocrine disrupting chemical used as a plasticizer in the manufacture of polycarbonate plastics and epoxy resins. Bisphenols interfere with estrogen receptor (ER) signaling, which modulates vascular function through stimulation of nitric oxide (NO) production via endothelial nitric oxide synthase (eNOS). BPS can cross into the placenta and accumulates in the fetal compartment to a greater extent than BPA, potentially interfering with key developmental events. Little is known regarding the developmental impact of exposure to BPA substitutes, particularly with respect to the vasculature. Objective: To determine if prenatal BPS exposure influences vascular health in adulthood. Methods: At the time of mating, female C57BL/6 dams were administered BPS (250 nM) or vehicle control in the drinking water, and exposure continued during lactation. At 12-week of age, mesenteric arteries were excised from male and female offspring and assessed for responses to an endothelium-dependent (acetylcholine, ACh) and endothelium-independent (sodium nitroprusside, SNP) vasodilator. Endothelium-dependent dilation was measured in the presence or absence of L-NAME, an eNOS inhibitor. To further explore the role of NO and ER signaling, wire myography was used to assess ACh responses in aortic rings after acute exposure to BPS in the presence or absence of L-NAME or an ER antagonist. Results: Increased ACh dilation and increased sensitivity to Phe were observed in microvessels from BPS-exposed females, while no changes were observed in male offspring. Differences in ACh-induced dilation between control or BPS-exposed females were eliminated with L-NAME. Increased dilatory responses to ACh after acute BPS exposure were observed in aortic rings from female mice only, and differences were eliminated with inhibition of eNOS or inhibition of ER. Conclusion: Prenatal BPS exposure leads to persistent changes in endothelium-dependent vascular function in a sex-specific manner that appears to be modulated by interaction of BPS with ER signaling.
Collapse
Affiliation(s)
- Liam T. Connors
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Hai-Lei Zhu
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Manvir Gill
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada
| | - Emma Walsh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Radha D. Singh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada,Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Sarah Easson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Sofia B. Ahmed
- Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Hamid R. Habibi
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - William C. Cole
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Jennifer A. Thompson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada,Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada,Cumming School of Medicine, University of Calgary, Calgary, AB, Canada,*Correspondence: Jennifer A. Thompson,
| |
Collapse
|
3
|
Mikolajczak A, Sallam NA, Singh RD, Scheidl TB, Walsh EJ, Larion S, Huang C, Thompson JA. Accelerated developmental adipogenesis programs adipose tissue dysfunction and cardiometabolic risk in offspring born to dams with metabolic dysfunction. Am J Physiol Endocrinol Metab 2021; 321:E581-E591. [PMID: 34459218 PMCID: PMC8791794 DOI: 10.1152/ajpendo.00229.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
This study determined if a perturbation in in utero adipogenesis leading to later life adipose tissue (AT) dysfunction underlies programming of cardiometabolic risk in offspring born to dams with metabolic dysfunction. Female mice heterozygous for the leptin receptor deficiency (Hetdb) had 2.4-fold higher prepregnancy fat mass and in late gestation had higher plasma insulin and triglycerides compared with wild-type (Wt) females (P < 0.05). To isolate the role of the intrauterine milieu, wild-type (Wt) offspring from each pregnancy were studied. Differentiation potential in isolated progenitors and cell size distribution analysis revealed accelerated adipogenesis in Wt pups born to Hetdb dams, accompanied by a higher accumulation of neonatal fat mass. In adulthood, whole body fat mass by NMR was higher in male (69%) and female (20%) Wt offspring born to Hetdb versus Wt pregnancies, along with adipocyte hypertrophy and hyperlipidemia (all P < 0.05). Lipidomic analyses by gas chromatography revealed an increased lipogenic index (16:0/18:2n6) after high-fat/fructose diet (HFFD). Postprandial insulin, ADIPO-IR, and ex vivo AT lipolytic responses to isoproterenol were all higher in Wt offspring born to Hetdb dams (P < 0.05). Intrauterine metabolic stimuli may direct a greater proportion of progenitors toward terminal differentiation, thereby predisposing to hypertrophy-induced adipocyte dysfunction.NEW & NOTEWORTHY This study reveals that accelerated adipogenesis during the perinatal window of adipose tissue development predisposes to later life hypertrophic adipocyte dysfunction, thereby compromising the buffering function of the subcutaneous depot.
Collapse
Affiliation(s)
- Anna Mikolajczak
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Nada A Sallam
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Faculty of Pharmacy, Cairo University, Giza, Egypt
| | - Radha D Singh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Libin Cardiovascular Institute, Calgary, Alberta, Canada
| | - Taylor B Scheidl
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Libin Cardiovascular Institute, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Emma J Walsh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sebastian Larion
- Division of Gastroenterology and Hepatology, Medical University of South Carolina, Charleston, South Carolina
| | - Carol Huang
- Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Jennifer A Thompson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Libin Cardiovascular Institute, Calgary, Alberta, Canada
- Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| |
Collapse
|
4
|
Callaghan MA, Alatorre-Hinojosa S, Connors LT, Singh RD, Thompson JA. Plasticizers and Cardiovascular Health: Role of Adipose Tissue Dysfunction. Front Pharmacol 2021; 11:626448. [PMID: 33716730 PMCID: PMC7947604 DOI: 10.3389/fphar.2020.626448] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 12/22/2020] [Indexed: 12/12/2022] Open
Abstract
Since the 1950s, the production of plastics has increased 200-fold, reaching 360 million tonnes in 2019. Plasticizers, additives that modify the flexibility and rigidity of the product, are ingested as they migrate into food and beverages. Human exposure is continuous and widespread; between 75 and 97% of urine samples contain detectable levels of bisphenols and phthalates, the most common plasticizers. Concern over the toxicity of plasticizers arose in the late 1990s, largely focused around adverse developmental and reproductive effects. More recently, many studies have demonstrated that exposure to plasticizers increases the risk for obesity, type 2 diabetes, and cardiovascular disease (CVD). In the 2000s, many governments including Canada, the United States and European countries restricted the use of certain plasticizers in products targeted towards infants and children. Resultant consumer pressure motivated manufacturers to substitute plasticizers with analogues, which have been marketed as safe. However, data on the effects of these new substitutes are limited and data available to-date suggest that many exhibit similar properties to the chemicals they replaced. The adverse effects of plasticizers have largely been attributed to their endocrine disrupting properties, which modulate hormone signaling. Adipose tissue has been well-documented to be a target of the disrupting effects of both bisphenols and phthalates. Since adipose tissue function is a key determinant of cardiovascular health, adverse effects of plasticizers on adipocyte signaling and function may underlie their link to cardiovascular disease. Herein, we discuss the current evidence linking bisphenols and phthalates to obesity and CVD and consider how documented impacts of these plasticizers on adipocyte function may contribute to the development of CVD.
Collapse
Affiliation(s)
- Mikyla A Callaghan
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.,Libin Cardiovascular Institute, Calgary, AB, Canada
| | | | - Liam T Connors
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.,Libin Cardiovascular Institute, Calgary, AB, Canada
| | - Radha D Singh
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.,Libin Cardiovascular Institute, Calgary, AB, Canada
| | - Jennifer A Thompson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada.,Libin Cardiovascular Institute, Calgary, AB, Canada.,Alberta Children's Health Research Institute, Calgary, AB, Canada
| |
Collapse
|
5
|
Singh RD, Shandilya R, Bhargava A, Kumar R, Tiwari R, Chaudhury K, Srivastava RK, Goryacheva IY, Mishra PK. Quantum Dot Based Nano-Biosensors for Detection of Circulating Cell Free miRNAs in Lung Carcinogenesis: From Biology to Clinical Translation. Front Genet 2018; 9:616. [PMID: 30574163 PMCID: PMC6291444 DOI: 10.3389/fgene.2018.00616] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 11/23/2018] [Indexed: 12/24/2022] Open
Abstract
Lung cancer is the most frequently occurring malignancy and the leading cause of cancer-related death for men in our country. The only recommended screening method is clinic based low-dose computed tomography (also called a low-dose CT scan, or LDCT). However, the effect of LDCT on overall mortality observed in lung cancer patients is not statistically significant. Over-diagnosis, excessive cost, risks associated with radiation exposure, false positive results and delay in the commencement of the treatment procedure questions the use of LDCT as a reliable technique for population-based screening. Therefore, identification of minimal-invasive biomarkers able to detect malignancies at an early stage might be useful to reduce the disease burden. Circulating nucleic acids are emerging as important source of information for several chronic pathologies including lung cancer. Of these, circulating cell free miRNAs are reported to be closely associated with the clinical outcome of lung cancer patients. Smaller size, sequence homology between species, low concentration and stability are some of the major challenges involved in characterization and specific detection of miRNAs. To circumvent these problems, synthesis of a quantum dot based nano-biosensor might assist in sensitive, specific and cost-effective detection of differentially regulated miRNAs. The wide excitation and narrow emission spectra of these nanoparticles result in excellent fluorescent quantum yields with a broader color spectrum which make them ideal bio-entities for fluorescence resonance energy transfer (FRET) based detection for sequential or simultaneous study of multiple targets. In addition, photo-resistance and higher stability of these nanoparticles allows extensive exposure and offer state-of-the art sensitivity for miRNA targeting. A major obstacle for integrating QDs into clinical application is the QD-associated toxicity. However, the use of non-toxic shells along with surface modification not only overcomes the toxicity issues, but also increases the ability of QDs to quickly detect circulating cell free miRNAs in a non-invasive mode. The present review illustrates the importance of circulating miRNAs in lung cancer diagnosis and highlights the translational prospects of developing QD-based nano-biosensor for rapid early disease detection.
Collapse
Affiliation(s)
- Radha D. Singh
- Department of Molecular Biology, ICMR-National Institute for Research in Environmental Health, Bhopal, India
| | - Ruchita Shandilya
- Department of Molecular Biology, ICMR-National Institute for Research in Environmental Health, Bhopal, India
| | - Arpit Bhargava
- Department of Molecular Biology, ICMR-National Institute for Research in Environmental Health, Bhopal, India
| | - Rajat Kumar
- Department of Molecular Biology, ICMR-National Institute for Research in Environmental Health, Bhopal, India
| | - Rajnarayan Tiwari
- Department of Molecular Biology, ICMR-National Institute for Research in Environmental Health, Bhopal, India
| | - Koel Chaudhury
- School of Medical Science and Technology, Indian Institute of Technology, Kharagpur, India
| | - Rupesh K. Srivastava
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, India
| | - Irina Y. Goryacheva
- Department of General and Inorganic Chemistry, Saratov State University, Saratov, Russia
| | - Pradyumna K. Mishra
- Department of Molecular Biology, ICMR-National Institute for Research in Environmental Health, Bhopal, India
| |
Collapse
|
6
|
Sallam NA, Palmgren VAC, Singh RD, John CM, Thompson JA. Programming of Vascular Dysfunction in the Intrauterine Milieu of Diabetic Pregnancies. Int J Mol Sci 2018; 19:E3665. [PMID: 30463313 PMCID: PMC6275067 DOI: 10.3390/ijms19113665] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 11/14/2018] [Accepted: 11/16/2018] [Indexed: 02/07/2023] Open
Abstract
With the rising global tide of obesity, gestational diabetes mellitus (GDM) burgeoned into one of the most common antenatal disorders worldwide. Macrosomic babies born to diabetic mothers are more likely to develop risk factors for cardiovascular disease (CVD) before they reach adulthood. Rodent studies in offspring born to hyperglycemic pregnancies show vascular dysfunction characterized by impaired nitric oxide (NO)-mediated vasodilation and increased production of contractile prostanoids by cyclooxygenase 2 (COX-2). Vascular dysfunction is a key pathogenic event in the progression of diabetes-related vascular disease, primarily attributable to glucotoxicity. Therefore, glucose-induced vascular injury may stem directly from the hyperglycemic intrauterine environment of GDM pregnancy, as evinced by studies showing endothelial activation and inflammation at birth or in childhood in offspring born to GDM mothers. This review discusses potential mechanisms by which intrauterine hyperglycemia programs dysfunction in the developing vasculature.
Collapse
Affiliation(s)
- Nada A Sallam
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4N1, Canada.
- Children's Hospital Research Institute; University of Calgary, Calgary, AB T2N 4N1, Canada.
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt.
| | - Victoria A C Palmgren
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4N1, Canada.
| | - Radha D Singh
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4N1, Canada.
- Children's Hospital Research Institute; University of Calgary, Calgary, AB T2N 4N1, Canada.
| | - Cini M John
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4N1, Canada.
| | - Jennifer A Thompson
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4N1, Canada.
- Children's Hospital Research Institute; University of Calgary, Calgary, AB T2N 4N1, Canada.
| |
Collapse
|
7
|
Singh RD, Banerjee J, Sasmal S, Muir J, Arora A. High xylan recovery using two stage alkali pre-treatment process from high lignin biomass and its valorisation to xylooligosaccharides of low degree of polymerisation. Bioresour Technol 2018; 256:110-117. [PMID: 29433045 DOI: 10.1016/j.biortech.2018.02.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 01/30/2018] [Accepted: 02/01/2018] [Indexed: 05/11/2023]
Abstract
In the present work, xylan from arecanut husk was extracted using 2 stage alkaline pretreatment process. In first step, biomass was incubated in alkali at different temperatures (25 °C, 50 °C and 65 °C), alkali concentrations (5%, 10%, 15% and 20% w/v), and incubation periods (8 h, 16 h and 24 h) and evaluated for xylan recovery. It was observed that 40-52% of available xylan could be recovered using 10% alkali when incubated for 8-24 h at 65 °C. Subsequently, the alkali pretreatment operating conditions which provided good xylan recovery were processed further using hydrothermal treatment to extract more xylan. For maximum xylan recovery (>90%), best operating conditions were identified when biomass was treated under hydrothermal treatment (1, 1.5 and 2 h) with varying incubation periods (8, 16, 24 h) and alkali concentrations (5%, 10%) using full factorial design. Incubating arecanut husk with 10% w/v NaOH, at 65 °C for a period of 8 h, followed by hydrothermal treatment at 121 °C for 1 h helped recover >94% xylan. In the next step, enzymatic hydrolysis process was optimized to recover maximum XOS (Optimized condition: 50 °C, pH 4 and 10 U enzyme dose). The hydrolysate comprised of xylobiose: 25.0 ± 1.2 g/100 g xylan (∼71% of XOS), xylotriose: 9.2 ± 0.65 g/100 g xylan (26.2% of XOS) and xylotetrose: 0.9 ± 0.04 g/100 g xylan (2% of XOS). The developed process enables to reduce alkali consumption for high recovery of xylan from biomass with relatively higher lignin content for its valorisation into a potential prebiotic oligosaccharide.
Collapse
Affiliation(s)
- R D Singh
- Indian Institute of Technology Bombay-Monash Research Academy, Indian Institute of Technology, Bombay, India; Bio-Processing Laboratory, Centre for Technology Alternatives for Rural Areas, Indian Institute of Technology, Bombay, India
| | - J Banerjee
- Indian Institute of Technology Bombay-Monash Research Academy, Indian Institute of Technology, Bombay, India; Bio-Processing Laboratory, Centre for Technology Alternatives for Rural Areas, Indian Institute of Technology, Bombay, India
| | - S Sasmal
- Bio-Processing Laboratory, Centre for Technology Alternatives for Rural Areas, Indian Institute of Technology, Bombay, India
| | - J Muir
- Department of Gastroenterology, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - A Arora
- Indian Institute of Technology Bombay-Monash Research Academy, Indian Institute of Technology, Bombay, India; Bio-Processing Laboratory, Centre for Technology Alternatives for Rural Areas, Indian Institute of Technology, Bombay, India.
| |
Collapse
|
8
|
Patel KR, Vajaria BN, Singh RD, Begum R, Patel PS. Clinical implications of p53 alterations in oral cancer progression: a review from India. Exp Oncol 2018; 40:10-18. [PMID: 29600984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
p53 plays a central role in prevention of normal cell from the development of the malignant phenotype. Somatic alterations (mutations, loss of heterozygosity, deletions) in p53 are a hallmark of most human cancers and cause defects in normal p53 function. However, in the tumors harboring wild-type p53, there are alterations in the regulation of the p53. Thus, understanding why p53 is unable to perform its role as a tumor suppressor in these wild-type tumors is very crucial. Germ-line polymorphisms in p53 are also anticipated to cause measurable disturbance in p53 function. Over-expression as well as polymorphic variants of MDM2 might have effects on cancer development. In addition, degradation of p53 by E6 protein of high risk human papillomavirus is also suggested as one of the mechanisms which attenuate p53 responses in oral carcinogenesis. p53 has also been demonstrated to mediate cellular responses upon various DNA damaging cancer therapies, importantly, apoptosis. These responses have been implicated in an individual's ability to respond to these cancer therapies. Thus, exploring mechanisms by which normal function of p53 is affected in the comprehensive way in oral cancer might aid in the identification of tumor characteristics, prognosis and thus in the development of a new approach to treat the oral cancer.
Collapse
Affiliation(s)
- K R Patel
- Biochemistry Research Division, Gujarat Cancer & Research Institute, Asarwa, Ahmedabad 380016, Gujarat, India
| | - B N Vajaria
- Biochemistry Research Division, Gujarat Cancer & Research Institute, Asarwa, Ahmedabad 380016, Gujarat, India
| | - R D Singh
- Biochemistry Research Division, Gujarat Cancer & Research Institute, Asarwa, Ahmedabad 380016, Gujarat, India
| | - R Begum
- Department of Biochemistry, M.S. University of Baroda, Vadodara 390002, Gujarat, India
| | - P S Patel
- Biochemistry Research Division, Gujarat Cancer & Research Institute, Asarwa, Ahmedabad 380016, Gujarat, India
| |
Collapse
|
9
|
Jaryan V, Uniyal SK, Gupta RC, Singh RD. Phenological documentation of an invasive species, Sapium sebiferum (L.) Roxb. Environ Monit Assess 2014; 186:4423-4429. [PMID: 24633786 DOI: 10.1007/s10661-014-3708-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 03/05/2014] [Indexed: 06/03/2023]
Abstract
Phenological documentation and plant invasion are key contemporary issues in the biological sciences. Recognizing this, the present paper describes the phenological stages of an invasive species, Sapium sebiferum (L.) Roxb. A tree of the species was marked, and daily visits were made for recording its phenology. The Biologische Bundesanstalt, Bundessortenamt and CHemical industry (BBCH) scale was used for documenting the same. Of the total ten principal stages, eight were observed in the species. These stages started with bud development (stage 01) in the month of March and ended with leaf fall (stage 97) in the month of December. Descriptions of the phenological stages and their dates are provided in the text. It is hoped that such a phenological scale will be helpful in managing plant invasion.
Collapse
Affiliation(s)
- Vikrant Jaryan
- Biodiversity Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, 176061, India
| | | | | | | |
Collapse
|
10
|
Qaiser D, Khan MS, Singh RD, Khan ZH. Time resolved spectroscopy and gain studies of Fullerenes C60 and C70. Spectrochim Acta A Mol Biomol Spectrosc 2013; 113:400-407. [PMID: 23747380 DOI: 10.1016/j.saa.2013.04.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 04/13/2013] [Accepted: 04/24/2013] [Indexed: 06/02/2023]
Abstract
The fluorescence decay time of Fullerenes C60 and C70 in pure form as well as in mixture with Coumarin C440 and Quinizarine dyes are studied. Results indicate that the decay of pure fullerenes is constant throughout the solute concentration and it is also independent of excitation wavelength, whereas in the case of mixture with dyes different behavior is noticed. We have also calculated the Stern-Volmer quenching constant and optical gain of both the fullerenes from which it is found that the optical gain is positive for Fullerene C70 only in a very narrow range of concentration.
Collapse
Affiliation(s)
- Darakhshan Qaiser
- Department of Physics, Jamia Millia Islamia, New Delhi 110 025, India.
| | | | | | | |
Collapse
|
11
|
Rashmikant US, Chand P, Singh SV, Singh RD, Arya D, Kant S, Agarwal SP. Cephalometric evaluation of mandibular advancement at different horizontal jaw positions in obstructive sleep apnoea patients: a pilot study. Aust Dent J 2013; 58:293-300. [PMID: 23981209 DOI: 10.1111/adj.12079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 09/21/2012] [Accepted: 10/24/2012] [Indexed: 12/01/2022]
Abstract
BACKGROUND The aim of this study was to comparatively evaluate the efficacy of the mandibular advancement device (MAD) at 50% (P2) and 75% (P3) of maximum mandibular advancement, relative to maximum intercuspation (P1) subjectively and objectively. METHODS Eighteen subjects previously diagnosed with obstructive sleep apnoea (OSA) were selected for the study. ESS score, VAS score, soft palate angle, MP-H distance, S-H distance, a C4 -H distance, a Pu -p Pu distance and total pharyngeal area were calculated at P1, P2 and P3 positions with the help of an adjustable MAD. The results were statistically analysed. RESULTS ESS score, VAS score, soft palate angle, MP-H distance, S-H distance and radius of curvature of airway at P2 and P3 were significantly lower compared to P1, but there was no significant difference between P2 and P3. CONCLUSIONS The MAD produced significant improvement in objective signs and subjective symptoms at both 50% and 75% of the maximum mandibular protrusion positions at comparable comfort levels. Therefore, MAD may be given at 50% of maximum advancement in order to reduce dental or temporomandibular joint disturbances.
Collapse
Affiliation(s)
- U S Rashmikant
- Department of Prosthodontics, Faculty of Dental Sciences, Chhatrapati Shahuji Maharaj Medical University (UP), Lucknow, Uttar Pradesh, India
| | | | | | | | | | | | | |
Collapse
|
12
|
Singh RD, Haridas N, Shah FD, Patel JB, Shukla SN, Patel PS. Gene polymorphisms, tobacco exposure and oral cancer susceptibility: a study from Gujarat, West India. Oral Dis 2013; 20:84-93. [DOI: 10.1111/odi.12079] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 01/08/2013] [Accepted: 01/12/2013] [Indexed: 12/23/2022]
Affiliation(s)
- RD Singh
- Biochemistry Research Division; The Gujarat Cancer and Research Institute; Ahmedabad Gujarat India
| | - N Haridas
- Pramukhswami Medical College; Karamsad Gujarat India
| | - FD Shah
- Biochemistry Research Division; The Gujarat Cancer and Research Institute; Ahmedabad Gujarat India
| | - JB Patel
- Biochemistry Research Division; The Gujarat Cancer and Research Institute; Ahmedabad Gujarat India
| | - SN Shukla
- The Gujarat Cancer and Research Institute; Ahmedabad Gujarat India
| | - PS Patel
- Biochemistry Research Division; The Gujarat Cancer and Research Institute; Ahmedabad Gujarat India
| |
Collapse
|
13
|
Eisenman ST, Gibbons SJ, Singh RD, Bernard CE, Wu J, Sarr MG, Kendrick ML, Larson DW, Dozois EJ, Shen KR, Farrugia G. Distribution of TMEM100 in the mouse and human gastrointestinal tract--a novel marker of enteric nerves. Neuroscience 2013; 240:117-28. [PMID: 23485812 DOI: 10.1016/j.neuroscience.2013.02.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 01/30/2013] [Accepted: 02/14/2013] [Indexed: 02/02/2023]
Abstract
Identification of markers of enteric neurons has contributed substantially to our understanding of the development, normal physiology, and pathology of the gut. Previously identified markers of the enteric nervous system can be used to label all or most neuronal structures or for examining individual cells by labeling just the nucleus or cell body. Most of these markers are excellent but have some limitations. Transmembrane protein 100 (TMEM100) is a gene at locus 17q32 encoding a 134-amino acid protein with two hypothetical transmembrane domains. TMEM100 expression has not been reported in adult mammalian tissues but does appear in the ventral neural tube of embryonic mice and plays a role in signaling pathways associated with development of the enteric nervous system. We showed that TMEM100 messenger RNA is expressed in the gastrointestinal tract and demonstrated that TMEM100 is a membrane-associated protein. Furthermore TMEM100 immunoreactivity was restricted to enteric neurons and vascular tissue in the muscularis propria of all regions of the mouse and human gastrointestinal tract. TMEM100 immunoreactivity colocalized with labeling for the pan-neuronal marker protein gene product 9.5 (PGP9.5) but not with the glial marker S100ß or Kit, a marker of interstitial cells of Cajal. The signaling molecule, bone morphogenetic protein (BMP) 4, was also expressed in enteric neurons of the human colon and co-localized with TMEM100. TMEM100 is also expressed in neuronal cell bodies and fibers in the mouse brain and dorsal root ganglia. We conclude that TMEM100 is a novel, membrane-associated marker for enteric nerves and is as effective as PGP9.5 for identifying neuronal structures in the gastrointestinal tract. The expression of TMEM100 in the enteric nervous system may reflect a role in the development and differentiation of cells through a transforming growth factor β, BMP or related signaling pathway.
Collapse
Affiliation(s)
- S T Eisenman
- Enteric Neuroscience Program, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Senthil Kumar AR, Goyal MK, Ojha CSP, Singh RD, Swamee PK. Application of artificial neural network, fuzzy logic and decision tree algorithms for modelling of streamflow at Kasol in India. Water Sci Technol 2013; 68:2521-2526. [PMID: 24355836 DOI: 10.2166/wst.2013.491] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The prediction of streamflow is required in many activities associated with the planning and operation of the components of a water resources system. Soft computing techniques have proven to be an efficient alternative to traditional methods for modelling qualitative and quantitative water resource variables such as streamflow, etc. The focus of this paper is to present the development of models using multiple linear regression (MLR), artificial neural network (ANN), fuzzy logic and decision tree algorithms such as M5 and REPTree for predicting the streamflow at Kasol located at the upstream of Bhakra reservoir in Sutlej basin in northern India. The input vector to the various models using different algorithms was derived considering statistical properties such as auto-correlation function, partial auto-correlation and cross-correlation function of the time series. It was found that REPtree model performed well compared to other soft computing techniques such as MLR, ANN, fuzzy logic, and M5P investigated in this study and the results of the REPTree model indicate that the entire range of streamflow values were simulated fairly well. The performance of the naïve persistence model was compared with other models and the requirement of the development of the naïve persistence model was also analysed by persistence index.
Collapse
Affiliation(s)
| | | | - C S P Ojha
- Indian Institute of Technology, Roorkee, India
| | - R D Singh
- National Institute of Hydrology, Roorkee, India
| | - P K Swamee
- Indian Institute of Technology, Roorkee, India
| |
Collapse
|
15
|
Jain CK, Singh RD. Technological options for the removal of arsenic with special reference to South East Asia. J Environ Manage 2012; 107:1-18. [PMID: 22579769 DOI: 10.1016/j.jenvman.2012.04.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 03/22/2012] [Accepted: 04/09/2012] [Indexed: 05/31/2023]
Abstract
Arsenic contamination in ground water, used for drinking purpose, has been envisaged as a problem of global concern. However, arsenic contamination of ground water in parts of South East Asia is assuming greater proportions and posing a serious threat to the health of millions of people. A variety of treatment technologies based on oxidation, co-precipitation, adsorption, ion exchange and membrane process are available for the removal of arsenic from ground water. However, question remains regarding the efficiency and applicability/appropriateness of the technologies, particularly because of low influent arsenic concentration and differences in source water composition. Some of these methods are quite simple, but the disadvantage associated with them is that they produce large amounts of toxic sludge, which needs further treatment before disposal into the environment. Besides, the system must be economically viable and socially acceptable. In this paper an attempt has been made to review and update the recent advances made in the technological development in arsenic removal technologies to explore the potential of those advances to address the problem of arsenic contamination in South East Asia.
Collapse
Affiliation(s)
- C K Jain
- NIH-Centre for Flood Management Studies, G.S. Road, Sapta Sahid Path, Mathura Nagar, Dispur, Guwahati, Assam 781 006, India.
| | | |
Collapse
|
16
|
Qaiser D, Khan MS, Singh RD, Khan ZH, Chawla S. Förster's resonance energy transfer between Fullerene C60 and Coumarin C440. Spectrochim Acta A Mol Biomol Spectrosc 2010; 77:1065-1068. [PMID: 20869302 DOI: 10.1016/j.saa.2010.08.074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 08/09/2010] [Accepted: 08/26/2010] [Indexed: 05/29/2023]
Abstract
The interaction between Coumarin C440 with Fullerene C60 has been studied by fluorescence and time resolved spectroscopic techniques. The Coumarin C440-Fullerene C60 pair shows Forster's resonance energy transfer (FRET) from Coumarin C440 (donor) to Fullerenes C60 (acceptor). The FRET efficiency of this pair increases with the increase of the acceptor concentration. The critical energy transfer distance (R0) at which transfer efficiency is 50% is found to be 34Ǻ. Stern-Volmer plot indicates static as well as dynamic quenching. However, the FRET studies show highest efficiency at the critical stage of dimer formation.
Collapse
Affiliation(s)
- Darakhshan Qaiser
- Department of Physics, Jamia Millia Islamia, New Delhi 110025, India.
| | | | | | | | | |
Collapse
|
17
|
Arora M, Rathore DS, Singh RD, Kumar R, Kumar A. Estimation of Melt Contribution to Total Streamflow in River Bhagirathi and River DhauliGanga at Loharinag Pala and Tapovan Vishnugad Project Sites. ACTA ACUST UNITED AC 2010. [DOI: 10.4236/jwarp.2010.27073] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
18
|
Sharma AK, Ahlawat DS, Mohan D, Singh RD. Concentration-dependent energy transfer studies in ternary dye mixture of Stilbene-420, Coumarin-540 and Nile Blue. Spectrochim Acta A Mol Biomol Spectrosc 2009; 71:1631-1633. [PMID: 18930436 DOI: 10.1016/j.saa.2007.05.067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Accepted: 05/26/2007] [Indexed: 05/26/2023]
Abstract
The energy transfer studies in the case of ternary dye mixture [Stilbene-420 (donor)+Coumarin-540 (intermediator)+Nile Blue (acceptor)] have been done and discussed through optical gain characteristics at various acceptor concentrations under nitrogen laser excitation. The concentration of the other two dyes were kept constant. It is observed that the concentration of the acceptor dye plays a very critical role in energy transfer dye laser (ETDL) as small change in its concentration varies the intensity of the laser output in the red region by large amount. Also, the highest laser output in the red region is obtained when the concentration of the acceptor dye is slightly higher than that of the intermediator dye. The present studies are helpful in deciding the optimum concentration of the acceptor dye to be used in ternary dye mixture for maximum gain and tuning range. The ternary dye mixture under study provides an ETDL tuning range up to 700 nm.
Collapse
Affiliation(s)
- A K Sharma
- Department of Physics, MD University, Rohtak 124001, India.
| | | | | | | |
Collapse
|
19
|
Singh RD, Bhagat A, Pandey AK. Bilateral ptosis following wasp sting. J Assoc Physicians India 2003; 51:828-9. [PMID: 14651153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
We report a case of bilateral ptosis due to wasp sting which was completely treatable.
Collapse
Affiliation(s)
- R D Singh
- Department of Medicine, Patna Medical College and Hospital, Patna, India
| | | | | |
Collapse
|
20
|
Kapoor S, Singh RD, Sharma PC, Khullar M. Anaerobiosis induced virulence of Salmonella typhi. Indian J Med Res 2002; 115:184-8. [PMID: 12362557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND & OBJECTIVES Anaerobic conditions are frequently encountered by pathogens invading the gastrointestinal tract due to low/limiting oxygen conditions prevalent in the small intestine. This anaerobic stress has been suggested to enhance the virulence of gut pathogens. In the present study, we examined the effect of anaerobiosis on the virulence of Salmonella Typhi, a Gram negative bacteria which invades through the gut mucosa and is responsible for typhoid fever. METHODS Salmonella Typhi (ty2) was cultured in aerobic and anaerobic conditions to compare its virulence by rabbit ileal loop assay, hydrophobicity assay, expression of outer membrane proteins (OMPs) and antioxidant enzymes assay. RESULTS Anaerobically grown S. Typhi showed significantly higher cell surface hydrophobicity as compared to aerobic bacteria. In vivo toxin production by rabbit ileal loop assay also showed significantly higher fluid accumulation with anaerobic S. Typhi. Expression of OMPs in anaerobic S. Typhi showed a distinct induction of five outer membrane proteins. We observed that exposure of anaerobic S. Typhi to aerobic conditions induced significantly higher level of antioxidant enzymes like superoxide dismutase (SOD) and catalase. INTERPRETATION & CONCLUSION Our results suggest that exposure of S. Typhi to anaerobic conditions enhances its virulence.
Collapse
Affiliation(s)
- Sarika Kapoor
- Department of Experimental Medicine & Biotechnology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | | | | | | |
Collapse
|
21
|
Puri V, Watanabe R, Singh RD, Dominguez M, Brown JC, Wheatley CL, Marks DL, Pagano RE. Clathrin-dependent and -independent internalization of plasma membrane sphingolipids initiates two Golgi targeting pathways. J Cell Biol 2001; 154:535-47. [PMID: 11481344 PMCID: PMC2196434 DOI: 10.1083/jcb.200102084] [Citation(s) in RCA: 259] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Sphingolipids (SLs) are plasma membrane constituents in eukaryotic cells which play important roles in a wide variety of cellular functions. However, little is known about the mechanisms of their internalization from the plasma membrane or subsequent intracellular targeting. We have begun to study these issues in human skin fibroblasts using fluorescent SL analogues. Using selective endocytic inhibitors and dominant negative constructs of dynamin and epidermal growth factor receptor pathway substrate clone 15, we found that analogues of lactosylceramide and globoside were internalized almost exclusively by a clathrin-independent ("caveolar-like") mechanism, whereas an analogue of sphingomyelin was taken up approximately equally by clathrin-dependent and -independent pathways. We also showed that the Golgi targeting of SL analogues internalized via the caveolar-like pathway was selectively perturbed by elevated intracellular cholesterol, demonstrating the existence of two discrete Golgi targeting pathways. Studies using SL-binding toxins internalized via clathrin-dependent or -independent mechanisms confirmed that endogenous SLs follow the same two pathways. These findings (a) provide a direct demonstration of differential SLs sorting into early endosomes in living cells, (b) provide a "vital marker" for endosomes derived from caveolar-like endocytosis, and (c) identify two independent pathways for lipid transport from the plasma membrane to the Golgi apparatus in human skin fibroblasts.
Collapse
Affiliation(s)
- V Puri
- Department of Biochemistry and Molecular Biology, Thoracic Diseases Research Unit, Mayo Clinic and Foundation, Rochester, MN 55905, USA
| | | | | | | | | | | | | | | |
Collapse
|
22
|
|
23
|
Abstract
Intestinal pathogens are exposed to various stress conditions during their infectious cycle. Anaerobiosis, one of such hostile condition, is offered by the host within gut and intestinal lumen, where survival, multiplication and entry into intestinal epithelial cells is priority for the invading pathogen. In the present study, a virulent strain of S. typhimurium (1402/84) was grown under anaerobic conditions and its virulence characteristics such as host cell binding, penetration and intracellular survival were compared with aerobic S. typhimurium. Anaerobically grown S. typhimurium showed significantly higher binding to immobilized mice enterocytes and intestinal mucus as compared to bacteria grown aerobically. Anaerobic bacteria also showed an early penetration of mucus and subsequent binding to underlying immobilized enterocytes, in vitro. Anaerobic S. typhimurium exhibited increased intracellular survival within spleen macrophages of mice and caused significantly higher fluid accumulation in ligated rabbit ileal loops as compared to aerobic bacteria. LD50 of anaerobic S. typhimurium was also observed to be 2 fold lower when compared to aerobic bacteria. Cell surface hydrophobicity of anaerobic S. typhimurium was also found to be significantly higher than aerobic bacteria. Thus, it appears that exposure of S. typhimurium to anaerobiosis results in its enhanced virulence, adhesion and penetration of host cells.
Collapse
Affiliation(s)
- R D Singh
- Department of Experimental Medicine and Biotechnology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | | | | |
Collapse
|
24
|
|
25
|
Abstract
Mental functions of 388 (6-8 years of age) rural primary school children matched for social and educational status were assessed in relation to anaemia and nutritional status. Malin's intelligence scale for Indian children and an arithmetic test were administered to assess intelligence, attention and concentration. No significant differences were found between the IQ scores of anaemic and non-anaemic groups, except for the subtest digit span. In contrast, there was an effect of nutritional status on IQ scores. Observations on the arithmetic test showed that anaemia is associated with lower levels of attention and concentration.
Collapse
Affiliation(s)
- D K Agarwal
- Department of Paediatrics, Banaras Hindu University, Varanasi, India
| | | | | | | | | |
Collapse
|
26
|
Singh RD. Dermatoglyphic variations in four castes of Uttar Pradesh, India. Hum Biol 1978; 50:251-6. [PMID: 721083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
27
|
Srivastava LS, Pescovitz H, Singh RD, Perisutti G, Knowles HC. Radioimmunoassay of some hormones simultaneously measured in serum and breast cyst fluid. Experientia 1977; 33:1659-60. [PMID: 590470 DOI: 10.1007/bf01934057] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Blood and breast cyst fluid were drawn simultaneously for hormonal determination. There was no difference between serum and cyst fluid values of PRL and TSH. A significant difference was noted for LH (p less than 0.01) and FSH (p less than 0.05), serum concentrations being higher than cyst fluid concentrations.
Collapse
|
28
|
Singh RD. Labour migration and its impact on employment and income in a small farm economy. Int Labour Rev 1977; 116:331-341. [PMID: 12278813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
29
|
Farkas WR, Singh RD. Guanine aminohydrolase in rat and mouse red cells: a potent inhibitor of guanylation of tRNA. Biochim Biophys Acta 1975; 377:166-73. [PMID: 1122285 DOI: 10.1016/0005-2744(75)90297-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
1. The red blood cells of mice and rats contained guanine aminohydrolase (EC 3.5.4.3). This enzyme was not present in rabbit, sheep or human red blood cells. 2. The enzyme from rat blood cells was separated into two activities by column chromatography on DEAE-cellulose. Both isozymes were labile but it was possible to show that the more abundant enzyme followed Michaelis-Menten kinetics, had an apparent Km of 4.0-10-6 M and was not activated by GTP nor inhibited by allantoin. 3. We believe, therefore, that guanine aminohydrolase was the protein in rat and mouse red blood cells that inhibited the enzyme (in rabbit reticulocytes) responsible for guanylation of tRNA.
Collapse
|
30
|
Singh RD. Problems of techniques in anthropometric studies in India. Am J Phys Anthropol 1974; 40:221-6. [PMID: 4815135 DOI: 10.1002/ajpa.1330400209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
31
|
Farkas WR, Singh RD. Guanylation of transfer ribonucleic acid by a cell-free lysate of rabbit reticulocytes. J Biol Chem 1973; 248:7780-5. [PMID: 4750426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
|
32
|
Gupta VD, Dwivedi AM, Singh RD. Dispersion curves of poly-L-proline I & II chains. Indian J Biochem Biophys 1973; 10:79-84. [PMID: 4779282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
33
|
|
34
|
|
35
|
Singh RD, Swami AK. Pulmonary amoeboma. Indian J Chest Dis 1968; 10:43-5. [PMID: 5761037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|