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Dresen M, Valentin-Weigand P, Berhanu Weldearegay Y. Role of Metabolic Adaptation of Streptococcus suis to Host Niches in Bacterial Fitness and Virulence. Pathogens 2023; 12:pathogens12040541. [PMID: 37111427 PMCID: PMC10144218 DOI: 10.3390/pathogens12040541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023] Open
Abstract
Streptococcus suis, both a common colonizer of the porcine upper respiratory tract and an invasive pig pathogen, successfully adapts to different host environments encountered during infection. Whereas the initial infection mainly occurs via the respiratory tract, in a second step, the pathogen can breach the epithelial barrier and disseminate within the whole body. Thereby, the pathogen reaches other organs such as the heart, the joints, or the brain. In this review, we focus on the role of S. suis metabolism for adaptation to these different in vivo host niches to encounter changes in nutrient availability, host defense mechanisms and competing microbiota. Furthermore, we highlight the close link between S. suis metabolism and virulence. Mutants deficient in metabolic regulators often show an attenuation in infection experiments possibly due to downregulation of virulence factors, reduced resistance to nutritive or oxidative stress and to phagocytic activity. Finally, metabolic pathways as potential targets for new therapeutic strategies are discussed. As antimicrobial resistance in S. suis isolates has increased over the last years, the development of new antibiotics is of utmost importance to successfully fight infections in the future.
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Affiliation(s)
- Muriel Dresen
- Institute for Microbiology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
| | - Peter Valentin-Weigand
- Institute for Microbiology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
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Indraratna AD, Everest-Dass A, Skropeta D, Sanderson-Smith M. OUP accepted manuscript. FEMS Microbiol Rev 2022; 46:6519265. [PMID: 35104861 PMCID: PMC9075583 DOI: 10.1093/femsre/fuac001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/29/2021] [Accepted: 01/25/2022] [Indexed: 11/12/2022] Open
Abstract
Host carbohydrates, or glycans, have been implicated in the pathogenesis of many bacterial infections. Group A Streptococcus (GAS) is a Gram-positive bacterium that readily colonises the skin and oropharynx, and is a significant cause of mortality in humans. While the glycointeractions orchestrated by many other pathogens are increasingly well-described, the understanding of the role of human glycans in GAS disease remains incomplete. Although basic investigation into the mechanisms of GAS disease is ongoing, several glycointeractions have been identified and are examined herein. The majority of research in this context has focussed on bacterial adherence, however, glycointeractions have also been implicated in carbohydrate metabolism; evasion of host immunity; biofilm adaptations; and toxin-mediated haemolysis. The involvement of human glycans in these diverse avenues of pathogenesis highlights the clinical value of understanding glycointeractions in combatting GAS disease.
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Affiliation(s)
- Anuk D Indraratna
- Illawarra Health and Medical Research Institute, Northfields Ave, Keiraville New South Wales 2522, Australia
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong, Northfields Avenue, Keiraville, New South Wales, 2522, Australia
| | - Arun Everest-Dass
- Institute for Glycomics, Griffith University, Gold Coast Campus, Parklands Drive, Southport, Queensland, 4215, Australia
| | - Danielle Skropeta
- Illawarra Health and Medical Research Institute, Northfields Ave, Keiraville New South Wales 2522, Australia
- School of Chemistry and Molecular Bioscience, Molecular Horizons, University of Wollongong, Northfields Avenue, Keiraville, New South Wales, 2522, Australia
| | - Martina Sanderson-Smith
- Corresponding author: Illawarra Health and Medical Research Institute, Bld 32, University of Wollongong, Northfields Avenue, Keiraville, New South Wales, 2522, Australia. Tel: +61 2 42981935; E-mail:
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Paediatric Autoimmune Neuropsychiatric Disorder Associated with Group A Beta-Haemolytic Streptococcal Infection: An Indication for Tonsillectomy? A Review of the Literature. Int J Otolaryngol 2018; 2018:2681304. [PMID: 29675045 PMCID: PMC5841079 DOI: 10.1155/2018/2681304] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 11/20/2017] [Accepted: 12/03/2017] [Indexed: 12/03/2022] Open
Abstract
Background. Paediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infection (PANDAS) is the acute onset of neuropsychiatric symptoms following group A beta-haemolytic streptococcal infection. The aetiology remains elusive. However, with group A streptococcus being the most common bacterial cause of tonsillitis, surgical intervention in the form of tonsillectomy has often been considered as a potential therapy. Methods. A MEDLINE® search was undertaken using keywords “PANDAS” or “paediatric autoimmune neuropsychiatric disorders associated with streptococcus” combined with “tonsillectomy”. Results. Six case reports and 3 case series met the inclusion criteria. Demesh et al. (case series) reported a dramatic reduction in neuropsychiatric symptom severity in the patient cohort undergoing tonsillectomy. Two case series suggest that there is no association between tonsillectomy and resolution of PANDAS. Conclusion. Due to the lack of uniform data and sporadic reports, tonsillectomy should be carefully adopted for the treatment of this disorder. In particular, tonsillectomies/adenoidectomies to alleviate neuropsychiatric symptoms should be avoided until more definitive evidence is at our disposal. This review highlights the importance of a potential collaborative prospective study.
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Madunić IV, Breljak D, Karaica D, Koepsell H, Sabolić I. Expression profiling and immunolocalization of Na +-D-glucose-cotransporter 1 in mice employing knockout mice as specificity control indicate novel locations and differences between mice and rats. Pflugers Arch 2017; 469:1545-1565. [PMID: 28842746 PMCID: PMC5691098 DOI: 10.1007/s00424-017-2056-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 07/24/2017] [Accepted: 08/10/2017] [Indexed: 12/23/2022]
Abstract
The expression and localization of sodium-D-glucose cotransporter SGLT1 (SLC5A1), which is involved in small intestinal glucose absorption and renal glucose reabsorption, is of high biomedical relevance because SGLT1 inhibitors are currently tested for antidiabetic therapy. In human and rat organs, detailed expression profiling of SGLT1/Sglt1 mRNA and immunolocalization of the transporter protein has been performed. Using polyspecific antibodies and preabsorption with antigenic peptide as specificity control, in several organs, different immunolocalizations of SGLT1/Sglt1 between human and rat were obtained. Because the preabsorption control does not exclude cross-reactivity with similar epitopes, some localizations remained ambiguous. In the present study, we performed an immunocytochemical localization of Sglt1 in various organs of mice. Specificities of the immunoreactions were evaluated using antibody preabsorption with the Sglt1 peptide and the respective organs of Sglt1 knockout mice. Because staining in some locations was abolished after antibody preabsorption but remained in the knockout mice, missing staining in knockout mice was used as specificity criterion. The immunolocalization in mouse was identical or similar to rat in many organs, including small intestine, liver, and kidney. However, the male-dominant renal Sglt1 protein expression in mice differed from the female-dominant expression in rats, and localization in lung, heart, and brain observed in rats was not detected in mice. In mice, several novel locations of Sglt1, e.g., in eyes, tongue epithelial cells, pancreatic ducts, prostate, and periurethral glands were detected. Using end-point and quantitative RT-PCR in various organs, different Sglt1 expression in mice and rats was confirmed.
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Affiliation(s)
- Ivana Vrhovac Madunić
- Molecular Toxicology Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000, Zagreb, Croatia
| | - Davorka Breljak
- Molecular Toxicology Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000, Zagreb, Croatia
| | - Dean Karaica
- Molecular Toxicology Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000, Zagreb, Croatia
| | - Hermann Koepsell
- Department of Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Ivan Sabolić
- Molecular Toxicology Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000, Zagreb, Croatia.
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Arora KS, Binjoo N, Reddy GVR, Kaur P, Modgil R, Negi LS. Determination of normal range for fasting salivary glucose in Type 1 diabetics. J Int Soc Prev Community Dent 2015; 5:377-82. [PMID: 26539389 PMCID: PMC4606601 DOI: 10.4103/2231-0762.165923] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Background: The most commonly employed investigative procedure for monitoring glucose levels is blood investigation, which is invasive and gives discomfort to the patient. The purpose of the study was to validate a noninvasive, easy, and reliable method for predicting glucose levels in Type 1 diabetics and to validate a regression equation for converting the known values of salivary glucose to blood glucose. Materials and Methods: 200 volunteers consisting of 100 Type 1 diabetics and 100 healthy controls were included, and their fasting blood and salivary glucose levels were assessed, using a semi-auto analyzer. Results: On analysis of the data, statistically significant positive results were obtained (P < 0.05) when the blood and salivary glucose levels were considered among the study group participants, control group participants, and both study and control group participants. A cut-off value for salivary glucose (11.60 mg%) was defined, above which a person may be considered as diabetic. Also, the regression equation was obtained which could be used for the conversion of known value of salivary glucose to blood glucose and vice versa. Conclusion: The present study successfully demonstrated the role of saliva as a noninvasive and reliable marker for the prediction of glucose levels in Type 1 diabetics who show elevated blood glucose levels.
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Affiliation(s)
- Karandeep Singh Arora
- Department of Oral Medicine and Radiology, Daswani Dental College and Research Centre, Kota, Rajasthan, India
| | - Nagesh Binjoo
- Department of Oral Medicine and Radiology, Dr. BR Ambedkar Institute of Dental Sciences and Hospital, Patna, Bihar, India
| | - G V Ramachandra Reddy
- Department of Oral Medicine and Radiology, Rajasthan Dental College and Hospital, Jaipur, India
| | - Prabhpreet Kaur
- Department of Oral and Maxillofacial Pathology, BRS Dental College and General Hospital, Panchkula, Haryana, India
| | - Richa Modgil
- Department of Oral Medicine and Radiology, Daswani Dental College and Research Centre, Kota, Rajasthan, India
| | - Lalit Singh Negi
- Department of Oral Medicine and Radiology, Surendra Dental College and Research Institute, Sriganganagar, Rajasthan, India
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Valentijn-Benz M, Nazmi K, Brand HS, van't Hof W, Veerman ECI. Growth of Candida albicans in human saliva is supported by low-molecular-mass compounds. FEMS Yeast Res 2015; 15:fov088. [PMID: 26392045 DOI: 10.1093/femsyr/fov088] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2015] [Indexed: 11/12/2022] Open
Abstract
Saliva plays a key role in the maintenance of a stable oral microflora. It contains antimicrobial compounds but also functions as a substrate for growth of bacteria under conditions of low external nutrient supply. Besides bacteria, yeasts, in particular Candida albicans, commonly inhabit the oral cavity. Under immunocompromised conditions, instantaneous outgrowth of this yeast occurs in oral carriers of C. albicans, suggesting that this yeast is able to survive in the oral cavity with saliva as sole source of growth substrate. The aim of the present study was to identify the salivary constituents that are used by C. albicans for growth and survival in saliva. In addition, we have explored the effect of growth in saliva on the susceptibility of C. albicans to histatin 5, a salivary antifungal peptide. It was found that C. albicans was able to grow in human saliva without addition of glucose, and in the stationary phase could survive for more than 400 h. Candida albicans grown in saliva was more than 10 times less susceptible for salivary histatin 5 than C. albicans cultured in Sabouraud medium.
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Affiliation(s)
- Marianne Valentijn-Benz
- Section of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit and Universiteit van Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands
| | - Kamran Nazmi
- Section of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit and Universiteit van Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands
| | - Henk S Brand
- Section of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit and Universiteit van Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands
| | - Wim van't Hof
- Section of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit and Universiteit van Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands
| | - Enno C I Veerman
- Section of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit and Universiteit van Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands
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Abstract
Acquisition and metabolism of carbohydrates are essential for host colonization and pathogenesis of bacterial pathogens. Different bacteria can uptake different lines of carbohydrates via ABC transporters, in which ATPase subunits energize the transport though ATP hydrolysis. Some ABC transporters possess their own ATPases, while some share a common ATPase. Here we identified MsmK, an ATPase from Streptococcus suis, an emerging zoonotic bacterium causing dead infections in pigs and humans. Genetic and biochemistry studies revealed that the MsmK was responsible for the utilization of raffinose, melibiose, maltotetraose, glycogen and maltotriose. In infected mice, the msmK-deletion mutant showed significant defects of survival and colonization when compared with its parental and complementary strains. Taken together, MsmK is an ATPase that contributes to multiple carbohydrates utilization and host colonization of S. suis. This study gives new insight into our understanding of the carbohydrates utilization and its relationship to the pathogenesis of this zoonotic pathogen.
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8
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Development of Gradient Retention Model in Ion Chromatography. Part I: Conventional QSRR Approach. Chromatographia 2014. [DOI: 10.1007/s10337-014-2653-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Ferrando ML, van Baarlen P, Orrù G, Piga R, Bongers RS, Wels M, De Greeff A, Smith HE, Wells JM. Carbohydrate availability regulates virulence gene expression in Streptococcus suis. PLoS One 2014; 9:e89334. [PMID: 24642967 PMCID: PMC3958366 DOI: 10.1371/journal.pone.0089334] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 01/17/2014] [Indexed: 12/04/2022] Open
Abstract
Streptococcus suis is a major bacterial pathogen of young pigs causing worldwide economic problems for the pig industry. S. suis is also an emerging pathogen of humans. Colonization of porcine oropharynx by S. suis is considered to be a high risk factor for invasive disease. In the oropharyngeal cavity, where glucose is rapidly absorbed but dietary α-glucans persist, there is a profound effect of carbohydrate availability on the expression of virulence genes. Nineteen predicted or confirmed S. suis virulence genes that promote adhesion to and invasion of epithelial cells were expressed at higher levels when S. suis was supplied with the α-glucan starch/pullulan compared to glucose as the single carbon source. Additionally the production of suilysin, a toxin that damages epithelial cells, was increased more than ten-fold when glucose levels were low and S. suis was growing on pullulan. Based on biochemical, bioinformatics and in vitro and in vivo gene expression studies, we developed a biological model that postulates the effect of carbon catabolite repression on expression of virulence genes in the mucosa, organs and blood. This research increases our understanding of S. suis virulence mechanisms and has important implications for the design of future control strategies including the development of anti-infective strategies by modulating animal feed composition.
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Affiliation(s)
- M. Laura Ferrando
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
- Department of Medical Microbiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Peter van Baarlen
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | - Germano Orrù
- Oral Biotechnology Laboratory, University of Cagliari, Cagliari, Italy
| | - Rosaria Piga
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | | | | | - Astrid De Greeff
- Central Veterinary Institute, Animal Sciences Group, Wageningen University, Lelystad, The Netherlands
| | - Hilde E. Smith
- Central Veterinary Institute, Animal Sciences Group, Wageningen University, Lelystad, The Netherlands
| | - Jerry M. Wells
- Host-Microbe Interactomics, Animal Sciences, Wageningen University, Wageningen, The Netherlands
- * E-mail:
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10
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Shafeeq S, Kloosterman TG, Rajendran V, Kuipers OP. Characterization of the ROK-family transcriptional regulator RokA of Streptococcus pneumoniae D39. MICROBIOLOGY-SGM 2012; 158:2917-2926. [PMID: 23082033 DOI: 10.1099/mic.0.062919-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Gram-positive human pathogen Streptococcus pneumoniae possesses an unusually high number of gene clusters specific for carbohydrate utilization. This provides it with the ability to use a wide array of sugars, which may aid during infection and survival in different environmental conditions present in the host. In this study, the regulatory mechanism of transcription of a gene cluster, SPD0424-8, putatively encoding a cellobiose/lactose-specific phosphotransferase system is investigated. We demonstrate that this gene cluster is transcribed as one transcriptional unit directed by the promoter of the SPD0424 gene. Upstream of SPD0424, a gene was identified encoding a ROK-family transcriptional regulator (RokA: SPD0423). DNA microarray and transcriptional reporter analyses with a rokA mutant revealed that RokA acts as a transcriptional repressor of the SPD0424-8 operon. Furthermore, we identified a 25 bp AT-rich DNA operator site (5'-TATATTTAATTTATAAAAAATAAAA-3') in the promoter region of SPD0424, which was validated by promoter truncation studies, DNase I footprinting and electrophoretic mobility-shift assays. We tested a large range of different sugars for their effect on the expression of the SPD0424-8 operon, but only moderate variation in expression was observed in the conditions applied. Therefore, a co-factor for RokA-mediated transcriptional control could not be identified.
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Affiliation(s)
- Sulman Shafeeq
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Tomas G Kloosterman
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Vijayanand Rajendran
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
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11
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Olsen RJ, Musser JM. Molecular pathogenesis of necrotizing fasciitis. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2010; 5:1-31. [PMID: 19737105 DOI: 10.1146/annurev-pathol-121808-102135] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Necrotizing fasciitis, also known as the flesh-eating disease, is a severe invasive infection associated with very high rates of human morbidity and mortality. It is most commonly caused by group A Streptococcus(GAS), a versatile human pathogen that causes diseases ranging in severity from uncomplicated pharyngitis (or strep throat) to life-threatening infections such as necrotizing fasciitis. Herein, we review recent discoveries bearing on the molecular pathogenesis of GAS necrotizing fasciitis. Importantly, the integration of new technologies and the development of human-relevant animal models have markedly expanded our understanding of the key pathogen-host interactions underlying GAS necrotizing fasciitis. For example, we now know that GAS organisms secrete a variety of proteases that disrupt host tissue and that these proteolytic enzymes are regulated by multiple transcriptional and posttranslational processes. This pathogenesis knowledge will be crucial to supporting downstream efforts that seek to develop novel vaccines and therapeutic agents for this serious human infection.
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Affiliation(s)
- Randall J Olsen
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, and Department of Pathology, The Methodist Hospital, Houston, Texas 77030, USA
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Olsen RJ, Shelburne SA, Musser JM. Molecular mechanisms underlying group A streptococcal pathogenesis. Cell Microbiol 2008; 11:1-12. [PMID: 18710460 DOI: 10.1111/j.1462-5822.2008.01225.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Group A Streptococcus (GAS) is a versatile human pathogen causing diseases ranging from uncomplicated mucosal infections to life-threatening invasive disease. The development of human-relevant animal models of GAS infection and introduction of new technologies have markedly accelerated the pace of discoveries related to GAS host-pathogen interactions. For example, recently investigators have identified pili on the GAS cell surface and learned that they are key components for adherence to eukaryotic cell surfaces. Similarly, the recent development of a transgenic mouse expressing human plasminogen has resulted in new understanding of the molecular processes contributing to invasive infection. Improved understanding of the molecular mechanisms underlying the pathogenesis of GAS pharyngeal, invasive and other infections holds the promise of assisting with the development of novel preventive or therapeutic agents for this prevalent human pathogen.
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Affiliation(s)
- Randall J Olsen
- Center for Molecular and Translational Human Infectious Disease Research, The Methodist Hospital Research Institute, Houston, TX 77030, USA
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Balen D, Ljubojević M, Breljak D, Brzica H, Z̆lender V, Koepsell H, Sabolić I. Revised immunolocalization of the Na+-d-glucose cotransporter SGLT1 in rat organs with an improved antibody. Am J Physiol Cell Physiol 2008; 295:C475-89. [DOI: 10.1152/ajpcell.00180.2008] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Previously, we characterized localization of Na+-glucose cotransporter SGLT1 ( Slc5a1) in the rat kidney using a polyclonal antibody against the synthetic COOH-terminal peptide of the rat protein (Sabolić I, Škarica M, Gorboulev V, Ljubojević M, Balen D, Herak-Kramberger CM, Koepsell H. Am J Physiol Renal Physiol 290: 913–926, 2006). However, the antibody gave some false-positive reactions in immunochemical studies. Using a shortened peptide for immunization, we have presently generated an improved, more specific anti-rat SGLT1 antibody (rSGLT1-ab), which in immunochemical studies with isolated membranes and tissue cryosections from male (M) and female (F) rats exhibited 1) in kidneys and small intestine, labeling of a major protein band of ∼75 kDa; 2) in kidneys of adult animals, localization of rSGLT1 to the proximal tubule (PT) brush-border membrane (S1 < S2 < S3) and intracellular organelles (S1 > S2 > S3), with zonal (cortex < outer stripe) and sex differences (M < F) in the protein expression, which correlated well with the tissue expression of its mRNA in RT-PCR studies; 3) in kidneys of castrated adult M rats, upregulation of the protein expression; 4) in kidneys of prepubertal rats, weak and sex-independent labeling of the 75-kDa protein band and immunostaining intensity; 5) in small intestine, sex-independent regional differences in protein abundance (jejunum > duodenum = ileum); and 6) thus far unrecognized localization of the transporter in cortical thick ascending limbs of Henle and macula densa in kidney, bile ducts in liver, enteroendocrine cells and myenteric plexus in the small intestine, and initial ducts in the submandibular gland. Our improved rSGLT1-ab may be used to identify novel sites of SGLT1 localization and thus unravel additional physiological functions of this transporter in rat organs.
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14
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Shelburne SA, Davenport MT, Keith DB, Musser JM. The role of complex carbohydrate catabolism in the pathogenesis of invasive streptococci. Trends Microbiol 2008; 16:318-25. [PMID: 18508271 DOI: 10.1016/j.tim.2008.04.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 04/03/2008] [Accepted: 04/11/2008] [Indexed: 01/09/2023]
Abstract
Historically, the study of bacterial catabolism of complex carbohydrates has contributed to understanding basic bacterial physiology. Recently, however, genome-wide screens of streptococcal pathogenesis have identified genes encoding proteins involved in complex carbohydrate catabolism as participating in pathogen infectivity. Subsequent studies have focused on specific mechanisms by which carbohydrate utilization proteins might contribute to the ability of streptococci to colonize and infect the host. Moreover, transcriptome and biochemical analyses have uncovered novel regulatory pathways by which streptococci link environmental carbohydrate availability to virulence factor production. Herein we review new insights into the role of complex carbohydrates in streptococcal host-pathogen interaction.
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Affiliation(s)
- Samuel A Shelburne
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
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15
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Di Gioia ML, Leggio A, Le Pera A, Liguori A, Napoli A, Siciliano C, Sindona G. Quantitative analysis of human salivary glucose by gas chromatography–mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 801:355-8. [PMID: 14751806 DOI: 10.1016/j.jchromb.2003.11.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A reference analytic methodology was developed for the determination of human salivary glucose concentration. The technique involves the glucose derivatization with acetic anhydride and subsequent analysis of glucose penta-acetylated by gas chromatography combined with mass spectrometry. Glucose concentration in the biological fluid depends on the physiological status of the donor.
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Affiliation(s)
- Maria Luisa Di Gioia
- Dipartimento di Scienze Farmaceutiche, Università degli Studi della Calabria, Arcavacata di Rende, Italy
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