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Jin YX, Zhang S, Xiao J, Wang ZH, Dong C, You LL, Kuai TT, Zhang Y, Liu SX. Association between serum β 2-microglobulin levels and the risk of all-cause and cardiovascular disease mortality in chinese patients undergoing maintenance hemodialysis. BMC Nephrol 2023; 24:170. [PMID: 37312042 DOI: 10.1186/s12882-023-03191-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/28/2023] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND The association between serum β2-microglobulin (β2M) levels and the risk of all-cause and cardiovascular disease (CVD) mortality and the incidence of cardiovascular events (CVEs) in patients undergoing maintenance hemodialysis (MHD) is inconclusive. Furthermore, no study has been performed in China on the significance of serum β2M levels in MHD patients. Therefore, this study investigated the aforementioned association in MHD patients. METHODS In this prospective cohort study, 521 MHD patients were followed at Dalian Municipal Central Hospital affiliated with Dalian University of Technology from December 2019 to December 2021. The serum β2M levels were categorized into three tertiles, and the lowest tertile served as the reference group. Survival curves were calculated by the Kaplan-Meier method. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazard models. Sensitivity analysis was performed by excluding patients with CVD at baseline. RESULTS During the follow-up period of 21.4 ± 6.3 months, there were 106 all-cause deaths, of which 68 were caused by CVD. When excluding CVD patients at baseline, there were 66 incident CVEs. Kaplan-Meier analysis revealed that the risk of all-cause and CVD mortality in the highest tertile of serum β2M levels was significantly higher than that in the lowest tertile (P < 0.05), but not for the CVEs (P > 0.05). After adjusting for potential confounders, serum β2M levels were positively associated with the risk of all-cause (HR = 2.24, 95% CI = 1.21-4.17) and CVD (HR = 2.54, 95% CI = 1.19-5.43) mortality, and a linear trend was evident (P < 0.05). Besides, the results of sensitivity analysis were consistent with the main findings. However, we didn't observed the significant association between serum β2M levels and CVEs (P > 0.05). CONCLUSION The serum β2M level may be a significant predictor of the risk of all-cause and CVD mortality in MHD patients. Further studies are needed to confirm this finding.
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Affiliation(s)
- Yu-Xin Jin
- Graduate School, Dalian Medical University, Dalian, China
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China
| | - Shuang Zhang
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China
| | - Jia Xiao
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China
| | - Zhi-Hong Wang
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China
| | - Cui Dong
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China
| | - Lian-Lian You
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China
| | - Ting-Ting Kuai
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China
| | - Yu Zhang
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China
| | - Shu-Xin Liu
- Dalian Key Laboratory of Intelligent Blood Purifcation, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, Dalian, China.
- Department of Nephrology, Dalian Municipal Central Hospital affiliated with Dalian University of Technology, No.826, Xinan Road Dalian, 116033, Liaoning, P. R. China.
- School of Clinical Medicine, Faculty of Medicine, Dalian University of Technology, Dalian, China.
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Chen H, Wang J, Ouyang Q, Peng X, Yu Z, Wang J, Huang J. Alterations of gut microbes and their correlation with clinical features in middle and end-stages chronic kidney disease. Front Cell Infect Microbiol 2023; 13:1105366. [PMID: 37033494 PMCID: PMC10079997 DOI: 10.3389/fcimb.2023.1105366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/07/2023] [Indexed: 04/11/2023] Open
Abstract
Gut microecosystem has been shown to play an important role in human health. In recent years, the concept of the gut-kidney axis has been proposed to explain the potential association between gut microbiota and chronic kidney disease (CKD). Here, a cohort of fecal samples collected from patients with CKD (n = 13) were involved. The composition of gut microbial communities and clinical features in CKD and end-stage renal disease (ESRD) were characterized. Our study focused on the changes in gut microbiome and the correlation with clinical features in patients with CKD and ESRD by analyzing high-throughput sequencing results of collected feces. We elucidated the alterations of gut microbiota in CKD patients at different stages of disease and initially identified the gut microbiota associated with CKD progression. We also combined correlation analysis to identify clinical features closely related to the gut microbiome. Our results offered the possibility of using non-invasive gut microbiome in the early diagnosis of course from CKD to ESRD and provide new insights into the association between clinical features and gut microbiota in CKD.
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Affiliation(s)
- Hao Chen
- Department of Parasitology, School of Basic Medical Science, Central South University, Changsha, China
| | - Jingyan Wang
- Department of Microbiology, School of Basic Medical Science, Central South University, Changsha, China
| | - Qin Ouyang
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xinyue Peng
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zheng Yu
- Department of Microbiology, School of Basic Medical Science, Central South University, Changsha, China
| | - Jianwen Wang
- Department of Nephrology, The Third Xiangya Hospital, Central South University, Changsha, China
- *Correspondence: Jing Huang, ; Jianwen Wang,
| | - Jing Huang
- Department of Parasitology, School of Basic Medical Science, Central South University, Changsha, China
- *Correspondence: Jing Huang, ; Jianwen Wang,
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3
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Homeostasis in the Gut Microbiota in Chronic Kidney Disease. Toxins (Basel) 2022; 14:toxins14100648. [PMID: 36287917 PMCID: PMC9610479 DOI: 10.3390/toxins14100648] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/10/2022] [Accepted: 09/15/2022] [Indexed: 11/17/2022] Open
Abstract
The gut microbiota consists of trillions of microorganisms, fulfilling important roles in metabolism, nutritional intake, physiology and maturation of the immune system, but also aiding and abetting the progression of chronic kidney disease (CKD). The human gut microbiome consists of bacterial species from five major bacterial phyla, namely Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, and Verrucomicrobia. Alterations in the members of these phyla alter the total gut microbiota, with a decline in the number of symbiotic flora and an increase in the pathogenic bacteria, causing or aggravating CKD. In addition, CKD-associated alteration of this intestinal microbiome results in metabolic changes and the accumulation of amines, indoles and phenols, among other uremic metabolites, which have a feedforward adverse effect on CKD patients, inhibiting renal functions and increasing comorbidities such as atherosclerosis and cardiovascular diseases (CVD). A classification of uremic toxins according to the degree of known toxicity based on the experimental evidence of their toxicity (number of systems affected) and overall experimental and clinical evidence was selected to identify the representative uremic toxins from small water-soluble compounds, protein-bound compounds and middle molecules and their relation to the gut microbiota was summarized. Gut-derived uremic metabolites accumulating in CKD patients further exhibit cell-damaging properties, damage the intestinal epithelial cell wall, increase gut permeability and lead to the translocation of bacteria and endotoxins from the gut into the circulatory system. Elevated levels of endotoxins lead to endotoxemia and inflammation, further accelerating CKD progression. In recent years, the role of the gut microbiome in CKD pathophysiology has emerged as an important aspect of corrective treatment; however, the mechanisms by which the gut microbiota contributes to CKD progression are still not completely understood. Therefore, this review summarizes the current state of research regarding CKD and the gut microbiota, alterations in the microbiome, uremic toxin production, and gut epithelial barrier degradation.
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Li B, Liu Z, Liu X, Liu D, Duan M, Gu Y, Liu Q, Ma Q, Wei Y, Wang Y. Efficacy and safety of tenofovir disoproxil fumarate and tenofovir alafenamide fumarate in preventing HBV vertical transmission of high maternal viral load. Hepatol Int 2021; 15:1103-1108. [PMID: 34312798 DOI: 10.1007/s12072-021-10235-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 07/08/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Hepatitis B virus (HBV) infection is a significant global health problem and > 42-52% of patients are infected during perinatal period. Tenofovir alafenamide fumarate (TAF) and tenofovir disoproxil fumarate (TDF) have been widely recognized as the main compounds used for antiviral treatment of hepatitis B. The present study evaluated the efficacy and safety of TAF in reducing HBV vertical transmission. METHODS A total of 72 pregnant women, who met the inclusion criteria, were randomly divided into the TDF (300 mg/day, n = 36) and TAF (25 mg/day, n = 36) groups. Clinical and laboratory data were analyzed and compared between the two groups. RESULTS No significant differences in alanine aminotransferase, total bilirubin, blood creatinine and blood urea nitrogen levels were noted between the two groups after treatment. The serum HBV DNA viral load and hepatitis B e antigen (HBeAg) levels of the two groups were significantly decreased following treatment, whereas the difference between the two groups was not statistically significant. The levels of urine retinol-binding protein and β2-microglobulin had no significant change after TAF treatment (p > 0.05), but increased significantly after TDF treatment (p < 0.05). All drug concentrations were undetectable in umbilical cord blood (UCB) and breast milk samples of the TAF group, while the drug concentration of UCB and breast milk samples in the TDF group was 2.98 ± 1.44 and 19.16 ± 15.26 ng/ml, respectively. All infants were tested negative for serum hepatitis B surface antigen, HBV DNA, and HBeAg. CONCLUSIONS Both TAF and TDF effectively block the mother-to-child transmission of hepatitis B. TAF was superior to TDF with regard to renal safety and breastfeeding.
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Affiliation(s)
- Baijun Li
- Cadre's Ward, The Sixth People's Hospital of Shenyang, Shenyang, 110006, Liaoning, People's Republic of China
| | - Zhaozhe Liu
- Oncology Department, General Hospital of Northern Theater Command, Shenyang, 110016, Liaoning, People's Republic of China
| | - Xing Liu
- Science and Education Department, The Sixth People's Hospital of Shenyang, Shenyang, 110006, Liaoning, People's Republic of China
| | - Dongchun Liu
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, People's Republic of China
| | - Mingyu Duan
- Clinical Chemistry Laboratory, Shenyang Beichuang Laboratory Co. Ltd, Shenyang, 110117, Liaoning, People's Republic of China
| | - Ye Gu
- Gastroenterology Departmentepartment, The Sixth People's Hospital of Shenyang, Shenyang, 110006, Liaoning, People's Republic of China
| | - Qiong Liu
- Cadre's Ward, The Sixth People's Hospital of Shenyang, Shenyang, 110006, Liaoning, People's Republic of China
| | - Qiang Ma
- Cadre's Ward, The Sixth People's Hospital of Shenyang, Shenyang, 110006, Liaoning, People's Republic of China
| | - Yushi Wei
- Liaoning University of Traditional Chinese Medicine, Shenyang, 110034, Liaoning, People's Republic of China
| | - Yan Wang
- Science and Education Department, The Sixth People's Hospital of Shenyang, Shenyang, 110006, Liaoning, People's Republic of China.
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Giorgi PD, Pallotta ML, Legrenzi S, Schirò GR. Spinal cord compression in dialysis-related upper cervical amyloidoma - a case report. Spinal Cord Ser Cases 2021; 7:40. [PMID: 34035225 DOI: 10.1038/s41394-021-00409-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/12/2021] [Accepted: 05/12/2021] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION Dialysis-related amyloidosis (DRA) can lead to various degenerative conditions but rarely involves the spine with a spinal cord compression. CASE REPORT The authors describe a progressive tetraparesis (AIS-B) in a 57-year-old woman with upper cervical dialysis-related amyloidoma. Magnetic resonance imaging (MRI) showed a solid focal mass lesion at the C2-odotoid level with severe spinal cord compression. Computed tomography (CT) outlined multiple lytic lesions in C1 lateral masses and odontoid process. The patient underwent urgent surgical treatment. A posterior C1-C2 spinal cord decompression with biopsy followed by occipito-cervical posterior fixation was performed. Histopathological examination revealed amyloid deposits representing DRA. An immediately postoperative neurological improvement was observed. DISCUSSION Even if the spinal amyloidoma is extremely rare, this condition has to be suspected in a long-term hemodialysis patient suffering from progressive neurological deficits. Differential diagnosis is mandatory between infections, rheumatologic and neoplastic lesions. Imaging evaluation with CT and MRI is recommended in order to assess the characteristics of the pathological mass, the extension of lytic lesions and the entity of neurological compression. Surgical treatment is mandatory if clinical evidence of root or spinal cord compression is present.
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Affiliation(s)
- Pietro Domenico Giorgi
- Orthopedics and Traumatology Unit, Emergency and Urgency Department, A.S.S.T. Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | | | - Simona Legrenzi
- Orthopedics and Traumatology Unit, Emergency and Urgency Department, A.S.S.T. Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Giuseppe Rosario Schirò
- Orthopedics and Traumatology Unit, Emergency and Urgency Department, A.S.S.T. Grande Ospedale Metropolitano Niguarda, Milan, Italy
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Galkin AP, Sysoev EI. Stress Response Is the Main Trigger of Sporadic Amyloidoses. Int J Mol Sci 2021; 22:ijms22084092. [PMID: 33920986 PMCID: PMC8071232 DOI: 10.3390/ijms22084092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 12/11/2022] Open
Abstract
Amyloidoses are a group of diseases associated with the formation of pathological protein fibrils with cross-β structures. Approximately 5-10% of the cases of these diseases are determined by amyloidogenic mutations, as well as by transmission of infectious amyloids (prions) between organisms. The most common group of so-called sporadic amyloidoses is associated with abnormal aggregation of wild-type proteins. Some sporadic amyloidoses are known to be induced only against the background of certain pathologies, but in some cases the cause of amyloidosis is unclear. It is assumed that these diseases often occur by accident. Here we present facts and hypotheses about the association of sporadic amyloidoses with vascular pathologies, trauma, oxidative stress, cancer, metabolic diseases, chronic infections and COVID-19. Generalization of current data shows that all sporadic amyloidoses can be regarded as a secondary event occurring against the background of diseases provoking a cellular stress response. Various factors causing the stress response provoke protein overproduction, a local increase in the concentration or modifications, which contributes to amyloidogenesis. Progress in the treatment of vascular, metabolic and infectious diseases, as well as cancers, should lead to a significant reduction in the risk of sporadic amyloidoses.
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Affiliation(s)
- Alexey P. Galkin
- St. Petersburg Branch, Vavilov Institute of General Genetics, 199034 St. Petersburg, Russia
- Department of Genetics and Biotechnology, St. Petersburg State University, 199034 St. Petersburg, Russia;
- Correspondence:
| | - Evgeniy I. Sysoev
- Department of Genetics and Biotechnology, St. Petersburg State University, 199034 St. Petersburg, Russia;
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7
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Loureiro RJS, Vila-Viçosa D, Machuqueiro M, Shakhnovich EI, Faísca PFN. A tale of two tails: The importance of unstructured termini in the aggregation pathway of β2-microglobulin. Proteins 2017; 85:2045-2057. [DOI: 10.1002/prot.25358] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/13/2017] [Accepted: 07/22/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Rui J. S. Loureiro
- BioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa; Lisboa Portugal
| | - Diogo Vila-Viçosa
- Centro de Química e Bioquímica; Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa; Lisboa Portugal
| | - Miguel Machuqueiro
- Centro de Química e Bioquímica; Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa; Lisboa Portugal
| | - Eugene I. Shakhnovich
- Department of Chemistry and Chemical Biology; Harvard University; Cambridge Massachusetts
| | - Patricia F. N. Faísca
- BioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa; Lisboa Portugal
- Departamento de Física; Faculdade de Ciências, Universidade de Lisboa; Lisboa Portugal
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8
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Argyropoulos CP, Chen SS, Ng YH, Roumelioti ME, Shaffi K, Singh PP, Tzamaloukas AH. Rediscovering Beta-2 Microglobulin As a Biomarker across the Spectrum of Kidney Diseases. Front Med (Lausanne) 2017; 4:73. [PMID: 28664159 PMCID: PMC5471312 DOI: 10.3389/fmed.2017.00073] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/26/2017] [Indexed: 12/28/2022] Open
Abstract
There is currently an unmet need for better biomarkers across the spectrum of renal diseases. In this paper, we revisit the role of beta-2 microglobulin (β2M) as a biomarker in patients with chronic kidney disease and end-stage renal disease. Prior to reviewing the numerous clinical studies in the area, we describe the basic biology of β2M, focusing in particular on its role in maintaining the serum albumin levels and reclaiming the albumin in tubular fluid through the actions of the neonatal Fc receptor. Disorders of abnormal β2M function arise as a result of altered binding of β2M to its protein cofactors and the clinical manifestations are exemplified by rare human genetic conditions and mice knockouts. We highlight the utility of β2M as a predictor of renal function and clinical outcomes in recent large database studies against predictions made by recently developed whole body population kinetic models. Furthermore, we discuss recent animal data suggesting that contrary to textbook dogma urinary β2M may be a marker for glomerular rather than tubular pathology. We review the existing literature about β2M as a biomarker in patients receiving renal replacement therapy, with particular emphasis on large outcome trials. We note emerging proteomic data suggesting that β2M is a promising marker of chronic allograft nephropathy. Finally, we present data about the role of β2M as a biomarker in a number of non-renal diseases. The goal of this comprehensive review is to direct attention to the multifaceted role of β2M as a biomarker, and its exciting biology in order to propose the next steps required to bring this recently rediscovered biomarker into the twenty-first century.
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Affiliation(s)
- Christos P Argyropoulos
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Shan Shan Chen
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Yue-Harn Ng
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Maria-Eleni Roumelioti
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Kamran Shaffi
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Pooja P Singh
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Antonios H Tzamaloukas
- Nephrology Division, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States.,Raymond G. Murphy VA Medical Center Albuquerque, Albuquerque, NM, United States
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Gershenson A, Gierasch LM, Pastore A, Radford SE. Energy landscapes of functional proteins are inherently risky. Nat Chem Biol 2014; 10:884-91. [PMID: 25325699 PMCID: PMC4416114 DOI: 10.1038/nchembio.1670] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 09/19/2014] [Indexed: 01/08/2023]
Abstract
Evolutionary pressure for protein function leads to unavoidable sampling of conformational states that are at risk of misfolding and aggregation. The resulting tension between functional requirements and the risk of misfolding and/or aggregation in the evolution of proteins is becoming more and more apparent. One outcome of this tension is sensitivity to mutation, in which only subtle changes in sequence that may be functionally advantageous can tip the delicate balance toward protein aggregation. Similarly, increasing the concentration of aggregation-prone species by reducing the ability to control protein levels or compromising protein folding capacity engenders increased risk of aggregation and disease. In this Perspective, we describe examples that epitomize the tension between protein functional energy landscapes and aggregation risk. Each case illustrates how the energy landscapes for the at-risk proteins are sculpted to enable them to perform their functions and how the risks of aggregation are minimized under cellular conditions using a variety of compensatory mechanisms.
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Affiliation(s)
- Anne Gershenson
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Lila M Gierasch
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Annalisa Pastore
- Department of Clinical Neurosciences, King’s College London, Denmark Hill Campus, London, UK
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, UK
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Chmielewski M, Cohen G, Wiecek A, Jesús Carrero J. The peptidic middle molecules: is molecular weight doing the trick? Semin Nephrol 2014; 34:118-34. [PMID: 24780468 DOI: 10.1016/j.semnephrol.2014.02.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Chronic kidney disease (CKD) is characterized by a gradual endogenous intoxication caused by the progressive accumulation of bioactive compounds that in normal conditions would be excreted and/or metabolized by the kidney. Uremic toxicity now is understood as one of the potential causes for the excess of cardiovascular disease and mortality observed in CKD. An important family of uremic toxins is that of the peptidic middle molecules, with a molecular weight ranging between 500 and 60,000 Da, which makes them, as a consequence, difficult to remove in the process of dialysis unless the dialyzer pore size is large enough. This review provides an overview of the main and best-characterized peptidic middle molecules and their role as potential culprits of the cardiometabolic complications inherent to CKD patients.
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Affiliation(s)
- Michal Chmielewski
- Department of Nephrology, Transplantology and Internal Medicine, Medical University of Gdansk, Gdansk, Poland
| | - Gerald Cohen
- Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Andrzej Wiecek
- Department of Nephrology, Endocrinology and Metabolic Diseases, Medical University of Silesia, Katowice, Poland
| | - Juan Jesús Carrero
- Division of Nephrology and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
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11
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Buck PM, Kumar S, Singh SK. On the role of aggregation prone regions in protein evolution, stability, and enzymatic catalysis: insights from diverse analyses. PLoS Comput Biol 2013; 9:e1003291. [PMID: 24146608 PMCID: PMC3798281 DOI: 10.1371/journal.pcbi.1003291] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 08/30/2013] [Indexed: 11/18/2022] Open
Abstract
The various roles that aggregation prone regions (APRs) are capable of playing in proteins are investigated here via comprehensive analyses of multiple non-redundant datasets containing randomly generated amino acid sequences, monomeric proteins, intrinsically disordered proteins (IDPs) and catalytic residues. Results from this study indicate that the aggregation propensities of monomeric protein sequences have been minimized compared to random sequences with uniform and natural amino acid compositions, as observed by a lower average aggregation propensity and fewer APRs that are shorter in length and more often punctuated by gate-keeper residues. However, evidence for evolutionary selective pressure to disrupt these sequence regions among homologous proteins is inconsistent. APRs are less conserved than average sequence identity among closely related homologues (≥80% sequence identity with a parent) but APRs are more conserved than average sequence identity among homologues that have at least 50% sequence identity with a parent. Structural analyses of APRs indicate that APRs are three times more likely to contain ordered versus disordered residues and that APRs frequently contribute more towards stabilizing proteins than equal length segments from the same protein. Catalytic residues and APRs were also found to be in structural contact significantly more often than expected by random chance. Our findings suggest that proteins have evolved by optimizing their risk of aggregation for cellular environments by both minimizing aggregation prone regions and by conserving those that are important for folding and function. In many cases, these sequence optimizations are insufficient to develop recombinant proteins into commercial products. Rational design strategies aimed at improving protein solubility for biotechnological purposes should carefully evaluate the contributions made by candidate APRs, targeted for disruption, towards protein structure and activity. Biotechnology requires the large-scale expression, yield, and storage of recombinant proteins. Each step in protein production has the potential to cause aggregation as proteins, not evolved to exist outside the cell, endure the various steps involved in commercial manufacturing processes. Mechanistic studies into protein aggregation have revealed that certain sequence regions contribute more to the aggregation propensity of a protein than other sequence regions do. Efforts to disrupt these regions have thus far indicated that rational sequence engineering is a useful technique to reduce the aggregation of biotechnologically relevant proteins. To improve our ability to rationally engineer proteins with enhanced expression, solubility, and shelf-life we conducted extensive analyses of aggregation prone regions (APRs) within protein sequences to characterize the various roles these regions play in proteins. Findings from this work indicate that protein sequences have evolved by minimizing their aggregation propensities. However, we also found that many APRs are conserved in protein families and are essential to maintain protein stability and function. Therefore, the contributions that APRs, targeted for disruption, make towards protein stability and function should be carefully evaluated when improving protein solubility via rational design.
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Affiliation(s)
- Patrick M Buck
- Pharmaceutical Research and Development, Biotherapeutics Pharmaceutical Sciences, Pfizer Inc., Chesterfield, Missouri, United States of America
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