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Tsai YC, Hsieh AH, Wang LC, Chou IJ, Tseng WY, Yu KH, Luo SF, Kuo CF. THU0241 ALTERATIONS OF THE FECAL MICROBIOTA ASSOCIATED WITH EXACERBATION OF LUPUS ACTIVITY BY HCMV PP65 422-439 IMMUNIZATION IN NZB/W F1 MICE. Ann Rheum Dis 2020. [DOI: 10.1136/annrheumdis-2020-eular.1846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:Systemic lupus erythematosus (SLE) is a multifactorial disease. Gut microbiota is an important environmental factor for SLE1. The perturbation of gut microbiota is often observed at onset or during the disease course. The fragment of HCMV phosphoprotein 65422-439(HCMVpp65422-439) containing B cell epitopes has been reported to elicit humoral immunity and accelerate the autoimmune response in murine lupus2,3. However, little is there to know about the interplay between viral trigger for SLE and the change of gut microbiota during lupus progression.Objectives:By using a murine lupus model with NZB/W F1, we investigated the differential alteration in gut microbiota associated with the progression of lupus disease in HCMVpp65422-439immunized mice and control mice.Methods:Ten weeks-old NZB/W F1 mice were given or not given an intraperitoneal injection of 100-μg HCMVpp65422-439peptide biweekly for four times. Fecal samples, urine and blood of mice were collected once every two weeks followed by 16S rRNA genes sequencing and ELISA tests. The pathological investigation of renal tissue from sacrificed mice was conducted at 24 weeks of mice age. Statistical analysis for dynamics and alteration of the gut microbiota as well as functional prediction of bacterial communities related to the progression of lupus-like activity was performed.Results:HCMVpp65422-439immunization results in the onset of lupus-like activities in NZB/W F1 mice with a higher titer of anti-dsDNA antibody, creatinine and proteinuria, and severe glomerular damage (figure 1). Also, higher diversity and increased family abundance of several bacterial species were observed in HCMVpp65422-439immunized mice (Table 1 and Figure 2a). The predicted metagenomic taxonomic profile in NZB/W F1 mice showed statistically significant enrichment of flagellar assembly, bacterial motility, and chemotaxis (Figure 2b). Spearman’s correlation analysis revealed that a significant association between the increased relative family abundance forSaccharimonadaceae, Marinifilaceae, Desulfovibrionaceae,andRikenellaceaeand HCMVpp65422-439induced lupus-like activity in NZB/W F1 mice (Figure 2c).Table 1.Significant test of microbial community structure between two groupsMRPPAdonisAnosimGroupsE-ΔPR2PRPPre-disease vs. Control0.430.10.770.110.112Pre-disease vs. HCMVpp65422-4390.520.0070.550.0090.970.01Control vs. HCMVpp65422-4390.450.0130.350.0140.580.019Conclusion:Our results demonstrated that HCMVpp65422-439immunization induced the change in gut microbiota composition and suggested the association of gut microbiota alteration with lupus-like activity in NZB/W F1 mice.References:[1]Azzouz D, Omarbekova A, Heguy A, Schwudke D, Gisch N, Rovin BH, et al. Lupus nephritis is linked to disease-activity associated expansions and immunity to a gut commensal. Ann Rheum Dis. 2019;78(7):947-56.[2]Sebastiani GD, Iuliano A, Canofari C, and Bracci M. Cytomegalovirus infection in Systemic Lupus Erythematosus: report of four cases challenging the management of the disease, and literature review. Lupus. 2019;28(3):432-7.[3]HoHsieh A, Wang CM, Wu YJ, Chen A, Chang MI, and Chen JY. B cell epitope of human cytomegalovirus phosphoprotein 65 (HCMV pp65) induced anti-dsDNA antibody in BALB/c mice. Arthritis Res Ther. 2017;19(1):65Disclosure of Interests: :None declared
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Twomey JD, Thakore PI, Hartman DA, Myers EGH, Hsieh AH. Roles of type VI collagen and decorin in human mesenchymal stem cell biophysics during chondrogenic differentiation. Eur Cell Mater 2014; 27:237-50; discussion 249-50. [PMID: 24668596 DOI: 10.22203/ecm.v027a17] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Human mesenchymal stem cells (hMSCs) induced towards chondrogenesis develop a pericellular matrix (PCM), rich in type VI collagen (ColVI) and proteoglycans such as decorin (DCN). Individual PCM protein functions still need to be elucidated to fully understand the mechanobiological role of this matrix. In this study we identified ColVI and DCN as important contributors in the mechanical function of the PCM and as biochemical modulators during chondrogenesis through targeted knockdown using shRNA lentiviral vectors. Gene expression, western blotting, immunofluorescence and cell deformation analysis were examined at 7, 14 and 28 days post chondrogenic induction. ColVI and DCN knockdown each affected gene expression of acan, bgn, and sox9 during chondrogenesis. ColVI was found to be of central importance in resisting applied strains, while DCN knockdown had strain dependent effects on deformation. We demonstrate that by using genetic engineering to control the biophysical microenvironment created by differentiating cells, it may be possible to guide cellular mechanotransduction.
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Affiliation(s)
- J D Twomey
- Jeong H. Kim Engineering Building, Room 3242, College Park, MD 20742,
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Lotz JC, Staples A, Walsh A, Hsieh AH. Mechanobiology in intervertebral disc degeneration and regeneration. Conf Proc IEEE Eng Med Biol Soc 2007; 2004:5459. [PMID: 17271585 DOI: 10.1109/iembs.2004.1404528] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The intervertebral disc is an avascular, pliant, composite structure that separates spinal vertebrae and, in health, serves to support compression and facilitate movement. Its morphological organization is directed by fluid pressure and consists of a central swelling gel (nucleus), surrounded peripherally by a constraining ligament (annulus fibrosus), and separated from adjacent vertebrae by semi-permeable membranes (endplate). These three tissues serve differing structural roles, are subjected to differing mechanical environments, and are composed of unique matrices and cells. Viewing disc cells as mechanosensors, we use in vivo models of disc loading to identify spatial and temporal relationships between stress/strain and cell function that define normal morphology and drive the architectural changes attributed to normal aging and degeneration. Intra-discal stress patterns consistent with disc health can then be elucidated based on these relationships, and in turn, help us develop spine-loading criteria that parameterize injury tolerance. This same perspective is critical for tissue engineering approaches for disc repair. Cells and matrices meant to guide healing need to withstand the demanding mechanical forces in the acute phases, and differentiate/remodel along the appropriate trajectory in the long-term. Because of their unique potential for adaptation, we are exploring the mechanoplasticity of mesenchymal stem cells (MSCs) and their use in disc repair strategies. Our data demonstrate that these cells respond differentially to pressure and distortion, and can be delivered, retained, and survive in the disc's demanding mechanical/biochemical environment. Because of these features, MSCs are qualified as an intriguing autograft cell type for disc repair.
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Affiliation(s)
- J C Lotz
- Orthopaedic Bioengineering Laboratory, University of California, San Francisco, USA
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Abstract
Intervertebral disc degeneration has been linked in humans to extreme spinal loading regimens. However, mechanisms by which spinal force influences disc cellularity, morphology and consequently biomechanical function are unclear. To gain insight into mechanobiological interactions within the disc, we developed an in vivo murine tail-compression model. Results from this model demonstrate how deviations in spinal stress induce a cycle of altered cell function and morphology as the disc remodels to a new homoeostatic configuration.
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Affiliation(s)
- J C Lotz
- Orthopaedic Bioengineering Laboratory, University of California, San Francisco 94143-0514, USA.
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Hsieh AH, Tsai CM, Ma QJ, Lin T, Banes AJ, Villarreal FJ, Akeson WH, Sung KL. Time-dependent increases in type-III collagen gene expression in medical collateral ligament fibroblasts under cyclic strains. J Orthop Res 2000; 18:220-7. [PMID: 10815822 DOI: 10.1002/jor.1100180209] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Numerous studies have demonstrated the capacity of mechanical strains to modulate cell behavior through several different signaling pathways. Understanding the response of ligament fibroblasts to mechanically induced strains may provide useful knowledge for treating ligament injury and improving rehabilitation regimens. Biomechanical studies that quantify strains in the anterior cruciate and medial collateral ligaments have shown that these ligaments are subjected to 4-5% strains during normal activities and can be strained to 7.7% during external application of loads to the knee joint. The objective of this study was to characterize the expression of types I and III collagen in fibroblast monolayers of anterior cruciate and medial collateral ligaments subjected to equibiaxial strains on flexible growth surfaces (0.05 and 0.075 strains) by quantifying levels of mRNA encoding these two proteins. Both cyclic strain magnitudes were studied under a frequency of 1 Hz. The results indicated marked differences in responses to strain regimens not only between types I and III collagen mRNA expression within each cell type but also in patterns of expression between anterior cruciate and medial collateral ligament cells. Whereas anterior cruciate ligament fibroblasts responded to cyclic strains by expression of higher levels of type-I collagen message with almost no significant increases in type-III collagen, medial collateral ligament fibroblasts exhibited statistically significant increases in type-III collagen mRNA at all time points after initiation of strain with almost no significant increases in type-I collagen. Furthermore, differences in responses by fibroblasts from the two ligaments were detected between the two strain magnitudes. In particular, 0.075 strains induced a time-dependent increase in type-III collagen mRNA levels in medial collateral ligament fibroblasts whereas 0.05 strains did not. The strain-induced changes in gene expression of these two collagens may have implications for the healing processes in ligament tissue. The differences may explain, in part, the healing differential between the anterior cruciate and medial collateral ligaments in vivo.
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Affiliation(s)
- A H Hsieh
- Department of Bioengineering, University of California, San Diego, La Jolla 92093-0412, USA
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Abstract
Fibroblasts embedded in the amorphous healing tissue matrix of ligaments migrate into damaged sites during the inflammatory process that precedes the formation of new connective tissue after ligament injury. Cell motility involved in this migration is strongly influenced by cellular adhesion to proteins of the extracellular matrix. The adhesion mechanism of interest in this study is the attachment of fibroblasts from the anterior cruciate and medial collateral ligaments to types I and III collagen, two fibrillar collagens secreted by fibroblasts during tissue repair. Types I and III collagen constitute a major portion of these ligaments and are assembled by fibroblasts into long cable-like fibrils in the extracellular space. In this study, a micropipette aspiration technique was used to measure the force required to separate fibroblasts of the anterior cruciate and medial collateral ligaments from substrates composed of type I or III collagen, each at a concentration of 2 or 5 microg/ml. Approximately 1,200 fibroblasts from the anterior cruciate ligament and 1,600 from the medial collateral ligament were used, and the adhesion force and area of these cells were determined. Fibroblasts from the anterior cruciate ligament exhibited greater adhesion force than did those from the medial collateral ligament for all concentrations of types I and III collagen. In addition, the adhesiveness of fibroblasts from both ligaments was dependent on seeding time for all experimental conditions. To determine the adhesiveness per unit area, defined here as the adhesion strength, the adhesion force was normalized by the adhesion area. At early seeding times (15-45 minutes), fibroblasts from the anterior cruciate ligament exhibited greater adhesion strength on surfaces coated with type-I collagen than did those from the medial collateral ligament. However, for both collagen substrates, adhesion strength for fibroblasts from the anterior cruciate ligament decreased with seeding time whereas that for fibroblasts from the medial collateral ligament remained relatively constant for all seeding periods (15-75 minutes).
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Affiliation(s)
- L Yang
- Department of Orthopaedics, University of California, San Diego, La Jolla 92093-0412, USA
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Sung KL, Yang L, Whittemore DE, Shi Y, Jin G, Hsieh AH, Akeson WH, Sung LA. The differential adhesion forces of anterior cruciate and medial collateral ligament fibroblasts: effects of tropomodulin, talin, vinculin, and alpha-actinin. Proc Natl Acad Sci U S A 1996; 93:9182-7. [PMID: 8799175 PMCID: PMC38616 DOI: 10.1073/pnas.93.17.9182] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have determined the effects of tropomodulin (Tmod), talin, vinculin, and alpha-actinin on ligament fibroblast adhesion. The anterior cruciate ligament (ACL), which lacks a functional healing response, and the medial collateral ligament (MCL), a functionally healing ligament, were selected for this study. The micropipette aspiration technique was used to determine the forces needed to separate ACL and MCL cells from a fibronectin-coated surface. Delivery of exogenous tropomodulin, an actin-filament capping protein, into MCL fibroblasts significantly increased adhesion, whereas its monoclonal antibody (mAb) significantly decreased cell adhesiveness. However, for ACL fibroblasts, Tmod significantly reduced adhesion, whereas its mAb had no effect. mAbs to talin, vinculin, and alpha-actinin significantly decreased the adhesion of both ACL and MCL cells with increasing concentrations of antibody, and also reduced stress fiber formation and cell spreading rate as revealed by immunofluorescence microscopy. Disruption of actin filament and microtubule assembly with cytochalasin D and colchicine, respectively, also significantly reduced adhesion in ACL and MCL cells. In conclusion, both ACL and MCL fibroblast adhesion depends on cytoskeletal assembly; however, this dependence differs between ACL and MCL fibroblasts in many ways, especially in the role of Tmod. These results add yet another possible factor in explaining the clinical differences in healing between the ACL and the MCL.
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Affiliation(s)
- K L Sung
- Department of Orthopaedics, University of California at San Diego, La Jolla 92093-0412, USA
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Abstract
Pneumonia is common among patients with artificial airways in place. Most prior studies of such pneumonia involve a heterogeneous group of patients, usually with major medical or surgical illnesses. We studied the incidence of pneumonia in a group of patients with isolated closed head injury (CHI) in an effort to determine the pattern of the problem in the absence of other injuries and to determine whether the pattern of development of pneumonia in these patients was comparable to that in more heterogeneous groups of mechanically ventilated patients. We studied 109 initially comatose patients with isolated CHI who were ventilated 24 h or more. The mean age was 30.3 +/- 20.2 yr, 72% were male, and the admission Glasgow coma score was 4.9T +/- 1.4. Overall, 45 patients (41%) developed pneumonia, with the majority (29/45) occurring during the first 3 days of hospitalization. No patient developed pneumonia after the first week despite the fact that many were still ventilated, others remained intubated, and yet others were extubated but comatose. Patients who developed pneumonia experienced a longer ICU stay (10.5 +/- 5.4 days versus 7.2 +/- 4.3 days, p = 0.001) and hospital stay (34.8 +/- 27.6 versus 22.5 +/- 20.2 days, p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A H Hsieh
- Department of Medicine (Pulmonary and Critical Care), Harborview Medical Center, University of Washington School of Medicine, Seattle 98104
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