| 1. |
- Alim, Abdul, 1983-, et al.
(författare)
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Tick-borne encephalitis virus protein expression to develop novel subunit vaccines and diagnostic tools
- 2023
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Konferensbidrag (refereegranskat)abstract
- Tick-borne encephalitis virus (TBEV) and Langat virus (LGTV) are both members of Flavivirus genus within the Flaviviridae family. TBEV is the main pathogenic arbovirus circulating in Europe, Russia, and China. Flaviviruses are characterized by a positive sense single-stranded RNA genome and an enveloped icosahedral virion structure. Previously, it has been observed that flavivirus envelope (E) protein and non-structural protein 1 (NS1) both play a critical role in the pathology of flavivirus. Therefore, in this study, we aim to investigate flavivirus E and NS1 protein as a good target for the development of a subunit vaccine with further potential as a putative diagnostic tool to distinguish between TBEV infected from TBEV vaccinated individuals. Thus, we have generated 4 different successful constructs with TBEV (E and NS1) and LGTV (E and NS1) in the pET SUMO vector. Restriction digestion and sequencing analysis confirmed successful clones of interest and their right orientation. Next, the right clones were transformed in BL21 (DE3) one shoot chemically competent E. coli and induce the expression with 0.5 mM IPTG in culture medium following 0-4h, and 24h incubation period. Next, bacterial cell pellets were collected and used for SDSPAGE/Western blot analysis. We used the champion™ pET SUMO expression system which may produce high levels of soluble protein in bacteria. It employs a small ubiquitin-related modifier (SUMO) fusion, belonging to the growing family of ubiquitin-related proteins, to enhance the solubility of expressed fusion proteins. We have stained with 6x-His tag antibody of interest (mouse monoclonal) for targeting both TBEV- E/NS1 and LGTV-E/NS1 proteins. Among them, the expression of TBEV-NS1 and LGTV-E proteins was verified and confirmed. Several attempts have also been made to obtain the TBEV-E and LGTV-NS1 protein in E. coli cells; however, these require further optimization with a suitable time and dose of IPTG induction. We have used the BL21(DE3) expression system, which could maximize the expression of soluble protein. After successful expression, the 13-kd SUMO moiety will be cleaved by the highly specific and active SUMO (ULP1) protease at the carboxyl terminal, producing a native protein. Furthermore, a protein purification assay (e-g., NI-NTA column/ÄKTA Protein Purification Systems) will be developed to obtain native recombinant protein. The purified proteins will be studied in combination with suitable adjuvants as putative TBE subunit vaccines. They will also be characterized with the potential to develop new tools for TBE diagnostics.
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| 2. |
- Ackermann, Paul W., et al.
(författare)
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Tendon pain : what are the mechanisms behind it?
- 2023
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Ingår i: Scandinavian Journal of Pain. - : Walter de Gruyter. - 1877-8860 .- 1877-8879. ; 23:1, s. 14-24
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Forskningsöversikt (refereegranskat)abstract
- ObjectivesManagement of chronic tendon pain is difficult and controversial. This is due to poor knowledge of the underlying pathophysiology of chronic tendon pain, priorly known as tendinitis but now termed tendinopathy. The objective of this topical review was to synthesize evolving information of mechanisms in tendon pain, using a comprehensive search of the available literature on this topic.ContentThis review found no correlations between tendon degeneration, collagen separation or neovascularization and chronic tendon pain. The synthesis demonstrated that chronic tendon pain, however, is characterized by excessive nerve sprouting with ingrowth in the tendon proper, which corresponds to alterations oberserved also in other connective tissues of chronic pain conditions. Healthy, painfree tendons are devoid of nerve fibers in the tendon proper, while innervation is confined to tendon surrounding structures, such as sheaths. Chronic painful tendons exhibit elevated amounts of pain neuromediators, such as glutamate and substance p as well as up-regulated expression and excitability of pain receptors, such as the glutamate receptor NMDAR1 and the SP receptor NK1, found on ingrown nerves and immune cells. Increasing evidence indicates that mast cells serve as an important link between the peripheral nervous system and the immune systems resulting in so called neurogenic inflammation.SummaryChronic painful tendons exhibit (1) protracted ingrowth of sensory nerves (2) elevated pain mediator levels and (3) up-regulated expression and excitability of pain receptors, participating in (4) neuro-immune pathways involved in pain regulation. Current treatments that entail the highest scientific evidence to mitigate chronic tendon pain include eccentric exercises and extracorporeal shockwave, which both target peripheral neoinnervation aiming at nerve regeneration.OutlookPotential mechanism-based pharmacological treatment approaches could be developed by blocking promotors of nerve ingrowth, such as NGF, and promoting inhibitors of nerve ingrowth, like semaphorins, as well as blocking glutamate-NMDA-receptor pathways, which are prominent in chronic tendon pain.
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| 3. |
- Alim, Abdul, 1983-, et al.
(författare)
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Do Mast Cells Have a Role in Tendon Healing and Inflammation?
- 2020
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Ingår i: Cells. - : MDPI AG. - 2073-4409. ; 9:5
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Forskningsöversikt (refereegranskat)abstract
- Understanding the links between the tendon healing process, inflammatory mechanisms, and tendon homeostasis/pain after tissue damage is crucial in developing novel therapeutics for human tendon disorders. The inflammatory mechanisms that are operative in response to tendon injury are not fully understood, but it has been suggested that inflammation occurring in response to nerve signaling, i.e., neurogenic inflammation, has a pathogenic role. The mechanisms driving such neurogenic inflammation are presently not clear. However, it has recently been demonstrated that mast cells present within the injured tendon can express glutamate receptors, raising the possibility that mast cells may be sensitive to glutamate signaling and thereby modulate neurogenic inflammation following tissue injury. In this review, we discuss the role of mast cells in the communication with peripheral nerves, and their emerging role in tendon healing and inflammation after injury.
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| 4. |
- Alim, Abdul, 1983-, et al.
(författare)
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Glutamate triggers the expression of functional ionotropic and metabotropic glutamate receptors in mast cells
- 2021
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Ingår i: Cellular & Molecular Immunology. - : Springer Nature. - 1672-7681 .- 2042-0226. ; 18:10, s. 2383-2392
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Tidskriftsartikel (refereegranskat)abstract
- Mast cells are emerging as players in the communication between peripheral nerve endings and cells of the immune system. However, it is not clear the mechanism by which mast cells communicate with peripheral nerves. We previously found that mast cells located within healing tendons can express glutamate receptors, raising the possibility that mast cells may be sensitive to glutamate signaling. To evaluate this hypothesis, we stimulated primary mast cells with glutamate and showed that glutamate induced the profound upregulation of a panel of glutamate receptors of both the ionotropic type (NMDAR1, NMDAR2A, and NMDAR2B) and the metabotropic type (mGluR2 and mGluR7) at both the mRNA and protein levels. The binding of glutamate to glutamate receptors on the mast cell surface was confirmed. Further, glutamate had extensive effects on gene expression in the mast cells, including the upregulation of pro-inflammatory components such as IL-6 and CCL2. Glutamate also induced the upregulation of transcription factors, including Egr2, Egr3 and, in particular, FosB. The extensive induction of FosB was confirmed by immunofluorescence assessment. Glutamate receptor antagonists abrogated the responses of the mast cells to glutamate, supporting the supposition of a functional glutamate-glutamate receptor axis in mast cells. Finally, we provide in vivo evidence supporting a functional glutamate-glutamate receptor axis in the mast cells of injured tendons. Together, these findings establish glutamate as an effector of mast cell function, thereby introducing a novel principle for how cells in the immune system can communicate with nerve cells.
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| 5. |
- Alim, Abdul, 1983-
(författare)
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Mechanisms in Tendon Healing : Pain, Biomarkers and the Role of Mast Cells
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tendon injuries and tendinopathy are common disorders, but the underlying mechanisms are not well understood. The overall aim of this thesis was to better understand the mechanisms underlying tendon healing, pain, and inflammation.The aim of the first study was to assess biomarkers of tendon healing, including procollagen type I (PINP) and type III (PIIINP) in relation to patient outcome in 65 patients with Achilles tendon rupture (ATR). At two weeks post-ATR, PINP and PIIINP-levels were quantified using microdialysis followed by ELISA. At one-year post-ATR patient outcome was assessed using the validated Achilles tendon Total Rupture Score. We found that higher ratio of PINP and PIIINP to total protein were significantly associated with less pain but more fatigue in the affected limb.In the second study, we applied Intermittent Pneumatic Compression (IPC) therapy for two weeks to stimulate tendon healing. The patients received either adjuvant IPC treatment or treatment-as-usual in a plaster cast without IPC. We observed that IPC therapy significantly increased PINP levels in the injured tendon, suggesting enhanced healing response.In our third study, we investigated healing response and the role of mast cells (MCs) in-vivo using an ATR rat model. Three weeks postoperatively, we demonstrated an increased number of MCs and a higher proportion of degranulated MCs in the injured tendon compared to the control. We further established that MCs in the injured tendon were positive for the glutamate receptor NMDAR1.In our final study, we assessed the effect of glutamate stimulation on in-vitro-derived mouse bone marrow MCs. Mast cell degranulation was quantified through β-hexosaminidase release, immunofluorescence was used to quantify NMDARs at the protein level, and RT-qPCR/microarray was used to study the expression of NMDARs and associated genes. Glutamate induced a robust upregulation of glutamate receptors of both ionotropic and metabotropic type, both at the mRNA and at protein level. NMDAR1 co-localized with glutamate in the membrane of MCs, thereby confirming an interaction between glutamate and its receptor. Glutamate also induced expression of pro-inflammatory compounds such as IL-6 and CCL2 and transcription factors such as Egr2, Egr3 and FosB. Moreover, the NMDA-channel blocker MK-801 completely abrogated the response of MCs to glutamate, supporting a functional glutamate–glutamate receptor axis in MCs.Together, findings presented in this dissertation reveal possible mechanisms of tendon healing in relation to pain and function, and establish a novel principle for how immune cells can communicate with nerve cells after ATR.
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