Characterization of fibroblasts responsible for cartilage destruction in arthritis

Anti-rheumatoid arthritis potential of Halodule pinifolia: development, characterization and in vivo evaluation of H. pinifolia-based oral suspension and lipid nano-emulsion

For treating chronic diseases like rheumatoid arthritis, herbal medicines are preferred due to their evident therapeutic effects and lesser side effects as compared to the long-term used conventional drugs. In this study, the anti-rheumatoid arthritis effect of an unexplored marine grass Halodule pinifolia (HP), and a combination of it with Glycyrrhiza glabra (liquorice; LQ), prepared as a conventional suspension (C1) and a lipid nano-emulsion (C1-N) was evaluated in Freund's complete adjuvant (FCA)- and collagen-induced arthritis (CIA) models. Formulations C1 and C1-N contained standardized extract HP (100 mg/kg) as major active ingredient and liquorice LQ (50 mg/kg) as both active ingredient (anti-inflammatory and anti-ulcer) and sweetening agent. Oral administration of HP and C1 to FCA-induced Sprague-Dawley rats significantly reduced the paw oedema, spleen index, controlled the haematological parameters, cytokine levels (IL-1β, IL-6, TNF-α estimated by ELISA), mRNA expression of cytokines and osteoclast markers (RANK, TRAP and cathepsin K measured by RTPCR). Histopathology and radiological scanning demonstrated lesser joint deterioration in sample-treated rats, as evident phenotypically. The downregulation of CD51 and MMP-3 (western blot) corroborated the anti-arthritic effect of HP and C1. HP showed better results among all. Further, under the CIA model, both C1 and C1-N were found to be potentially active as evidenced by their effect on rat paw oedema, spleen index, haematological parameters, rheumatoid factor, cytokines, osteoclast markers, histology and X-rays. The results proved the anti-arthritic effect of HP and the formulations, particularly the lipid nano-emulsion that showed improved stability as well as activity.

NIH/3T3 Fibroblasts Selectively Activate T Cells Specific for Posttranslationally Modified Collagen Type II

It has been shown that synovial fibroblasts (SF) play a key role in the initiation of inflammation and joint destruction, leading to arthritis progression. Fibroblasts may express major histocompatibility complex class II region (MHCII) molecules, and thus, they could be able to process and present antigens to immunocompetent cells. Here we examine whether different types of fibroblasts (synovial, dermal, and thymic murine fibroblasts, destructive LS48 fibroblasts, and noninvasive NIH/3T3 fibroblasts) may be involved in the initiation of rheumatoid arthritis (RA) pathogenesis and can process and present type II collagen (COL2)-an autoantigen associated with RA. Using a panel of MHCII/Aq-restricted T-cell hybridoma lines that specifically recognize an immunodominant COL2 epitope (COL2_259-273), we found that NIH/3T3 fibroblasts activate several T-cell clones that recognize the posttranslationally glycosylated or hydroxylated COL2_259-273 epitope. The HCQ.3 hybridoma, which is specific for the glycosylated immunodominant COL2 epitope 259-273 (Gal264), showed the strongest response. Interestingly, NIH/3T3 cells, but not destructive LS48 fibroblasts, synovial, dermal, or thymic fibroblasts, were able to stimulate the HCQ.3 hybridoma and other COL2-specific T-cell hybridomas. Our experiments revealed that NIH/3T3 fibroblasts are able to activate COL2-specific T-cell hybridomas even in the absence of COL2 or a posttranslationally modified COL2 peptide. The mechanism of this unusual activation is contact-dependent and involves the T-cell receptor (TCR) complex.

CD147 mediates intrahepatic leukocyte aggregation and determines the extent of liver injury

Background

Chronic inflammation is the driver of liver injury and results in progressive fibrosis and eventual cirrhosis with consequences including both liver failure and liver cancer. We have previously described increased expression of the highly multifunctional glycoprotein CD147 in liver injury. This work describes a novel role of CD147 in liver inflammation and the importance of leukocyte aggregates in determining the extent of liver injury.

Methods

Non-diseased, progressive injury, and cirrhotic liver from humans and mice were examined using a mAb targeting CD147. Inflammatory cell subsets were assessed by multiparameter flow cytometry.

Results

In liver injury, we observe abundant, intrahepatic leukocyte clusters defined as ≥5 adjacent CD45⁺ cells which we have termed “leukocyte aggregates”. We have shown that these leukocyte aggregates have a significant effect in determining the extent of liver injury. If CD147 is blocked in vivo, these leukocyte aggregates diminish in size and number, together with a marked significant reduction in liver injury including fibrosis. This is accompanied by no change in overall intrahepatic leukocyte numbers. Further, blocking of aggregation formation occurs prior to an appreciable increase in inflammatory markers or fibrosis. Additionally, there were no observed, “off-target” or unpredicted effects in targeting CD147.

Conclusion

CD147 mediates leukocyte aggregation which is associated with the development of liver injury. This is not a secondary effect, but a cause of injury as aggregate formation proceeds other markers of injury. Leukocyte aggregation has been previously described in inflammation dating back over many decades. Here we demonstrate that leukocyte aggregates determine the extent of liver injury.

The Effect of SHH-Gli Signaling Pathway on the Synovial Fibroblast Proliferation in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by chronic synovitis. This study aims to investigate the role of sonic hedgehog (SHH)-Gli signaling pathway in synovial fibroblast proliferation in rheumatoid arthritis. The expression of serum SHH in RA patients group was significantly increased compared with the systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), and healthy subject (healthy control, HC) groups, respectively; serum SHH expression of RA patients was positively correlated with rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP Ab), while there was no significant correlation between SHH expression and erythrocyte sedimentation rate (ESR). SHH, Ptch, Smo, and Gli molecules were highly expressed in rat RA-synovial fibroblast (RA-SF); after blocking the SHH-Gli signaling pathway with a Gli specific inhibitor, Gli-antagonist 61 (GANT61), RA-SF proliferation was inhibited in a dose-dependent manner and the apoptosis rate of RA-SF was increased as well; the expression levels of fibroblast growth factor receptor 1 (FGFR1) and FGFR3 declined in SF cells after GANT61 treatment. Our results suggest that SHH-Gli pathway is involved in the pathogenesis of RA, and blocking SHH-Gli pathway inhibits RA-SF cell proliferation and increases cell apoptosis, which may shed light on developing new ideas for RA treatment.

Au@pNIPAM SERRS Tags for Multiplex Immunophenotyping Cellular Receptors and Imaging Tumor Cells

Detection technologies employing optically encoded particles have gained much interest toward clinical diagnostics and drug discovery, but the portfolio of available systems is still limited. The fabrication and characterization of highly stable surface-enhanced resonance Raman scattering (SERRS)-encoded colloids for the identification and imaging of proteins expressed in cells are reported. These plasmonic nanostructures are made of gold octahedra coated with poly(N-isopropylacrylamide) microgels and can be readily encoded with Raman active dyes while retaining high colloidal stability in biofluids. A layer-by-layer polyelectrolyte coating is used to seal the outer surface of the encoded particles and to provide a reactive surface for covalent conjugation with antibodies. The targeted multiplexing capabilities of the SERRS tags are demonstrated by the simultaneous detection and imaging of three tumor-associated surface biomarkers: epidermal growth factor receptor (EGFR), epithelial cell adhesion molecule (EpCAM), and homing cell adhesion molecule (CD44) by SERRS spectroscopy. The plasmonic microgels are able to discriminate tumor A431 (EGFR+/EpCAM+/CD44+) and nontumor 3T3 2.2 (EGFR-/EpCAM-/CD44+) cells while cocultured in vitro.

Hepatocyte produced matrix metalloproteinases are regulated by CD147 in liver fibrogenesis

BACKGROUND

The classical paradigm of liver injury asserts that hepatic stellate cells (HSC) produce, remodel and turnover the abnormal extracellular matrix (ECM) of fibrosis via matrix metalloproteinases (MMPs). In extrahepatic tissues MMP production is regulated by a number of mechanisms including expression of the glycoprotein CD147. Previously, we have shown that CD147 is expressed on hepatocytes but not within the fibrotic septa in cirrhosis [1]. Therefore, we investigated if hepatocytes produce MMPs, regulated by CD147, which are capable of remodelling fibrotic ECM independent of the HSC.

METHODS

Non-diseased, fibrotic and cirrhotic livers were examined for MMP activity and markers of fibrosis in humans and mice. CD147 expression and MMP activity were co-localised by in-situ zymography. The role of CD147 was studied in-vitro with siRNA to CD147 in hepatocytes and in-vivo in mice with CCl4 induced liver injury using ãCD147 antibody intervention.

RESULTS

In liver fibrosis in both human and mouse tissue MMP expression and activity (MMP-2, -9, -13 and -14) increased with progressive injury and localised to hepatocytes. Additionally, as expected, MMPs were abundantly expressed by activated HSC. Further, with progressive fibrosis there was expression of CD147, which localised to hepatocytes but not to HSC. Functionally significant in-vitro regulation of hepatocyte MMP production by CD147 was demonstrated using siRNA to CD147 that decreased hepatocyte MMP-2 and -9 expression/activity. Further, in-vivo α-CD147 antibody intervention decreased liver MMP-2, -9, -13, -14, TGF-β and α-SMA expression in CCl4 treated mice compared to controls.

CONCLUSION

We have shown that hepatocytes produce active MMPs and that the glycoprotein CD147 regulates hepatocyte MMP expression. Targeting CD147 regulates hepatocyte MMP production both in-vitro and in-vivo, with the net result being reduced fibrotic matrix turnover in-vivo. Therefore, CD147 regulation of hepatocyte MMP is a novel pathway that could be targeted by future anti-fibrogenic agents.

Cyclophilin-CD147 interactions: a new target for anti-inflammatory therapeutics

CD147 is a widely expressed plasma membrane protein that has been implicated in a variety of physiological and pathological activities. It is best known for its ability to function as extracellular matrix metalloproteinase inducer (hence the other name for this protein, EMMPRIN), but has also been shown to regulate lymphocyte responsiveness, monocarboxylate transporter expression and spermatogenesis. These functions reflect multiple interacting partners of CD147. Among these CD147-interacting proteins cyclophilins represent a particularly interesting class, both in terms of structural considerations and potential medical implications. CD147 has been shown to function as a signalling receptor for extracellular cyclophilins A and B and to mediate chemotactic activity of cyclophilins towards a variety of immune cells. Recent studies using in vitro and in vivo models have demonstrated a role for cyclophilin-CD147 interactions in the regulation of inflammatory responses in a number of diseases, including acute lung inflammation, rheumatoid arthritis and cardiovascular disease. Agents targeting either CD147 or cyclophilin activity showed significant anti-inflammatory effects in experimental models, suggesting CD147-cyclophilin interactions may be a good target for new anti-inflammatory therapeutics. Here, we review the recent literature on different aspects of cyclophilin-CD147 interactions and their role in inflammatory diseases.

Basics of standardization and calibration in cytometry--a review

Standardization, calibration, and controls (negative and positive controls) are essential for quality assurance. Cytometers are capable of reliable and repeatable cellular analyses. However, a prerequisite is instrument calibration and standardized preanalytics. Calibration is often done by beads. Beads are available for different quality control applications, e.g. calibration of size and measuring scale, compensation, absolute cell counting, and laser alignment. Results can be standardized by converting MFI values into MESF or ABC values. Standardized data allow comparison of experiments over a long period of time and between different instruments and laboratories. Alterations in the sensitivity of the cytometer can be detected by routinely performing quality control. The process of quality assurance quantifies and helps manage the variance from the desired value. Results can thus be compared objectively with those of other laboratories. Standardization is the basis of cytometry and a prerequisite for obtaining reliable data.

Expression of Brachyury in mesenchymal progenitor cells leads to cartilage-like tissue that is resistant to the destructive effect of rheumatoid arthritis synovial fibroblasts

Our objectives were to determine the chondrogenic potential of a murine Brachyury-transformed mesenchymal progenitor cell line in the presence of rheumatoid arthritis-activated synovial fibroblasts (RASFs). Brachyury-transformed mesenchymal progenitor cells were implanted alone or combined with RASFs isolated from diseased human joints in each of six immunodeficient SCID mice. De novo tissue formation was analysed by histology and immunohistochemistry after 60 days. Spheroid nodules resembling cartilage morphologically and by the expression of proteoglycans and collagen II developed in four of six implants in the absence and in five of six implants in the presence of RASFs. No evidence for hypertrophic differentiation could be observed. Mesenchymal progenitor cells transformed with Brachyury are able to produce a cartilage like tissue in vivo over an extended period of time that is resistant to the destructive effect of RASF. This observation may provide opportunities for a cell-based reconstructive treatment in joint disease.