Human amnion epithelial cell transplantation abrogates lung fibrosis and augments repair

Rationale: Chronic lung disease characterized by loss of lung tissue,inflammation, and fibrosis represents a major global health burden. Cellular therapies that could restore pneumocytes and reduce inflammation and fibrosis would be a major advance in management. Objectives: To determine whether human amnion epithelial cells (hAECs), isolated from term placenta and having stem cell–like and antiinflammatory properties, could adopt an alveolar epithelial phenotype and repair a murine model of bleomycin-induced lung injury. Methods: Primary hAECs were cultured in small airway growth medium to determine whether the cells could adopt an alveolar epithelial phenotype. Undifferentiated primary hAECs were also injected parenterally into SCID mice after bleomycin-induced lung injury and analyzed for production of surfactant protein (SP)-A, SP-B, SP-C, and SP-D. Mouse lungs were also analyzed for inflammation and collagen deposition. Measurements and Main Results: hAECs grown in small airway growth medium developed an alveolar epithelial phenotype with lamellar body formation, production of SPs A–D, and SP-D secretion. Although hAECs injected into mice lacked SPs, hAECs recovered from mouse lungs 2 weeks posttransplantation produced SPs. hAECs remained engrafted over the 4-week test period. hAEC administration reduced inflammation in association with decreased monocyte chemoattractant protein-1, tumor necrosis factor-a, IL-1 and -6, and profibrotic transforming growth factor-b in mouse lungs. In addition,lung collagen content was significantly reduced by hAEC treatment as a possible consequence of increased degradation by matrix metalloproteinase-2 and down-regulation of the tissue inhibitors f matrix metalloproteinase-1 and 2. Conclusions: hAECs offer promise as a cellular therapy for alveolar restitution and to reduce lung inflammation and fibrosis.

Effect of tocopherol on atherosclerosis, vascular function and inflammation in Apolipoprotein E knockout mice with subtotal nephrectomy

Background/Aims: Inflammation and endothelial dysfunction contribute to cardiovascular disease, prevalent in chronic kidney disease (CKD). Antioxidant supplements such as tocopherols may reduce inflammation and atherosclerosis. This study aimed to investigate the effect of tocopherol supplementation on vascular function, aortic plaque formation, and inflammation in apolipoprotein E−/− mice with 5/6 nephrectomy as a model of combined cardiovascular and kidney disease. Methods: Nephrectomized mice were assigned to a normal chow diet group (normal chow), a group receiving 1000 mg/kg diet of α-tocopherol supplementation or a group receiving 1000 mg/kg diet mixed-tocopherol (60% γ-tocopherol). Results: Following 12 weeks, in vitro aortic endothelial-independent relaxation was enhanced with both α-tocopherol and mixed-tocopherol (P < 0.05), while mixed-tocopherol enhanced aortic contraction at noradrenaline concentrations of 3 × 10−7 M to 3 × 10−5 M (P < 0.05), when compared to normal chow. Supplementation with α- and mixed-tocopherol reduced systemic concentrations of IL-6 (P < 0.001 and P < 0.001, respectively) and IL-10 (P < 0.05 and P < 0.001, respectively), while α-tocopherol also reduced MCP-1 (P < 0.05) and tumor necrosis factor (TNF)-α (P < 0.05). Aortic sinus plaque area was significantly reduced with α-tocopherol supplementation when compared to normal chow (P < 0.01). Conclusion: Tocopherol supplementation favorably influenced vascular function and cytokine profile, while it was also effective in reducing atherosclerosis in the apolipoprotein E−/− mouse with CKD.

Cytokine expression and secretion by skeletal muscle cells : regulatory mechanisms and exercise effects

Cytokines are important mediators of various aspects of health and disease, including appetite, glucose and lipid metabolism, insulin sensitivity, skeletal muscle hypertrophy and atrophy. Over the past decade or so, considerable attention has focused on the potential for regular exercise to counteract a range of disease states by modulating cytokine production. Exercise stimulates moderate to large increases in the circulating concentrations of interleukin (IL)-6, IL-8, IL-10, IL-1 receptor antagonist, granulocyte-colony stimulating factor, and smaller increases in tumor necrosis factor-α, monocyte chemotactic protein-1, IL-1β, brain-derived neurotrophic factor, IL-12p35/p40 and IL-15. Although many of these cytokines are also expressed in skeletal muscle, not all are released from skeletal muscle into the circulation during exercise. Conversely, some cytokines that are present in the circulation are not expressed in skeletal muscle after exercise. The reasons for these discrepant cytokine responses to exercise are unclear. In this review, we address these uncertainties by summarizing the capacity of skeletal muscle cells to produce cytokines, analyzing other potential cellular sources of circulating cytokines during exercise, and discussing the soluble factors and intracellular signaling pathways that regulate cytokine synthesis (e.g., RNA-binding proteins, microRNAs, suppressor of cytokine signaling proteins, soluble receptors).

Reduced intensity conditioning for allogeneic hematopoietic stem cell transplant determines the kinetics of acute Graft-Versus-Host Disease

Background Preparative myeloablative conditioning regimens for allogeneic hematopoietic stem-cell transplantation (HSCT) may control malignancy and facilitate engraftment but also contribute to transplant related mortality, cytokine release, and acute graft-versus-host disease (GVHD). Reduced intensity conditioning (RIC) regimens have decreased transplant related mortality but the incidence of acute GVHD, while delayed, remains unchanged. There are currently no in vivo allogeneic models of RIC HSCT, limiting studies into the mechanism behind RIC-associated GVHD. Methods We developed two RIC HSCT models that result in delayed onset GVHD (major histocompatibility complex mismatched (UBI-GFP/BL6 [H-2b]→BALB/c [H-2d]) and major histocompatibility complex matched, minor histocompatibility mismatched (UBI-GFP/BL6 [H-2b]→BALB.B [H-2b])) enabling the effect of RIC on chimerism, dendritic cell (DC) chimerism, and GVHD to be investigated. Results In contrast with myeloablative conditioning, we observed that RIC-associated delayed-onset GVHD is characterized by low production of tumor necrosis factor-α, maintenance of host DC, phenotypic DC activation, increased T-regulatory cell numbers, and a delayed emergence of activated donor DC. Furthermore, changes to the peritransplant milieu in the recipient after RIC lead to the altered activation of DC and the induction of T-regulatory responses. Reduced intensity conditioning recipients suffer less early damage to GVHD target organs. However, as donor cells engraft, activated donor DC and rising levels of tumor necrosis factor-α are associated with a later onset of severe GVHD. Conclusions Delineating the mechanisms underlying delayed onset GVHD in RIC HSCT recipients is vital to improve the prediction of disease onset and allow more targeted interventions for acute GVHD.

Soluble mediators in platelet concentrates modulate dendritic cell inflammatory responses in an experimental model of transfusion

The transfusion of platelet concentrates (PCs) is widely used to treat thrombocytopenia and severe trauma. Ex vivo storage of PCs is associated with a storage lesion characterized by partial platelet activation and the release of soluble mediators, such as soluble CD40 ligand (sCD40L), RANTES, and interleukin (IL)-8. An in vitro whole blood culture transfusion model was employed to assess whether mediators present in PC supernatants (PC-SNs) modulated dendritic cell (DC)-specific inflammatory responses (intracellular staining) and the overall inflammatory response (cytometric bead array). Lipopolysaccharide (LPS) was included in parallel cultures to model the impact of PC-SNs on cell responses following toll-like receptor-mediated pathogen recognition. The impact of both the PC dose (10%, 25%) and ex vivo storage period was investigated [day 2 (D2), day 5 (D5), day 7 (D7)]. PC-SNs alone had minimal impact on DC-specific inflammatory responses and the overall inflammatory response. However, in the presence of LPS, exposure to PC-SNs resulted in a significant dose associated suppression of the production of DC IL-12, IL-6, IL-1a, tumor necrosis factor-a (TNF-a), and macrophage inflammatory protein (MIP)-1b and storage-associated suppression of the production of DC IL-10, TNF-a, and IL-8. For the overall inflammatory response, IL-6, TNF-a, MIP-1a, MIP-1b, and inflammatory protein (IP)-10 were significantly suppressed and IL-8, IL-10, and IL-1b significantly increased following exposure to PC-SNs in the presence of LPS. These data suggest that soluble mediators present in PCs significantly suppress DC function and modulate the overall inflammatory response, particularly in the presence of an infectious stimulus. Given the central role of DCs in the initiation and regulation of the immune response, these results suggest that modulation of the DC inflammatory profile is a probable mechanism contributing to transfusion-related complications.

Acute inflammatory response to low-, moderate- and high-load resistance exercise in women with breast cancer-related lymphoedema

Background Resistance exercise is emerging as a potential adjunct therapy to aid in the management of breast cancer-related lymphedema (BCRL). However, the mechanisms underlying the relationships between the acute and long-term benefits of resistance exercise on BCRL are not well understood. Purpose. To examine the acute inflammatory response to upper-body resistance exercise in women with BCRL and to compare these effects between resistance exercises involving low-, moderate- and high-loads. The impact on lymphoedema status and associated symptoms was also compared. Methods Twenty-one women aged 62 ± 10 years with mild to severe BCRL participated in the study. Participants completed a low-load (15-20 repetition maximum), moderate-load (10-12 repetition maximum) and high-load (6-8 repetition maximum) exercise sessions consisting of three sets of six upper-body resistance exercises. Sessions were completed in a randomized order separated by a seven to 10 day wash-out period. Venous blood samples were obtained to assess markers of exercise-induced muscle damage and inflammation (creatine kinase [CK], C-reactive protein [CRP], interleukin-6 [IL-6] and tumour necrosis factor-alpha [TNF-α]). Lymphoedema status was assessed using bioimpedance spectroscopy and arm circumferences, and associated symptoms were assessed using visual analogue scales (VAS) for pain, heaviness and tightness. Measurements were conducted before and 24 hours after the exercise sessions. Results No significant changes in CK, CRP, IL-6 and TNF-α were observed following the low-, moderate- or high-load resistance exercise sessions. There were no significant changes in arm swelling or symptom severity scores across the three resistance exercise conditions. Conclusions The magnitude of acute exercise-induced inflammation following upper-body resistance exercise in women with BCRL does not vary between resistance exercise loads. Given these observations, moderate- to high-load resistance training is recommended for this patient population as these loads prompt superior physiological and functional benefits.

Association of STAT3 and TNFRSF1A with ankylosing spondylitis in Han Chinese

Objectives: Recent association studies by the Australo-Anglo-American Spondyloarthritis Consortium (TASC) in Caucasian European populations from Australia, North America and the UK have identified a number of genes as being associated with ankylosing spondylitis (AS). A candidate gene study in a Han Chinese population was performed based on these findings to identify associated genes in this population. Methods: A case-control study was performed in a Han Chinese population of patients with AS (n=775) and controls (n=1587) from Shanghai and Nanjing. All patients met the modified New York criteria for AS. The cases and controls were genotyped for 115 single nucleotide polymorphisms (SNPs) tagging IL23R, ERAP1, STAT3, JAK2, TNFRSF1A and TRADD, as well as other confirmation SNPs from the TASC study, using the Sequenom iPlex and the ABI OpenArray platforms. Statistical analysis of genotyped SNPs was performed using the Cochran - Armitage test for trend and meta-analysis was performed using METAL. SNPs in AS-associated genes in this study were then imputed using MaCH, and association with AS tested by logistic regression. Results: SNPs in TNFRSF1A (rs4149577, p=8.2×10-4), STAT3 (rs2293152, p=0.0015; rs1053005, p=0.017) and ERAP1 (rs27038, p=0.0091; rs27037, p=0.0092) were significantly associated with AS in Han Chinese. Association was also observed between AS and the intergenic region 2p15 (rs10865331, p=0.023). The lack of association between AS and IL23R in Han Chinese was confirmed (all SNPs p>0.1). Conclusions: The study results demonstrate for the first time that genetic polymorphisms in STAT3, TNFRSF1A and 2p15 are associated with AS in Han Chinese, suggesting common pathogenic mechanisms for the disease in Chinese and Caucasian European populations. Furthermore, previous findings demonstrating that ERAP1, but not IL23R, is associated with AS in Chinese patients were confirmed.

Brief report: Intestinal dysbiosis in ankylosing spondylitis

Objective Ankylosing spondylitis (AS) is a common, highly heritable immune-mediated arthropathy that occurs in genetically susceptible individuals exposed to an unknown but likely ubiquitous environmental trigger. There is a close relationship between the gut and spondyloarthritis, as exemplified in patients with reactive arthritis, in whom a typically self-limiting arthropathy follows either a gastrointestinal or urogenital infection. Microbial involvement in AS has been suggested; however, no definitive link has been established. The aim of this study was to determine whether the gut in patients with AS carries a distinct microbial signature compared with that in the gut of healthy control subjects. Methods Microbial profiles for terminal ileum biopsy specimens obtained from patients with recent-onset tumor necrosis factor antagonist-naive AS and from healthy control subjects were generated using culture-independent 16S ribosomal RNA gene sequencing and analysis techniques. Results Our results showed that the terminal ileum microbial communities in patients with AS differ significantly (P < 0.001) from those in healthy control subjects, driven by a higher abundance of 5 families of bacteria (Lachnospiraceae [P = 0.001], Ruminococcaceae [P = 0.012], Rikenellaceae [P = 0.004], Porphyromonadaceae [P = 0.001], and Bacteroidaceae [P = 0.001]) and a decrease in the abundance of 2 families of bacteria (Veillonellaceae [P = 0.01] and Prevotellaceae [P = 0.004]). Conclusion We show evidence for a discrete microbial signature in the terminal ileum of patients with AS compared with healthy control subjects. The microbial composition was demonstrated to correlate with disease status, and greater differences were observed between disease groups than within disease groups. These results are consistent with the hypothesis that genes associated with AS act, at least in part, through effects on the gut microbiome.

Progress in the genetics of ankylosing spondylitis

Ankylosing spondylitis (AS) is a common, highly heritable, inflammatory arthropathy. In addition to being strongly associated with HLA-B27, a further 13 genes have been robustly associated with the disease. These genes highlight the involvement of the IL-23 pathway in disease pathogenesis, and indicate overlaps between the pathogenesis of AS, and of inflammatory bowel disease. Genetic associations in B27-positive and -negative disease are similar, with the main exception of association with ERAP1, which is restricted in association to B27-positive cases. This restriction, and the known function of ERAP1 in peptide trimming prior to HLA Class I presentation, indicates that HLA-B27 is likely to operate in AS by a mechanism involving aberrant peptide handling. These advances point to several potential novel therapeutic approaches in AS.

Unique and cross-reactive T cell epitope peptides of the major bahia grass pollen allergen, pas n 1

Background Bahia grass pollen (BaGP) is a major cause of allergic rhinitis. Subcutaneous allergen-specific immunotherapy is effective for grass pollen allergy, but is unsuitable for patients with moderate to severe asthma due to the risk of anaphylaxis. T cell-reactive but IgE nonreactive peptides provide a safer treatment option. This study aimed to identify and characterize dominant CD4+ T cell epitope peptides of the major BaGP allergen, Pas n 1. Methods Pas n 1-specific T cell lines generated from the peripheral blood of BaGP-allergic subjects were tested for proliferative and cytokine response to overlapping 20-mer Pas n 1 peptides. Cross-reactivity to homologous peptides from Lol p 1 and Cyn d 1 of Ryegrass and Bermuda grass pollen, respectively, was assessed using Pas n 1 peptide-specific T cell clones. MHC class II restriction of Pas n 1 peptide T cell recognition was determined by HLA blocking assays and peptide IgE reactivity tested by dot blotting. Results Three Pas n 1 peptides showed dominant T cell reactivity; 15 of 18 (83%) patients responded to one or more of these peptides. T cell clones specific for dominant Pas n 1 peptides showed evidence of species-specific T cell reactivity as well as cross-reactivity with other group 1 grass pollen allergens. The dominant Pas n 1 T cell epitope peptides showed HLA binding diversity and were non-IgE reactive. Conclusions The immunodominant T cell-reactive Pas n 1 peptides are candidates for safe immunotherapy for individuals, including those with asthma, who are allergic to Bahia and possibly other grass pollens.

Antibody treatments of inflammatory arthritis

Inflammatory arthropathies such as rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis are extremely common in the community, with a prevalence of up to 5%, and they cause substantial morbidity. The development of anti-TNF agents for use initially in rheumatoid arthritis, and subsequently more broadly in inflammatory arthritis, represents the biggest advance in management of these conditions since the introduction of corticosteroid agents, and is a major vindication of public funded arthritis research. However, there are limitations of even these highly effective agents. A significant minority of patients with inflammatory arthritis do not respond to these anti-TNF agents, they are associated with substantial risk of toxicity, require parenteral administration, and are extremely expensive. New antibody treatments in development can be divided into anti-cytokine agents, cell-targeted therapies, co-stimulation inhibitors, and treatments aimed at preventing joint erosion consequent on inflammation. This review discusses the state of the art in the development of these agents for management of this common group of diseases.

Genetic susceptibility to ankylosing spondylitis

Ankylosing spondylitis is a highly heritable, common rheumatic condition, primarily affecting the axial skeleton. The association with HLA-B27 has been demonstrated worldwide, and evidence for a role of HLA-B27 in disease comes from linkage and association studies in humans, and transgenic animal models. However, twin studies indicate that HLA-B27 contributes only 16% of the total genetic risk for disease. Furthermore, there is compelling evidence that non-B27 genes, both within and outwith the major histocompatability complex, are involved in disease aetiology. In this post-genomic era we have the tools to help elicit the genetic basis of disease. This review describes methods for genetic investigation of ankylosing spondylitis, and summarises the status of current research in this exciting area.

Fine mapping of the MHC Class III region demonstrates association of AIF1 and rheumatoid arthritis

Objective. The heritability of RA has been estimated to be ∼55%, of which the MHC contributes about one-third. HLA-DRB1 alleles are strongly associated with RA, but it is likely that significant non-DRB1 MHC genetic susceptibility factors are involved. Previously, we identified two three-marker haplotypes in a 106-kb region in the MHC class III region immediately centromeric to TNF, which are strongly associated with RA on HLA-DRB1*0404 haplotypes. In the present study, we aimed to refine these associations further using a combination of genotyping and gene expression studies. Methods. Thirty-nine nucleotide polymorphisms (SNPs) were genotyped in 95 DRB1*0404 carrying unrelated RA cases, 125 DRB1*0404 - carrying healthy controls and 87 parent-case trio RA families in which the affected child carried HLA-DRB1*04. Quantitative RT-PCR was used to assess the expression of the positional candidate MHC class III genes APOM, BAT2, BAT3, BAT4, BAT5, AIF1, C6orf47, CSNK2β and LY6G5C, and the housekeeper genes, hypoxanthine-guanine phosphoribosyltransferase (HPRT) and β2-microglobulin (B2M) in 31 RA cases and 21 ethnically, age- and sex-matched healthy controls. Synovial membrane specimens from RA, PsA and OA cases were stained by an indirect immunoperoxidase technique using a mouse-anti-human AIF1 monoclonal antibody. Results. Association was observed between RA and single markers or two marker haplotypes involving AIF1, BAT3 and CSNK. AIF1 was also significantly overexpressed in RA mononuclear cells (1.5- to 1.9-fold difference, P = 0.02 vs HPRT, P = 0.002 vs B2M). AIF1 protein was clearly expressed by synovial macrophages in all the inflammatory synovial samples in contrast to the non-inflammatory OA samples. Conclusions. The results of the genotyping and expression studies presented here suggest a role for AIF1 in both the aetiology and pathogenesis of RA.

Genome-wide association studies and musculoskeletal diseases

Bone and joint diseases are major causes of morbidity and mortality worldwide, and their prevalence is increasing as the average population age increases. Most common musculoskeletal diseases show significant heritability, and few have treatments that prevent disease or can induce true treatment-free, disease-free remission. Furthermore, despite valiant efforts of hypothesis-driven research, our understanding of the etiopathogenesis of these conditions is, with few exceptions, at best moderate. Therefore, there has been a long-standing interest in genetics research in musculoskeletal disease as a hypothesis-free method for investigating disease etiopathogenesis. Important contributions have been made through the identification of monogenic causes of disease, but the holy grail of human genetics research has been the identification of the genes responsible for common diseases. The development of genome-wide association (GWA) studies has revolutionized this field, and led to an explosion in the number of genes identified that are definitely involved in musculoskeletal disease pathogenesis. However, this approach will not identify all common disease genes, and although the current progress is exciting and proves the potential of this research discipline, other approaches will be required to identify many of the types of genetic variation likely to be involved.

A review of the MHC genetics of rheumatoid arthritis

Rheumatoid arthritis is a common complex genetic disease, and, despite a significant genetic element, no gene other than HLA-DRB1 has been clearly demonstrated to be involved in the disease. However, this association accounts for less than half the overall genetic susceptibility. Investigation of other candidate genes, in particular those that reside within the major histocompatibility complex, are hampered by the presence of strong linkage disequilibrium and problems with study design. © 2004 Nature Publishing Group All rights reserved.