Objective Accumulation of myofibroblasts in fibrotic skin is a hallmark of systemic sclerosis (SSc; scleroderma), but the origins of these cells remain unknown. Because loss of intradermal adipose tissue is a consistent feature of cutaneous fibrosis, we sought to examine the hypothesis that myofibroblasts populating fibrotic dermis derive from adipocytic progenitors. Methods We performed genetic fate mapping studies to investigate the loss of intradermal adipose tissue and its potential role in fibrosis in mice with bleomycin-induced scleroderma. Modulation of adipocytic phenotypes ex vivo was investigated in adipose tissue–derived cells in culture. Results A striking loss of intradermal adipose tissue and its replacement with fibrous tissue were consistently observed in mice with bleomycin-induced fibrosis. Loss of adipose tissue and a decline in the expression of canonical adipogenic markers in lesional skin preceded the onset of dermal fibrosis and expression of fibrogenic markers. Ex vivo, subcutaneous adipocytes were driven by transforming growth factor β to preferentially undergo fibrogenic differentiation. Cell fate mapping studies in mice with the adiponectin promoter–driven Cre recombinase transgenic construct indicated that adiponectin-positive progenitors that are normally confined to the intradermal adipose tissue compartment were distributed throughout the lesional dermis over time, lost their adipocytic markers, and expressed myofibroblast markers in bleomycin-treated mice. Conclusion These observations establish a novel link between intradermal adipose tissue loss and dermal fibrosis and demonstrate that adiponectin-positive intradermal progenitors give rise to dermal myofibroblasts. Adipose tissue loss and adipocyte–myofibroblast transition might be primary events in the pathogenesis of cutaneous fibrosis that represent novel potential targets for therapeutic intervention.

Characterization of the cell cycle–regulated transcripts in U2OS cells yielded 1871 unique genes. FOXM1 targets were identified via ChIP-seq, and novel targets in G2/M and S phases were verified using a real-time luciferase assay. ChIP-seq data were used to map cell cycle transcriptional regulators of cell cycle–regulated gene expression in U2OS cells.

Heterogeneity in systemic sclerosis/SSc confounds clinical trials. We previously identified ‘intrinsic’ gene expression subsets by analysis of SSc skin. Here we test the hypotheses that skin gene expression signatures including intrinsic subset are associated with skin score/MRSS improvement during mycophenolate mofetil (MMF) treatment. Gene expression and intrinsic subset assignment were measured in 12 SSc patients’ biopsies and ten controls at baseline, and from serial biopsies of one cyclophosphamide-treated patient, and nine MMF-treated patients. Gene expression changes during treatment were determined using paired t-tests corrected for multiple hypothesis testing. MRSS improved in four of seven MMF-treated patients classified as the inflammatory intrinsic subset. Three patients without MRSS improvement were classified as normal-like or fibroproliferative intrinsic subsets. 321 genes (FDR <5%) were differentially expressed at baseline between patients with and without MRSS improvement during treatment. Expression of 571 genes (FDR <10%) changed between pre- and post-MMF treatment biopsies for patients demonstrating MRSS improvement. Gene expression changes in skin are only seen in patients with MRSS improvement. Baseline gene expression in skin, including intrinsic subset assignment, may identify SSc patients whose MRSS will improve during MMF treatment, suggesting that gene expression in skin may allow targeted treatment in SSc.

Potentially pathogenic, multidrug-resistant bacterial organisms are transmitted during the practice of general anesthesia to both the anesthesia work area and intravenous stopcock sets. Implementation of infection control measures in this area may help to reduce both the evolving problem of increasing bacterial resistance and the development of life-threatening infectious complications.

Objective T cells play a key role in the pathogenesis of early systemic sclerosis. This study was undertaken to assess the safety and efficacy of abatacept in patients with diffuse cutaneous systemic sclerosis (dcSSc). Methods In this 12‐month, randomized, double‐blind, placebo‐controlled trial, participants were randomized 1:1 to receive either subcutaneous abatacept 125 mg or matching placebo, stratified by duration of dcSSc. Escape therapy was allowed at 6 months for worsening disease. The coprimary end points were change in the modified Rodnan skin thickness score (MRSS) compared to baseline and safety over 12 months. Differences in longitudinal outcomes were assessed according to treatment using linear mixed models, with outcomes censored after initiation of escape therapy. Skin tissue obtained from participants at baseline was classified into intrinsic gene expression subsets. Results Among 88 participants, the adjusted mean change in the MRSS at 12 months was −6.24 units for those receiving abatacept and −4.49 units for those receiving placebo, with an adjusted mean treatment difference of −1.75 units (P = 0.28). Outcomes for 2 secondary measures (Health Assessment Questionnaire disability index and a composite measure) were clinically and statistically significantly better with abatacept. The proportion of subjects in whom escape therapy was needed was higher in the placebo group relative to the abatacept group (36% versus 16%). In the inflammatory and normal‐like skin gene expression subsets, decline in the MRSS over 12 months was clinically and significantly greater in the abatacept group versus the placebo group (P < 0.001 and P = 0.03, respectively). In the abatacept group, adverse events occurred in 35 participants versus 40 participants in the placebo group, including 2 deaths and 1 death, respectively. Conclusion In this phase II trial, abatacept was well‐tolerated, but change in the MRSS was not statistically significant. Secondary outcome measures, including gene expression subsets, showed evidence in support of abatacept. These data should be confirmed in a phase III trial.