The Caveolin-1 Scaffolding Domain Peptide Reverses Aging-Associated Deleterious Changes in Multiple Organs.

Aging is a progressive, multifactorial, degenerative process in which deleterious changes occur in the biochemistry and function of organs. We showed that angiotensin II (AngII)-induced pathologies in the heart and kidney of young (3-month-old) mice are suppressed by the caveolin-1 scaffolding domain (CSD) peptide. Because AngII mediates many aging-associated changes, we explored whether CSD could reverse pre-existing pathologies and improve organ function in aged mice. Using 18-month-old mice (similar to 60-year-old humans), we found that >5-fold increases in leakage of serum proteins and >2-fold increases in fibrosis are associated with aging in the heart, kidney, and brain. Because tyrosine phosphorylation of cell junction proteins leads to the loss of microvascular barrier function, we analyzed the activation of the receptor tyrosine kinase PDGFR and the nonreceptor tyrosine kinases c-Src and Pyk2. We observed 5-fold activation of PDGFR and 2- to 3-fold activation of c-Src and Pyk2 in aged mice. Treatment with CSD for 4 weeks reversed these pathologic changes (microvascular leakage, fibrosis, kinase activation) in all organs almost down to the levels in healthy, young mice. In studies of heart function, CSD reduced the aging-associated increase in cardiomyocyte cross-sectional area and enhanced ventricular compliance in that echocardiographic studies demonstrated improved ejection fraction and fractional shortening and reduced isovolumic relation time. These results suggest that versions of CSD may be developed as treatments for aging-associated diseases in human patients based on the concept that CSD inhibits tyrosine kinases, leading to the inhibition of microvascular leakage and associated fibrosis, thereby improving organ function. SIGNIFICANCE STATEMENT: The caveolin-1 scaffolding domain (CSD) peptide reverses aging-associated fibrosis, microvascular leakage, and organ dysfunction in the heart, kidneys, and brain via a mechanism that involves the suppression of the activity of multiple tyrosine kinases, suggesting that CSD can be developed as a treatment for a wide range of diseases found primarily in the aged.

Sensorineural hearing loss after spine surgery treated with hyperbaric oxygen therapy: two case reports.

Acute idiopathic sudden sensorineural hearing loss (ISSNHL) following lumbar spinal surgery is an exceedingly rare phenomenon. This paper presents a case of ISSNHL presenting acutely after lumbar spine decompression and fusion treated with transtympanic steroids and hyperbaric oxygen (HBO2) therapy. It also presents the ironic case of SSNHL secondary to presumed viral pathology sustained by the patient's operative surgeon who was treated with transtympanic steroids and HBO2 as well. Proposed etiologies of the patient's ISSNHL include: hypotension, prone operative position, malfitted/malpositioned headrest, microemboli from a cell-saver, and nitrous oxide anesthesia. The role of systemic hypotension as an etiology of ISSNHL is discussed given the fact that there are no reported cases of ISSNHL in orthopedic procedures performed with permissive hypotension. The initiation of steroids and HBO2 therapy has been shown to be an effective treatment for ISSNHL when started within 14 days of symptom onset. HBO2 and transtympanic steroids were initiated 10 days earlier in the operative surgeon, which showed to be a better treatment modality compared to the postoperative patient. ISSNHL in the acute postoperative period of lumbar spinal fusion surgery presents a unique treatment dilemma because systemic steroids are routinely avoided over concerns of pseudarthrosis. Of the seven documented cases of ISSNHL following lumbar spine surgery, none underwent HBO2 as a treatment modality.

Reversal of maladaptive fibrosis and compromised ventricular function in the pressure overloaded heart by a caveolin-1 surrogate peptide.

Chronic ventricular pressure overload (PO) results in congestive heart failure (CHF) in which myocardial fibrosis develops in concert with ventricular dysfunction. Caveolin-1 is important in fibrosis in various tissues due to its decreased expression in fibroblasts and monocytes. The profibrotic effects of low caveolin-1 can be blocked with the caveolin-1 scaffolding domain peptide (CSD, a caveolin-1 surrogate) using both mouse models and human cells. We have studied the beneficial effects of CSD on mice in which PO was induced by trans-aortic constriction (TAC). Beneficial effects observed in TAC mice receiving CSD injections daily included: improved ventricular function (increased ejection fraction, stroke volume, and cardiac output; reduced wall thickness); decreased collagen I, collagen chaperone HSP47, fibronectin, and CTGF levels; decreased activation of non-receptor tyrosine kinases Pyk2 and Src; and decreased activation of eNOS. To determine the source of cells that contribute to fibrosis in CHF, flow cytometric studies were performed that suggested that myofibroblasts in the heart are in large part bone marrow-derived. Two CD45+ cell populations were observed. One (Zone 1) contained CD45+/HSP47-/macrophage marker+ cells (macrophages). The second (Zone 2) contained CD45moderate/HSP47+/macrophage marker- cells often defined as fibrocytes. TAC increased the number of cells in Zones 1 and 2 and the level of HSP47 in Zone 2. These studies are a first step in elucidating the mechanism of action of CSD in heart fibrosis and promoting the development of CSD as a novel treatment to reduce fibrosis and improve ventricular function in CHF patients.

Risk-Adjusted Variation of Publicly Reported Emergency Department Timeliness Measures.

STUDY OBJECTIVE: The Centers for Medicare & Medicaid Services (CMS) recently published emergency department (ED) timeliness measures. These data show substantial variation in hospital performance and suggest the need for process improvement initiatives. However, the CMS measures are not risk adjusted and may provide misleading information about hospital performance and variation. We hypothesize that substantial hospital-level variation will persist after risk adjustment. METHODS: This cross-sectional study included hospitals that participated in the Emergency Department Benchmarking Alliance and CMS ED measure reporting in 2012. Outcomes included the CMS measures corresponding to median annual boarding time, length of stay of admitted patients, length of stay of discharged patients, and waiting time of discharged patients. Covariates included hospital structural characteristics and case-mix information from the American Hospital Association Survey, CMS cost reports, and the Emergency Department Benchmarking Alliance. We used a γ regression with a log link to model the skewed outcomes. We used indirect standardization to create risk-adjusted measures. We defined "substantial" variation as coefficient of variation greater than 0.15. RESULTS: The study cohort included 723 hospitals. Risk-adjusted performance on the CMS measures varied substantially across hospitals, with coefficient of variation greater than 0.15 for all measures. Ratios between the 10th and 90th percentiles of performance ranged from 1.5-fold for length of stay of discharged patients to 3-fold for waiting time of discharged patients. CONCLUSION: Policy-relevant variations in publicly reported CMS ED timeliness measures persist after risk adjustment for nonmodifiable hospital and case-mix characteristics. Future "positive deviance" studies should identify modifiable process measures associated with high performance.

Bleomycin delivery by osmotic minipump: similarity to human scleroderma interstitial lung disease.

The interstitial lung diseases (ILD) include a large number of chronic, progressive, irreversible respiratory disorders involving pulmonary fibrosis, the most common of which are idiopathic pulmonary fibrosis and scleroderma lung disease (SSc ILD). Because bleomycin causes lung fibrosis when used in cancer chemotherapy, it is used to model human ILD in rodents. In most studies, bleomycin has been delivered directly into the lung by intratracheal or intraoral administration. Here we have compared the effects in mice of bleomycin delivered directly into the lungs (direct model) or systemically using osmotic minipumps (pump model) to determine which more closely resembles human ILD. The pump model is more similar to human SSc ILD in that: 1) lung injury/fibrosis is limited to the subpleural portion of the lung in the pump model and in SSc ILD, whereas the entire lung is affected in the direct model; 2) conversely, there is massive inflammation throughout the lung in the direct model, whereas inflammation is limited in the pump model and in SSc ILD; 3) hypertrophic type II alveolar epithelial cells are present at high levels in SSc ILD and in the pump model but not in the direct model; and 4) lung fibrosis is accompanied by dermal fibrosis. The pump model is also move convenient and humane than the direct model because there is less weight loss and mortality.

Overall ED efficiency is associated with decreased time to percutaneous coronary intervention for ST-segment elevation myocardial infarction.

BACKGROUND: Performance of percutaneous coronary intervention (PCI) within 90 minutes of hospital arrival for ST-segment elevation myocardial infarction patients is a commonly cited clinical quality measure. The Centers for Medicare and Medicaid Services use this measure to adjust hospital reimbursement via the Value-Based Purchasing Program. This study investigated the relationship between hospital performance on this quality measure and emergency department (ED) operational efficiency. METHODS: Hospital-level data from Centers for Medicare and Medicaid Services on PCI quality measure performance was linked to information on operational performance from 272 US EDs obtained from the Emergency Department Benchmarking Alliance annual operations survey. Standard metrics of ED size, acuity, and efficiency were compared across hospitals grouped by performance on the door-to-balloon time quality measure. RESULTS: Mean hospital performance on the 90-minute arrival to PCI measure was 94.0% (range, 42-100). Among hospitals failing to achieve the door-to-balloon time performance standard, median ED length of stay was 209 minutes, compared with 173 minutes among those hospitals meeting the benchmark standard (P < .001). Similarly, median time from ED patient arrival to physician evaluation was 39 minutes for hospitals below the performance standard and 23 minutes for hospitals at the benchmark standard (P < .001). Markers of ED size and acuity, including annual patient volume, admission rate, and the percentage of patients arriving via ambulance did not vary with door-to-balloon time. CONCLUSION: Better performance on measures associated with ED efficiency is associated with more timely PCI performance.

A water-soluble caveolin-1 peptide inhibits psoriasis-like skin inflammation by suppressing cytokine production and angiogenesis.

The plasma membrane protein caveolin-1 (CAV-1) regulates signaling by inhibiting a wide range of kinases and other enzymes. Our previous study demonstrated that the downregulation of CAV-1 in psoriatic epidermal cells contributes to inflammation by enhancing JAK/STAT signaling, cell proliferation, and chemokine production. Administration of the CAV-1 scaffolding domain (CSD) peptide suppressed imiquimod (IMQ)-induced psoriasis-like dermatitis. To identify an optimal therapeutic peptide derived from CAV-1, we have compared the efficacy of CSD and subregions of CSD that have been modified to make them water soluble. We refer to these modified peptides as sCSD, sA, sB, and sC. In IMQ-induced psoriasis-like dermatitis, while all four peptides showed major beneficial effects, sB caused the most significant improvements of skin phenotype and number of infiltrating cells, comparable or superior to the effects of sCSD. Phosphorylation of STAT3 was also inhibited by sB. Furthermore, sB suppressed angiogenesis both in vivo in the dermis of IMQ-induced psoriasis mice and in vitro by blocking the ability of conditioned media derived from CAV-1-silenced keratinocytes to inhibit tube formation by HUVEC. In conclusion, sB had similar or greater beneficial effects than sCSD not only by cytokine suppression but by angiogenesis inhibition adding to its ability to target psoriatic inflammation.

Differential regulation of cell functions by CSD peptide subdomains.

BACKGROUND: In fibrotic lung diseases, expression of caveolin-1 is decreased in fibroblasts and monocytes. The effects of this deficiency are reversed by treating cells or animals with the caveolin-1 scaffolding domain peptide (CSD, amino acids 82-101 of caveolin-1) which compensates for the lack of caveolin-1. Here we compare the function of CSD subdomains (Cav-A, Cav-B, Cav-C, Cav-AB, and Cav-BC) and mutated versions of CSD (F92A and T90A/T91A/F92A). METHODS: Migration toward the chemokine CXCL12 and the associated expression of F-actin, CXCR4, and pSmad 2/3 were studied in monocytes from healthy donors and SSc patients. Fibrocyte differentiation was studied using PBMC from healthy donors and SSc patients. Collagen I secretion and signaling were studied in fibroblasts derived from the lung tissue of healthy subjects and SSc patients. RESULTS: Cav-BC and CSD at concentrations as low as 0.01 µM inhibited the hypermigration of SSc monocytes and TGFß-activated Normal monocytes and the differentiation into fibrocytes of SSc and Normal monocytes. While CSD also inhibited the migration of poorly migrating Normal monocytes, Cav-A (and other subdomains to a lesser extent) promoted the migration of Normal monocytes while inhibiting the hypermigration of TGFß-activated Normal monocytes. The effects of versions of CSD on migration may be mediated in part via their effects on CXCR4, F-actin, and pSmad 2/3 expression. Cav-BC was as effective as CSD in inhibiting fibroblast collagen I and ASMA expression and MEK/ERK signaling. Cav-C and Cav-AB also inhibited collagen I expression, but in many cases did not affect ASMA or MEK/ERK. Cav-A increased collagen I expression in scleroderma lung fibroblasts. Full effects on fibroblasts of versions of CSD required 5 µM peptide. CONCLUSIONS: Cav-BC retains most of the anti-fibrotic functions of CSD; Cav-A exhibits certain pro-fibrotic functions. Results obtained with subdomains and mutated versions of CSD further suggest that the critical functional residues in CSD depend on the cell type and readout being studied. Monocytes may be more sensitive to versions of CSD than fibroblasts and endothelial cells because the baseline level of caveolin-1 in monocytes is much lower than in these other cell types.

Sensorineural hearing loss incidence among U.S. military aviators between 1997 and 2011.

INTRODUCTION: Noise-induced hearing loss is the most common cause of sensorineural hearing loss (SNHL) in military aviation. Few published studies compare SNHL rates between fixed and rotary-wing military pilots. The study's objective was to determine whether a difference in mean annual SNHL incidence rate exists between fixed and rotary wing aviators in the U.S. Army, Navy, Air Force, and Marines. METHODS: SNHL rates (new cases annually/1000 persons-per-year) for U.S. military aviators from 1997-2011 were extracted from the Defense Medical Epidemiology Database (DMED). ANOVA was conducted for mean annual SNHL incidence rate differences and for interaction effects between aircraft type, fixed or rotary-wing, and service branch. RESULTS: A total of 467,064 person-years were analyzed. A main effect existed for aircraft type, such that the mean annual rate of SNHL was higher for fixed (M = 15.8, SD = 10.2) than for rotary-wing aviators (M = 8.7, SD = 5.0, RR = 1.8). Service branch main effect was significant, such that the mean SNHL rates were greater for the Army (M = 19.6, SD =11.2) and Air Force (M = 14.7, SD = 11.2) than for the Navy (M = 7.2, SD = 3.9) and Marines (M = 7.3, SD = 3.6). The interaction effect was significant, indicating that the within branch differences in SNHL rate between fixed and rotary-wing aviators is greater in the Army and Air Force than in the Navy and Marines. DISCUSSION: The average annual incidence rate of SNHL between 1997-2011 was higher for fixed than for rotary-wing aviators, and higher for U.S. Army and Air Force than Navy and Marine aviators. An examination of hearing conservation programs and engineering controls may be warranted.

Multiple subregions within the caveolin-1 scaffolding domain inhibit fibrosis, microvascular leakage, and monocyte migration.

The caveolin-1 scaffolding domain (CSD, amino acids 82-101 of caveolin-1) has been shown to suppress bleomycin-induced lung and skin fibrosis and angiotensin II (AngII)-induced myocardial fibrosis. To identify active subregions within CSD, we split its sequence into three slightly overlapping 8-amino acid subregions (82-89, 88-95, and 94-101). Interestingly, all three peptides showed activity. In bleomycin-treated mice, all three subregions suppressed the pathological effects on lung and skin tissue morphology. In addition, while bone marrow monocytes isolated from bleomycin-treated mice showed greatly enhanced migration in vitro toward CXCL12, treatment in vivo with CSD and its subregions almost completely suppressed this enhanced migration. In AngII-induced heart failure, both 82-89 and 88-95 significantly suppressed fibrosis (both Col I and HSP47 levels), microvascular leakage, and heart weight/ body weight ratio (HW/BW) while improving ventricular function. In contrast, while 94-101 suppressed the increase in Col I, it did not improve the other parameters. The idea that all three subregions can be active depending on the assay was further supported by experiments studying the in vitro migration of human monocytes in which all three subregions were extremely active. These studies are very novel in that it has been suggested that there is only one active region within CSD that is centered on amino acids 90-92. In contrast, we demonstrate here the presence of other active regions within CSD.

Regioselective semihydrogenation of dienes.

A one-pot, three-step strategy for the regioselective semihydrogenation of dienes is described. This procedure uses 9-BBN-H as a temporary protective group for alkenes. Yields range from 55% to 95%, and the reaction is tolerant of a variety of common functional groups. Additionally, the final elimination step of the sequence can be replaced with a peroxide-mediated alkylborane oxidation, generating regioselectively semihydrogenated product alcohols.

Adipose-derived mesenchymal stromal/stem cells in systemic sclerosis: Alterations in function and beneficial effect on lung fibrosis are regulated by caveolin-1.

The potential value of mesenchymal stromal/stem cell therapy in treating skin fibrosis in scleroderma (systemic sclerosis) and of the caveolin-1 scaffolding domain peptide in treating lung, skin, and heart fibrosis is known. To understand how these observations may relate to differences between mesenchymal stromal/stem cells from healthy subjects and subjects with fibrosis, we have characterized the fibrogenic and adipogenic potential of adipose-derived mesenchymal stromal/stem cells from systemic sclerosis patients, from mice with fibrotic lung and skin disease induced by systemic bleomycin treatment, and from healthy controls. Early passage systemic sclerosis adipose-derived mesenchymal stromal/stem cells have a profibrotic/anti-adipogenic phenotype compared to healthy adipose-derived mesenchymal stromal/stem cells (low caveolin-1, high α-smooth muscle actin, high HSP47, low pAKT, low capacity for adipogenic differentiation). This phenotype is mimicked by treating healthy adipose-derived mesenchymal stromal/stem cells with transforming growth factor beta or caveolin-1 small interfering RNA and is reversed in systemic sclerosis adipose-derived mesenchymal stromal/stem cells by treatment with caveolin-1 scaffolding domain peptide, but not scrambled caveolin-1 scaffolding domain peptide. Similar results were obtained with adipose-derived mesenchymal stromal/stem cells from systemic sclerosis patients and from bleomycin-treated mice, indicating the central role of caveolin-1 in mesenchymal stromal/stem cell differentiation in fibrotic disease.

The Aeromedical Management of Allergic Rhinitis.

INTRODUCTION: Allergic rhinitis is a prevalent condition warranting special aeromedical consideration due to its potential for acute and painful manifestations involving the middle ear or paranasal sinuses during rapid barometric pressure changes. Although second generation antihistamines and intranasal steroids are safe and effective treatments for this common condition, aeromedical management varies. METHODS: An aeromedical policy review of 14 public access civil and military data repositories was undertaken. Policy within a convenience sample of nine countries (Australia, Canada, Croatia, France, New Zealand, Norway, Sweden, United Kingdom, and United States) was further ascertained through subject matter expert consultation. A convenience sample of recent primary care review articles and ENT guidelines were reviewed in order to substantiate the evidence basis for aeromedical practices. RESULTS: Policies range from disqualification of flight applicants with any history of allergic rhinitis to the authorization of short-term, select undeclared medication use for the management of mild symptoms, with military authorities applying a more conservative approach. A range of intranasal and oral therapies are approved and requirements for waiver vary across most authorities. DISCUSSION: Variation in practices must be considered when managing flight crews as part of military coalition peacetime and combat operations, as well as for international civil aviation missions conducted in support of natural disaster relief, rescue, and other stability efforts. Standardization of approved therapies for allergic rhinitis could be a useful starting point for the harmonization of aeromedical global policies in the future. Beneficial national specific policy updates may be undertaken on the basis of international experience.Powell-Dunford N, Reese C, Bushby A, Munkeby BH, Coste S, Pezer VL, Rosenkvist L. The aeromedical management of allergic rhinitis. Aerosp Med Hum Perform. 2018; 89(5):453-463.

Suppression of angiotensin II-induced pathological changes in heart and kidney by the caveolin-1 scaffolding domain peptide.

Dysregulation of the renin-angiotensin system leads to systemic hypertension and maladaptive fibrosis in various organs. We showed recently that myocardial fibrosis and the loss of cardiac function in mice with transverse aortic constriction (TAC) could be averted by treatment with the caveolin-1 scaffolding domain (CSD) peptide. Here, we used angiotensin II (AngII) infusion (2.1 mg/kg/day for 2 wk) in mice as a second model to confirm and extend our observations on the beneficial effects of CSD on heart and kidney disease. AngII caused cardiac hypertrophy (increased heart weight to body weight ratio (HW/BW) and cardiomyocyte cross-sectional area); fibrosis in heart and kidney (increased levels of collagen I and heat shock protein-47 (HSP47)); and vascular leakage (increased levels of IgG in heart and kidney). Echocardiograms of AngII-infused mice showed increased left ventricular posterior wall thickness (pWTh) and isovolumic relaxation time (IVRT), and decreased ejection fraction (EF), stroke volume (SV), and cardiac output (CO). CSD treatment (i.p. injections, 50 µg/mouse/day) of AngII-infused mice significantly suppressed all of these pathological changes in fibrosis, hypertrophy, vascular leakage, and ventricular function. AngII infusion increased ß1 and ß3 integrin levels and activated Pyk2 in both heart and kidney. These changes were also suppressed by CSD. Finally, bone marrow cell (BMC) isolated from AngII-infused mice showed hyper-migration toward SDF1. When AngII-infused mice were treated with CSD, BMC migration was reduced to the basal level observed in cells from control mice. Importantly, CSD did not affect the AngII-induced increase in blood pressure (BP), indicating that the beneficial effects of CSD were not mediated via normalization of BP. These results strongly indicate that CSD suppresses AngII-induced pathological changes in mice, suggesting that CSD can be developed as a treatment for patients with hypertension and pressure overload-induced heart failure.

Deficient Adipogenesis of Scleroderma Patient and Healthy African American Monocytes.

Monocytes from systemic sclerosis (SSc, scleroderma) patients and healthy African Americans (AA) are deficient in the regulatory protein caveolin-1 leading to enhanced migration toward chemokines and fibrogenic differentiation. While dermal fibrosis is the hallmark of SSc, loss of subcutaneous adipose tissue is a lesser-known feature. To better understand the etiology of SSc and the predisposition of AA to SSc, we studied the adipogenic potential of SSc and healthy AA monocytes. The ability of SSc and healthy AA monocytes to differentiate into adipocyte-like cells (ALC) is inhibited compared to healthy Caucasian (C) monocytes. We validated that monocyte-derived ALCs are distinct from macrophages by flow cytometry and immunocytochemistry. Like their enhanced fibrogenic differentiation, their inhibited adipogenic differentiation is reversed by the caveolin-1 scaffolding domain peptide (CSD, a surrogate for caveolin-1). The altered differentiation of SSc and healthy AA monocytes is additionally regulated by peroxisome proliferator-activated receptor γ (PPARγ) which is also present at reduced levels in these cells. In vivo studies further support the importance of caveolin-1 and PPARγ in fibrogenesis and adipogenesis. In SSc patients, healthy AA, and mice treated systemically with bleomycin, adipocytes lose caveolin-1 and PPARγ and the subcutaneous adipose layer is diminished. CSD treatment of these mice leads to a reappearance of the caveolin-1+/PPARγ+/FABP4+ subcutaneous adipose layer. Moreover, many of these adipocytes are CD45+, suggesting they are monocyte derived. Tracing experiments with injected EGFP+ monocytes confirm that monocytes contribute to the repair of the adipose layer when it is damaged by bleomycin treatment. Our observations strongly suggest that caveolin-1 and PPARγ work together to maintain a balance between the fibrogenic and adipogenic differentiation of monocytes, that this balance is altered in SSc and in healthy AA, and that monocytes make a major contribution to the repair of the adipose layer.

Enhanced chemokine-receptor expression, function, and signaling in healthy African American and scleroderma-patient monocytes are regulated by caveolin-1.

BACKGROUND: A major health disparity suffered by African Americans (AA) is a predisposition toward fibrotic diseases of the skin, lung, and other organs. We previously showed that healthy AA and scleroderma (systemic sclerosis (SSc)) patient monocytes share biochemical and functional differences from control Caucasian (C) monocytes that may predispose AA to SSc. The central difference is a decrease in caveolin-1. Low caveolin-1 levels promote monocyte migration, their differentiation into fibrocytes, and fibrocyte recruitment into fibrotic tissues. Here we have greatly expanded our studies on the mechanism of action in fibrosis of caveolin-1 in AA and SSc monocytes. RESULTS: Expression of chemokine receptors (CCR1, CCR2, CCR3) is enhanced in healthy AA monocytes compared to healthy C monocytes and further increased in SSc monocytes. A parallel increase in function occurs assessed by migration toward chemokines MCP-1 and MCP-3. Chemokine-receptor expression and function are inhibited by the caveolin-1 scaffolding domain peptide (CSD) via its action as a surrogate for caveolin-1. Cells bearing chemokine receptors accumulate to high levels in fibrotic lung and skin tissue from SSc patients and from mice treated with bleomycin. This accumulation is almost completely blocked in mice treated with CSD. In signaling studies, Src activation is enhanced in AA monocytes compared to C monocytes and further increased in SSc monocytes. Lyn is also highly activated in SSc monocytes. Src and Lyn activation are inhibited by CSD. Src and Lyn's roles in monocyte migration were demonstrated using specific inhibitors. CONCLUSIONS: To the best of our knowledge, this is the first report that the expression and function of CCR1, CCR2, and CCR3 are upregulated in monocytes from healthy AA and from SSc patients via molecular mechanisms involving caveolin-1, Src/Lyn, and MEK/ERK. The results suggest that the migration/recruitment of monocytes and fibrocytes into fibrotic tissues, mediated at least in part by CCR1, CCR2, and CCR3, plays a major role in the progression of lung and skin fibrosis and in the predisposition of AA to fibrotic diseases. Our findings further suggest that chemokine receptors and signaling molecules, particularly caveolin-1, that control their expression/function are promising targets for treating fibrotic diseases.

Caveolin-1 deficiency may predispose African Americans to systemic sclerosis-related interstitial lung disease.

OBJECTIVE: Interstitial lung disease (ILD) is the leading cause of death in patients with systemic sclerosis (SSc; scleroderma). Although SSc-related ILD is more common and severe in African Americans than in Caucasians, little is known about factors underlying this significant health disparity. The aim of this study was to examine the role that low expression of caveolin-1 might play in susceptibility to ILD among African Americans. METHODS: Assays of monocyte migration toward stromal cell-derived factor 1 (SDF-1) were performed using monocytes from Caucasian and African American healthy donors and patients with SSc. For fibrocyte differentiation studies, total peripheral blood mononuclear cells were incubated on fibronectin-coated plates. Protein expression was evaluated by immunohistochemistry and Western blotting. RESULTS: Monocytes from healthy African American donors and those from patients with SSc had low caveolin-1 levels, enhanced migration toward the CXCR4 ligand SDF-1, and enhanced differentiation to fibrocytes. Enhanced migration and differentiation of monocytes from African Americans and patients with SSc appeared to be attributable to the lack of caveolin-1, because restoring caveolin-1 function using a caveolin-1 scaffolding domain peptide inhibited these processes. Although they differed from monocytes from Caucasians, monocytes from both African Americans and patients with SSc were not identical, because SSc monocytes showed major increases from baseline in ERK, JNK, p38, and Smad2/3 activation, while monocytes from African Americans showed only limited ERK activation and no activation of JNK, p38, or Smad2/3. In contrast, SDF-1 exposure caused no additional ERK activation in SSc monocytes but did cause significant additional activation in monocytes from African Americans. CONCLUSION: African Americans may be predisposed to SSc-related ILD due to low baseline caveolin-1 levels in their monocytes, potentially affecting signaling, migration, and fibrocyte differentiation. The monocytes of African Americans may lack caveolin-1 due to high levels of transforming growth factor ß in their blood.

Fibrocytes in the fibrotic lung: altered phenotype detected by flow cytometry.

Fibrocytes are bone marrow hematopoietic-derived cells that also express a mesenchymal cell marker (commonly collagen I) and participate in fibrotic diseases of multiple organs. Given their origin, they or their precursors must be circulating cells before recruitment into target tissues. While most previous studies focused on circulating fibrocytes, here we focus on the fibrocyte phenotype in fibrotic tissue. The study's relevance to human disease is heightened by use of a model in which bleomycin is delivered systemically, recapitulating several features of human scleroderma including multi-organ fibrosis not observed when bleomycin is delivered directly into the lungs. Using flow cytometry, we find in the fibrotic lung a large population of CD45(high) fibrocytes (called Region I) rarely found in vehicle-treated control mice. A second population of CD45+ fibrocytes (called Region II) is observed in both control and fibrotic lung. The level of CD45 in circulating fibrocytes is far lower than in either Region I or II lung fibrocytes. The chemokine receptors CXCR4 and CCR5 are expressed at higher levels in Region I than in Region II and are present at very low levels in all other lung cells including CD45+/collagen I- leucocytes. The collagen chaperone HSP47 is present at similar high levels in both Regions I and II, but at a higher level in fibrotic lung than in control lung. There is also a major population of HSP47(high)/CD45- cells in fibrotic lung not present in control lung. CD44 is present at higher levels in Region I than in Region II and at much lower levels in all other cells including CD45+/collagen I- leucocytes. When lung fibrosis is inhibited by restoring caveolin-1 activity using a caveolin-1 scaffolding domain peptide (CSD), a strong correlation is observed between fibrocyte number and fibrosis score. In summary, the distinctive phenotype of fibrotic lung fibrocytes suggests that fibrocyte differentiation occurs primarily within the target organ.

Caveolin-1 regulates chemokine receptor 5-mediated contribution of bone marrow-derived cells to dermal fibrosis.

In fibrotic diseases caveolin-1 underexpression in fibroblasts results in collagen overexpression and in monocytes leads to hypermigration. These profibrotic behaviors are blocked by the caveolin-1 scaffolding domain peptide (CSD) which compensates for caveolin-1 deficiency. Monocytes and fibroblasts are related in that monocytes are the progenitors of fibrocytes (CD45+/Collagen I+ cells) that, in turn, are the progenitors of many fibroblasts in fibrotic tissues. In an additional anti-fibrotic activity, CSD blocks monocyte differentiation into fibrocytes. We studied a mouse fibrosis model (Pump Model) involving systemic bleomycin delivery that closely models scleroderma (SSc) in several ways, the most important of which for this study is that fibrosis is observed in the lungs, skin, and internal organs. We show here that dermal thickness is increased 2-fold in the Pump Model and that this effect is almost completely blocked by CSD (p < 0.001). Concomitantly, the subcutaneous fat layer becomes >80% thinner. This effect is also blocked by CSD (p < 0.001). Even in mice receiving vehicle instead of bleomycin, CSD increases the thickness of the fat layer. To study the mechanisms of action of bleomycin and CSD, we examined the accumulation of the chemokine receptor CCR5 and its ligands MIP1α and MIP1ß in fibrotic tissue and their roles in monocyte migration. Fibrocytes and other leukocytes expressing CCR5 and its ligands were present at high levels in the fibrotic dermis of SSc patients and Pump Model mice while CSD blocked their accumulation in mouse dermis. Migration toward CCR5 ligands of SSc monocytes and Pump Model bone marrow cells was 3-fold greater than cells from control subjects. This enhanced migration was almost completely blocked by CSD. These results suggest that low monocyte caveolin-1 promotes fibrosis by enhancing the recruitment of fibrocytes and their progenitors into affected tissue.

Survival and neurologic recovery in patients with ST-segment elevation myocardial infarction resuscitated from cardiac arrest.

OBJECTIVES: We examined outcomes of patients resuscitated from cardiac arrest owing to ST-segment elevation myocardial infarction (STEMI) and predictors of survival and neurologic recovery. BACKGROUND: Immediately after resuscitation from cardiac arrest owing to STEMI, many patients show signs of neurologic impairment, and benefits of percutaneous coronary intervention and subsequent prognosis are not well defined. METHODS: Between January 1, 2002, and December 31, 2006, we retrospectively identified consecutive patients resuscitated from cardiac arrest, regardless of time to return of spontaneous circulation (ROSC) and neurologic status, and reviewed the outcomes of those who had STEMI. Mortality and neurologic recovery at discharge and long-term mortality were assessed by individual chart review for those who underwent emergent angiography. RESULTS: Our study population consisted of 98 patients; 64% survived to discharge, and 92% had a full neurologic recovery. Predictors of survival were shorter time to ROSC, younger age, neurologic status post-resuscitation (alert or minimally responsive), and male sex. Predictors of neurologic recovery included shorter time to ROSC, neurologic status post-resuscitation (alert or minimally responsive), and younger age. Ninety-six percent of patients who were alert post-resuscitation survived. Ninety-three percent of patients who were minimally responsive post-resuscitation survived. Fifty-nine patients were unresponsive post-resuscitation, with 44% survival, of whom 88% had full neurologic recovery. In the unresponsive group, unwitnessed arrest, prolonged ROSC, and older age were associated with increased risk of death, and older age and prolonged ROSC predicted poor neurologic recovery. CONCLUSIONS: When resuscitated patients with STEMI are being evaluated in the emergency department, serious consideration should be given to emergent angiography and revascularization, regardless of neurologic status.