Citations

AbstractNoninflammatory subsynovial connective tissue (SSCT) fibrosis with nerve compression is a prominent feature of carpal tunnel syndrome (CTS). Studies have shown that SSCT matrix synthesis and material property changes in CTS are associated with increased activity of transforming growth factor (TGF)‐β1. The aim of this study were to (1) investigate the ability of SSCT fibroblasts from CTS patients and unaffected individuals to contract a collagen gel ring and (2) determine how the addition of TGF‐β1 affects this ability. SSCT fibroblasts from three normal cadavers and three age‐matched female patients who had undergone surgery for CTS were used. Results showed patient cell‐seeded gels had a significantly higher contraction rate (p < 0.001) than control cells, and fully contracted gel rings possessed a significantly higher tensile strength (p = 0.003) and stiffness (p < 0.001). Furthermore, TGF‐β1 significantly intensified contraction rate (p < 0.001), tensile strength (p < 0.001), and stiffness (p < 0.001). In conclusion, SSCT cells from normal donors and CTS patients contract collagen gel rings differently, and this ability is affected by TGF‐β1 treatment. This cell‐seeded collagen gel model may be useful for developing new methods of stopping or eliminating the effect of TGF‐β1 on the SSCT fibroblasts and surrounding matrix, which might aid in the identification of medical treatment for CTS. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 574–580, 2015.

Background— Sex-specific differences affect the evaluation, treatment, and prognosis of coronary artery disease. We tested the hypothesis that long-term outcomes of fractional flow reserve (FFR)–guided percutaneous coronary intervention (PCI) are different between women and men. Methods and Results— Consecutive 1090 patients, referred for PCI and undergoing FFR measurements at the Mayo Clinic between October 2002 and December 2009, were included in this registry study. Clinical events were compared between the sexes during a median follow-up of 50.9 months. Of all patients, women had higher FFR adjusted by visual coronary stenosis than men ( P =0.03). The Kaplan–Meier percent of major adverse cardiac events at 5 years was 35% in women and 38% in men ( P =0.54). Interestingly, in patients undergoing PCI with an FFR <0.75, the incidence of death or myocardial infarction was significantly higher in women than in men (hazard ratio, 2.16; 95% confidence interval, 1.04–4.51; P =0.04). Moreover, compared with patients with FFR >0.80, deferral of PCI for those with FFR between 0.75 and 0.80 was associated with an increased rate of major adverse cardiac events, particularly death or myocardial infarction in women (hazard ratio, 3.25; 95% confidence interval, 1.56–6.74; P =0.002) and revascularization in men (hazard ratio, 2.66; 95% confidence interval, 1.66–4.54; P <0.001). Conclusions— Long-term outcome differs between women and men undergoing FFR-guided PCI. Our data suggest that the sex-based treatment strategy is necessary to further optimize prognosis of patients with coronary artery disease.

SUMMARYFibrosis of the subsynovial connective tissue (SSCT) in the carpal tunnel is the most common histological finding in carpal tunnel syndrome (CTS). Fibrosis may result from damaged SSCT. Previous studies found that with low‐velocity (2 mm/s), tendon excursions can irreversibly damage the SSCT. We investigated the effect of tendon excursion velocity in the generation of SSCT damage. Nine human cadaver wrists were used. Three repeated cycles of ramp‐stretch testing were performed simulating 40%, 60%, 90%, and 120% of the middle finger flexor tendon superficialis physiological excursion with an excursion velocity of 60 mm/s. Energy and force were calculated and normalized by values obtained in the first cycle for each excursion level. Data were compared with low‐velocity excursion data. For high‐velocity excursions, a significant drop in the excursion energy ratio was first observed at an excursion level of 60% physiological excursion (p < 0.024) and that for low‐velocity excursions was first observed at 90% physiological excursion (p < 0.038). Furthermore, the energy ratio was lower at 60% for high velocities (p ≤ 0.039). Increasing velocity lowers the SSCT damage threshold. This finding may be relevant for understanding the pathogenesis of SSCT fibrosis, such as that accompanying CTS, and a relationship with occupational factors. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:123–128, 2014.

Abstract Leukotrienes (i.e., products of the 5-lipoxygenase pathway) are thought to be contributors to lung pathologies. Moreover, eosinophils have been linked with pulmonary leukotriene activities both as potential sources of these mediators and as responding effector cells. The objective of the present study was to define the role(s) of leukotrienes in the lung pathologies accompanying eosinophil-associated chronic respiratory inflammation. A transgenic mouse model of chronic T helper (Th) 2–driven inflammation expressing IL-5 from T cells and human eotaxin-2 locally in the lung (I5/hE2) was used to define potential in vivo relationships among eosinophils, leukotrienes, and chronic Th2-polarized pulmonary inflammation. Airway levels of cys-leukotrienes and leukotriene B4 (LTB4) are both significantly elevated in I5/hE2 mice. The eosinophil-mediated airway hyperresponsiveness (AHR) characteristic of these mice was abolished in the absence of leukotrienes (i.e., 5-lipoxygenase–deficient I5/hE2). More importantly, the loss of leukotrienes led to an unexpectedly significant decrease in collagen deposition (i.e., pulmonary fibrosis) that accompanied elevated levels of IL-4/-13 and TGF-β in the lungs of I5/hE2 mice. Further studies using mice deficient for the LTB4 receptor (BLT-1−/− /I5/hE2) and I5/hE2 animals administered a cys-leukotriene receptor antagonist (montelukast) demonstrated that the AHR and the enhanced pulmonary fibrosis characteristic of the I5/hE2 model were uniquely cys-leukotriene–mediated events. These data demonstrate that, similar to allergen challenge models of wild-type mice, cys-leukotrienes underlie AHR in this transgenic model of severe pulmonary Th2 inflammation. These data also suggest that an underappreciated link exists among eosinophils, cys-leukotriene–mediated events, and fibrotic remodeling associated with elevated levels of IL-4/-13 and TGF-β.

Quantifying the pathological features of flexor tendon pulleys is essential for grading the trigger finger since it provides clinicians with objective evidence derived from microscopic images. Although manual grading is time consuming and dependent on the observer experience, there is a lack of image processing methods for automatically extracting pulley pathological features. In this paper, we design and develop a color-based image segmentation system to extract the color and shape features from pulley microscopic images. Two parameters which are the size ratio of abnormal tissue regions and the number ratio of abnormal nuclei are estimated as the pathological progression indices. The automatic quantification results show clear discrimination among different levels of diseased pulley specimens which are prone to misjudgments for human visual inspection. The proposed system provides a reliable and automatic way to obtain pathological parameters instead of manual evaluation which is with intra- and interoperator variability. Experiments with 290 microscopic images from 29 pulley specimens show good correspondence with pathologist expectations. Hence, the proposed system has great potential for assisting clinical experts in routine histopathological examinations.

Aberrant connectivity is implicated in many neurological and psychiatric disorders, including Alzheimer’s disease and schizophrenia. However, other than a few disease-associated candidate genes, we know little about the degree to which genetics play a role in the brain networks; we know even less about specific genes that influence brain connections. Twin and family-based studies can generate estimates of overall genetic influences on a trait, but genome-wide association scans (GWASs) can screen the genome for specific variants influencing the brain or risk for disease. To identify the heritability of various brain connections, we scanned healthy young adult twins with high-field, high-angular resolution diffusion MRI. We adapted GWASs to screen the brain’s connectivity pattern, allowing us to discover genetic variants that affect the human brain’s wiring. The association of connectivity with the SPON1 variant at rs2618516 on chromosome 11 (11p15.2) reached connectome-wide, genome-wide significance after stringent statistical corrections were enforced, and it was replicated in an independent subsample. rs2618516 was shown to affect brain structure in an elderly population with varying degrees of dementia. Older people who carried the connectivity variant had significantly milder clinical dementia scores and lower risk of Alzheimer’s disease. As a posthoc analysis, we conducted GWASs on several organizational and topological network measures derived from the matrices to discover variants in and around genes associated with autism ( MACROD2 ), development ( NEDD4 ), and mental retardation ( UBE2A ) significantly associated with connectivity. Connectome-wide, genome-wide screening offers substantial promise to discover genes affecting brain connectivity and risk for brain diseases.

AbstractBackgroundTransforming growth factor (TGF)‐β1 produced in airway epithelia has been suggested as a contributor to the airway remodeling observed in asthma patients. The protein tyrosine phosphatase SHP2 is a demonstrable modulator of TGF‐β1 production and thus a potential regulator of airway remodeling.ObjectivesTo define the signal event by which SHP2 regulates asthmatic responses in airway epithelial cells by using a mouse model of experimental OVA‐induced airway remodeling.MethodsThe airways of Shp2flox/flox mice were infected with recombinant adenovirus vectors expressing a Cre recombinase–green fluorescence protein (GFP) fusion protein as part of allergen provocation studies using mice sensitized with ovalbumin (OVA) and repeatedly challenged with OVA. Several endpoint pathologies were assessed, including airway hyper‐responsiveness (AHR), lung inflammatory score, peribronchial collagen deposition, and α‐smooth muscle actin (SMA) hyperplasia. In vitro studies using airway epithelial cells (BEAS‐2B) were used to investigate the role of SHP2 in the regulation of pulmonary remodeling events, including the expression of collagen, α‐SMA, and TGF‐β1.ResultsChronic OVA challenges in wild‐type mice resulted in airway remodeling and lung dysfunction (e.g., increased inflammatory scores, collagen deposition (fibrosis), smooth muscle hyperplasia, and a significant increase in AHR). These endpoint pathology metrics were each significantly attenuated by conditional shp2 gene knockdown in airway epithelia. In vitro studies using BEAS‐2B cells also demonstrated that the level of TGF‐β1 production by these cells correlated with the extent of shp2 gene expression.ConclusionsSHP2 activities in airway epithelial cells appear to modulate TGF‐β1 production and, in turn, regulate allergic airway remodeling following allergen provocation.Clinical ImplicationsOur findings identify SHP2 as a previously underappreciated contributor to the airway remodeling and lung dysfunction associated with allergen challenge. As such, SHP2 represents a potentially novel therapeutic target for the treatment of asthmatics.Capsule summaryAirway epithelial protein tyrosine phosphatase SHP2 appears to modulate TGF‐β1 activities as part of one or more cellular pathways leading to regulating the airway remodeling and lung dysfunction occurring in mouse models of allergic respiratory inflammation.

Abstract Recent RNA-sequencing studies have identified variant transcripts, fusion transcripts and novel transcripts in cancer. However, little is known about the role of these variant transcripts in tumor development. To identify a specific role of these variant transcripts in tumor development toward chemotherapy resistance, we generated a custom retroviral cDNA expression library from 10 ovarian tumors with resistance to chemotherapy. Retrovirues were generated from the custom library, and they were used to transduced exogenous genes into ovarian cancer cell line A1847, a cell line chosen for its sensitivity to paclitaxel. A1847 cells transduced with retroviruses carrying alkaline phosphatase was used as a control. Transuced cells were selected with 25 nM paclitaxel. 87 clones survived the selection in library-tranduced cells whereas none survived the selection in alkaline phosphatase-tranduced control cells. Forty seven clones survive the secondary screens. Sequence analysis of transduced genes in these surviving clones indicate that 4 paclitaxel-resistant clones contain RABL3 splice variant. Although 195 accessions corresponding to wildtype transcripts are reported in AceView, there is a single accession corresponding to RABL splice variant that we identified in this screen. RNAi-mediated downregulation of RABL3 resulted in enhance sensitivity toward paclitaxel in these resistant clones. Ectopic expression of RABL3 splice variant resulted in increased resistant to paclitaxel. Collectively, these results demonstrate the feasibility of performing functional genetic screens to identify novel splice variants involved in tumor development. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5120. doi:1538-7445.AM2012-5120

Abstract Ischemic stroke (IS) is among the leading causes of death in Western countries. There is a significant genetic component to IS susceptibility, especially among young adults. To date, research to identify genetic loci predisposing to stroke has met only with limited success. We performed a genome-wide association (GWA) analysis of early-onset IS to identify potential stroke susceptibility loci. The GWA analysis was conducted by genotyping 1 million SNPs in a biracial population of 889 IS cases and 927 controls, ages 15–49 years. Genotypes were imputed using the HapMap3 reference panel to provide 1.4 million SNPs for analysis. Logistic regression models adjusting for age, recruitment stages, and population structure were used to determine the association of IS with individual SNPs. Although no single SNP reached genome-wide significance (P &lt; 5 × 10−8), we identified two SNPs in chromosome 2q23.3, rs2304556 (in FMNL2; P = 1.2 × 10−7) and rs1986743 (in ARL6IP6; P = 2.7 × 10−7), strongly associated with early-onset stroke. These data suggest that a novel locus on human chromosome 2q23.3 may be associated with IS susceptibility among young adults.

Background— Approximately 10% of sudden infant death syndrome (SIDS) may stem from cardiac channelopathies. The KCNJ8 -encoded Kir6.1 (K ATP ) channel critically regulates vascular tone and cardiac adaptive response to systemic metabolic stressors, including sepsis. KCNJ8 -deficient mice are prone to premature sudden death, particularly with infection. We determined the spectrum, prevalence, and function of KCNJ8 mutations in a large SIDS cohort. Methods and Results— Using polymerase chain reaction, denaturing high-performance liquid chromatography, and DNA sequencing, comprehensive open reading frame/splice-site mutational analysis of KCNJ8 was performed on genomic DNA isolated from necropsy tissue on 292 unrelated SIDS cases (178 males, 204 white; age, 2.9±1.9 months). KCNJ8 mutations were coexpressed heterologously with SUR2A in COS-1 cells and characterized using whole-cell patch-clamp. Two novel KCNJ8 mutations were identified. A 5-month-old white male had an in-frame deletion (E332del) and a 2-month-old black female had a missense mutation (V346I). Both mutations localized to Kir6.1's C-terminus, involved conserved residues and were absent in 400 and 200 ethnic-matched reference alleles respectively. Both cases were negative for mutations in established channelopathic genes. Compared with WT, the pinacidil-activated K ATP current was decreased 45% to 68% for Kir6.1-E332del and 40% to 57% for V346I between −20 mV and 40 mV. Conclusions— Molecular and functional evidence implicated loss-of-function KCNJ8 mutations as a novel pathogenic mechanism in SIDS, possibly by predisposition of a maladaptive cardiac response to systemic metabolic stressors akin to the mouse models of KCNJ8 deficiency.