Project description:The expression of bird song is expected to signal male quality to females. 'Quality' is determined by genetic and environmental factors, but, surprisingly, there is very limited evidence if and how genetic aspects of male quality are reflected in song. Here, we manipulated the genetic make-up of canaries (Serinus canaria) via inbreeding, and studied its effects upon song output, complexity, phonetics and, for the first time, song learning. To this end, we created weight-matched inbred and outbred pairs of male fledglings, which were subsequently exposed to the same tutor male during song learning. Inbreeding strongly affected syllable phonetics, but there were little or no effects on other song features. Nonetheless, females discriminated among inbred and outbred males, as they produced heavier clutches when mated with an outbred male. Our study highlights the importance of song phonetics, which has hitherto often been overlooked.
Project description:Successful navigation in complex acoustic scenes requires focusing on relevant sounds while ignoring irrelevant distractors. It has been argued that the ability to track stimulus statistics and generate predictions supports the choice of what to attend and what to ignore. However, the role of these predictions about future auditory events in drafting decisions remains elusive. While most psychophysical studies in humans indicate that expected stimuli are more easily detected, most work studying physiological auditory processing in animals highlights the detection of unexpected, surprising stimuli. Here, we tested whether in the mouse, high target probability results in enhanced detectability or whether detection is biased towards low-probability deviants using an auditory detection task. We implemented a probabilistic choice model to investigate whether a possible dependence on stimulus statistics arises from short-term serial correlations or from integration over longer periods. Our results demonstrate that target detectability in mice decreases with increasing probability, contrary to humans. We suggest that mice indeed track probability over a timescale of at least several minutes but do not use this information in the same way as humans do: instead of maximizing reward by focusing on high-probability targets, the saliency of a target is determined by surprise.
Project description:Congenital disorders of glycosylation (CDG) are characterized by a generalized underglycosylation of proteins. CDG is associated with multiple symptoms such as psychomotor retardation, hypotonia, hormonal disturbances, liver fibrosis and coagulopathies. The molecular basis of these symptoms is poorly understood considering the large extent of affected glycoproteins. To better understand the cellular responses to protein underglycosylation in CDG, we have investigated the differences in gene expression between healthy control and CDG fibroblasts by transcriptome comparison. This analysis revealed a strong induction of several genes encoding components of the extracellular matrix, such as collagens, COMP, IGFBP5 and biglycan. The extent of this response was confirmed at the protein level by showing increased production of collagen type-I for example. This fibrotic response of CDG fibroblasts was not paralleled by a differentiation to myofibroblasts and by increased TGF-? signalling. We could show that the addition of recombinant IGFBP5, one of the induced proteins in CDG, to healthy control fibroblasts increased the production of collagen type-I to levels similar to those found in CDG fibroblasts. The fibrotic response identified in CDG fibroblasts may account for the elevated tissue fibrosis, which is often encountered in CDG patients.
Project description:Genetically abnormal fibroblasts are notably more prevalent in colorectal cancer (CRC) than in adjacent normal tissue, emphasizing their significance in driving the heterogeneity of the tumor microenvironment. Functioning as a significant regulatory gene in the context of fibrosis, FOXF1 adjacent non-coding developmental regulatory RNA (FENDRR) has exhibited abnormal expression in colorectal cancer and interstitial localization in our experiments. However, current research on the role of FENDRR in cancer has focused solely on its impact on cancer cells. Its crucial role in the tumor stroma is yet to be explored. The goal of this study was to understand the relationship between atypical FENDRR expression, its distinct localization, and genetically abnormal fibroblasts in CRC. We aimed to establish the function of FENDRR within the stromal compartment of patients through bioinformatics. Our study confirmed that FENDRR suppresses cancer-associated fibroblasts by inhibiting their activation and collagen generation in CRC. Furthermore, our findings suggest that low FENDRR expression indicates a poor prognosis. Therefore, we propose that FENDRR is a promising therapeutic target for future studies in CRC.
Project description:BACKGROUND:Scleroderma (systemic sclerosis; SSc) is a clinically heterogeneous and often lethal acquired disorder of the connective tissue that is characterized by vascular, immune/inflammatory and fibrotic manifestations. Tissue fibrosis is the main cause of morbidity and mortality in SSc and an unmet medical challenge, mostly because of our limited understanding of the molecular factors and signalling events that trigger and sustain disease progression. Recent evidence has correlated skin fibrosis in SSc with stabilization of proto-oncogene Ha-Ras secondary to auto-antibody stimulation of reactive oxygen species production. The goal of the present study was to explore the molecular connection between Ha-Ras stabilization and collagen I production, the main read-out of fibrogenesis, in a primary dermal fibroblast culture system that replicates the early stages of disease progression in SSc. RESULTS:Forced expression of proto-oncogene Ha-Ras in dermal fibroblasts demonstrated the promotion of an immediate collagen I up-regulation, as evidenced by enhanced activity of a collagen I-driven luciferase reporter plasmid and increased accumulation of endogenous collagen I proteins. Moreover, normal levels of Tgf? transcripts and active transforming growth factor-beta (TGF?) implied Ha-Ras stimulation of the canonical Smad2/3 signalling pathway independently of TGF? production or activation. Heightened Smad2/3 signalling was furthermore correlated with greater Smad3 phosphorylation and Smad3 protein accumulation, suggesting that Ha-Ras may target both Smad2/3 activation and turnover. Additional in vitro evidence excluded a contribution of ERK1/2 signalling to improper Smad3 activity and collagen I production in cells that constitutively express Ha-Ras. CONCLUSIONS:Our study shows for the first time that constitutively elevated Ha-Ras protein levels can directly stimulate Smad2/3 signalling and collagen I accumulation independently of TGF? neo-synthesis and activation. This finding therefore implicates the Ha-Ras pathway with the early onset of fibrosis in SSc and implicitly identifies new therapeutic targets in SSc.
Project description:LR8 gene was first reported in a subpopulation of cultured human lung fibroblasts expressing the receptor for C1q-globular domain, and it was not detectable in cultured endothelial cells and smooth muscle cells. LR8 mRNA levels were higher in fibrotic lungs. In this study we assessed LR8 production in human tissues and determined if the distribution of fibroblasts producing LR8 is affected in fibrosis. Normal and fibrotic tissue sections from human liver, lung and kidneys were immunostained with antibodies to LR8 and examined for the presence of fibroblasts staining positively and negatively. The cells were also examined for co-expression of α-smooth muscle actin (SMA), a marker for myofibroblasts. The results showed that LR8 was expressed by fibroblasts, smooth muscle cells, endothelial cells, bile duct cells, pulmonary alveolar cells and distal and proximal kidney tubule cells. Connective tissues of normal and fibrotic tissues contained fibroblasts staining positively and negatively with anti- LR8 antibody. The number of LR8-positive cells was higher in fibrotic tissues, but differences were not statistically significant. Fibroblasts producing both LR8 and SMA were present in higher numbers in fibrotic tissues as compared to normal tissues and the differences were statistically significant (p<0.05). Our results show that fibroblast subtypes differing in LR8 expression are present in human tissues, and that in fibrotic tissues cells co-expressing LR8 and SMA are present. Our results indicate that LR8 expressing cells may participate in the early stages of fibrotic diseases and that fibroblasts expressing LR8, not LR8 negative cells, have potential to become myofibroblasts in fibrotic tissues.
Project description:Idiopathic pulmonary fibrosis (IPF) is a deadly disease characterized by chronic inflammation and excessive collagen accumulation in the lung. Myofibroblasts are the primary collagen-producing cells in pulmonary fibrosis. Histone deacetylase inhibitor (HDACi) can affect gene expression, and some, such as suberoylanilide hydroxamic acid (SAHA), are US FDA approved for cancer treatment. In this study, we investigated SAHA's effects on the expression of collagen III alpha 1 (COL3A1) in primary human IPF fibroblasts and in a murine model of pulmonary fibrosis. We observed that increased COL3A1 expression in IPF fibroblasts can be substantially reduced by SAHA treatment at the level of transcription as detected by RT-PCR; collagen III protein level was also reduced, as detected by Western blots and immunofluorescence. The deacetylation inhibitor effect of SAHA was verified by observing higher acetylation levels of both histone H3 and H4 in treated IPF cells. Chromatin immunoprecipitation (ChIP) experiments demonstrated that the reduced expression of COL3A1 by SAHA is with increased association of the repressive chromatin marker, H3K27Me3, and decreased association of the active chromatin marker, H3K9Ac. In our murine model of bleomycin-induced pulmonary fibrosis, the SAHA treated group demonstrated significantly less collagen III, as detected by immunohistochemistry. Our data indicate that the HDACi SAHA alters the chromatin associated with COL3A1, resulting in its decreased expression.
Project description:Scar formation following skin injury can be a major psychosocial and physiological problem. However, the mechanisms of scar formation are still not completely understood. Previous studies have shown that wound healing in oral mucosa is faster, associates with a reduced inflammatory response and results to significantly reduced scar formation compared with skin wounds. In the present study, we hypothesized that oral mucosal fibroblasts from human gingiva are inherently distinct from fibroblasts from breast and abdominal skin, two areas prone to excessive scar formation, which may contribute to the preferential wound healing outcome in gingiva. To this end, we compared the phenotype of human gingival and skin fibroblasts cultured in in vivo-like three-dimensional (3D) cultures that mimic the cells' natural extracellular matrix (ECM) niche. To establish 3D cultures, five parallel fibroblast lines from human gingiva (GFBLs) and breast skin (SFBLs) were seeded in high density, and cultured for up to 21 days in serum and ascorbic acid containing medium to induce expression of wound-healing transcriptome and ECM deposition. Cell proliferation, morphology, phenotype and expression of wound healing and scar related genes were analyzed by real-time RT-PCR, Western blotting and immunocytochemical methods. The expression of a set of genes was also studied in three parallel lines of human abdominal SFBLs. Findings showed that GFBLs displayed morphologically distinct organization of the 3D cultures and proliferated faster than SFBLs. GFBLs expressed elevated levels of molecules involved in regulation of inflammation and ECM remodeling (MMPs) while SFBLs showed significantly higher expression of TGF-? signaling, ECM and myofibroblast and cell contractility-related genes. Thus, GFBLs display an inherent phenotype conducive for fast resolution of inflammation and ECM remodeling, characteristic for scar-free wound healing, while SFBLs have a profibrotic, scar-prone phenotype.
Project description:Angiogenesis is essential for the development of tumors. Studies have shown that carcinoma-associated fibroblasts (CAFs) are involved in regulating tumor angiogenesis, but the mechanism remains unclear. Recently, long noncoding RNAs (lncRNAs) have been proved to play an important role in the angiogenesis of various tumors. However, there is currently no research involving the regulation of CAFs on the angiogenesis of oral squamous cell carcinoma (OSCC) mediated by lncRNAs. By analyzing microarray data, we identified that the expression of lncRNA FOXF1 adjacent noncoding developmental regulatory RNA (FENDRR) in OSCC patients is downregulated, compared to that in normal tissues. Quantitative polymerase chain reaction (qPCR) results demonstrated that FENDRR expression is lower in CAFs compared to normal fibroblasts (NFs) of OSCC patients. KEGG pathway analysis revealed that some genes differentially expressed between CAFs and NFs of HNSCC patients are enriched to the PI3K/AKT pathway. Further experiments confirmed that the downregulation of FENDRR can activate the PI3K/AKT pathway in NFs and enhances the expression of matrix metalloproteinase 9 (MMP9). The overexpression of FENDRR had the opposite effect. Besides, we co-cultured human umbilical vein endothelial cells (HUVECs) with CAFs, and the tube-forming ability of HUVECs co-cultured with CAFs overexpressing FENDRR decreased significantly. However, activation of the AKT pathway of CAFs overexpressing FENDRR can weaken the inhibitory effect of FENDRR on angiogenesis. In summary, our experiments are focused on the influence of lncRNAs in CAFs on OSCC angiogenesis for the first time and prove that FENDRR mediates CAFs' regulation of OSCC angiogenesis through the PI3K/AKT pathway.