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Simple Summary: The pancreatic cancer field suffers from a lack of effective treatment options in part due to the severely compromised tumor vasculature that leads to hypoxia and an immunosuppressive environment. Our study aimed to identify and characterize pathological pericyte phenotypes that contribute to the defective tumor vasculature. We found that a large population of PDAC pericytes present ectopic α-smooth muscle actin (αSMA) expression, and this subtype was induced by cancer cell-derived exosomes. We also showed that the PDAC exosome-induced αSMA+ pericyte exhibits aberrant biomechanical properties and an acquired immunomodulatory phenotype. Considering a lack of efficient anti-angiogenic approaches in PDAC, identifying a unique molecular phenotype or the target molecule of a pathological pericyte will be an entry point toward a vascular normalization approach. The subpopulations of tumor pericytes undergo pathological phenotype switching, affecting their normal function in upholding structural stability and cross-communication with other cells. In the case of pancreatic ductal adenocarcinoma (PDAC), a significant portion of blood vessels are covered by an α-smooth muscle actin (αSMA)-expressing pericyte, which is normally absent from capillary pericytes. The DesminlowαSMAhigh phenotype was significantly correlated with intratumoral hypoxia and vascular leakiness. Using an in vitro co-culture system, we demonstrated that cancer cell-derived exosomes could induce ectopic αSMA expression in pericytes. Exosome-treated αSMA+ pericytes presented altered pericyte markers and an acquired immune-modulatory feature. αSMA+ pericytes were also linked to morphological and biomechanical changes in the pericyte. The PDAC exosome was sufficient to induce αSMA expression by normal pericytes of the healthy pancreas in vivo, and the vessels with αSMA+ pericytes were leaky. This study demonstrated that tumor pericyte heterogeneity could be dictated by cancer cells, and a subpopulation of these pericytes confers a pathological feature. [ABSTRACT FROM AUTHOR]

Corneal fibrosis (or scarring) occurs in response to ocular trauma or infection, and by reducing corneal transparency, it can lead to visual impairment and blindness. Studies highlight important roles for transforming growth factor (TGF)-β1 and -β3 as modulators in corneal wound healing and fibrosis, leading to increased extracellular matrix (ECM) components and expression of α-smooth muscle actin (αSMA), a myofibroblast marker. In this study, human corneal fibroblasts (hCF) were cultured as a monolayer culture (2D) or on poly-transwell membranes to generate corneal stromal constructs (3D) that were treated with TGF-β1, TGF-β3, or TGF-β1 + FAK inhibitor (FAKi). Results show that hCF 3D constructs treated with TGF-β1 or TGF-β3 impart distinct effects on genes involved in wound healing and fibrosis—ITGAV, ITGB1, SRC and ACTA2. Notably, in the 3D construct model, TGF-β1 enhanced αSMA and focal adhesion kinase (FAK) protein expression, whereas TGF-β3 did not. In addition, in both the hCF 2D cell and 3D construct models, we found that TGF-β1 + FAKi attenuated TGF-β1-mediated myofibroblast differentiation, as shown by abrogated αSMA expression. This study concludes that FAK signaling is important for the onset of TGF-β1-mediated myofibroblast differentiation, and FAK inhibition may provide a novel beneficial therapeutic avenue to reduce corneal scarring.

Highlights: [•] Chronic oral administration of Cd2+ reduced the body weight, food intake and plasma level of leptin in rats. [•] Plasma lysophosphatidic acid level was reduced, but plasma sphingosine-1-phosphate level was elevated after Cd2+-exposure. [•] Lysophosphatidic acid and sphingosine-1-phosphate protected rat renal fibroblastic and epithelial cells from Cd2+-toxicity. [ABSTRACT FROM AUTHOR]

Carriers of oncogenic human T-cell leukemia virus type 1 (HTLV-1) can develop adult T-cell leukemia/lymphoma (ATLL). While an increasing number of animal models of HTLV-1 infection have revealed that malignant tumors with a histiocytic phenotype can arise, they have not been reported in humans. Here, we present a 79-year-old female HTLV-1 carrier who presented with a swollen lymph node. Histological examination revealed that the lymph node was replaced with a malignant spindle cell tumor, but not ATLL. Immunohistochemical analysis indicated that the tumor was positive for histiocytic (CD68 and CD163) and myogenic (α-smooth muscle actin, desmin, and caldesmon) markers, suggesting some differential diagnoses. We could not reach a definitive diagnosis under the current notion of the disease entity. In addition, we could not provide an exact causal relationship between HTLV-1 infection and the development of the current tumor. Nevertheless, this tumor may be a human counterpart of murine HTLV-1-related histiocytic tumors. Curiously, the tumor showed a good response to chemotherapy with the combination of cyclophosphamide, vincristine, and prednisone, a standard approach for ATLL. This case might represent a novel entity of an HTLV-1-related malignant tumor. Further accumulation of case reports will certainly contribute to our understanding of human HTLV-1-related disease and the mechanism of viral oncogenesis. [ABSTRACT FROM AUTHOR]

Abstract: Fibrosis underlies the pathogenesis of numerous diseases and leads to severe damage of vital body organs and, frequently, to death. Better understanding of the mechanisms resulting in fibrosis is essential for developing appropriate treatment solutions and is therefore of upmost importance. Recent evidence suggests a significant antifibrotic potential of an integral membrane protein, caveolin-1. While caveolin-1 has been widely studied for its role in the regulation of cell signaling and endocytosis, its possible implication in fibrosis remains largely unclear. In this review we survey involvement of caveolin-1 in various cellular processes and highlight different aspects of its antifibrotic activity. We hypothesize that caveolin-1 conveys a homeostatic function in the process of fibrosis by (a) regulating TGF-β1 and its downstream signaling; (b) regulating critical cellular processes involved in tissue repair, such as migration, adhesion and cellular response to mechanical stress; and (c) antagonizing profibrotic processes, such as proliferation. Finally, we consider this homeostatic function of caveolin-1 as a possible novel approach in treatment of fibroproliferative diseases. [Copyright &y& Elsevier]

Abstract: Autoimmune hepatitis type 2 (AIH-2) is a severe autoimmune liver disease with unknown etiology. We recently developed the CYP2D6 mouse model for AIH-2, in which mice are challenged with an adenovirus (Ad-2D6) expressing human cytochrome P450 2D6 (hCYP2D6), the major autoantigen in AIH-2. Such mice develop chronic hepatitis with cellular infiltrations and generation of hCYP2D6-specific antibodies and T cells. Importantly, the CYP2D6 model represents the only model displaying chronic fibrosis allowing for a detailed investigation of the mechanisms of chronic autoimmune-mediated liver fibrogenesis. We found that hCYP2D6-dependent chronic activation of hepatic stellate cells (HSC) resulted in an increased extracellular matrix deposition and elevated expression of α-smooth muscle actin predominantly in and underneath the liver capsule. The route of Ad-2D6 infection dramatically influenced the activation and trafficking of inflammatory monocytes, NK cells and hCYP2D6-specific T cells. Intraperitoneal Ad-2D6 infection caused subcapsular fibrosis and persistent clustering of inflammatory monocytes. In contrast, intravenous infection caused an accumulation of hCYP2D6-specific CD4 T cells throughout the liver parenchyma and induced a strong NK cell response preventing chronic HSC activation and fibrosis. In summary, we found that the location of the initial site of inflammation and autoantigen expression caused a differential cellular trafficking and activation and thereby determined the outcome of AIH-2-like hepatic damage and fibrosis. [Copyright &y& Elsevier]

We report a case of lymphangioma involving oral mucosa and mandible of an elderly female. The surgical and radiological examinations indicated that the lymphangioma was mainly distributed in the labial rnucosa tissue, but had gradually extended into the periosteum and intrabony space of mandible. Immunohistochemical staining was also performed using antiseras of &alpah;-smooth muscle actin (&alpah;-SMA), von Willebrand factor (vWF), angiogenin, vascular endothelial growth factor (VEGF), and proliferating cell nuclear antigen (PCNA) to elucidate the pathogenetic implications of the intraosseous lymphangioma. The present case of lymphangioma showed strong immunohistochemical reactivity of angiogenin and vWF, while it showed weak reactions of VEGF and PCNA. The immunostaining of (&alpah;-SMA disclosed an abnormally thinned and discontinuous smooth muscle layer in the lymphatics. Both the X-rays and histological examination showed that the lymphangioma lesion was gradually extending into the adjacent osteoporotic marrow space of mandible. Therefore, we believe that the present case of intraosseous lymphangioma. which showed the harmatomatous growth of the lymphatics into the marrow space of mandible, is closely related to osteoporotic changes of old age. [ABSTRACT FROM AUTHOR]

Corneal fibrosis (or scarring) occurs in response to ocular trauma or infection, and by reducing corneal transparency, it can lead to visual impairment and blindness. Studies highlight important roles for transforming growth factor (TGF)-β1 and -β3 as modulators in corneal wound healing and fibrosis, leading to increased extracellular matrix (ECM) components and expression of α-smooth muscle actin (αSMA), a myofibroblast marker. In this study, human corneal fibroblasts (hCF) were cultured as a monolayer culture (2D) or on poly-transwell membranes to generate corneal stromal constructs (3D) that were treated with TGF-β1, TGF-β3, or TGF-β1 + FAK inhibitor (FAKi). Results show that hCF 3D constructs treated with TGF-β1 or TGF-β3 impart distinct effects on genes involved in wound healing and fibrosis—ITGAV, ITGB1, SRC and ACTA2. Notably, in the 3D construct model, TGF-β1 enhanced αSMA and focal adhesion kinase (FAK) protein expression, whereas TGF-β3 did not. In addition, in both the hCF 2D cell and 3D construct models, we found that TGF-β1 + FAKi attenuated TGF-β1-mediated myofibroblast differentiation, as shown by abrogated αSMA expression. This study concludes that FAK signaling is important for the onset of TGF-β1-mediated myofibroblast differentiation, and FAK inhibition may provide a novel beneficial therapeutic avenue to reduce corneal scarring. [ABSTRACT FROM AUTHOR]

Aim of the Study: To investigate, in vivo and in vitro, the fibroblast-to-myofibroblast transition in patients with hypermobile Ehlers-Danlos Syndrome (EDS). To analyze the dermis of patients with classical form of EDS (cEDS) and with hEDS, to identify qualitative and/or quantitative differences in ECM component and ultrastructural changes in collagen., Materials and Methods: Seven subjects, aged over 18, two with cEDS and five with hEDS underwent two skin biopsy. One sample was prepared for transmission electron microscopy (TEM), the other for immunofluorescence. The diameter of collagen fibers was measured with TEM. Fibrils were analyzed in four patients: the two with cEDS and two with hEDS. For each patient, the diameter of n=250 collagen fibrils was measured. αSMA was used as specific marker for myofibroblast to highlight their presence in vivo in the skin of patients with hEDS., Result: IF observation could not assess an increased expression of αSMA in hEDS patients, which showed no statistical difference compared to classic form patients. The major result from the analysis of TEM images is the clear difference in ECM composition between the two forms of EDS: ECM in hEDS is optically more dense and more prominently composed of elastic fibers., Conclusion: Our study provides the following important evidence: 1) the absence in vivo of dermal fibroblasts in patients with hEDS, demonstrated by αSMA negativity; 2) the presence of statistically significant changes in the diameter of collagen fibrils between the classic and the hypermobile forms.

Clinical applications of mesenchymal stromal cells (MSCs) require the manufacture of large cell lots, which involves multiple passages for cell expansion and sometimes genetic modification. MSCs from various sources, including bone marrow (BM), exhibit high donor-to-donor variability in their growth characteristics. This can lead to unpredictable manufacturing outcomes with respect to success or failure of individual lots. Early determination of lot success has the potential to reduce the cost and improve the efficiency of the MSC manufacturing process. However, methods that effectively predict lot growth potential early in the manufacturing process are currently lacking. Here we report that the growth potential of an MSC lot can be predicted a few days after BM plating based on α-smooth muscle actin (αSMA) protein expression in large colony-forming unit-fibroblast (CFU-f) colonies. The proposed prediction method could be a useful tool to prospectively determine MSC lot success or failure.

Background & Aims: Infantile hypertrophic pyloric stenosis is a common birth anomaly characterized by obstruction of the pyloric lumen. A genome-wide association study implicated NKX2-5, which encodes a transcription factor that is expressed in embryonic heart and pylorus, in the pathogenesis of infantile hypertrophic pyloric stenosis. However, the function of the NKX2-5 in pyloric smooth muscle development has not been examined directly. We investigated the pattern of Nkx2-5 during the course of murine pyloric sphincter development and examined coexpression of Nkx2-5 with Gata3 and Sox9—other transcription factors with pyloric-specific mesenchymal expression. We also assessed pyloric sphincter development in mice with disruption of Nkx2-5 or Gata3. Methods: We used immunofluorescence analysis to compare levels of NKX2-5, GATA3, and SOX9 in different regions of smooth muscle cells. Pyloric development was assessed in mice with conditional or germline deletion of Nkx2-5 or Gata3, respectively. Results: Gata3, Nkx2-5, and Sox9 are coexpressed in differentiating smooth muscle cells of a distinct fascicle of the pyloric outer longitudinal muscle. Expansion of this fascicle coincides with development of the pyloric sphincter. Disruption of Nkx2-5 or Gata3 causes severe hypoplasia of this fascicle and alters pyloric muscle shape. Although expression of Sox9 requires Nkx2-5 and Gata3, there is no apparent hierarchical relationship between Nkx2-5 and Gata3 during pyloric outer longitudinal muscle development. Conclusions: Nkx2-5 and Gata3 are independently required for the development of a pyloric outer longitudinal muscle fascicle, which is required for pyloric sphincter morphogenesis in mice. These data indicate that regulatory changes that alter Nkx2-5 or Gata3 expression could contribute to pathogenesis of infantile hypertrophic pyloric stenosis. [Copyright &y& Elsevier]

Objective: Myocardial infarction (MI) can lead to irreversible adverse left ventricular remodeling resulting in subsequent severe dysfunction. The objective of this study was to investigate the potential for biodegradable, elastomeric patch implantation to positively alter the remodeling process after MI in a porcine model. Methods: Yorkshire pigs underwent a 60-minute catheter balloon occlusion of the left circumflex artery. Two weeks after MI animals underwent epicardial placement of a biodegradable, porous polyurethane (poly(ester urethane)urea; PEUU) patch (MI+PEUU, n = 7) or sham surgery (MI+sham, n = 8). Echocardiography before surgery and at 4 and 8 weeks after surgery measured the end-diastolic area (EDA) and fractional area change (%FAC). All animals were humanely killed 8 weeks after surgery and hearts were histologically assessed. Results: At 8 weeks, echocardiography revealed greater EDA values in the MI+sham group (23.6 ± 6.6 cm2, mean ± standard deviaation) than in the MI+PEUU group (15.9 ± 2.5 cm2) (P < .05) and a lower %FAC in the MI+sham group (24.8 ± 7.6) than in the MI+PEUU group (35.9 ± 7.8) (P < .05). The infarcted ventricular wall was thicker in the MI+PEUU group (1.56 ± 0.5 cm) than in the MI+sham group (0.91 ± 0.24 cm) (P < .01). Conclusions: Biodegradable elastomeric PEUU patch implantation onto the porcine heart 2 weeks post-MI attenuated left ventricular adverse remodeling and functional deterioration and was accompanied by increased neovascularization. These findings, although limited to a 2-month follow-up, may suggest an attractive clinical option to moderate post-MI cardiac failure. [Copyright &y& Elsevier]