Fibrosis-Related Gene Profiling in Liver Biopsies of PiZZ α1-Antitrypsin Children with Different Clinical Courses.

PiZZ (Glu342Lys) α1-antitrypsin deficiency (AATD) is characterized by intrahepatic AAT polymerization and is a risk factor for liver disease development in children. The majority of PiZZ children are disease free, hence this mutation alone is not sufficient to cause the disease. We investigated Z-AAT polymers and the expression of fibrosis-related genes in liver tissues of PiZZ children with different clinical courses. Liver biopsies obtained during 1979-2010 at the Department of Paediatrics, Karolinska University Hospital, Sweden, were subjected to histological re-evaluation, immunohistochemistry and NanoString-based transcriptome profiling using a panel of 760 fibrosis plus 8 bile acid-related genes. Subjects were divided into three groups based on clinical outcomes: NCH (neonatal cholestasis, favourable outcome, n = 5), NCC (neonatal cholestasis, early cirrhosis and liver transplantation, n = 4), and NNCH (no neonatal cholestasis, favourable outcome, n = 5, six biopsies). Hepatocytes containing Z-AAT polymers were abundant in all groups whereas NCC showed higher expression of genes related to liver fibrosis/cirrhosis and lower expression of genes related to lipid, aldehyde/ketone, and bile acid metabolism. Z-AAT accumulation per se cannot explain the clinical outcomes of PiZZ children; however, changes in the expression of specific genes and pathways involved in lipid, fatty acid, and steroid metabolism appear to reflect the degree of liver injury.

Interstitial Lung Disease in Patients With Systemic Sclerosis: Toward Personalized-Medicine-Based Prediction and Drug Screening Models of Systemic Sclerosis-Related Interstitial Lung Disease (SSc-ILD).

Systemic sclerosis (SSc) is an autoimmune connective tissue disease, characterized by immune dysregulation and progressive fibrosis. Interstitial lung disease (ILD) is the most common cause of death among SSc patients and there are currently very limited approved disease-modifying treatment options for systemic sclerosis-related interstitial lung disease (SSc-ILD). The mechanisms underlying pulmonary fibrosis in SSc-ILD are not completely unraveled, and knowledge on fibrotic processes has been acquired mostly from studies in idiopathic pulmonary fibrosis (IPF). The incomplete knowledge of SSc-ILD pathogenesis partly explains the limited options for disease-modifying therapy for SSc-ILD. Fibrosis in IPF appears to be related to aberrant repair following injury, but whether this also holds for SSc-ILD is less evident. Furthermore, immune dysregulation appears to contribute to pro-fibrotic responses in SSc-ILD, perhaps more than in IPF. In addition, SSc-ILD patient heterogeneity complicates the understanding of the underlying mechanisms of disease development, and more importantly, limits correct clinical diagnosis and treatment effectivity. Therefore, there is an unmet need for patient-relevant (in vitro) models to examine patient-specific disease pathogenesis, predict disease progression, screen appropriate treatment regimens and identify new targets for treatment. Technological advances in in vitro patient-relevant disease modeling, including (human induced pluripotent stem cell (hiPSC)-derived) lung epithelial cells, organoids and organ-on-chip technology offer a platform that has the potential to contribute to unravel the underlying mechanisms of SSc-ILD development. Combining these models with state-of-the-art analysis platforms, including (single cell) RNA sequencing and (imaging) mass cytometry, may help to delineate pathogenic mechanisms and define new treatment targets of SSc-ILD.

Continuous Light Does Not Affect Atherosclerosis in APOE*3-Leiden.CETP Mice.

Artificial light exposure is associated with dyslipidemia in humans, which is a major risk factor for the development of atherosclerotic cardiovascular disease. However, it remains unclear whether artificial light at night can exacerbate atherosclerosis. In this study, we exposed female APOE*3-Leiden.CETP mice, a well-established model for human-like lipid metabolism and atherosclerosis, to either a regular light-dark cycle or to constant bright light for 14 weeks. Mice exposed to constant light demonstrated a minor reduction in food intake, without any effect on body weight, body composition, or the weight of metabolic organs. Constant light increased the plasma levels of proatherogenic non-high-density lipoprotein (HDL) cholesterol but did not increase the size or severity of atherosclerotic lesions in the aortic root. Mice exposed to constant light did show lower immune cell counts, which could explain the absence of an effect of atherosclerosis despite increased non-HDL cholesterol levels. Behavioral analysis demonstrated variability in the response of mice to the light intervention. Constant light completely blunted behavioral rhythms in some mice, while others extended their behavioral period. However, rhythm strength was not an important determinant of atherosclerosis. Altogether, these results demonstrate that constant bright light does not affect atherosclerosis in APOE*3-Leiden.CETP mice. Whether artificial light exposure contributes to cardiovascular disease risk in humans remains to be investigated.

Modulation of Airway Epithelial Innate Immunity and Wound Repair by M(GM-CSF) and M(M-CSF) Macrophages.

Airway epithelial cells and macrophages participate in inflammatory responses to external noxious stimuli, which can cause epithelial injury. Upon injury, epithelial cells and macrophages act in concert to ensure rapid restoration of epithelial integrity. The nature of the interactions between these cell types during epithelial repair is incompletely understood. We used an in vitro human coculture model of primary bronchial epithelial cells cultured at the air-liquid interface (ALI-PBEC) and polarized primary monocyte-derived macrophages. Using this coculture, we studied the contribution of macrophages to epithelial innate immunity, wound healing capacity, and epithelial exposure to whole cigarette smoke (WCS). Coculture of ALI-PBEC with lipopolysaccharide (LPS)-activated M(GM-CSF) macrophages increased the expression of DEFB4A, CXCL8, and IL6 at 24 h in the ALI-PBEC, whereas LPS-activated M(M-CSF) macrophages only increased epithelial IL6 expression. Furthermore, wound repair was accelerated by coculture with both activated M(GM-CSF) and M(M-CSF) macrophages, also following WCS exposure. Coculture of ALI-PBEC and M(GM-CSF) macrophages resulted in increased CAMP expression in M(GM-CSF) macrophages, which was absent in M(M-CSF) macrophages. CAMP encodes LL-37, an antimicrobial peptide with immune-modulating and repair-enhancing activities. In conclusion, dynamic crosstalk between ALI-PBEC and macrophages enhances epithelial innate immunity and wound repair, even upon concomitant cigarette smoke exposure.

Mesenchymal stromal cells: a novel therapy for the treatment of chronic obstructive pulmonary disease?

COPD is characterised by tissue destruction and inflammation. Given the lack of curative treatments and the progressive nature of the disease, new treatments for COPD are highly relevant. In vitro cell culture and animal studies have demonstrated that mesenchymal stromal cells (MSCs) have the capacity to modify immune responses and to enhance tissue repair. These properties of MSCs provided a rationale to investigate their potential for treatment of a variety of diseases, including COPD. Preclinical models support the hypothesis that MSCs may have clinical efficacy in COPD. However, although clinical trials have demonstrated the safety of MSC treatment, thus far they have not provided evidence for MSC efficacy in the treatment of COPD. In this review, we discuss the rationale for MSC-based cell therapy in COPD, the main findings from in vitro and in vivo preclinical COPD model studies, clinical trials in patients with COPD and directions for further research.

Resveratrol protects against atherosclerosis, but does not add to the antiatherogenic effect of atorvastatin, in APOE*3-Leiden.CETP mice.

Resveratrol is a major constituent of traditional Asian medicinal herbs and red wine and is suggested to be a potential antiatherosclerotic drug due to its proposed hypolipidemic, anti-inflammatory and antioxidative properties. The aim of this study was to evaluate whether resveratrol protects against atherosclerosis development in APOE*3-Leiden.CETP (E3L.CETP) mice and adds to the antiatherogenic effect of mild statin treatment, currently the most widely used antiatherogenic therapy. E3L.CETP mice were fed a cholesterol-rich diet without (control) or with resveratrol (0.01% w/w), atorvastatin (0.0027% w/w) or both for 14 weeks. During the study plasma lipid, inflammatory and oxidative stress parameters were determined. Resveratrol reduced atherosclerotic lesion area (-52%) in the aortic root, comparable to atorvastatin (-40%) and the combination of both drugs (-47%). The collagen/macrophage ratio in the atherosclerotic lesion, a marker of plaque stability, was increased by resveratrol (+108%), atorvastatin (+124%) and the combination (+154%). Resveratrol decreased plasma cholesterol levels (-19%) comparable to atorvastatin (-19%) and the combination (-22%), which was completely confined to (very)low-density lipoprotein cholesterol levels in all groups. Post hoc analyses showed that the antiatherogenic effect of atorvastatin could be explained by cholesterol lowering, while the antiatherosclerotic effect of resveratrol could be attributed to factors additional to cholesterol lowering. Markers of inflammation and oxidative stress were not different, but resveratrol improved macrophage function. We conclude that resveratrol potently reduces atherosclerosis development and induces a more stable lesion phenotype in E3L.CETP mice. However, under the experimental conditions tested, resveratrol does not add to the antiatherogenic effect of atorvastatin.

Lack of primary cilia primes shear-induced endothelial-to-mesenchymal transition.

RATIONALE: Primary cilia are cellular protrusions that serve as mechanosensors for fluid flow. In endothelial cells (ECs), they function by transducing local blood flow information into functional responses, such as nitric oxide production and initiation of gene expression. Cilia are present on ECs in areas of low or disturbed flow and absent in areas of high flow. In the embryonic heart, high-flow regime applies to the endocardial cushion area, and the absence of cilia here coincides with the process of endothelial-to-mesenchymal transition (EndoMT). OBJECTIVE: In this study, we investigated the role of the primary cilium in defining the responses of ECs to fluid shear stress and in EndoMT. METHODS AND RESULTS: Nonciliated mouse embryonic ECs with a mutation in Tg737/Ift88 were used to compare the response to fluid shear stress to that of ciliated ECs. In vitro, nonciliated ECs undergo shear-induced EndoMT, which is accompanied by downregulation of Klf4. This Tgfß/Alk5-dependent transformation is prevented by blocking Tgfß signaling, overexpression of Klf4, or rescue of the primary cilium. In the hearts of Tg737(orpk/orpk) embryos, Tgfß/Alk5 signaling was activated in areas in which ECs would normally be ciliated but now lack cilia because of the mutation. In these areas, ECs show increased Smad2 phosphorylation and expression of α-smooth muscle actin. CONCLUSIONS: This study demonstrates the central role of primary cilia in rendering ECs prone to shear-induced activation of Tgfß/Alk5 signaling and EndoMT and thereby provides a functional link between primary cilia and flow-related endothelial performance.

Differential distribution and phenotype of decidual macrophages in preeclamptic versus control pregnancies.

Maternal immune tolerance of the semiallogeneic fetus is a complex phenomenon. Macrophages are an abundant cell population in the human decidua, and changes in distribution or phenotype may be involved in the development of preeclampsia. The aim of this study was to assess the distribution and phenotype of macrophages in preterm preeclamptic, preterm control, and term control placentas. Placentas of preterm preeclamptic (n = 6), preterm control (n = 5), and term control pregnancies (n = 6) were sequentially immunohistochemically stained for CD14, CD163, DC SIGN, and IL-10. The distributions of CD14(+), CD163(+), DC SIGN(+), IL-10(+), CD163(+)/CD14(+), DC SIGN(+)/CD14(+), and Flt-1/CD14(+) cells were determined by double staining and by digital image analysis of sequential photomicrographs. CD14 and CD163 expression increased significantly in preterm preeclamptic decidua basalis compared with preterm control pregnancies (P = 0.0006 and P = 0.034, respectively). IL-10 expression was significantly lower in the decidua parietalis of preterm preeclamptic pregnancies compared with preterm control pregnancies (P = 0.03). The CD163/CD14 ratio was significantly lower in the decidua basalis (P = 0.0293) and the DC SIGN/CD14 ratio was significantly higher in the decidua basalis (P < 0.0001) and parietalis (P < 0.0001) of preterm preeclamptic pregnancies compared with preterm control pregnancies. CD14(+) macrophages did express Flt-1. Alterations in distribution and phenotype of macrophages in the decidua of preterm preeclamptic pregnancies compared with control pregnancies may contribute to the pathogenesis of preeclampsia.