In vitro electroretinogram for the study of the functionality of differentiated retinal pigment epithelium cells

The purpose of this study is to develop and test a method to reveal if the retinal pigment epithelium (RPE) cells differentiated from human embryonic stem cells (hESC) support the functions of photoreceptors. hESC-derived RPE (hESC–RPE) cells offer a potent cell source for cell replacement therapy that may be used to prevent certain eye diseases. Methods to assure the functionality of the RPE cells are well warranted. Electroretinograms (ERG) measure the electrophysiological response of the retina to light stimuli. A setup was developed that enables the measurement of ERG in vitro from mice retinas cultured together with hESC–RPE cells. The co-culture of RPE and retinas seems to be a viable tool to assess the functionality of RPE in vitro. However, owing to limited sample size results were somewhat mixed, and thus it was not possible to prove that hESC–RPE cells enhance the ERG response of a mouse retina in vitro. The long-term culturing of the retinas needs to be refined to acquire more conclusive evidence of the supporting role of the RPE and to explore the full potential of the co-culture and ERG methods in assessing RPE functionality.     

Central nervous system abnormalities in Fanconi anaemia: patterns and frequency on magnetic resonance imaging

Objective:

Fanconi anaemia (FA) is an inherited disease associated with congenital and developmental abnormalities resulting from the disruption of a multigenic DNA damage response pathway. This study aimed to define the MRI appearances of the brain in patients with FA in correlation with their genetic and clinical features.

Methods:

A review of the brain MRI in 20 patients with FA was performed. Pituitary size and frequencies of the radiological findings of individuals with FA and age-matched controls were determined.

Results:

Abnormalities were identified in 18 (90%) patients with FA, the commonest being a small pituitary (68%, p < 0.01 females and p < 0.001 males). In five cases (25%, p = 0.02), the pituitary morphology was also abnormal. Posterior fossa abnormalities were seen in six cases (30%, p = 0.01) including Chiari I malformation (n = 3), Dandy–Walker variant (n = 2) and cerebellar atrophy (n = 2). Six patients (30%, p = 0.01) had morphological structural variation of the corpus callosum (CC).

Conclusion:

The incidence of central nervous system (CNS) abnormalities in FA is higher than previously reported, with a midline predominance that points to impact in the early stages of CNS development. MRI brain imaging is important for endocrine assessment and pre-transplant evaluation and can make an important contribution to clinical decision-making.

Advances in knowledge:

The incidence of brain structural abnormalities in FA is higher than previously reported, with abnormalities of the posterior fossa, CC and pituitary being common. There is an association with gender and reduction in pituitary size which does not strongly correlate with biochemically evident endocrine abnormality.     

Celiac disease in patients with severe liver disease: gluten-free diet may reverse hepatic failure

BACKGROUND & AIMS: Mild liver abnormalities are common in patients with celiac disease and usually resolve with a gluten-free diet. We investigated the occurrence of celiac disease in patients with severe liver failure. METHODS: Four patients with untreated celiac disease and severe liver disease are described. Further, the occurrence of celiac disease was studied in 185 adults with previous liver transplantation using serum immunoglobulin A endomysial and tissue transglutaminase antibodies in screening. RESULTS: Of the 4 patients with severe liver disease and celiac disease, 1 had congenital liver fibrosis, 1 had massive hepatic steatosis, and 2 had progressive hepatitis without apparent origin. Three were even remitted for consideration of liver transplantation. Hepatic dysfunction reversed in all cases when a gluten-free diet was adopted. In the transplantation group, 8 patients (4.3%) had celiac disease. Six cases were detected before the operation: 3 had primary biliary cirrhosis, 1 had autoimmune hepatitis, 1 had primary sclerosing cholangitis, and 1 had congenital liver fibrosis. Only 1 patient had maintained a long-term strict gluten-free diet. Screening found 2 cases of celiac disease, 1 with autoimmune hepatitis and 1 with secondary sclerosing cholangitis. CONCLUSIONS: The possible presence of celiac disease should be investigated in patients with severe liver disease. Dietary treatment may prevent progression to hepatic failure, even in cases in which liver transplantation is considered.     

CD14 Influences Host Immune Responses and Alternative Activation of Macrophages during Schistosoma mansoni Infection

Antigen-presenting cell (APC) plasticity is critical for controlling inflammation in metabolic diseases and infections. The roles that pattern recognition receptors (PRRs) play in regulating APC phenotypes are just now being defined. We evaluated the expression of PRRs on APCs in mice infected with the helminth parasite Schistosoma mansoni and observed an upregulation of CD14 expression on macrophages. Schistosome-infected Cd14^−/− mice showed significantly increased alternative activation of (M2) macrophages in the livers compared to infected wild-type (wt) mice. In addition, splenocytes from infected Cd14^−/− mice exhibited increased production of CD4⁺-specific interleukin-4 (IL-4), IL-5, and IL-13 and CD4⁺Foxp3⁺IL-10⁺ regulatory T cells compared to cells from infected wt mice. S. mansoni-infected Cd14^−/− mice also presented with smaller liver egg granulomas associated with increased collagen deposition compared to granulomas in infected wt mice. The highest expression of CD14 was found on liver macrophages in infected mice. To determine if the Cd14^−/− phenotype was in part due to increased M2 macrophages, we adoptively transferred wt macrophages into Cd14^−/− mice and normalized the M2 and CD4⁺ Th cell balance close to that observed in infected wt mice. Finally, we demonstrated that CD14 regulates STAT6 activation, as Cd14^−/− mice had increased STAT6 activation in vivo, suggesting that lack of CD14 impacts the IL-4Rα-STAT6 pathway, altering macrophage polarization during parasite infection. Collectively, these data identify a previously unrecognized role for CD14 in regulating macrophage plasticity and CD4⁺ T cell biasing during helminth infection.