Cardiovascular malformations in Fryns syndrome: is there a pathogenic role for neural crest cells?

We performed a comprehensive literature and case report review to characterize the cardiovascular malformations (CVMs) associated with Fryns syndrome (OMIM #229850), a multiple congenital anomaly/mental retardation syndrome consisting of diaphragmatic defects, significant pulmonary hypoplasia, distinctive facial appearance, distal digital hypoplasia, and numerous other external and internal anomalies. A total of 112 patients meeting diagnostic guidelines for Fryns syndrome were identified, of whom 82 met narrowly defined criteria (Group I) and 30 met broader diagnostic criteria (Group II). Twelve patients reported as having Fryns syndrome with atypical features (Group III) were also analyzed. A CVM was reported in 51% (42 of 82) of Group I patients, most commonly an atrial or ventricular septal defect (VSD) (23 of 42, 55%). Conotruncal and aortic arch CVMs were common (11 of 42, 26%), but not significantly so compared to the general population of infants to age 1 year [Ferencz et al., 1997]. Recognizing that minor septal defects associated with congenital diaphragmatic hernia (CDH) may occur in response to altered hemodynamics (instead of being a bonafide CVM), we excluded four patients reported as having hemodynamically insignificant VSDs. Following these exclusions, conotruncal CVMs were found more commonly than in the general population (11 of 38, 29%, P < or = 0.025). In Group II, 9 of 30 (30%) had a CVM with no predominant type among the small number of cases reviewed. Among the atypical Fryns syndrome patients in Group III, half (6 of 12, 50%) had a CVM; most (4 of 6, 67%) were conotruncal, in particular, type B interrupted aortic arch (3 of 4). Patients with Fryns syndrome have a high rate of CVMs, warranting thorough cardiac evaluation including echocardiogram (fetal and/or postnatal) in all patients, similar to the evaluation for other patients with diaphragmatic hernia. The possible association between conotruncal CVMs and Fryns syndrome may provide additional support for an etiologic role of genes related to neural crest cell development in the pathogenesis of Fryns syndrome and hence, congenital diaphragmatic hernia.     

Is the cranial accessory nerve really a portion of the accessory nerve? Anatomy of the cranial nerves in the jugular foramen

The accessory nerve is traditionally described as having both spinal and cranial roots, with the spinal root originating from the upper cervical segments of the spinal cord and the cranial root originating from the dorsolateral surface of the medulla oblongata. The spinal rootlets and cranial rootlets converge either before entering the jugular foramen or within it. In a recent report, this conventional view has been challenged by finding no cranial contribution to the accessory nerve. The present study was undertaken to re-examine the accessory and vagus nerves within the cranium and jugular foramen, with particular emphasis on the components of the accessory nerve. These nerves were traced from their rootlets attaching to the spinal cord and the medulla and then through the jugular foramen. The jugular foramen was exposed by removing the dural covering and surrounding bone. A surgical dissecting microscope was used to trace the roots of the glossopharyngeal nerve (CN IX), vagus nerve (CN X) and accessory nerve (CN XI) before they entered the jugular foramen and during their travel through it. The present study demonstrates that the accessory nerve exists in two forms within the cranial cavity. In the majority of cases (11 of 12), CN XI originated from the spinal cord with no distinct contribution from the medulla. However, in one of 12 cases, a small but distinct connection was seen between the vagus and the spinal accessory nerves within the jugular foramen.     

Adenovirus-mediated delivery of interferon-γ gene inhibits the growth of nasopharyngeal carcinoma

Background

Epidermal growth factor receptor (EGFR) is suggested to predict the radiosensitivity and/or prognosis of human esophageal squamous cell carcinoma (ESCC). The objective of this study was to investigate the efficacy of Nimotuzumab (an anti-EGFR monoclonal antibody) on ESCC radiotherapy (RT) and underlying mechanisms.

Methods

Nimotuzumab was administrated to 2 ESCC cell lines KYSE30 and TE-1 treated with RT. Cell growth, colony formation and apoptosis were used to measure anti-proliferation effects. The method of RNA interference was used to investigate the role of insulin-like growth factor binding protein-3 (IGFBP-3) in ESCC cells radiosensitivity treated with Nimotuzumab. In vivo effect of Nimotuzumab on ESCC radiotherapy was done using a mouse xenograft model.

Results

Nimotuzumab enhanced radiation response of KYSE30 cells (with high EGFR expression) in vitro, as evidenced by increased radiation-inhibited cell growth and colony formation and radiation-mediated apoptosis. Mechanism study revealed that Nimotuzumab inhibited phosphorylated EGFR (p-EGFR) induced by EGF in KYSE30 cells. In addition, knockdown of IGFBP-3 by short hairpin RNA significantly reduced KYSE30 cells radiosensitivity (P<0.05), and even after the administration of Nimotuzumab, the RT response of IGFBP-3 silenced KYSE30 cells was not enhanced (P>0.05). In KYSE30 cell xenografts, Nimotuzumab combined with radiation led to significant tumor growth delay, compared with that of radiation alone (P=0.029), and also with IGFBP-3 up-regulation in tumor tissue.

Conclusions

Nimotuzumab could enhance the RT effect of ESCC cells with a functional active EGFR pathway. In particular, the increased ESCC radiosensitivity by Nimotuzumab might be dependent on the up-regulation of IGFBP-3 through EGFR-dependent pathway.

     

Rearrangement and expression of the immunoglobulin μ-chain gene in human myeloid cells

Immunoglobulin （Ig）, a characteristic marker of B cells, has been reported to be expressed in epithelial cells, with a suggested role in their growth and survival. We have previously reported that IgG heavy chain is expressed in acute myeloid leukemia （AML）, but not in the monocytes or neutrophils from patients with non-hematopoietic neoplasms or healthy controls. In the present study, we assessed IgM heavy chain expression and repertoire in human myeloid cells. We detected VHIzDJHp- rearrangement and expression in 7/7 AML cell lines, 7/14 primary myeloblasts from AML patients, and interestingly, 8/20 monocytes and 3/20 neutrophils from patients with non-hematopoietic neoplasms and healthy individuals. We also found evidence of somatic hypermutation of the variable （V） gene segments in AML-derived IgM gene rearrangements but not in IgM from monocytes or neutrophils from patients with non-hematopoietic neoplasms and healthy individuals. Furthermore, IgM VH~DJH~ gene rearrangements in AML cell lines, primary myeloblasts, and monocytes and neutrophils from patients with non-hematopoietic neoplasms showed a restricted V usage and repertoire, whereas the VH~DJH~ gene rearrangements in monocytes and neutrophils from healthy individuals displayed more diversity. Anti-human IgM inhibited cell proliferation, but did not induce apoptosis in AML cell lines. Our findings suggest that AML-derived IgM might be a novel AML-related molecule that is involved in leukemogenesis and AML progression and might serve as a useful molecular marker for designing targeted therapy and monitoring minimal residual disease.     

Overexpression of dominant negative peroxisome proliferator-activated receptor-γ (PPARγ) in alveolar type II epithelial cells causes inflammation and T-cell suppression in the lung

Peroxisome proliferator-activated receptor-γ (PPARγ) is an anti-inflammatory molecule. To assess its biological function in lung alveolar epithelial cells, a CCSP-rtTA/(tetO)(7)-dnPPARγ bitransgenic mouse model was generated. In this model, a dominant negative (dn) PPARγ-Flag fusion protein was overexpressed in lung alveolar type II (AT II) epithelial cells in an inducible manner to suppress the endogenous PPARγ function. Overexpression of dnPPARγ induces up-regulation of proinflammatory cytokines and chemokines at both mRNA and protein levels in AT II epithelial cells. This up-regulation was due to dnPPARγ directly DNA binding on the promoter regions. Up-regulation of proinflammatory molecules activated multiple intracellular signaling pathways in AT II epithelial cells. In addition, inflammatory CD11b(+)Gr-1(+) myeloid-derived suppressor cells were significantly accumulated but T cells were decreased in the lung and circulation system of doxycycline-treated mice. In vitro, myeloid-derived suppressor cells from the lung suppressed T-cell proliferation and function. As a pathogenic consequence, emphysema was observed in the doxycycline-treated lung in association with up-regulation of matrix metalloproteases. Chronic inflammation and lung injury also induced conversion of bone marrow mesenchymal stem cells into AT II epithelial cells in bitransgenic mice. These findings support that PPARγ and its negatively regulated downstream genes in AT II epithelial cells possess multiple functions to control alveolar homeostasis through inflammatory and noninflammatory mechanisms.     

Synergistic effect of IFN-γ gene on LIGHT-induced apoptosis in HepG2 cells via down regulation of Bcl-2

To detect the expression of anti-apoptotic factor Bcl-2 and Survivin in transferred HepG2 cells and evaluate the synergistic effect of IFN-γ gene on LIGHT-induced apoptosis signal transduction pathways, the full-length ORF of LIGHT and IFN-γ gene were cloned into pcDNA4 and verified by DNA sequencing. After being optimized by EGFP, recombinant LIGHT and IFN-γ were transferred into the HepG2 cells mediated by a cationic liposome in vitro. The expression of LIGHT and IFN-γ was identified in the supernatants by ELISA. The HepG2 cells were divided into three groups: the control, LIGHT gene transfection alone, and simultaneous transfection of LIGHT and IFN-γ genes. The cell apoptosis and expression of Bcl-2 and Survivin in cell lysate were detected through FCM. After transfection, the apoptosis rate of HepG2 cells was increased with the prolonged time, and the apoptosis rate of LIGHT group was higher than the control group, while the LIGHT/IFN-γ group was higher than the LIGHT group P < 0.01). The expression of Bcl-2 and Survivin in LIGHT group and LIGHT/IFN-γ group decreased dramatically compared with the control group. LIGHT gene alone can result in significant inhibition of HepG2 cells proliferation. INF-γ can synergistically precede LIGHT-induced apoptotic processes through down-regulation of Bcl-2 expression, but not survivin expression.     

Influence of a mutation in IFN-γ receptor 2 (IFNGR2) in human cells on the generation of Th17 cells in memory T cells

The T cell subsets involved in inflammatory reactions are mainly the IFN-γ secreting Th1 cells and IL17-producing Th17 cells. Although Th17 cells are primed in the thymus, there is evidence that Th17 cells can be generated from effector memory CD4⁺ T cells. Cytokines as IL-6, TGF-β, IL-21 and IL-23 involved in development of Th17 cells are well described. Here we analyzed the impact of a mutation in the IFN-γ receptor 2 (IFN-γR2) on the induction of Th17 cells. By isolation of T cells and monocytes of a patient with this mutation we could demonstrate an inhibitory role of IFN-γ signaling as IFN-γR2-deficient monocytes induce a higher percentage of IL-17⁺ cells from both healthy and IFN-γR2-deficient CD4⁺ T cells. This data confirm the interference of these two T helper subsets and points to a balance of Th1 and Th17 cells obtained by their own cytokine production and their interplay with APCs.     

The neural crest is contiguous with the cardiac conduction system in the mouse embryo: a role in induction?

In this study we present data on the spatial relationship between neural crest-derived cells (NCC) and the specialized cardiac conduction system (CCS) in the developing murine heart. Using Wnt1-Cre/R26R conditional reporter mice that express -galactosidase from ROSA26 upon Cre-mediated recombination, two populations of NCC are seen: one migrates through the arterial pole and contributes to the bundle branches, whereas the second population enters by way of the venous pole and provides cells to the sinoatrial and atrioventricular node areas. The CCS/lacZ construct is found in the myocardium of the early embryonic heart and afterward only persists in the definitive CCS and is acknowledged as a reporter for the developing conduction system. The contiguous expression of both reporters is suggestive for a potential role of cardiac NCC in the induction of the final differentiation of the CCS.     

Application of the back-error propagation artificial neural network （BPANN） on genetic variants in the PPAR-γ and RXR-α gene and risk of metabolic syndrome in a Chinese Han population

This study was aimed to explore the associations between the combined effects of several polymorphisms in the PPAR-γ and RXR-α gene and environmental factors with the risk of metabolic syndrome by back-error propaga- tion artificial neural network （BPANN）. We established the model based on data gathered from metabolic syndrome patients （n = 1012） and normal controls （n = 1069） by BPANN. Mean impact value （MIV） for each input variable was calculated and the sequence of factors was sorted according to their absolute MIVs. Generalized multifactor dimensionality reduction （GMDR） confirmed a joint effect of PPAR-9＂ and RXR-a based on the results from BPANN. By BPANN analysis, the sequences according to the importance of metabolic syndrome risk fac- tors were in the order of body mass index （BMI）, serum adiponectin, rs4240711, gender, rs4842194, family history of type 2 diabetes, rs2920502, physical activity, alcohol drinking, rs3856806, family history of hypertension, rs1045570, rs6537944, age, rs17817276, family history of hyperlipidemia, smoking, rs1801282 and rs3132291. However, no polymorphism was statistically significant in multiple logistic regression analysis. After controlling for environmental factors, A1, A2, B1 and B2 （rs4240711, rs4842194, rs2920502 and rs3856806） models were the best models （cross-validation consistency 10/10, P = 0.0107） with the GMDR method. In conclusion, the interaction of the PPAR-γ and RXR-α gene could play a role in susceptibility to metabolic syndrome. A more realistic model is obtained by using BPANN to screen out determinants of diseases of multiple etiologies like metabolic syndrome.     

Expression of natriuretic peptides in rat Müller cells

Natriuretic peptides (NPs) have been shown to modulate neuronal activities. By immunohistochemistry and confocal microscopy, we examined expression of atrial NP (ANP), brain NP (BNP) and C-type NP (CNP) in rat retina. Our results showed that these peptides were differentially expressed in the neural retina. While strong ANP-, BNP- and CNP-immunoreactivity (IR) was clearly seen in the outer and inner plexiform layers and on numerous neurons in the inner nuclear layer, BNP- and CNP-, but not ANP-IR, was present in some ganglion cells. Furthermore, ANP, BNP and CNP were expressed in Müller cells with distinct profiles, as shown by double labeling of NPs and vimentin. Labeling for BNP was rather strong in the main trunks, major processes, but hardly detectable in the endfeet. The expression profile for ANP was similar, but with a much lower level. On the contrary, the endfeet and major processes in the inner retina were strongly CNP-positive, with the main trunks and other major processes in the outer retina much less labeled. These results raise a possibility that NPs, when released from Müller cells, may perform layer dependent functions.     

Isolation of new nonsense and frameshift mutants in the immunoglobulin μ heavy-chain gene of hybridoma cells

In order to expand the experimental material available for genetic and biochemical analyses of the natural immunoglobulin genes, we have isolated a variety of mutant mouse hybridoma cell lines. Some of these mutants have partial or complete deletions of the gene. Other mutants have nonsense or frameshift mutations in the exons encoding the variable and the second and third constant region domains of the heavy chain. When combined with earlier mutant data, this collection of genotypically and phenotypically tight mutants of known sequence spans most of the 10 kb of the gene, providing material for a variety of studies of genetic recombination and mRNA metabolism.     

Pretreatment with interferon-γ enhances the therapeutic activity of mesenchymal stromal cells in animal models of colitis

Mesenchymal stromal cells (MSCs) are currently under investigation for the treatment of inflammatory disorders, including Crohn's disease. MSCs are pluripotent cells with immunosuppressive properties. Recent data suggest that resting MSCs do not have significant immunomodulatory activity, but that the immunosuppressive function of MSCs has to be elicited by interferon-γ (IFN-γ). In this article, we assessed the effects of IFN-γ prestimulation of MSCs (IMSCs) on their immunosuppressive properties in vitro and in vivo. To this end, we pretreated MSCs with IFN-γ and assessed their therapeutic effects in dextran sodium sulfate (DSS)- and trinitrobenzene sulfonate (TNBS)-induced colitis in mice. We found that mice treated with IMSCs (but not MSCs) showed a significantly attenuated development of DSS-induced colitis. Furthermore, IMSCs alleviated symptoms of TNBS-induced colitis. IMSC-treated mice displayed an increase in body weight, lower colitis scores, and better survival rates compared with untreated mice. In addition, serum amyloid A protein levels and local proinflammatory cytokine levels in colonic tissues were significantly suppressed after administration of IMSC. We also observed that IMSCs showed greater migration potential than unstimulated MSCs to sites within the inflamed intestine. In conclusion, we show that prestimulation of MSCs with IFN-γ enhances their capacity to inhibit Th1 inflammatory responses, resulting in diminished mucosal damage in experimental colitis. These data demonstrate that IFN-γ activation of MSCs increases their immunosuppresive capacities and importantly, their therapeutic efficacy in vivo.