The hyaloid vascular system (HVS) is a transient network of capillaries that nourishes the embryonic lens and the primary vitreous of the developing eye. We used proteomic analysis and immunohistochemical staining to identify activin receptor-like kinase-1 (ALK1), a type I receptor for transforming growth factor-beta1, during the HVS regression phase. In addition, we overexpressed ALK1 in corneas implanted with bFGF (basic fibroblast growth factor) pellets and observed that ALK1 overexpression resulted in inhibition of bFGF-induced corneal neovascularization in vivo. Our data suggest that ALK1 may play a role in HVS regression during ocular development.

BACKGROUND

Basmati rice, originated in the foothills of Himalayas, commands a premium price in the domestic and international markets on account of its unique quality traits. The complex genetic nature of unique traits of Basmati as well as tedious screening methodologies involved in quality testing have been serious constraints to breeding quality Basmati. In the present study, we made an attempt to identify the genomic regions governing unique traits of Basmati rice.

RESULTS

A total of 34 Quantitative Trait Loci (QTLs) for 16 economically important traits of Basmati rice were identified employing F(2), F(3) and Recombinant Inbred Line (RIL) mapping populations derived from a cross between Basmati370 (traditional Basmati) and Jaya (semi-dwarf rice). Out of which, 12 QTLs contributing to more than 15 % phenotypic variance were identified and considered as major effect QTLs. Four major effect QTLs coincide with the already known genes viz., sd1, GS3, alk1 and fgr governing plant height, grain size, alkali spreading value and aroma, respectively. For the remaining major QTLs, candidate genes were predicted as auxin response factor for filled grains, soluble starch synthase 3 for chalkiness and VQ domain containing protein for grain breadth and grain weight QTLs, based on the presence of non-synonymous single nucleotide polymorphism (SNPs) that were identified by comparing Basmati genome sequence with that of Nipponbare.

CONCLUSIONS

To the best of our knowledge, the current study is the first attempt ever made to carry out genome-wide mapping for the dissection of the genetic basis of economically important traits of Basmati rice. The promising QTLs controlling important traits in Basmati rice, identified in this study, can be used as candidates for future marker-assisted breeding.

Expression of the endothelin (ET)-1 gene is subject to complex regulation by numerous factors, among which the cytokine transforming growth factor-beta (TGF-beta) is one of the most important. TGF-beta action is based on the activation of the Smad signaling pathway. Smad proteins activate transcription of the gene by cooperation with activator protein-1 (AP-1) at specific sites on the ET-1 promoter. Smad signaling pathway is initiated by binding of the cytokine to a heteromeric complex of type I and type II receptors. Signal is then propagated to the nucleus by specific members of the Smad family. Most cell types contain a type I receptor known as ALK5. However, endothelial cells are unique because they coexpress an additional type I receptor named ALK1. These forms do not constitute redundant receptors with the same function, but they actually activate different Smad-mediated expression programs that lead to specific endothelial phenotypes. TGF-beta/ALK5/Smad3 pathway is associated to a mature endothelium because it leads to inhibition of cell migration/proliferation. Conversely, TGF-beta/ALK1/Smad5 activates both processes and is more related to the angiogenic state. We have analyzed the TGF-beta receptor subtype requirements for the activation of the ET-1 gene. For that purpose, we have overexpressed type I receptor and Smad isoforms in endothelial cells and analyzed the effect on ET-1 expression. Our experiments indicate that TGF-beta induces ET-1 expression preferentially through the activation of the ALK5/Smad3 pathway and, therefore, the expression of the vaso-constrictor may be associated to a quiescent and mature endothelial phenotype.

Specification of the dorsal-ventral axis in the highly regulative sea urchin embryo critically relies on the zygotic expression of nodal, but whether maternal factors provide the initial spatial cue to orient this axis is not known. Although redox gradients have been proposed to entrain the dorsal-ventral axis by acting upstream of nodal, manipulating the activity of redox gradients only has modest consequences, suggesting that other factors are responsible for orienting nodal expression and defining the dorsal-ventral axis. Here we uncover the function of Panda, a maternally provided transforming growth factor beta (TGF-β) ligand that requires the activin receptor-like kinases (Alk) Alk3/6 and Alk1/2 receptors to break the radial symmetry of the embryo and orient the dorsal-ventral axis by restricting nodal expression. We found that the double inhibition of the bone morphogenetic protein (BMP) type I receptors Alk3/6 and Alk1/2 causes a phenotype dramatically more severe than the BMP2/4 loss-of-function phenotype, leading to extreme ventralization of the embryo through massive ectopic expression of nodal, suggesting that an unidentified signal acting through BMP type I receptors cooperates with BMP2/4 to restrict nodal expression. We identified this ligand as the product of maternal Panda mRNA. Double inactivation of panda and bmp2/4 led to extreme ventralization, mimicking the phenotype caused by inactivation of the two BMP receptors. Inhibition of maternal panda mRNA translation disrupted the early spatial restriction of nodal, leading to persistent massive ectopic expression of nodal on the dorsal side despite the presence of Lefty. Phylogenetic analysis indicates that Panda is not a prototypical BMP ligand but a member of a subfamily of TGF-β distantly related to Inhibins, Lefty, and TGF-β that includes Maverick from Drosophila and GDF15 from vertebrates. Indeed, overexpression of Panda does not appear to directly or strongly activate phosphoSmad1/5/8 signaling, suggesting that although this TGF-β may require Alk1/2 and/or Alk3/6 to antagonize nodal expression, it may do so by sequestering a factor essential for Nodal signaling, by activating a non-Smad pathway downstream of the type I receptors, or by activating extremely low levels of pSmad1/5/8. We provide evidence that, although panda mRNA is broadly distributed in the early embryo, local expression of panda mRNA efficiently orients the dorsal-ventral axis and that Panda activity is required locally in the early embryo to specify this axis. Taken together, these findings demonstrate that maternal panda mRNA is both necessary and sufficient to orient the dorsal-ventral axis. These results therefore provide evidence that in the highly regulative sea urchin embryo, the activity of spatially restricted maternal factors regulates patterning along the dorsal-ventral axis.

We report an unusual presentation of a sporadic intra-abdominal desmoid tumour, possibly arising from the diaphragm, masquerading as a hepatic mass in a young female without any history of surgery or trauma. Histopathology ruled out a hepatic origin of the tumour as was inferred from pre- and intraoperative evaluation. Immunohistochemistry showed positivity of lesional fibroblastic cells for β-catenin and negativity for CD34, CD117, EMA, SMA, desmin, vimentin, cytokeratin, and ALK1 thereby confirming the diagnosis of a desmoid tumour. There exist only a few reports in the literature on desmoids related to the diaphragm, but only one on a diaphragmatic desmoid that is possibly primary.

Hereditary hemorrhagic telangiectasia (HHT) is a vascular dysplasia caused by mutations in endoglin (ENG; HHT1) or activin receptor-like kinase (ALK1; HHT2) genes, coding for transforming growth factor-β (TGF-β) superfamily receptors. We demonstrated previously that endoglin and ALK1 interact with endothelial NO synthase (eNOS) and affect its activation. Endothelial cells deficient in endoglin or ALK1 proteins show eNOS uncoupling, reduced NO, and increased reactive oxygen species (ROS) production. In this study, we measured NO and H(2)O(2) levels in several organs of adult Eng and Alk1 heterozygous mice, to ascertain whether decreased NO and increased ROS production is a generalized manifestation of HHT. A significant reduction in NO and increase in ROS production were found in several organs, known to be affected in patients. ROS overproduction in mutant mice was attributed to eNOS, as it was L-NAME inhibitable. Mitochondrial ROS contribution, blocked by antimycin, was highest in liver while NADPH oxidase, inhibited by apocynin, was a major source of ROS in the other tissues. However, there was no difference in antimycin- and apocynin-inhibitable ROS production between mutant and control mice. Our results indicate that eNOS-derived ROS contributes to endothelial dysfunction and likely predisposes to disease manifestations in several organs of HHT patients.

Development of anti-angiogenic therapy including the vascular endothelial growth factor (VEGF) antibodies and VEGF-tyrosine kinase receptors has been a major landmark in cancer therapy leading improvement in survival in several cancers. While anti-angiogenic therapy is effective in some settings, resistance often develops owing to evasive, alternative pathways. Novel targets for anti-angiogenic therapy are urgently required to provide treatment alternatives in patients whose tumors are unresponsive to approved anti-angiogenic agents; one such pathway is the bone morphogenetic proteins (BMP 9 and BMP 10) that activate the type I activin receptor-like kinase-1 (ALK1), which has been implicated in the development of functional vasculature. Dalantercept (ACE-041) is a novel anti-angiogenic agent, which is a soluble form of ALK1, and acts as a ligand trap for BMP 9 and BMP 10, inhibiting their interaction with ALK1, which further disrupts the process of vascular development. This review will discuss the preclinical and clinical development of dalantercept as a novel anti-angiogenic therapy in treating a variety of cancers and its distinct safety profile compared to other anti-VEGF agents. We will also discuss the ongoing and completed studies of dalantercept, including combination studies with other VEGF-directed therapies.

Inflammatory pseudotumor (IPT) is an uncommon, benign lesion of unclear etiology, which is sometimes associated with Epstein-Barr virus (EBV). In this study, we discuss a case of hepatic EBV positive IPT and discuss mimickers, prognosis, and treatment. The case we describe was located in the liver and composed of a mixture of spindle cells and polymorphic inflammatory cells with areas of necrosis. The spindle cells were negative for CAM5.2, ALK1, CD21, CD23, CD35, actin, S-100, and CD34. EBV-encoded small RNA in situ hybridization showed a large number of EBV positive cells. The diagnosis of hepatic EBV positive IPT with uncertain biological behavior was issued, presenting numerous difficulties with diagnostic and therapeutic challenges.

Advanced unresectable squamous cell carcinoma of the skin (SCCS) is a rare condition, which is difficult to treat. Because of its rarity, few therapeutic trials are available. Moreover, SCCS often occur in elderly. Conventional treatment options for advanced SCCS are chemotherapy mainly with cisplatin-based regimens. Immunotherapy with interferon alpha and retinoids combination was also shown to be efficient. Toxicity of these treatments limits, however, their use in elderly patients and an initial work up for a global assessment is needed in order to adapt the choice. More recently, epithelial growth factor receptor (EGFR) targeted therapies have been developed and induced interesting response rates in small series of patients with unresectable SCCS. Their efficacy in SCCS must be confirmed by larger phase III trials and the identification of predictive biological factors of response is warranted. New therapeutic approaches combining EGFR inhibitors either with IGFR inhibitors, or immunomodulators or inhibitors of the PI3K/AKT/mTOR pathway are currently under evaluation in head and neck carcinomas and might represent valuable therapeutic approaches for unresectable SCCS. Moreover, there are several new molecular candidate treatment targets for unresectable SCCS including somatic NOTCH1 or NOTCH2 inactivating mutations, ALK1, which could be a good candidate for antiangiogenic therapy and matrix metallopeptidase 7, which enhances proliferation, migration, and invasion of cancer cells. Organ transplant recipients often develop SCCS and in some patients, SCCS are rapidly progressing. Management of SCCS in this subgroup of patients includes both carcinologic treatment and modification of immunosuppression. Specific treatment is generally the same as in immunocompetent patients. Switching from calcineurin inhibitors to sirolimus or reducing immunosuppression has to be considered.

Classic Hodgkin's lymphoma (cHL) most often involves lymph nodes, and gastric involvement is rare. Hodgkin's and Reed-Sternberg (H-RS) cells in cHL are known to often lack expression of several B-lineage markers, such as CD20, CD79a, Oct-2, and Bob-1. We present an extremely rare case of mixed-cellularity cHL in the stomach in which expression of these B-cells was detected immunohistochemically. The patient was an 83-year-old Japanese woman who developed a sensation of abdominal fullness and appetite loss. Endoscopic and abdominal computed tomography examinations revealed a gastric ulcer lesion and swelling of para-aortic lymph nodes, respectively. A subtotal gastrectomy was performed, and the histopathologic diagnosis was established as a typical cHL compatible with stomach origin. The patient underwent postoperative chemotherapy of 3 cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) and has since been in complete remission. Immunohistochemically, the H-RS cells in the cHL were positive not only for CD30 but also for CD20, CD79a, Oct-2, and Bob-1, whereas they were negative for CD3, CD15, CD45, EMA, and ALK1. Our patient may have had an intermediate cHL disease overlapping that of non-Hodgkin's peripheral B-cell lymphoma, possibly reflecting derivation from germinal-center B-cells.

OBJECTIVE

The purpose of this study was to examine the relationship between coping strategies measured by Coping Orientation to Problems Experienced Scale (COPE) and psychological distress measured by Hospital Anxiety and Depression Scale (HADS) and Becks Hopelessness Scale (BHS) in individuals living with Hereditary hemorrhagic telangiectasia (HHT) and to examine if coping strategies might have a mediating role between experienced illness and psychological distress. HHT is mainly caused by mutations in the ENG- or ALK1-genes and associated with a shorter life span. 90% of patients have recurrent nosebleeds.

METHODS

66 individuals affected of HHT participated in this cross-sectional study, completing questions due to demographic variables, Experience of illness, COPE, BHS and HADS. X(2) test, bivariate correlations with Pearson r and hierarchical multiple regression were used using PASW 18.

RESULTS

Experience of illness made the highest variance in anxiety, depression and hopelessness and the coping strategy "behavioral disengagement" seems to have a mediating role between nose bleedings, being afraid of complications, satisfied with life and psychological distress.

CONCLUSIONS

Experience of illness is of big importance in psychological distress in individuals affected of HHT, and behavioral disengagement explained the actual relationship between experience of illness and psychological distress.

Hepatic angiomyolipoma (AML) is rare. Based on its wide histomorphological range, several distinctive histological variants have been delineated. However, hepatic AML displaying predominantly or exclusively inflammatory pattern closely mimicking inflammatory pseudotumor (IPT) is exceptionally rare with only 7 cases reported so far. We herein describe a new case of hepatic inflammatory AML in a 51-year-old woman who presented with unexplained constitutional symptoms suggesting an infectious disease. A liver mass was detected during imaging examination and resected (4.3 cm in maximum diameter). The patient's symptoms resolved completely after surgery. Currently, she is alive and well 7 years after surgery. She has no evidence of other organ manifestations of IgG4-related systemic disease. The tumor displayed a pure IPT-like histological pattern with dense infiltrates of plasma cells, lymphocytes and histiocytes admixed with scattered few adipocytes, irregularly distributed thick-walled vessels (some of them showed obliterative phlebitis) as well as aggregates and fascicles of histiocytoid and spindle-shaped myoid cells that were immunoreactive for HMB45 and Melan A with focal expression of alpha smooth muscle actin. Lesional cells were negative for desmin, protein S100, CD21, CD23, CD15, CD30, HepPar-1, pankeratin (KL-1), ALK1, and EBV in situ hybridization (EBER). The surrounding liver parenchyma showed striking lymphoplasmacytic non-destructive pericholangitis. Numerous scattered and aggregated IgG4 positive plasma cells were seen within the mass and in the peritumoral inflammatory lesions (mean, 37 cells/HPF; IgG4: IgG ratio = 28%). To our knowledge, this is the first report of hepatic inflammatory AML closely resembling IgG4-related IPT of the liver. A possible role for IgG4 seems likely to explain the peculiar histological features and the unusual clinical presentation in this case.

We report the case of a two patients who presented with a solitary, asymptomatic, angiomatoid nodule on the right thigh. Histopathological finding showed a poorly circumscribed lesion, located in the dermis. The morphological aspect strongly suggested the diagnosis of atypical fibrous histiocytoma (AFH), but surprisingly, the neoplastic cells were diffusely CD30+, with a membrane staining devoid of paranuclear dot. The lesions were tested for p80/ALK1 expression. Surprisingly, we found a diffuse cytoplasmic positivity. Interestingly, using break-apart fluorescent in situ hybridization (FISH), we evidenced an ALK rearrangement in nearly 50% of the neoplastic cells. The expression of CD30 and ALK1 with ALK gene rearrangement raised the possibility of three diagnoses: a primary cutaneous anaplastic large cell lymphoma (ALCL), a cutaneous inflammatory myofibroblastic tumor (IMT), an AFH of the skin associated with ALK gene rearrangement and CD30 positivity. The three hypotheses were discussed and finally, although p80/ALK1 expression and cytogenetic abnormalities in fibrous histiocytoma (FH) are not yet reported to the best of our knowledge, we favored the diagnosis of AFH.

Inflammatory myofibroblastic tumor (IMT) is a benign lesion composed of myofibroblasts accompanied by varying numbers of inflammatory cells. Various pathogenetic factors have been proposed, but the etiology of most IMTs remains unknown. This article presents a case of IMT occurring in the left maxillary sinus. A 24-year-old man complained of throbbing pain in the maxillary left molars and swelling of the left cheek. His maxillary left second molar was diagnosed as pulp necrosis and root canal treatment performed. After that, his symptoms continued and he was referred to the Department of Otolaryngology. Computerized tomography disclosed compact soft tissue masses in the left maxillary sinus with obstruction of maxillary ostium. Under general anesthesia, the lesions were fully excised. Histopathologically, the lesions were composed of plump or spindled myofibroblasts. Cells were immunoreactive for smooth muscle actin and β-catenin, and were negative for ALK1, CD34, and EMA. The diagnosis was IMT of left maxillary sinus. Although it is very rare, IMT should be included as a differential diagnosis in patients with compact masses in maxillary sinus.

The initial hydroxylation of n-alkane is catalyzed by cytochrome P450ALK of the CYP52 family in the n-alkane-assimilating yeast Yarrowia lipolytica. A mutant with a deletion of all 12 genes, ALK1 to ALK1ALK1 promoter by n-alkanes was observed in Δalk1-12 as in the wild-type strain, implying that n-alkanes per se, but not their metabolites, trigger n-alkane-induced transcriptional activation in Y. lipolytica.

OBJECTIVE

Brain arteriovenous malformation (bAVM) is an important risk factor for intracranial hemorrhage. Current treatments for bAVM are all associated with considerable risks. There is no safe method to prevent bAVM hemorrhage. Thalidomide reduces nose bleeding in patients with hereditary hemorrhagic telangiectasia, an inherited disorder characterized by vascular malformations. In this study, we tested whether thalidomide and its less toxic analog, lenalidomide, reduce bAVM hemorrhage using a mouse model.

METHODS

bAVMs were induced through induction of brain focal activin-like kinase 1 (Alk1, an AVM causative gene) gene deletion and angiogenesis in adult Alk1-floxed mice. Thalidomide was injected intraperitoneally twice per week for 6 weeks, starting either 2 or 8 weeks after AVM induction. Lenalidomide was injected intraperitoneally daily starting 8 weeks after AVM induction for 6 weeks. Brain samples were collected at the end of the treatments for morphology, mRNA, and protein analyses. The influence of Alk1 downregulation on PDGFB (platelet-derived growth factor B) expression was also studied on cultured human brain microvascular endothelial cells. The effect of PDGFB in mural cell recruitment in bAVM was explored by injection of a PDGFB overexpressing lentiviral vector to the mouse brain.

RESULTS

Thalidomide or lenalidomide treatment reduced the number of dysplastic vessels and hemorrhage and increased mural cell (vascular smooth muscle cells and pericytes) coverage in the bAVM lesion. Thalidomide reduced the burden of CD68+ cells and the expression of inflammatory cytokines in the bAVM lesions. PDGFB expression was reduced in ALK1-knockdown human brain microvascular endothelial cells and in mouse bAVM lesion. Thalidomide increased Pdgfb expression in bAVM lesion. Overexpression of PDGFB mimicked the effect of thalidomide.

CONCLUSIONS

Thalidomide and lenalidomide improve mural cell coverage of bAVM vessels and reduce bAVM hemorrhage, which is likely through upregulation of Pdgfb expression.

Hereditary haemorrhagic telangiectasia (HHT), or Rendu-Osler-Weber syndrome, is a dominant genetic vascular disorder. In HHT, blood vessels are weak and prone to bleeding, leading to epistaxis and anaemia, severely affecting patients' quality of life. Development of vascular malformations in HHT patients is originated mainly by mutations in ACVRL1/ALK1 (activin receptor-like kinase type I) or Endoglin (ENG) genes. These genes encode proteins of the TGF-β signalling pathway in endothelial cells, controlling angiogenesis. Haploinsufficiency of these proteins is the basis of HHT pathogenicity. It was our objective to study the efficiency of Bazedoxifene, a selective estrogen receptor modulator (SERM) in HHT, looking for a decrease in epistaxis, and understanding the underlying molecular mechanism. Plasma samples of five HHT patients were collected before, and after 1 and 3 months of Bazedoxifene treatment. ENG and ALK1 expression in activated mononuclear cells derived from blood, as well as VEGF plasma levels, were measured. Quantification of Endoglin and ALK1 mRNA was done in endothelial cells derived from HHT and healthy donors, after in vitro treatment with Bazedoxifene. Angiogenesis was also measured by tubulogenesis and wound healing assays. Upon Bazedoxifene treatment, haemoglobin levels of HHT patients increased and the quantity and frequency of epistaxis decreased. Bazedoxifene increased Endoglin and ALK1 mRNA levels, in cells derived from blood samples and in cultured endothelial cells, promoting tube formation. In conclusion, Bazedoxifene seems to decrease bleeding in HHT by partial compensation of haploinsufficiency. The results shown here are the basis of a new orphan drug designation for HHT by the European Medicine Agency (EMA).

In this study, the authors investigated the expression of activin receptor-like kinase 1 (ALK1) in pancreatic carcinoma and evaluated its potential role as a tumor suppressor in vitro and in vivo. Endogenous ALK1 expression was demonstrated by immunohistochemistry in both pancreatic tumor tissue and peritumoral normal tissue from 6 patients and by RT-PCR in 8/12 established pancreatic cancer cell lines. Ectopic expression of a constitutively active (ca) ALK1 mutant in TGF-beta sensitive PANC-1 and COLO-357 cells augmented transcriptional activation of a Smad2/3 responsive reporter, and slowed down basal growth in vitro. Both effects were further enhanced by TGF-beta/ALK5 stimulation, suggesting largely independent nuclear Smad signaling by both type I receptors. Upon orthotopic transplantation of PANC-1-caALK1 into immunodeficient mice, tumor size was strongly reduced and was associated with a lower microvessel density in the PANC-1-caALK1-derived tumors. In vitro, this mutant efficiently blocked TGF-beta-induced epithelial-to-mesenchymal transdifferentiation and suppressed TGF-beta/ALK5-mediated activation of the p38 MAPK pathway. Mechanistically, caALK1 silenced MyD118, an immediate TGF-beta target gene whose protein product, GADD45beta, couples Smad signaling to p38 activation. These results show that ALK1 activation in pancreatic tumor cells is antioncogenic by inducing ALK5-independent growth inhibition and by blocking TGF-beta/ALK5-mediated epithelial-to-mesenchymal transdifferentiation and, possibly, invasion and metastatic progression.

In endothelial cells, two type I receptors of the transforming growth factor β (TGF-β) family, ALK1 and ALK5, coordinate to regulate embryonic angiogenesis in response to BMP9/10 and TGF-β. Whereas TGF-β binds to and activates ALK5, leading to Smad2/3 phosphorylation and inhibition of endothelial cell proliferation and migration, BMP9/10 and TGF-β also bind to ALK1, resulting in the activation of Smad1/5. SnoN is a negative regulator of ALK5 signaling through the binding and repression of Smad2/3. Here we uncover a positive role of SnoN in enhancing Smad1/5 activation in endothelial cells to promote angiogenesis. Upon ligand binding, SnoN directly bound to ALK1 on the plasma membrane and facilitated the interaction between ALK1 and Smad1/5, enhancing Smad1/5 phosphorylation. Disruption of this SnoN-Smad interaction impaired Smad1/5 activation and up-regulated Smad2/3 activity. This resulted in defective angiogenesis and arteriovenous malformations, leading to embryonic lethality at E12.5. Thus, SnoN is essential for TGF-β/BMP9-dependent biological processes by its ability to both positively and negatively modulate the activities of Smad-dependent pathways.

BACKGROUND

Pulmonary arterial hypertension (PAH) has been linked to mutations in genes encoding two members of the transforming growth factor-beta family, BMPR2 and ALK1, the latter of which is also associated with hereditary haemorrhagic telangiectasia (HHT). Relatively little is known about the genetics of childhood PAH, or about the clinical features of PAH in young patients with an ALK1 mutation.

RESULTS

Three individuals diagnosed with PAH at 4, 16 and 17 years of age were found on subsequent genetic screening to have non-synonymous mutations of ALK1. All probands met criteria for HHT, although two presented with PAH before HHT was diagnosed. Extended family history revealed relatives with HHT in all three kindreds, a presumptive family history of PAH in two, one with multiple family members dying from PAH at young ages. All three patients in this series had systemic or suprasystemic right ventricular pressure and significantly elevated pulmonary vascular resistance, initially not responsive to oxygen and/or inhaled nitric oxide. All patients had pulmonary arteriovenous malformations and systemic arterial desaturation.

CONCLUSIONS

This report highlights ALK1 mutations associated with a variable PAH phenotype, including pulmonary arteriovenous malformations and severe PAH presenting early in life. Echocardiographic screening for elevated right ventricular pressure may be indicated in patients with HHT, particularly those with an identified ALK1 mutation. Clinical features or a family history of HHT should be elicited in children and adolescents with idiopathic PAH; ALK1 screening may be appropriate when such features are present.

Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis.

BACKGROUND

Systemic sclerosis (SSc)-related pulmonary arterial hypertension (PAH) has emerged as a major mortality prognostic factor. Mutations of transforming growth factor beta (TGFβ) receptor genes strongly contribute to idiopathic and familial PAH.

OBJECTIVE

To explore the genetic bases of SSc-PAH, we combined direct sequencing and genotyping of candidate genes encoding TGFβ receptor family members.

METHODS

TGFβ receptor genes, BMPR2, ALK1, TGFR2 and ENG, were sequenced in 10 SSc-PAH patients, nine SSc and seven controls. In addition, 22 single-nucleotide polymorphisms (SNP) of these four candidate genes were tested for association in a first set of 824 French Caucasian SSc patients (including 54 SSc-PAH) and 939 controls. The replication set consisted of 1516 European SSc (including 219 SSc-PAH) and 3129 controls from the European League Against Rheumatism Scleroderma Trials and Research group network.

RESULTS

No mutation was identified by direct sequencing. However, two repertoried SNP, ENG rs35400405 and ALK1 rs2277382, were found in SSc-PAH patients only. The genotyping of 22 SNP including the latter showed that only rs2277382 was associated with SSc-PAH (p=0.0066, OR 2.13, 95% CI 1.24 to 3.65). Nevertheless, this was not replicated with the following result in combined analysis: p=0.123, OR 0.79, 95% CI 0.59 to 1.07.

CONCLUSIONS

This study demonstrates the lack of association between these TGFβ receptor gene polymorphisms and SSc-PAH using both sequencing and genotyping methods.

Non-Hodgkin's lymphoma (NHL) occasionally involves the placenta, and information of such occurrence should be useful for management of the mother and fetus. We report the first case of anaplastic large cell lymphoma (ALCL) disseminated to the placenta. The diagnosis was made via excisional biopsy of cervical lymphadenopathy in a 20-year-old woman at 27 weeks' gestation. Involvement of the placenta was noted on gross examination after cesarean section delivery of a girl at 30 weeks' gestation. The ALCL was microscopically confined to intervillous spaces in a manner similar to previous reports of other NHLs. The immunophenotype was characteristic (CD30+, EMA+, BNH9+), and the now frequently associated t(2;5)(p23;q35) translocation with this lymphoma was detected by the recently produced monoclonal antibody ALK1 against the nucleophosmin/anaplastic lymphoma kinase (NPM/ALK) chimeric protein. Complete remission was induced in the mother after delivery. Both mother and child are healthy at 10 years' follow-up. The case is reported in light of the sparse literature on lymphomatous involvement of the placenta.

BACKGROUND

Patients with hereditary hemorrhagic telangiectasia (HHT) often present with recurrent anemia because of epistaxis or GI bleeding in relation to telangiectases mostly located in the stomach or small bowel. Capsule endoscopy is considered a major diagnostic tool for small-bowel diseases, but the impact of capsule endoscopy imaging on patient management in HHT is poorly understood.

OBJECTIVE

To clarify the contribution of capsule endoscopy in selected patients with HHT.

METHODS

Prospective, descriptive study.

METHODS

Multicenter, two university hospital tertiary-care centers, from January 2003 to June 2007.

METHODS

This study involved 30 patients with HHT and severe anemia (hemoglobin <9 g/dL; normal: 11-15 g/dL) and minimal epistaxis or moderate anemia but overt GI bleeding.

METHODS

Capsule endoscopy investigation.

METHODS

Clinical characteristics and capsule endoscopy results and their clinical consequences.

RESULTS

Capsule endoscopy detected gastric and small-bowel telangiectases in 14 (46.7%) and 26 (86.7%) cases, respectively. Active bleeding was present in 36.7% of cases. Diffuse telangiectases were detected in 42.3% without correlation with age, sex, or type of HHT mutation. Further investigations were carried out as a consequence of the capsule endoscopy results in 67% of cases. Treatment, consisting mostly of endoscopic argon plasma coagulation, was scheduled in 46.7% of patients.

CONCLUSIONS

Our population was essentially composed of patients with the ALK1 mutation.

CONCLUSIONS

This study shows that there is a high diagnostic yield for capsule endoscopy in selected patients with HHT. Capsule endoscopy makes possible precise mapping of lesions and has a considerable impact on the management of these selected patients by using a predefined algorithm: a limited number of accessible lesions is suitable for endoscopic treatment, whereas innumerable diffuse lesions require a medical approach. We suggest that capsule endoscopy could be a first-line, noninvasive, digestive tract examination in selected patients with HHT.