Transforming growth factor beta (TGF-beta) induces both apoptosis and cell-cycle arrest in some cell lines, but only growth arrest in others. It is not clear how this differential response to TGF-beta is specified. Smad proteins are critical mediators of TGF-beta signalling. After stimulation by TGF-beta, Smad2 and Smad3 become phosphorylated by the activated TGF-beta receptor kinases, oligomerize with Smad4, translocate to the nucleus and regulate the expression of TGF-beta target genes. Here we report that the sensitivity to TGF-beta induced apoptosis is regulated by crosstalk between the Akt/PKB serine/threonine kinase and Smad3 through a mechanism that is independent of Akt kinase activity. Akt interacts directly with unphosphorylated Smad3 to sequester it outside the nucleus, preventing its phosphorylation and nuclear translocation. This results in inhibition of Smad3-mediated transcription and apoptosis. Furthermore, the ratio of Smad3 to Akt correlates with the sensitivity of cells to TGF-beta induced apoptosis. Alteration of this ratio changes the apoptotic, but not the growth-inhibitory, responses of cells to TGF-beta. These findings identify an important determinant of sensitivity to TGF-beta-induced apoptosis that involves crosstalk between the TGF-beta and phosphatidylinositol-3-OH kinase (PI(3)K) pathways.

Background Clinical studies have shown that resuscitation with fresh frozen plasma (FFP) is associated with improved outcome after severe hemorrhagic shock (HS). We hypothesized that in addition to its effects on hemostasis, FFP has protective and stabilizing effects on the endothelium that translate into diminished endothelial cell (EC) permeability and improved resuscitation in vivo after HS. We further hypothesized that the beneficial effects of FFP would diminish over 5 days of routine storage at 4°C. Methods EC permeability was induced by hypoxia and assessed by the passage of 70-kDa Dextran between monolayers. Thrombin generation time and coagulation factor levels or activity were assessed in FFP. An in vivo rat model of HS and resuscitation was used to determine the effects of FFP on hemodynamic stability. Results Thawed FFP inhibits EC permeability in vitro by 10.2-fold. Protective effects diminish (to 2.5-fold) by day 5. Thrombin generation time is increased in plasma that has been stored between days 0 and 5. In vivo data show that day 0 FFP is superior to day 5 FFP in maintaining mean arterial pressure in rats undergoing HS with resuscitation. Conclusion Both in vitro and in vivo studies show that FFP has beneficial effects on endothelial permeability, vascular stability, and resuscitation in rats after HS. The benefits are independent of hemostasis and diminish between days 0 and 5 of storage.

Our study suggests that CLN5 mutations 1) are more common in patients with neuronal ceroid lipofuscinosis (NCL) than previously reported, 2) are found in non-Finnish NCL patients of broad ethnic diversity, and 3) can be identified in NCL patients with disease onset in adult and juvenile epochs. CLN5 genetic testing is warranted in a wider population with clinical and pathologic features suggestive of an NCL disorder.

Activation of pancreatic stellate cells (PSCs) by transforming growth factor (TGF)-β is the key step in the development of pancreatic fibrosis, a common pathological feature of chronic pancreatitis (CP). Bone morphogenetic proteins (BMPs), members of the TGF-β superfamily, have anti-fibrogenic functions, in contrast to TGF-β, in the kidney, lung, and liver. However, it is not known whether BMPs have an anti-fibrogenic role in the pancreas. The current study was designed to investigate the potential anti-fibrogenic role of BMPs in the pancreas using an in vivo CP model and an in vitro PSC model. CP was induced by repetitive intraperitoneal injections of cerulein in adult Swiss Webster mice. The control mice received saline injections. Compared with the control, cerulein injections induced a time-dependent increase in acinar injury and progression of fibrosis and a steady increase in inflammation. Cerulein injections also induced increases of the extracellular matrix (ECM) protein fibronectin and of α-smooth muscle actin (α-SMA)-positive stellate cells (PSCs). The mice receiving cerulein injections showed increased BMP2 protein levels and phosphorylated Smad1 levels up to 4 wk and then declined at 8 wk to similar levels as the control. In vitro, the isolated mouse and human PSCs were cultured and pretreated with BMP2 followed by TGF-β treatment. BMP2 pretreatment inhibited TGF-β-induced α-SMA, fibronectin, and collagen type Ia expression. Knocking down Smad1 with small-interfering RNA reversed the inhibitory effect of BMP2 on TGF-β-induced α-SMA and fibronectin expression. Thus, BMP2 opposes the fibrogenic function of TGF-β in PSCs through the Smad1 signaling pathway.

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Idiopathic pulmonary fibrosis (IPF) is a lethal lung disease of unknown etiology. The development of pulmonary hypertension (PH) is considered the single most significant predictor of mortality in patients with chronic lung diseases. The processes that govern the progression and development of fibroproliferative and vascular lesions in IPF are not fully understood. Using human lung explant samples from patients with IPF with or without a diagnosis of PH as well as normal control tissue, we report reduced BMPR2 expression in patients with IPF or IPF+PH. These changes were consistent with dampened P-SMAD 1/5/8 and elevated P-SMAD 2/3, demonstrating reduced BMPR2 signaling and elevated TGF-β activity in IPF. In the bleomycin (BLM) model of lung fibrosis and PH, we also report decreased BMPR2 expression compared with control animals that correlated with vascular remodeling and PH. We show that genetic abrogation or pharmacological inhibition of interleukin-6 leads to diminished markers of fibrosis and PH consistent with elevated levels of BMPR2 and reduced levels of a collection of microRNAs (miRs) that are able to degrade BMPR2. We also demonstrate that isolated bone marrow-derived macrophages from BLM-exposed mice show reduced BMPR2 levels upon exposure with IL6 or the IL6+IL6R complex that are consistent with immunohistochemistry showing reduced BMPR2 in CD206 expressing macrophages from lung sections from IPF and IPF+PH patients. In conclusion, our data suggest that depletion of BMPR2 mediated by a collection of miRs induced by IL6 and subsequent STAT3 phosphorylation as a novel mechanism participating to fibroproliferative and vascular injuries in IPF.

Magnetization of adipose derived stem cells with NanoShuttle magnetic nanoparticles kept adipose derived stem cells in the corpus cavernosum and improved adipose derived stem cell therapy of erectile dysfunction in an animal model.

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