Angiocrine FSTL1 (Follistatin-Like Protein 1) Insufficiency Leads to Atrial and Venous Wall Fibrosis via SMAD3 Activation.

OBJECTIVE: Angiocrine factors, mediating the endothelial-mural cell interaction in vascular wall construction as well as maintenance, are incompletely characterized. This study aims to investigate the role of endothelial cell-derived FSTL1 (follistatin-like protein 1) in vascular homeostasis. Approach and Results: Using conditional knockout mouse models, we show that loss of FSTL1 in endothelial cells (Fstl1ECKO) led to an increase of pulmonary vascular resistance, resulting in the heart regurgitation especially with tricuspid valves. However, this abnormality was not detected in mutant mice with Fstl1 knockout in smooth muscle cells or hematopoietic cells. We further showed that there was excessive αSMA (α-smooth muscle actin) associated with atrial endocardia, heart valves, veins, and microvessels after the endothelial FSTL1 deletion. There was also an increase in collagen deposition, as demonstrated in livers of Fstl1ECKO mutants. The SMAD3 (mothers against decapentaplegic homolog 3) phosphorylation (pSMAD3) was significantly enhanced, and pSMAD3 staining was colocalized with αSMA in vein walls, suggesting the activation of TGFß (transforming growth factor ß) signaling in vascular mural cells of Fstl1ECKO mice. Consistently, treatment with a TGFß pathway inhibitor reduced the abnormal association of αSMA with the atria and blood vessels in Fstl1ECKO mutant mice. CONCLUSIONS: The findings imply that endothelial FSTL1 is critical for the homeostasis of vascular walls, and its insufficiency may favor cardiovascular fibrosis leading to heart failure.

Apelin-13 attenuates traumatic brain injury-induced damage by suppressing autophagy.

The adipocytokine apelin is a peptide, Apelin and its receptor are abundantly expressed in the nervous and cardiovascular systems. Previous studies had found apelin-13 reduces brain injuries and postischemic cerebral edema through blocking programmed cell death, Apelin-13 is also able to inhibit glucose deprivation induced cardiomyocyte autophagy in a concentration dependent fashion. To observe the effect of Apelin-13 on the brain injury induced by traumatic brain injury (TBI), and explore the effect of Apelin-13 on autophagy in TBI, We performed The neurological test, and the numbers of TBI-induced neural cell death were also counted by propidium iodide labeling. At last, the autophagy associated proteins LC3, Beclin-1, Bcl-2, p62 were also assessed with western-blotting. Compared with saline vehicle groups, the neural cell death, lesion volume, and neural dysfunction were attenuated by apelin-13 after TBI. In additionally, Apelin-13 also reversed TBI induced downregulation of LC3, Beclin-1, Bcl-2, p62 expression, compared with saline vehicle groups, at 24 and 48 h post TBI. Apelin-13 attenuates TBI induced brain damage by suppressing autophagy. All these results revealed that Apelin-13 suppressed autophagy. The autophagy may be involved in the mechanism of Apelin-13 rescue the subsequent damaged neuron in TBI.

CWC22-Mediated Alternative Splicing of Spp1 Regulates Nociception in Inflammatory Pain.

Increasing evidence suggests that alternative splicing plays a critical role in pain, but its underlying mechanism remains elusive. Herein, we employed complete Freund's adjuvant (CFA) to induce inflammatory pain in mice. A combination of genomics research techniques, lentivirus-based genetic manipulations, behavioral tests, and molecular biological technologies confirmed that splicing factor Cwc22 mRNA and CWC22 protein were elevated in the spinal dorsal horn at 3 days after CFA injection. Knockdown of spinal CWC22 by lentivirus transfection (lenti-shCwc22) reversed CFA-induced thermal hyperalgesia and mechanical allodynia, whereas upregulation of spinal CWC22 (lenti-Cwc22) in naïve mice precipitated pain. Comprehensive transcriptome and genome analysis identified the secreted phosphoprotein 1 (Spp1) as a potential gene of CWC22-mediated alternative splicing, however, only Spp1 splicing variant 4 (Spp1 V4) was involved in thermal and mechanical nociceptive regulation. In conclusion, our findings demonstrate that spinal CWC22 regulates Spp1 V4 to participate in CFA-induced inflammatory pain. Blocking CWC22 or CWC22-mediated alternative splicing may provide a novel therapeutic target for the treatment of persistent inflammatory pain.

Apelin-13 as a novel target for intervention in secondary injury after traumatic brain injury.

The adipocytokine, apelin-13, is an abundantly expressed peptide in the nervous system. Apelin-13 protects the brain against ischemia/reperfusion injury and attenuates traumatic brain injury by suppressing autophagy. However, secondary apelin-13 effects on traumatic brain injury-induced neural cell death and blood-brain barrier integrity are still not clear. Here, we found that apelin-13 significantly decreases cerebral water content, mitigates blood-brain barrier destruction, reduces aquaporin-4 expression, diminishes caspase-3 and Bax expression in the cerebral cortex and hippocampus, and reduces apoptosis. These results show that apelin-13 attenuates secondary injury after traumatic brain injury and exerts a neuroprotective effect.

High expression of COUP-TF II cooperated with negative Smad4 expression predicts poor prognosis in patients with colorectal cancer.

OBJECTIVE: In order to evaluate whether the role of chicken ovalbumin upstream promoter transcription factor II (COUP-TF II) could sever as a predictor to stratify risk of human colorectal cancer (CRC) patients, and to elucidate the preliminary molecular mechanisms of COUP-TF II involved in the development and advancement of CRC reflected by investigating the relationship of COUP-TF II with PTEN, Smad4. METHODS: 112 cases tissue microarray and immunohistochemical SP method were used to detect the expression of COUP-TF II, PTEN and Smad4 in CRC tissues and adjacent non-tumorous tissues. The clinical relevance and prognosis of COUP-TF II, PTEN, Smad4 in CRC patients were analyzed. Furthermore, Cox proportional hazards model was performed to indicate the independent prognostic factors for CRC patients using various clinicopathological parameters and COUP-TF II, PTEN and Smad4. RESULTS: COUP-TF II proteins were positively expressed in 65.2% of CRC tissues and 15.5% paired non-CRC tissues, respectively. The expression of COUP-TF II was significantly correlated with TNM stage and lymph node metastasis and a negative correlation with Smad4 expression. Patients bearing higher levels of COUP-TF II expression showed lower DFS and OS. Most importantly, Cox proportional hazards regression analyses showed COUP-TF II positive/Smad4 negative status (DFS, P=0.001; OS, P=0.005) were independent prognostic factors for CRC patients. CONCLUSION: Positive COUP-TF II expression levels has significant value in determining CRC stage and metastasis and cooperates with negative Smad4 expression contributing to assess prognosis in patients with colorectal cancer, suggesting Smad4 may be involved in the above regulation progress probably.

Peripheral lymphadenopathy as the initial manifestation of malignant mesothelioma in a child.

Peripheral lymphadenopathy is a rare presentation in malignant mesothelioma. We describe a unique case of malignant mesothelioma arising in an 11-year-old boy, for whom peripheral lymphadenopathy was the initial manifestation of the disease. The final diagnosis was confirmed by a broad panel of immunohistochemical markers. Literature review disclosed only 2 cases in childhood that initially presented with peripheral lymphadenopathy. Pathologists should be aware of this rare biologic behavior of malignant mesothelioma to reach the correct and prompt diagnosis.

VEGFR-3 ligand-binding and kinase activity are required for lymphangiogenesis but not for angiogenesis.

Although VEGFR-3 deficiency disrupts blood vascular development during early embryogenesis, the underlying mechanism was not clear. To characterize its function in angiogenesis and lymphangiogenesis, we employed two genetically modified mouse models in this study, targeting the coding region for the ligand-binding domain (Vegfr3(ΔLBD)) or the tyrosine kinase domain with an inactivation point mutation (Vegfr3(TKmut)). We show that lymphatic growth was disrupted in Vegfr3(ΔLBD/ΔLBD) and Vegfr3(TKmut/TKmut) mice, but blood vessels developed normally in both embryo and yolk sac. Interestingly, in Vegfr3(ΔLBD/ΔLBD) but not Vegfr3(TKmut/TKmut) mice, lymph sac was present but there was lack of lymphangiogenic sprouting. We further demonstrate that both the wild-type and mutant forms of VEGFR-3 could form heterodimers with VEGFR-2, and decreased the level of phospho-VEGFR-2 and the downstream phospho-Erk1/2 in endothelial cells when they were treated with VEGF-A. These findings indicate that signaling mediated via VEGFR-3 activation by its cognate ligands (VEGF-C/-D) is not required for angiogenesis, and that VEGFR-3 may play a role in this process by modulating VEGFR-2-mediated signals.

Angiopoietin-1 overexpression modulates vascular endothelium to facilitate tumor cell dissemination and metastasis establishment.

The angiopoietin-1 (Ang1)/Tie2 signaling pathway is known to play an important role in the regulation of vascular maturation and maintenance of vessel integrity. In this study, we have investigated the effect of systemic Tie2 activation or inhibition on tumor growth and metastasis. We found that treatment with Ang1 delivered via an adenoviral vector promoted s.c. implanted tumor metastasis to the lungs. Ang1 treatment did not significantly increase vascular density in the tumors but induced enlargement of blood vessels in both the tumor and normal tissues, which increased tumor cell dissemination into the blood circulation. Ang1 also enhanced the formation of metastatic foci in the lungs when tumor cells were injected into the circulation via the tail vein. The effect of Ang1 on metastasis was validated by a simultaneous treatment with a soluble form of Tie2 (sTie2), which led to the suppression of Ang1-induced increase of tumor metastasis. Furthermore, using a highly metastatic tumor model, we confirmed that systemic treatment with sTie2 suppressed tumor metastasis to the lungs and lymph nodes, whereas tumor-associated angiogenesis and lymphangiogenesis were not significantly affected. This suggests that the Ang1/Tie2 signals contribute to tumor progression by increasing vascular entry and exit of tumor cells to facilitate tumor dissemination and establishment of metastases.