HGF/R-spondin1 rescues liver dysfunction through the induction of Lgr5+ liver stem cells.

Induction of endogenous adult stem cells by administering soluble molecules provides an advantageous approach for tissue damage repair, which could be a clinically applicable and cost-effective alternative to transplantation of embryonic or pluripotent stem cell-derived tissues for the treatment of acute organ failures. Here, we show that HGF/Rspo1 induce liver stem cells and rescue liver dysfunction. Carbon tetrachloride treatment promotes both fibrosis and Lgr5+ liver stem cell proliferation, whereas Lgr5 knockdown worsens fibrosis. Injection of HGF in combination with Rspo1 increases the number of Lgr5+ liver stem cells and improves liver function by attenuating fibrosis. We observe Lgr5+ liver stem cells in human liver fibrosis tissues, and once they are isolated, these cells are able to form organoids, and treatment with HGF/Rspo1 promotes their expansion. We suggest that Lgr5+ liver stem cells represent a valuable target for liver damage treatment, and that HGF/Rspo1 can be used to promote liver stem cell expansion.

Rpb3 promotes hepatocellular carcinoma through its N-terminus.

The expression of RNA polymerase II subunit 3 (Rpb3) was found frequent up-regulation in Hepatocellular carcinoma (HCC) tumors. Significant associations could also be drawn between increased expressions of Rpb3 and advance HCC staging and shorter disease-free survival of patients. Overexpression of Rpb3 increased HCC cell proliferation, migratory rate and tumor growth in nude mice, whereas suppression of Rpb3 using shRNA inhibited these effects. For mechanism study, we found that Rpb3 bound directly to Snail, downregulated E-cadherin, induced HCC cells epithelial-mesenchymal transition (EMT). In particular, N-terminus of Rpb3 blocked Rpb3 binding to Snail, inhibited Rpb3-high-expression HCC cells proliferation, migration, tumor growth in nude mice, and also inhibited DEN-induced liver tumorigenesis. Furthermore, N-terminus of Rpb3 did not inhibit normal liver cells or Rpb3-low-expression HCC cells proliferation. These findings suggest that N-terminus of Rpb3 selectively inhibits Rpb3-high-expression HCC cells proliferation. N-terminus of Rpb3 may be useful in treating patients diagnosed with Rpb3-high-expression HCC.

Over-expression of Slit2 induces vessel formation and changes blood vessel permeability in mouse brain.

AIM: To investigate the effect of the axon guidance cue Slit2 on the density of blood vessels and permeability of the blood-brain barrier in mouse brain. METHODS: hSlit2 transgenic mouse line was constructed, and the phenotypes of the mice were compared with wild-type mice in respect to the lateral ventricle (LV), ventricle pressure, and the choroids plexus. An in vivo Miles permeability assay and an amyloid-ß permeability assay were used to assess the permeability of brain blood vessels. Brain vessel casting and intracerebral hemorrhage models were built to investigate vessel density in the transgenic mice. An in vitro permeability assay was used to test whether Slit2 could change the permeability and tight junctions of blood vessel endothelial cells. RESULTS: Hydrocephalus occurred in some transgenic mice, and a significantly larger lateral ventricle area and significantly higher ventricle pressure were observed in the transgenic mice. The transgenic mice displayed changed construction of the choroids plexus, which had more micro vessels, dilated vessels, gaps between epithelial cells and endothelial cells than wild-type mice. Slit2 significantly increased brain vessel density and the permeability of brain vessels to large molecules. These blood vessels were more sensitive to cues that induce brain hemorrhage. At the cellular level, Slit2 disturbed the integrity of tight junctions in blood vessel endothelial cells and improved the permeability of the endothelial cell layer. Thus, it promoted the entry of amyloid-ß peptides from the serum into the central nervous system, where they bound to neurons. CONCLUSION: Slit2 increases vessel density and permeability in the brains of transgenic mice. Thus, Slit2 induces numerous changes in brain vessels and the barrier system.

Slit-Robo signaling mediates lymphangiogenesis and promotes tumor lymphatic metastasis.

The Slit family of guidance cues binds to Roundabout (Robo) receptors to modulate neuronal, leukocytic, and endothelial migration. Slit-Robo signaling had been reported to function as chemoattractive signal for vascular endothelial cells during angiogenesis. In this study, we found that Robo1 was expressed in lymphatic endothelial cells to mediate the migration and tube formation of these cells upon Slit2 stimulation, which were specifically inhibited by the function-blocking antibody R5 to Slit2/Robo1 interaction. To further explore the lymphangiogenic effect and significance mediated by Slit-Robo signaling, we intercrossed Slit2 transgenic mice with a non-metastatic RIP1-Tag2 mouse tumor model, and found that transgenic overexpression of Slit2 significantly enhanced tumor lymphangiogenesis and subsequently promoted mesenteric lymph node metastasis of pancreatic islet tumors. Taken together, our findings reveal that through interacting with Robo1, Slit2 is a novel and potent lymphangiogenic factor and contributes to tumor lymphatic metastasis.

[Study on gamma-synuclein gene in patients with idiopathic Parkinson's disease].

OBJECTIVE: To evaluate the relationship between idiopathic Parkinson's disease (PD) and two polymorphisms (C243G and A377T) of the gamma-synuclein gene in a Chinese Han population of Shanghai area. METHODS: Polymorphic genotyping was performed with PCR-RPLP technique. Association analysis was carried out in 145 unrelated idiopathic PD patients and 184 age-matched healthy controls. RESULTS: The authors failed to detect any distributional difference of the C243G and A377T polymorphisms of the gamma-synuclein gene between PD cases and control subjects, nor did they find any association. CONCLUSION: These data do not support that gamma-synuclein gene C243G and A377T polymorphisms are involved in idiopathic PD onset in the Han population of Shanghai area.