PKM2 allosteric converter: A self-assembly peptide for suppressing renal cell carcinoma and sensitizing chemotherapy.

Stronger intrinsic Warburg effect and resistance to chemotherapy are the responses to high mortality of renal cell carcinoma (RCC). Pyruvate kinase M2 (PKM2) plays an important role in this process. Promoting PKM2 conversion from dimer to tetramer is a critical strategy to inhibit Warburg effect and reverse chemotherapy resistance. Herein, a PKM2 allosteric converter (PAC) is constructed based on the "in vivo self-assembly" strategy, which is able to continuously stimulate PKM2 tetramerization. The PAC contains three motifs, a serine site that is protected by enzyme cleavable ß-N-acetylglucosamine, a self-assembly peptide and a AIE motif. Once PAC nanoparticles reach tumor site via the EPR effect, the protective and hydrophilic ß-N-acetylglucosamine will be removed by over-expressed O-GlcNAcase (OGA), causing self-assembled peptides to transform into nanofibers with large serine (PKM2 tetramer activator) exposure and long-term retention, which promotes PKM2 tetramerization continuously. Our results show that PAC-induced PKM2 tetramerization inhibits aberrant metabolism mediated by Warburg effect in cytoplasm. In this way, tumor proliferation and metastasis behavior could be effectively inhibited. Meanwhile, PAC induced PKM2 tetramerization impedes the nuclear translocation of PKM2 dimer, which restores the sensitivity of cancer cells to first-line anticancer drugs. Collectively, the innovative PAC effectively promotes PKM2 conversion from dimer to tetramer, and it might provide a novel approach for suppressing RCC and enhancing chemotherapy sensitivity.

Effects and mechanism of adenovirus-mediated phosphatase and tension homologue deleted on chromosome ten gene on collagen deposition in rat liver fibrosis.

AIM: To evaluate the effects of phosphatase and tension homologue deleted on chromosome ten (PTEN) gene on collagen metabolism in hepatic fibrosis and the underlying mechanisms. METHODS: Rat primary hepatic stellate cells (HSCs) and human LX-2 cells were transfected with adenovirus containing cDNA constructs encoding wild-type PTEN (Ad-PTEN), PTEN mutant G129E gene (Ad-G129E), and RNA interference constructs targeting the PTEN sequence PTEN short hairpin RNA to up-regulate and down-regulate the expression of PTEN. HSCs were assayed using fluorescent microscopy, real-time polymerase chain reaction, and western blotting. Moreover, a CCl4-induced rat hepatic fibrosis model was established to investigate the in vivo effects. Hematoxylin and eosin, and Masson's trichrome were used to assess the histological changes. The expression of collagen I and III was assessed using immunohistochemistry and western blot analysis. RESULTS: Elevated expression of PTEN gene reduced serum levels of alanine transaminase and aspartate transaminase, decreased collagen deposition in the liver, and reduced hepatocyte necrosis. In contrast, knockdown of PTEN expression had an opposite effect, such as increased collagen deposition in the liver, and was molecularly characterized by the increased expression of matrix metalloproteinase (MMP)-13 (P < 0.01) and MMP-2 (P < 0.01), as well as decreased expression of the tissue inhibitor of metalloproteinase (TIMP)-1 (P < 0.01) and TIMP-2 (P < 0.01). CONCLUSION: These data indicated that gene therapy using recombinant adenovirus encoding PTEN might be a novel way of treating hepatic fibrosis.

In vivo hepatic differentiation potential of human umbilical cord-derived mesenchymal stem cells: Therapeutic effect on liver fibrosis/cirrhosis.

AIM: To investigate the hepatic differentiation potential of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) and to evaluate their therapeutic effect on liver fibrosis/cirrhosis. METHODS: A CCl4-induced liver fibrotic/cirrhotic rat model was used to assess the effect of hUC-MSCs. Histopathology was assessed by hematoxylin and eosin (H&E), Masson trichrome and Sirius red staining. The liver biochemical profile was measured using a Beckman Coulter analyzer. Expression analysis was performed using immunofluorescent staining, immunohistochemistry, Western blot, and real-time PCR. RESULTS: We demonstrated that the infused hUC-MSCs could differentiate into hepatocytes in vivo. Functionally, the transplantation of hUC-MSCs to CCl4-treated rats improved liver transaminases and synthetic function, reduced liver histopathology and reversed hepatobiliary fibrosis. The reversal of hepatobiliary fibrosis was likely due to the reduced activation state of hepatic stellate cells, decreased collagen deposition, and enhanced extracellular matrix remodeling via the up-regulation of MMP-13 and down-regulation of TIMP-1. CONCLUSION: Transplanted hUC-MSCs could differentiate into functional hepatocytes that improved both the biochemical and histopathologic changes in a CCl4-induced rat liver fibrosis model. hUC-MSCs may offer therapeutic opportunities for treating hepatobiliary diseases, including cirrhosis.

Immunopathology of inflammatory bowel disease.

Inflammatory bowel disease (IBD) results from a complex series of interactions between susceptibility genes, the environment, and the immune system. The host microbiome, as well as viruses and fungi, play important roles in the development of IBD either by causing inflammation directly or indirectly through an altered immune system. New technologies have allowed researchers to be able to quantify the various components of the microbiome, which will allow for future developments in the etiology of IBD. Various components of the mucosal immune system are implicated in the pathogenesis of IBD and include intestinal epithelial cells, innate lymphoid cells, cells of the innate (macrophages/monocytes, neutrophils, and dendritic cells) and adaptive (T-cells and B-cells) immune system, and their secreted mediators (cytokines and chemokines). Either a mucosal susceptibility or defect in sampling of gut luminal antigen, possibly through the process of autophagy, leads to activation of innate immune response that may be mediated by enhanced toll-like receptor activity. The antigen presenting cells then mediate the differentiation of naïve T-cells into effector T helper (Th) cells, including Th1, Th2, and Th17, which alter gut homeostasis and lead to IBD. In this review, the effects of these components in the immunopathogenesis of IBD will be discussed.

Specific shRNA targeting of FAK influenced collagen metabolism in rat hepatic stellate cells.

AIM: To investigate the effects and mechanism of disruption of focal adhesion kinase (FAK) expression on collagen metabolism in rat hepatic stellate cells (HSC). METHODS: The plasmids expressing FAK short hairpin RNA (shRNA) were transfected into HSC-T6 cells, and the level of FAK expression was determined by both real-time quantitative polymerase chain reaction (Q-PCR) and Western blotting analysis. The production of type I collagen and type III collagen in FAK-disrupted cells was analyzed by real-time Q-PCR. The level of collagen metabolism proteins, including matrix metalloproteinases-13 (MMP-13) and tissue inhibitors of metalloproteinases-1 (TIMP-1) was also determined by both real-time Q-PCR and Western blotting analysis. RESULTS: The transfection of FAK shRNA plasmids into HSC resulted in disrupted FAK expression. Compared with the HK group, the levels of type I collagen and type III collagen mRNA transcripts in FAK shRNA plasmid group were significantly decreased (0.69 +/- 0.03 vs 1.96 +/- 0.15, P = 0.000; 0.59 +/- 0.07 vs 1.62 +/- 0.12, P = 0.020). The production of TIMP-1 in this cell type was also significantly reduced at both mRNA and protein levels (0.49 +/- 0.02 vs 1.72 +/- 0.10, P = 0.005; 0.76 +/- 0.08 vs 2.31 +/- 0.24, P = 0.000). However, the expression of MMP-13 mRNA could be significantly up-regulated by the transfection of FAK shRNA plasmids into HSC (1.74 +/- 0.20 vs 1.09 +/- 0.09, P = 0.000). CONCLUSION: These data support the hypothesis that shRNA-mediated disruption of FAK expression could attenuate extracellular matrix (ECM) synthesis and promote ECM degradation, making FAK a potential target for novel anti-fibrosis therapies.

[Characteristics of soil organic carbon and total nitrogen under different land use types in Shanghai].

By the methods of field sampling and laboratory analysis, this paper studied the variations of soil organic carbon (SOC) and total nitrogen (TN) contents and SOC density under different land use types in Shanghai. Significant differences were observed in the test parameters among different land use types. The SOC density was the highest in paddy field (3.86 kg x m(-2)), followed by in upland (3.17 kg x m(-2)), forestland (3.15 kg x m(-2)), abandoned land (2.73 kg x m(-2)), urban lawn (2.65 kg x m(-2)), garden land (2.13 kg x m(-2)), and tidal flat (1.38 kg x m(-2)). The assessment on the effects of three types of land use change on the test parameters showed that the conversion of paddy field into upland resulted in a significant decrease of SOC and TN contents and SOC density; the abandonment of farmland was not an effective way in improving SOC storage in the Yangtze Delta region with abundant water and heat resources, high soil fertility, and high level of field management; while the 4-5 years conversion of paddy field into artificial forestland decreased the SOC and TN contents and SOC density, suggesting that in a short term, the soil carbon sequestration effect of the conversion from paddy field to forestland was at a low level, due to the limitation of vegetation productivity.