Kill two birds with one stone: making multi-transgenic pre-diabetes mouse models through insulin resistance and pancreatic apoptosis pathogenesis

Role of Fibrinogen in Type-2 Diabetes Mellitus with Diabetic Neuropathy and its Preliminary Mechanism

INTRODUCTION

Diabetic peripheral neuropathy (DN) is the most common complication of type 2 diabetes mellitus (T2DM).

OBJECTIVE

This study aimed to explore the role of fibrinogen (FIB) in T2DM neuropathy and its preliminary mechanism.

METHODS

Ten male Sprague-Dawley rats were divided into a normal control group (NC group) and a T2DM neuropathy model group (DN group). The DN group was given a high-energy diet and streptozotocin, while the NC group was given a normal diet and a citric acid buffer. The expression levels of related proteins were analysed.

RESULTS

Electrophysiology: Compared with the NC group, the conduction latency of the somatosensory-evoked potential and nerve conduction velocity was prolonged in the DN group, while the motor nerve action potential was decreased. As seen under a light microscope, the peripheral nerve fibres in the DN group were swollen, and the nerve fibres in the posterior funiculus of the spinal cord were loose or missing. Moreover, as seen under an electron microscope, the peripheral nerve demyelination of the DN group was severe, with microvascular blood coagulation, luminal stenosis, and collapse. Compared with the NC group, in the DN group, the expression of FIB was positively correlated with the expression of both ionised calcium-binding adaptor molecule-1 and glial fibrillary acidic protein. Compared with the NC group, in the DN group, the expression of platelet/endothelial cell adhesion molecule-1 and B-cell lymphoma 2 was negatively correlated.

CONCLUSION

The increased concentration of FIB may be the cause of neuropathy, and its mechanism may be related to its promotion of inflammatory response, blood coagulation, and vascular stenosis.

iTRAQ-Based Proteome Profiling of Differentially Expressed Proteins in Insulin-Resistant Human Hepatocellular Carcinoma

Recently, the incidences of insulin resistance (IR) and IR-related complications have increased throughout the world, which also associate with poor prognosis in hepatocellular carcinoma (HCC). Numerous studies had been focused on the role of IR in tumorigenesis and prognosis of HCC. The proteomic analysis of IR related hepatocellular carcinoma had not been reported by now. In the present study, 196 differentially expressed proteins (DEPs) were identified between insulin resistant HepG2 cells and their parental cells, of which 109 proteins were downregulated and 87 proteins were upregulated. Bioinformatics analysis indicated that these DEPs were highly enriched in process of tumorigenesis and tumor progression. PPI network analysis showed that SOX9, YAP1 and GSK3β as the key nodes, were involved in Wnt and Hippo signaling pathways. Survival analysis revealed that high expression of SOX9 and PRKD3 were strongly associated with reduced patient survival rate. parallel reaction monitoring (PRM) and Western blot analysis were applied to verify the protein level of these four key nodes mentioned above, which showed the same trend as quantified by isobaric tags for relative and absolute quantitation (iTRAQ) and confirmed the reliability of our Proteome Profiling analysis. Our results indicated that IR related dysregulation of protein expression might participated in tumorigenesis and malignant phenotype of hepatocarcinoma cells.

Amylin antibodies frequently display cross-reactivity with CGRP: characterization of eight amylin antibodies

Amylin is a 37-amino acid endocrine hormone secreted from the pancreas in response to nutrient intake, acting centrally to promote meal-ending satiation. With many studies linking amylin action to the nervous system, determining the distribution or expression of amylin in the nervous system is critical. However, amylin shares sequence identity and structural homology to the related neuropeptide calcitonin gene-related peptide (CGRP). This creates challenges in identifying selective amylin antibodies that do not cross-react with CGRP, especially in neural tissues, where CGRP is densely packed into secretory vesicles. Here, we characterized eight amylin antibodies to determine their ability to detect amylin and cross-react with rat or human αCGRP, using immunoblots and preabsorption controls in rat pancreas. We observed that amylin antibodies frequently cross-reacted with αCGRP and are therefore not suitable for use in tissues that highly express CGRP. Earlier work using these antibodies should be revisited in light of our findings.

Identification of ACTB Gene as a Potential Safe Harbor Locus in Pig Genome

Transgenic pigs play an important role in biomedicine and agriculture. The "safe harbor" locus maintains consistent foreign gene expression in cells and is important for transgenic pig generation. However, as only several safe harbor loci(Rosa26, pH11 and Pifs501) have been identified in pigs, meeting the needs of the insertion of various foreign genes is difficult. In this study, we develop a novel strategy for the efficient knock-in of gene-of-interest fragments into endogenous beta-actin(ACTB) gene via CRISPR/Cas9 mediated homologous recombination with normal expression of ACTB. Thus, we provide an alternative strategy to integrate exogenous genes into the pig genome that can be applied to agricultural breeding and biomedical models.

Retinol-Binding Protein 4 Accelerates Metastatic Spread and Increases Impairment of Blood Flow in Mouse Mammary Gland Tumors

Retinol-binding protein 4 (RBP4) is proposed as an adipokine that links obesity and cancer. We analyzed the role of RBP4 in metastasis of breast cancer in patients and in mice bearing metastatic 4T1 and nonmetastatic 67NR mammary gland cancer. We compared the metastatic and angiogenic potential of these cells transduced with Rbp4 (4T1/RBP4 and 67NR/RBP4 cell lines). Higher plasma levels of RBP4 were observed in breast cancer patients with metastatic tumors than in healthy donors and patients with nonmetastatic cancer. Increased levels of RBP4 were observed in plasma, tumor tissue, liver, and abdominal fat. Moreover, the blood vessel network was highly impaired in mice bearing 4T1 as compared to 67NR tumors. RBP4 transductants showed further impairment of blood flow and increased metastatic potential. Exogenous RBP4 increased lung settlement by 67NR and 4T1 cells. In vitro studies showed increased invasive and clonogenic potential of cancer cells treated with or overexpressing RBP4. This effect is not dependent on STAT3 phosphorylation. RBP4 enhances the metastatic potential of breast cancer tumors through a direct effect on cancer cells and through increased endothelial dysfunction and impairment of blood vessels within the tumor.