INPPL1 is associated with the metabolic syndrome in men with Type 1 diabetes, but not with diabetic nephropathy

The Functional Roles of the Src Homology 2 Domain-Containing Inositol 5-Phosphatases SHIP1 and SHIP2 in the Pathogenesis of Human Diseases

The src homology 2 domain-containing inositol 5-phosphatases SHIP1 and SHIP2 are two proteins involved in intracellular signaling pathways and have been linked to the pathogenesis of several diseases. Both protein paralogs are well known for their involvement in the formation of various kinds of cancer. SHIP1, which is expressed predominantly in hematopoietic cells, has been implicated as a tumor suppressor in leukemogenesis especially in myeloid leukemia, whereas SHIP2, which is expressed ubiquitously, has been implicated as an oncogene in a wider variety of cancer types and is suggested to be involved in the process of metastasis of carcinoma cells. However, there are numerous other diseases, such as inflammatory diseases as well as allergic responses, Alzheimer's disease, and stroke, in which SHIP1 can play a role. Moreover, SHIP2 overexpression was shown to correlate with opsismodysplasia and Alzheimer's disease, as well as metabolic diseases. The SHIP1-inhibitor 3-α-aminocholestane (3AC), and SHIP1-activators, such as AQX-435 and AQX-1125, and SHIP2-inhibitors, such as K161 and AS1949490, have been developed and partly tested in clinical trials, which indicates the importance of the SHIP-paralogs as possible targets in the therapy of those diseases. The aim of this article is to provide an overview of the current knowledge about the involvement of SHIP proteins in the pathogenesis of cancer and other human diseases and to create awareness that SHIP1 and SHIP2 are more than just tumor suppressors and oncogenes.

Novel Sulfonanilide Inhibitors of SHIP2 Enhance Glucose Uptake into Cultured Myotubes

A series of substituted sulfonanilide analogs were prepared and evaluated as novel potent inhibitors of SH2 domain-containing inositol polyphosphate 5'-phosphatase 2 (SHIP2). SHIP2 has been shown to be a new attractive target for the treatment of insulin resistance in type 2 diabetes mellitus (T2D), which can lead to life-threatening diabetic kidney disease (DKD). Amongst the synthesized compounds, the two most promising candidates, 10 and 11, inhibited SHIP2 significantly. Additionally, these compounds induced Akt activation in a dose-dependent manner, increased the presence of glucose transporter 4 at the plasma membrane, and enhanced glucose uptake in cultured myotubes in vitro at lower concentrations than metformin, the most widely used antidiabetic drug. These results show that the novel SHIP2 inhibitors have insulin sensitizing capacity and provide prototypes for further drug development for T2D and DKD.

SHIPping out diabetes-Metformin, an old friend among new SHIP2 inhibitors

SHIP2 (Src homology 2 domain‐containing inositol 5′‐phosphatase 2) belongs to the family of 5′‐phosphatases. It regulates the phosphoinositide 3‐kinase (PI3K)‐mediated insulin signalling cascade by dephosphorylating the 5′‐position of PtdIns(3,4,5)P3 to generate PtdIns(3,4)P2, suppressing the activity of the pathway. SHIP2 mouse models and genetic studies in human propose that increased expression or activity of SHIP2 contributes to the pathogenesis of the metabolic syndrome, hypertension and type 2 diabetes. This has raised great interest to identify SHIP2 inhibitors that could be used to design new treatments for metabolic diseases. This review summarizes the central mechanisms associated with the development of diabetic kidney disease, including the role of insulin resistance, and then moves on to describe the function of SHIP2 as a regulator of metabolism in mouse models. Finally, the identification of SHIP2 inhibitors and their effects on metabolic processes in vitro and in vivo are outlined. One of the newly identified SHIP2 inhibitors is metformin, the first‐line medication prescribed to patients with type 2 diabetes, further boosting the attraction of SHIP2 as a treatment target to ameliorate metabolic disorders.

Locus and gene-based GWAS meta-analysis identifies new diabetic nephropathy genes

Objective Assimilation of SNPs Interacting in Synchrony (OASIS) is a locus-based clustering algorithm recently described that can potentially address false positives and negatives in genome-wide association studies (GWAS) of complex disorders. Diabetic nephropathy (DN) is incompletely understood due to a paucity of genes identified despite several GWAS. OASIS was applied to three DN dbGAP GWAS datasets (4725 subjects; 1.06 million SNPs). OASIS identified 19 DN genes which were verified using single variant replication in a standard association study and gene-based analysis using GATES. CARS and FRMD3 were confirmed as DN genes, and five known diabetes-associated genes, viz. NLRP3, INPPL1, PIK3C2G, NRXN3, and TBC1D4, not previously identified using these datasets were discovered. Furthermore, three additional novel DN genes were found which replicated in two sets of analysis, viz. NTN1, EBF2, and DNAH11. Hence, composite analysis with OASIS, gene-based, and single variant association testing can be universally applied to existing GWAS datasets for the identification of new genes.

Transcriptomic evaluation of bovine blastocysts obtained from peri-pubertal oocyte donors

Assisted reproduction technologies (ART) and high selection pressure in the dairy industry are leading towards the use of younger females for reproduction, thereby reducing the interval between generations. This situation may have a negative impact on embryo quality, thus reducing the success rate of the procedures. This study aimed to document the effects of oocyte donor age on embryo quality, at the transcriptomic level, in order to characterize the effects of using young females for reproduction purpose. Young Holstein heifers (n = 10) were used at three different ages for ovarian stimulation protocols and oocyte collections (at 8, 11 and 14 months). All of the oocytes were fertilized in vitro with the semen of one adult bull, generating three lots of embryos per animal. Each animal was its own control for the evaluation of the effects of age. The EmbryoGENE platform was used for the assessment of gene expression patterns at the blastocyst stage. Embryos from animals at 8 vs 14 months and at 11 vs 14 months were used for microarray hybridization. Validation was done by performing RT-qPCR on seven candidate genes. Age-related contrast analysis (8 vs 14 mo and 11 vs 14 mo) identified 242 differentially expressed genes (DEGs) for the first contrast, and 296 for the second. The analysis of the molecular and biological functions of the DEGs suggests a metabolic cause to explain the differences that are observed between embryos from immature and adult subjects. The mTOR and PPAR signaling pathways, as well as the NRF2-mediated oxidative stress response pathways were among the gene expression pathways affected by donor age. In conclusion, the main differences between embryos produced at peri-pubertal ages are related to metabolic conditions resulting in a higher impact of in vitro conditions on blastocyts from younger heifers.