Expression changes of hypothalamic Ahi1 in mice brain: implication in sensing insulin signaling

Alzheimer's Disease and Diabetes: Insulin Signaling as the Bridge Linking Two Pathologies

Alzheimer's (or Alzheimer) disease (AD) is the most prevalent subset of dementia, affecting elderly populations worldwide. The cumulative costs of the AD care are rapidly accelerating as the average lifespan increases. Onset and risk factors for AD and AD-like dementias have been largely unknown until recently. Studies show that chronic type II diabetes mellitus (DM) is closely associated with neurodegeneration, especially AD. Type II DM is characterized by the cells' inability to take up insulin, as well as chronic hyperglycemia. In the central nervous system, insulin has crucial regulatory roles, while chronic hyperglycemia leads to formation and accumulation of advanced glycation end products (AGEs). AGEs are the major contributor to insulin resistance in diabetic cells, due to their regulatory role on sirtuin expression. Insulin activity in the central nervous system is known to interact with key proteins affected in neurodegenerative conditions, such as amyloid-β precursor protein (AβPP or APP), huntingtin-associated protein-1 (HAP1), Abelson helper integration site-1 (AHI1 or Jouberin), kinesin, and tau. Sirtuins have been theorized to be the mechanism for insulin resistance, and have been found to be affected in neurodegenerative conditions as well. There are hints that all these neuronal proteins may be closely related, although the mechanisms remain unclear. This review will gather existing research on these proteins and highlight the link between neurodegenerative conditions and diabetes mellitus.

Genomic analyses provide insights into breed-of-origin effects from purebreds on three-way crossbred pigs

Crossbreeding is widely used aimed at improving crossbred performance for poultry and livestock. Alleles that are specific to different purebreds will yield a large number of heterozygous single-nucleotide polymorphisms (SNPs) in crossbred individuals, which are supposed to have the power to alter gene function or regulate gene expression. For pork production, a classic three-way crossbreeding system of Duroc × (Landrace × Yorkshire) (DLY) is generally used to produce terminal crossbred pigs with stable and prominent performance. Nonetheless, little is known about the breed-of-origin effects from purebreds on DLY pigs. In this study, we first estimated the distribution of heterozygous SNPs in three kinds of three-way crossbred pigs via whole genome sequencing data originated from three purebreds. The result suggested that DLY is a more effective strategy for three-way crossbreeding as it could yield more stably inherited heterozygous SNPs. We then sequenced a DLY pig family and identified 95, 79, 132 and 42 allele-specific expression (ASE) genes in adipose, heart, liver and skeletal muscle, respectively. Principal component analysis and unrestricted clustering analyses revealed the tissue-specific pattern of ASE genes, indicating the potential roles of ASE genes for development of DLY pigs. In summary, our findings provided a lot of candidate SNP markers and ASE genes for DLY three-way crossbreeding system, which may be valuable for pig breeding and production in the future.

Zfp462 deficiency causes anxiety-like behaviors with excessive self-grooming in mice

Zfp462 is a newly identified vertebrate-specific zinc finger protein that contains nearly 2500 amino acids and 23 putative C2H2-type zinc finger domains. So far, the functions of Zfp462 remain unclear. In our study, we showed that Zfp462 is expressed predominantly in the developing brain, especially in the cerebral cortex and hippocampus regions from embryonic day 7.5 to early postnatal stage. By using a piggyBac transposon-generated Zfp462 knockout (KO) mouse model, we found that Zfp462 KO mice exhibited prenatal lethality with normal neural tube patterning, whereas heterozygous (Het) Zfp462 KO (Zfp462^+/- ) mice showed developmental delay with low body weight and brain weight. Behavioral studies showed that Zfp462^+/- mice presented anxiety-like behaviors with excessive self-grooming and hair loss, which were similar to the pathological grooming behaviors in Hoxb8 KO mice. Further analysis of grooming microstructure showed the impairment of grooming patterning in Zfp462^+/- mice. In addition, the mRNA levels of Pbx1 (pre-B-cell leukemia homeobox 1, an interacting protein of Zfp462) and Hoxb8 decreased in the brains of Zfp462^+/- mice, which may be the cause of anxiety-like behaviors. Finally, imipramine, a widely used and effective anti-anxiety medicine, rescued anxiety-like behaviors and excessive self-grooming in Zfp462^+/- mice. In conclusion, Zfp462 deficiency causes anxiety-like behaviors with excessive self-grooming in mice. This provides a novel genetic mouse model for anxiety disorders and a useful tool to determine potential therapeutic targets for anxiety disorders and screen anti-anxiety drugs.

The influence of AHI1 variants on the diagnosis and treatment outcome in schizophrenia

The present study aimed to explore whether four single nucleotide polymorphisms (SNPs) within the AHI1 gene could be associated with schizophrenia (SCZ) and whether they could predict the clinical outcomes in SCZ patients treated with antipsychotics. Four hundred twenty-six (426) in-patients with SCZ and 345 controls were genotyped for four AHI1 SNPs (rs11154801, rs7750586, rs9647635 and rs9321501). Baseline and clinical measures for SCZ patients were assessed through the Positive and Negative Syndrome Scale (PANSS). Allelic and genotypic frequencies in SCZ subjects were compared with those of controls using the χ² statistics. The repeated-measure ANOVA was used for the assessment of treatment outcomes measured by PANSS changes. The case-control analysis did not show any difference in the genotypic distribution of the SNPs, while in the allelic analysis, a weak association was found between the rs9647635 A allele and SCZ. Furthermore, in the haplotype analysis, three haplotypes resulted in being associated with SCZ. On the other hand, two SNPs (rs7750586 and rs9647635) were associated with clinical improvement of negative symptoms in the allelic analysis, although in the genotypic analysis, only trends of association were found for the same SNPs. Our findings suggest a possible influence of AHI1 variants on SCZ susceptibility and antipsychotic response, particularly concerning negative symptomatology. Subsequent well-designed studies would be mandatory to confirm our results due to the methodological shortcomings of the present study.