Proteomics Analysis of Testis of Rats Fed a High-Fat Diet.

BACKGROUND/AIMS: The adverse effects of obesity on male fertility have been widely reported. In recent years, the relationship between the differential expression of proteins and long non-coding RNAs with male reproductive disease has been reported. However, the exact mechanism in underlying obesity-induced decreased male fertility remains unclear. METHODS: We used isobaric tags for relative and absolute quantification to identify differential protein expression patterns in the testis of rats fed a high-fat diet and normal diet. A microarray-based gene expression analysis protocol was used to compare the differences in long non-coding RNAs in high-fat diet-fed and normal diet-fed rats. Five obviously upregulated or downregulated proteins were examined using western blot to verify the accuracy of their expression. Then, we carried out functional enrichment analysis of the differentially expressed proteins using gene ontology and pathway analysis. Finally, the metabolic Gene Ontology terms and pathways involved in the differential metabolites were analyzed using the MetaboAnalyst 2.0 software to explore the co-expression relationship between long non-coding RNAs and proteins. RESULTS: We found 107 proteins and 263 long non-coding RNAs differentially expressed between rats fed a high-fat diet and normal diet. The Gene Ontology term enrichment analysis showed that the protein function most highly enriched was related to negative regulation of reproductive processes. We also found five Gene Ontology terms and two metabolic pathways upregulated or downregulated for both proteins and long non-coding RNAs. CONCLUSION: The study revealed different expression levels for both proteins and long non-coding RNAs and showed that the function and metabolic pathways of differently expressed proteins were related to reproductive processes. The Gene Ontology terms and metabolic pathways upregulated or downregulated in both proteins and long non-coding RNAs may provide new candidates to explore the mechanisms of obesity-induced male infertility for both protein and epigenetic pathways.

Comparative analysis of proteomes between diabetic and normal human sperm: Insights into the effects of diabetes on male reproduction based on the regulation of mitochondria-related proteins.

This study sought to identify sources of the reduced fertility of men with type 2 diabetes mellitus. Significant reductions in semen volume, sperm concentration, and total sperm count were observed in diabetic individuals, while transmission electron microscopy revealed that the structure of mitochondria in the tail of sperm from diabetic patients was damaged. Proteins potentially associated with these sperm defects were identified using proteomics. Isobaric tagging for relative and absolute quantitation labeling and high-performance liquid chromatography-tandem mass spectrometry allowed us to identify 357 proteins significantly differentially expressed in diabetic versus control semen (>1.2 or <0.83). According to gene ontology enrichment and pathway analyses, many of these differentially expressed proteins are associated with sperm function, including binding of sperm to the zona pellucida and proteasome function; of particular interest, half of these proteins were related to mitochondrial metabolism. Protein-interaction networks revealed that a decrease in Cystatin C and Dipeptidyl peptidase 4 in the mitochondria may be sources of the decreased motility of sperm from diabetic patients.

Correction: Long non-coding RNAs could act as vectors for paternal heredity of high fat diet-induced obesity.

[This corrects the article DOI: 10.18632/oncotarget.18138.].

Relationships of circular RNA with diabetes and depression.

Type 2 diabetes mellitus (T2DM) is closely related to depression; however, the exact molecular mechnisms of this association are unknown. Here, we investigated whether circular RNAs (circRNAs) in the blood are related to the occurrence of depression in patients with T2DM. Fourteen patients with T2DM and depressive symptoms, as assessed by the Self-Rating Depression Scale, were included in this study. Cutoff points of 44 (total coarse points) and 55 (standard score) were used to define depression. The Patient Health Questionnaire 9 was used for common mental disorders, and a score of 5 or more the cutoff for depression. Microarray assays and quantitative real-time reverse transcription polymerase chain reaction showed that 183 hsa-circRNAs were significantly upregulated, whereas 64 were downregulated in the T2DM with depression group (p < 0.05) compared with that in the T2DM group. Differentially expressed hsa-circRNAs could interact with microRNAs to target mRNA expression. KEGG pathway analysis predicted that upregulation of hsa-circRNA_003251, hsa-circRNA_015115, hsa-circRNA_100918, and hsa_circRNA_001520 may participate in the thyroid hormone, Wnt, ErbB, and mitogen-activated protein kinase signalling pathways. We speculate that differentially expressed hsa-circRNAs could help us to clarify the pathogenesis of depression in patients with T2DM and could represent novel molecular targets for clinical diagnosis and therapy.

Long non-coding RNAs could act as vectors for paternal heredity of high fat diet-induced obesity.

Long non-coding RNAs (lncRNAs) play an important role in epigenetic regulation, and abnormalities may lead to male infertility. To investigate whether lncRNAs are involved in intergenerational inheritance of obesity and obesity-induced decline in fertility, we divided mice into obesity (F0 mice fed a high-fat diet, F0-HFD) and non-obese (F0 mice fed normal chow, F0-NC) model groups and their male offspring (F1-HFD and F1-NC, respectively). We examined the differences in the expression levels of lncRNAs and mRNAs in the F0-HFD/F0-NC and F1-HFD/F1-NC groups. The results revealed similar expression patterns in the F1-HFD/F0-HFD groups at both the lncRNA and mRNA levels. The maximum difference in the lncRNA expression was observed between the F0-HFD and F0-NC groups. The differentially expressed lncRNA targets and mRNAs identified in our study are mainly involved in GnRH signalling pathway, metabolic process, and Hippo signalling pathway; similarly expressed lncRNAs and mRNAs in F1-HFD/F0-HFD are closely linked with G-protein coupled receptor signalling pathway, pancreatic polypeptide receptor activity, and lysine biosynthesis, which may play an important role in the molecular mechanism of intergenerational inheritance of obesity. Furthermore, potential genes that might play important roles in the pathogenesis of obesity-related low fertility were revealed by lncRNA-and mRNA-interaction studies based on the microarray expression profiles. In conclusion, we found that lncRNA could be involved in obesity-induced infertility by expressing abnormalities, which could act as genetic vectors of paternal inheritance of obesity.