Milk microbiota has a great influence on the safety and quality of dairy products. However, few studies have investigated the variations of bacterial composition in raw milk. In this study, raw milk samples were collected in 12 successive months, and their bacterial compositions were determined by 16 S rRNA gene sequencing. The highest diversity of bacterial composition was detected in June, while the lowest was in December. Firmicutes, Proteobacteria and Actinobacteria were the most abundant phyla and exhibited a counter-balanced relationship. Pseudomonas, Lactococcus and Acinetobacter were the most prevalent genera (>1%), and a tiny core microbiota (Acinetobacter and Pseudomonas) was observed. Temperature and humidity were the determining factors for most variation in bacterial compositions at both the phylum and genus levels. Higher abundances of Pseudomonas, Propionibacterium and Flavobacterium were correlated with low temperature. Furthermore, Pseudomonas/Propionibacterium and Lactobacillus/Bifidobacterium were two pairs of genera that had synergistic effects. Associations between the microbiota and milk quality parameters were analyzed. The abundances of Propionibacterium and Pseudoalteromonas were negatively correlated to total bacterial count, which meant that they helped to maintain milk quality, while a series of environmental microorganisms contributed to the spoilage of raw milk.

Cytosine methylation is critical in mammalian development and plays a role in diverse biologic processes such as genomic imprinting, X chromosome inactivation, and silencing of repeat elements. Several factors regulate DNA methylation in early embryogenesis, but their precise role in the establishment of DNA methylation at a given site remains unclear. We have generated a comprehensive methylation map in fibroblasts derived from the murine DNA methylation mutant Hells -/-(helicase, lymphoid specific, also known as LSH). It has been previously shown that HELLS can influence de novo methylation of retroviral sequences and endogenous genes. Here, we describe that HELLS controls cytosine methylation in a nuclear compartment that is in part defined by lamin B1 attachment regions. Despite widespread loss of cytosine methylation at regulatory sequences, including promoter regions of protein-coding genes and noncoding RNA genes, overall relative transcript abundance levels in the absence of HELLS are similar to those in wild-type cells. A subset of promoter regions shows increases of the histone modification H3K27me3, suggesting redundancy of epigenetic silencing mechanisms. Furthermore, HELLS modulates CG methylation at all classes of repeat elements and is critical for repression of a subset of repeat elements. Overall, we provide a detailed analysis of gene expression changes in relation to DNA methylation alterations, which contributes to our understanding of the biological role of cytosine methylation.

Several studies have described phenotypic changes in the offspring of mice exposed to a variety of environmental factors, including diet, toxins, and stress; however, the molecular pathways involved in these changes remain unclear. Using a high fat diet (HFD)-induced obesity mouse model, we examined liver gene expression in male offspring and analyzed chromatin of paternal spermatozoa. We found that the hepatic mRNA level of 7 genes (out of 20 evaluated) was significantly altered in HFD male offspring compared to control mice, suggesting that phenotypic changes in the offspring depend on parental diet. We examined 7 imprinted loci in spermatozoa DNA from HFD-treated and control fathers by bisulfite sequencing, but did not detect changes in DNA methylation associated with HFD. Using chromatin immunoprecipitation followed by high-throughput sequencing, we found differential histone H3-occupancy at genes involved in the regulation of embryogenesis and differential H3K4me1-enrichment at transcription regulatory genes in HFD fathers vs. control mice. These results suggest that dietary exposure can modulate histone composition at regulatory genes implicated in developmental processes.

Lsh, a chromatin remodeling protein of the SNF2 family, is critical for normal heterochromatin structure. In particular, DNA methylation at repeat elements, a hallmark of heterochromatin, is greatly reduced in Lsh−/− (KO) cells. Here, we examined the presumed nucleosome remodeling activity of Lsh on chromatin in the context of DNA methylation. We found that dynamic CG methylation was dependent on Lsh in embryonic stem cells. Moreover, we demonstrate that ATP function is critical for de novo methylation at repeat sequences. The ATP binding site of Lsh is in part required to promote stable association of the DNA methyltransferase 3b with the repeat locus. By performing nucleosome occupancy assays, we found distinct nucleosome occupancy in KO ES cells compared to WT ES cells after differentiation. Nucleosome density was restored to wild-type level by re-expressing wild-type Lsh but not the ATP mutant in KO ES cells. Our results suggest that ATP-dependent nucleosome remodeling is the primary molecular function of Lsh, which may promote de novo methylation in differentiating ES cells.

Aims/hypothesis The aim of the study was to address the importance of mitochondrial function in insulin resistance and type 2 diabetes, and also to identify effective agents for ameliorating insulin resistance in type 2 diabetes. We examined the effect of two mitochondrial nutrients, R-α-lipoic acid (LA) and acetyl-L-carnitine (ALC), as well as their combined effect, on mitochondrial biogenesis in 3T3-L1 adipocytes. Methods Mitochondrial mass and oxygen consumption were determined in 3T3-L1 adipocytes cultured in the presence of LA and/or ALC for 24 h. Mitochondrial DNA and mRNA from peroxisome proliferator-activated receptor gamma and alpha (Pparg and Ppara) and carnitine palmitoyl transferase 1a (Cpt1a), as well as several transcription factors involved in mitochondrial biogenesis, were evaluated by real-time PCR or electrophoretic mobility shift (EMSA) assay. Mitochondrial complexes proteins were measured by western blot and fatty acid oxidation was measured by quantifying CO 2 production from [1-14 C] palmitate. Results Treatments with the combination of LA and ALC at concentrations of 0.1, 1 and 10 μmol/l for 24 h significantly increased mitochondrial mass, expression of mitochondrial DNA, mitochondrial complexes, oxygen consumption and fatty acid oxidation in 3T3L1 adipocytes. These changes were accompanied by an increase in expression of Pparg, Ppara and Cpt1a mRNA, as well as increased expression of peroxisome proliferator-activated receptor (PPAR) gamma coactivator 1 alpha (Ppargc1a), mitochondrial transcription factor A (Tfam) and nuclear respiratory factors 1 and 2 (Nrf1 and Nrf2). However, the treatments with LA or ALC alone at the same concentrations showed little effect on mitochondrial function and biogenesis. Conclusions/interpretation We conclude that the combination of LA and ALC may act as PPARG/A dual ligands to complementarily promote mitochondrial synthesis and adipocyte metabolism.

Although aberrant metabolism in tumors has been well described, the identification of cancer subsets with particular metabolic vulnerabilities has remained challenging. Here, we conducted an siRNA screen focusing on enzymes involved in the tricarboxylic acid (TCA) cycle and uncovered a striking range of cancer cell dependencies on OGDH, the E1 subunit of the alpha-ketoglutarate dehydrogenase complex. Using an integrative metabolomics approach, we identified differential aspartate utilization, via the malate-aspartate shuttle, as a predictor of whether OGDH is required for proliferation in 3D culture assays and for the growth of xenograft tumors. These findings highlight an anaplerotic role of aspartate and, more broadly, suggest that differential nutrient utilization patterns can identify subsets of cancers with distinct metabolic dependencies for potential pharmacological intervention.

PurposeThe purpose of this paper is to model Chinese consumers' purchase intentions for imported soy‐based dietary supplements (DS) based on the theory of planned behavior (TPB) and the health belief model (HBM). The central hypotheses for this study are that purchase intentions of Chinese DS consumers are a result of attitudes toward using DS, subjective norms, and perceived behavioral control. Health value and perceived susceptibility to illness, as well as product knowledge and marketer distrust, are integrated into the model.Design/methodology/approachData were collected from 251 consumers in Shanghai, China. Structural equation modeling was used to analyze the data.FindingsThe TPB model is effective in predicting Chinese consumers' imported soy‐based DS purchase intentions. Attitudes toward using soy‐based DS, subjective norms, and perceived behavioral control have significant influences on purchase intention. Perceived behavioral control also plays an important role in the formation of attitudes. Subjective norm significantly influences perceived behavioral control. Chinese consumers' marketer distrust plays a significant role in forming their attitudes and purchase intentions. On the other hand, product knowledge has no moderating influences on the relationships between health value and attitudes and perceived susceptibility to illness and attitudes. Neither health value nor susceptibility to illness has any influence on attitudes.Practical implicationsThe findings of this study regarding the impact of marketer distrust on attitude and purchase behavior have important implications for western marketers exporting to China and the Chinese government. The western marketers of soy‐based DS should consider taking specific actions to decrease consumer distrust of marketers promoting soy‐based DS products. In regards to production of goods for the domestic market in China, relevant Chinese state agencies, such as the State Food and Drug Administration, would be well‐advised to continue to step up their efforts in product inspections and regulation of pharmaceutical ingredients and also to strengthen legislation such as the Consumer Rights Protection Law.Originality/valueConsidering the growing popularity of DS in China, the current research is the first academic attempt to identify factors that affect purchase of imported soy‐based DS among Chinese consumers.

The development of type 2 diabetes is accompanied by decreased immune function and the mechanisms are unclear. We hypothesize that oxidative damage and mitochondrial dysfunction may play an important role in the immune dysfunction in diabetes. In the present study, we investigated this hypothesis in diabetic Goto-Kakizaki rats by treatment with a combination of four mitochondrial-targeting nutrients, namely, R-α-lipoic acid, acetyl-L-carnitine, nicotinamide and biotin. We first studied the effects of the combination of these four nutrients on immune function by examining cell proliferation in immune organs (spleen and thymus) and immunomodulating factors in the plasma. We then examined, in the plasma and thymus, oxidative damage biomarkers, including lipid peroxidation, protein oxidation, reactive oxygen species, calcium and antioxidant defence systems, mitochondrial potential and apoptosis-inducing factors (caspase 3, p53 and p21). We found that immune dysfunction in these animals is associated with increased oxidative damage and mitochondrial dysfunction and that the nutrient treatment effectively elevated immune function, decreased oxidative damage, enhanced mitochondrial function and inhibited the elevation of apoptosis factors. These effects are comparable to, or greater than, those of the anti-diabetic drug pioglitazone. These data suggest that a rational combination of mitochondrial-targeting nutrients may be effective in improving immune function in type 2 diabetes through enhancement of mitochondrial function, decreased oxidative damage, and delayed cell death in the immune organs and blood.