[Effect of Polygonati Rhizoma in improving pyroptosis injury of diabetic macroangiopathy via NLRP3/caspase-1/GSDMD pathway].

This study aims to explore the influence of Polygonati Rhizoma on the pyroptosis in the rat model of diabetic macroangiopathy via the NOD-like receptor thermal protein domain associated protein 3(NLRP3)/cysteinyl aspartate specific proteinase-1(caspase-1)/gasdermin D(GSDMD) pathway. The rat model of diabetes was established by intraperitoneal injection of streptozotocin(STZ) combined with a high-fat, high-sugar diet. The blood glucose meter, fully automated biochemical analyzer, hematoxylin-eosin(HE) staining, enzyme-linked immunosorbent assay, immunofluorescence, immunohistochemistry, and Western blot were employed to measure blood glucose levels, lipid levels, vascular thickness, inflammatory cytokine levels, and expression levels of pyroptosis-related proteins. The mechanism of pharmacological interventions against the injury in the context of diabetes was thus explored. The results demonstrated the successful establishment of the model of diabetes. Compared with the control group, the model group showed elevated levels of fasting blood glucose, total cholesterol(TC), triglycerides(TG) and low-density lipoprotein cholesterol(LDL-c), lowered level of high-density lipoprotein cholesterol(HDL-c), thickened vascular intima, and elevated serum and aorta levels of tumor necrosis factor-α(TNF-α), interleukin-1ß(IL-1ß) and interleukin-18(IL-18). Moreover, the model group showed increased NLRP3 inflammasomes and up-regulated levels of caspase-1 and GSDMD in aortic vascular cells. Polygonati Rhizoma intervention reduced blood glucose and lipid levels, inhibited vascular thickening, lowered the levels of TNF-α, IL-1ß, IL-18 in the serum and aorta, attenuated NLRP3 inflammasome expression, and down-regulated the expression levels of caspase-1 and GSDMD, compared with the model group. In summary, Polygonati Rhizoma can slow down the progression of diabetic macroangiopathy by inhibiting pyroptosis and alleviating local vascular inflammation.

Transcriptome analysis of probiotic Lactobacillus casei Zhang during fermentation in soymilk.

Lactobacillus casei Zhang is a widely recognized probiotic bacterium, which is being commercially used in China. To study the gene expression dynamics of L. casei Zhang during fermentation in soymilk, a whole genome microarray was used to screen for differentially expressed genes when grown to the lag phase, the late logarithmic phase, and the stationary phase. Comparisons of different transcripts next to each other revealed 162 and 63 significantly induced genes in the late logarithmic phase and stationary phase, of which the expression was at least threefold up-regulated and down-regulated, respectively. Approximately 38.4% of the up-regulated genes were associated with amino acid transport and metabolism notably for histidine and lysine biosynthesis, followed by genes/gene clusters involved in carbohydrate transport and metabolism, lipid transport and metabolism, and inorganic ion transport and metabolism. The analysis results suggest a complex stimulatory effect of soymilk-based ecosystem on the L. casei Zhang growth. On the other hand, it provides the very first insight into the molecular mechanism of L. casei strain for how it will adapt to the protein-rich environment.

Occurrence and dominance of yeast species in naturally fermented milk from the Tibetan Plateau of China.

To determine which yeasts are present in the naturally fermented milks of China, 69 samples made by the nomads of Tibet were collected from the Tibetan Plateau in China. From these samples, 225 strains of yeast were isolated and identified using conventional microbiological analysis and gene sequencing analysis of the D1/D2 domain of the large subunit (26S) ribosomal DNA. The results showed that the total concentration of yeasts in these samples ranged from 5.01 to 8.97 log10 colony-forming units (CFU)/mL (6.91 ± 1.02 log10 CFU/mL; mean ± SD). The number of cultivable yeasts was higher in the samples from Qinghai (7.55 ± 0.75 log10 CFU/mL) than those from Tibet (6.21 ± 0.79 log10 CFU/mL, P < 0.05). Moreover, there were 15 phylotypes in these 69 samples. Among these phylotypes, Kluyveromyces marxianus (49.3%, frequency percentage), Saccharomyces cerevisiae (62.3%), and Pichia fermentans (46.4%) appeared frequently and can be considered the most common culturable species in naturally fermented milk products. Traditional fermented Mongolian cow milk featured a wide diversity of yeast species, including Issatchenkia orientalis, Kazachstania unisporus, Rhodotorula mucilaginosa, Candida pararugosa, Torulaspora delbrueckii, Geotrichum sp., Kazachstania unisporus, Geotrichum fragrans, Debaryomyces hansenii, Yarrowia lipolytica, Trichosporon gracile, and Pichia membranifaciens. This study provides new data on yeast composition in naturally fermented milk and shows the yeast biodiversity of fermented milk products from the Tibetan Plateau of China.

[Identification and biodiversity of yeasts isolated from Koumiss in Xinjiang of China].

A total of 87 yeast strains were isolated from 28 home-made koumiss samples, a traditional fermented mare milk product in Xinjiang of China. The isolates were identified by standard physiological and biochemical tests and analysis of the large-subunit (26S) rDNA gene D1/D2 domain sequences. They are proved to be Saccharomyces unisporus (48.3% of the isolates), Kluyveromyces marxianus (27.6%) and Pichia membranaefaciens (15.0%), Saccharomyces cerevisiae (9.2%). Among them, six isolates and a standard yeast strain were selected for analysis of D1/D2 domain sequences. They are indicated as S. unisporus, K. marxianus, S. cerevisiae, P. membranifaciens, P. fermentans, P. galeiformis and the standard yeast strain is indicated as K. lactis (100%). The results obtained demonstrate the value of using analysis of D1/D2 domain sequences methods, in conjunction with the traditional taxonomic methods based on phenotypic characteristics. This study forms an essential step towards the preservation and exploitation of the hidden oenological potential of the wealth of yeast biodiversity of the koumiss in Xinjiang Province. The result obtained shown that S. unisporus and K. marxianus were the predominant strains of koumiss in Xingjiang of China.