Siderophores of Bacillus pumilus promote 2-keto-L-gulonic acid production in a vitamin C microbial fermentation system.

The precursor of vitamin C, 2-keto-l-gulonic acid (2-KLG), is bio-converted from l-sorbose by a microbial consortium of Ketogulonicigenium vulgare and a helper strain (Bacillus spp.). Most helper strains produce siderophores. To understand the effects of siderophores on promoting 2-KLG yield, the siderophores of Bacillus pumilus SY-A9 were purified and added to a monoculture fermentation system of K. vulgare 25B-1. The results revealed that the titer of 2-KLG reached 7.18 g/L within 60 h and increased by 71.45% when the added concentration of siderophores was 500 µg/L. Moreover, the increased production of 2-KLG was accompanied by the overexpressed iron uptake system-related genes, electron transfer chain-related genes, ATP synthesis enzyme-related genes, antioxidant enzyme-related genes, and 2-KLG producing enzyme-related genes, which reduced oxidative stress and ensured the normal energy metabolism of K. vulgare 25B-1. This study demonstrated that siderophores of the helper strain play a key role in the enhancement of 2-KLG biosynthesis.

Urinary proteomics for noninvasive monitoring of biomarkers of chronic mountain sickness in a young adult population using data-independent acquisition (DIA)-based mass spectrometry.

Different populations exhibit varying pathophysiological responses to plateau environments. Therefore, it is crucial to identify molecular markers in body fluids with high specificity and sensitivity to aid in determination. Proteomics offers a fresh perspective for investigating protein changes linked to diseases. We utilize urine as a specific biomarker for early chronic mountain sickness (CMS) detection, as it is a simple-to-collect biological fluid. We collected urine samples from three groups: plains health, plateau health and CMS. Using DIA's proteomic approach, we found differentially expressed proteins between these groups, which will be used as a basis for future studies to identify protein markers. Compared with the healthy plain population, 660 altering proteins were identified in plateau health, which performed the resistance to altitude response function by boosting substance metabolism and reducing immune stress function. Compared to the healthy plateau population, the CMS group had 140 different proteins identified, out of which 8 were potential biomarkers for CMS. Our study has suggested that CMS may be closely related to increased thyroid hormone levels, oxidative damage to the mitochondria, impaired cell detoxification function and inhibited hydrolase activity. SIGNIFICANCE: Our team has compiled a comprehensive dataset of urine proteomics for AMS disease. We successfully identified differentially expressed proteins between healthy and AMS groups using the DIA proteomic approach. We discovered that 660 proteins were altered in plateau health compared to the healthy plain population, resulting in a heightened resistance to altitude response function by boosting substance metabolism and reducing immune stress function. Additionally, we pinpointed 140 different proteins in the AMS group compared to the healthy plateau population, with 8 showing potential as biomarkers for AMS. Our findings suggest that the onset of AMS may be closely linked to increased thyroid hormone levels, oxidative damage to the mitochondria, impaired cell detoxification function and inhibited hydrolase activity.

Heat stress-induced response of the proteomes of leaves from Salvia splendens Vista and King.

BACKGROUND: Salvia splendens Ker-Gawl, most commonly used in China to add a splash of brilliant color to the surroundings during the warm season, is subject to heat stress, which can greatly affect its growth and yield. RESULTS: To gain a comprehensive understanding of heat-tolerance mechanisms of S. splendens, we assessed the heat-stress responses and characterized the proteomes of leaves from two varieties, Vista (heat resistant) and King (heat sensitive). Denaturing two-dimensional gel electrophoresis (2-DE) and tandem mass spectrometry were used to identify heat-responsive proteins. Heat stress induced the reversible inactivation of photosystem II reaction centers and increased the amounts of antioxidative enzymes, thereby decreasing oxidative damage. Vista leaves had a much greater ability than King leaves to develop light-protective and oxygen-scavenging systems in response to heat stress. More than 1213 leaf proteome spots were reproducibly detected in the gels, with a total of 33 proteins in each leaf type differentially regulated when Salvia splendens were heat stress treated. Of these proteins, 23 and 28 from Vista and King, respectively, were identified. CONCLUSIONS: Most of the identified proteins are involved in photosynthesis, metabolism, protein processing, or stress response, indicating that many different processes work together to establish a new cellular homeostasis in response to heat stress.

Novel bilayer cell patch combining epidermal stem cells and angiogenic adipose stem cells for diabetic wound healing.

Diabetic foot ulcer (DFU) is one of the most severe complications in patients with diabetes. However, the development of a promising therapeutic strategy for DFU is still challenging. In this article, we demonstrate a novel bilayer cell patch, and its therapeutic effects on diabetic wound healing have been systematically investigated. The experimental results revealed that diabetes mellitus exosomes (DM-Exos) could inhibit wound healing in normal C57/B6 mice. We identified three microRNAs (miRs) including miR-15a, miR-16, and miR-214 as anti-angiogenesis factors in DM-Exos. Furthermore, angiogenic-modified adipose stem cells (ADSCs, transfected with antagomiR-15a, antagomiR-16, and antagomiR-214) were found to enhance the angiogenesis ability of human umbilical vein endothelial cells (HUVECs) by co-culture. In addition, our findings exhibited that the bilayer cell patch combining epidermal stem cells (EpSCs) and angiogenic-modified ADSCs transplantation could promote diabetic wound healing through enhancing angiogenesis and re-epithelization. These findings illustrate that the novel bilayer cell patch has great potential in diabetic wound healing.