Oxygen Atom‑Concentrating Short Fibrous Sponge Regulates Cellular Respiration for Wound Healing

Cellular respiration can provide energy for wound healing.However,some of retarded healing processes in local hyperglycemic environment suffer from a decrease in cellular adaptation to oxygen,thus reducing in situ oxidative metabolism.Herein,a three-dimensional(3D)extracellular matrix(ECM)bionic short fibrous sponge was prepared for chronic diabetic wound healing and effectively regulated cellular respiration by enhancing cellular adaptation to oxygen and remolding the local tissue microenvironment.The 3D bionic sponge scaffold exhibited good cell adhesion,biocompatibility,bioactivity,and,most importantly,aggregated oxygen atoms on the graphene oxide(GO)surface.In an in vitro assay,the oxygen atom-concentrating short fibrous sponge activated monocyte chemoattractant protein-1(MCP-1),induced the expression of vascular endothelial growth factor(VEGF),and effectively promoted angiogenesis in a hyperglycemic environment.The sponge was also applied to diabetic wounds in vivo to verify its roles in the promotion of angiogenesis and collagen deposition.These experiments confirmed the synergistic effect of GO with adipose-derived stem cells(ADSCs),which could further promote diabetic wound healing.Therefore,oxygen atom-concentrating short fibrous sponges that regulate cellular respiration provide a new idea for the repair of poorly healing wounds by improving oxidative metabolism and have importantclinical significance.

Gossypol inhibits proliferation of endometrioma cells in culture

Aim： To evaluate the anti-proliferative activity and mitochondrial toxicity of gossypol in endometrioma cells maintained in short-term cultures. Methods： （A） Three endometrioma cell lines from patients were treated with 25 or 50 nmol/L gossypol for up to 12 days. The effect of gossypol on the cell growth was recorded. （B） A phosphorescence oxygen analyzer was used to determine the effects of gossypol on mitochondrial oxygen consumption of six endometrioma cell lines from patients. （C） Cellular gossypol accumulations in three endometrioma cell lines from patients were measured by high-pressure liquid chromatography. Results： Proliferation of the endometrioma cells was inhibited by 25 and 50 nmol/L gossypol. Respiration of the endometrioma cells was inhibited by 10 μmol/L gossypol. Cellular gossypol was detected in the endometrioma cell lines that were treated for 24 h with l0 and 0.3 μmol/L gossypol. Conclusion： Gossypol invokes a potent toxicity on cultured endometrioma cells.

Amazing structure of respirasome： unveiling the secrets of cell respiration

Respirasome, a huge molecular machine that carries out cellular respiration, has gained growing attention since its discovery, because respiration is the most indis- pensable biological process in almost all living crea- tures. The concept of respirasome has renewed our understanding of the respiratory chain organization, and most recently, the structure of respirasome solved by Yang＇s group from Tsinghua University （Gu et al. Nature 237（7622）：639-643, 2016） firstly presented the detailed interactions within this huge molecular machine, and provided important information for drug design and screening. However, the study of cellular respiration went through a long history. Here, we briefly showed the detoured history of respiratory chain investigation, and then described the amazing structure of respirasome.

Research journey of respirasome

Respirasome,as a vital part of the oxidative phosphorylation system,undertakes the task of transferring electrons from the electron donors to oxygen and produces a proton concentration gradient across the inner mitochondrial membrane through the coupled translocation of protons.Copious research has been carried out on this lynchpin of respiration.From the discovery of individual respiratory complexes to the report of the high-resolution structure of mammalian respiratory supercomplex I1III2IV1,scientists have gradually uncovered the mysterious veil of the electron transport chain(ETC).With the discovery of the mammalian respiratory mega complex I2III2IV2,a new perspective emerges in the research field of the ETC.Behind these advances glitters the light of the revolution in both theory and technology.Here,we give a short review about how scientists‘see’the structure and the mechanism of respirasome from the macroscopic scale to the atomic scale during the past decades.