Fat deposition and lipid metabolism are closely related to the morphology, structure and function of mitochondria. The morphology of mitochondria between fusion and fission processes is mainly regulated by protein posttranslational modification. Intermittent fasting (IF) promotes high expression of Sirtuin 3 (Sirt3) and induces mitochondrial fusion in high-fat diet (HFD)-fed mice. However, the mechanism by which Sirt3 participates in mitochondrial protein acetylation during IF to regulate mitochondrial fusion and fission dynamics remains unclear. This article demonstrates that IF promotes mitochondrial fusion and improves mitochondrial function in HFD mouse inguinal white adipose tissue. Proteomic sequencing revealed that IF increased protein deacetylation levels in HFD mice and significantly increased Sirt3 mRNA and protein expression. After transfecting with Sirt3 overexpression or interference vectors into adipocytes, we found that Sirt3 promoted adipocyte mitochondrial fusion and improved mitochondrial function. Furthermore, Sirt3 regulates the JNK-FIS1 pathway by deacetylating malate dehydrogenase 2 (MDH2) to promote mitochondrial fusion. In summary, our study indicates that IF promotes mitochondrial fusion and improves mitochondrial function by upregulating the high expression of Sirt3 in HFD mice, promoting deacetylation of MDH2 and inhibiting the JNK-FIS1 pathway. This research provides theoretical support for studies related to energy limitation and animal lipid metabolism.

A Debye–Scherrer film that had been stored for several years in an office environment file cabinet was observed to be shriveled and distorted in appearance. An investigation using X-ray diffraction was carried out to determine the cause of the physical change in the film strip. As expected, silver phases were detected, due to the photographic capture layer coated on the surface of all traditional X-ray films. An unexpected result was the presence of cellulose II, an indication that a chemical change had occurred in the original cellulose triacetate (CTA) polymer film base. Laboratory experiments used to demonstrate an accelerated method of deacetylation of CTA were carried out, resulting in phase pure cellulose II. A density functional geometry optimization allowed for the generation of an improved structural model for cellulose II. Calculated and experimental powder patterns for cellulose II have been submitted to the International Centre for Diffraction Data for inclusion in future releases of the Powder Diffraction File.