Fructose 1,6-Bisphosphate as a Protective Agent for Experimental Fat Grafting

Regulation of Glucose Metabolism for Cell Energy Supply In Situ via High-Energy Intermediate Fructose Hydrogels

The cellular functions, such as tissue-rebuilding ability, can be directly affected by the metabolism of cells. Moreover, the glucose metabolism is one of the most important processes of the metabolism. However, glucose cannot be efficiently converted into energy in cells under ischemia hypoxia conditions. In this study, a high-energy intermediate fructose hydrogel (HIFH) is developed by the dynamic coordination between sulfhydryl-functionalized bovine serum albumin (BSA-SH), the high-energy intermediate in glucose metabolism (fructose-1,6-bisphosphate, FBP), and copper ion (Cu2+). This hydrogel system is injectable, self-healing, and biocompatible, which can intracellularly convert energy with high efficacy by regulating the glucose metabolism in situ. Additionally, the HIFH can greatly boost cell antioxidant capacity and increase adenosine triphosphate (ATP) in the ischemia anoxic milieu by roughly 1.3 times, improving cell survival, proliferation and physiological functions in vitro. Furthermore, the ischemic skin tissue model is established in rats. The HIFH can speed up the healing of damaged tissue by promoting angiogenesis, lowering reactive oxygen species (ROS), and eventually expanding the healing area of the damaged tissue by roughly 1.4 times in vivo. Therefore, the HIFH can provide an impressive perspective on efficient in situ cell energy supply of damaged tissue.

Effect of Hyperbaric Oxygen Therapy on the Survival Rate of Autologous Fat Transplantation

OBJECTIVE

To investigate whether hyperbaric oxygen therapy can improve the survival rate of fat transplantation and analyze the possible mechanisms.

METHODS

Ninety SD rats were randomly divided into 3 groups. All the rats were cut into pieces with about 5 mL of fat from the abdominal cavity, rinsed with normal saline for 3 times, and cleaned with cotton pad adsorption method. Then, 3 ml was removed, divided into 3 parts, and injected into three adjacent but not touching parts of the back. Group A received 1h/d hyperbaric oxygen therapy, group B received 2 h/d hyperbaric oxygen therapy, and group C received no hyperbaric oxygen therapy. The hyperbaric oxygen therapy lasted for 10 consecutive days. Fat grafts from one site were randomly removed at 2, 4, and 6 weeks after surgery, respectively. ① the survival rate of fat transplantation in three groups was compared. ② observe the pathological section; ③ immunohistochemistry was used to detect and compare the expression of vascular endothelial growth factor.

RESULTS

The survival rate of fat transplantation in group A was the highest. After subcutaneous transplantation of 1 ml of fat and 1 hour/day of continuous hyperbaric oxygen treatment for 10 days, the fat survival rates were 0.796 ± 0.071 ml, 0.644 ± 0.151 ml, and 0.473 ± 0.127 ml at the second, fourth, and sixth weeks, respectively. The survival rate of fat transplantation in group B was the second. After subcutaneous transplantation of 1 ml of fat and 2 hour/day of continuous hyperbaric oxygen treatment for 10 days, the survival rate of fat was 0.624 ± 0.220 ml, 0.494 ± 0.125 ml, and 0.329 ± 0.153 ml at the second, fourth, and sixth weeks, respectively. The survival rate of fat transplantation in group C was the lowest. After subcutaneous transplantation of 1 ml of fat and no hyperbaric oxygen treatment for 10 days, the fat survival rates were 0.461 ± 0.132 ml, 0.290 ± 0.112 ml and 0.169 ± 0.091 ml at the second, fourth, and sixth weeks, respectively. We have made changes in the abstract of the article and marked in red color.

CONCLUSION

Hyperbaric oxygen therapy is conducive to the survival of transplanted fat. Importantly, a short period of hyperbaric oxygen therapy (1 h/d) can promote the survival of transplanted fat.

NO LEVEL ASSIGNED

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The metabolic characteristic of decidual immune cells and their unique properties in pregnancy loss

Maternal tolerance to semi- or fully allograft conceptus is a prerequisite for the maintenance of pregnancy. Once this homeostasis is disrupted, it may result in pregnancy loss. As a potential approach to prevent pregnancy loss, targeting decidual immune cells (DICs) at the maternal-fetal interface has been suggested. Although the phenotypic features and functions of DIC have been extensively profiled, the regulatory pathways for this unique immunological adaption have yet to be elucidated. In recent years, a pivotal mechanism has been highlighted in the area of immunometabolism, by which the changes in intracellular metabolic pathways in DIC and interaction with the adjacent metabolites in the microenvironment can alter their phenotypes and function. More inspiringly, the manipulation of metabolic profiling in DIC provides a novel avenue for the prevention and treatment of pregnancy loss. Herein, this review highlights the major metabolic programs (specifically, glycolysis, ATP-adenosine metabolism, lysophosphatidic acid metabolism, and amino acid metabolism) in multiple immune cells (including decidual NK cells, macrophages, and T cells) and their integrations with the metabolic microenvironment in normal pregnancy. Importantly, this perspective may help to provide a potential therapeutic strategy for reducing pregnancy loss via targeting this interplay.

LRG-1 promotes fat graft survival through the RAB31-mediated inhibition of hypoxia-induced apoptosis

Autologous adipose tissue is an ideal soft tissue filling material, and its biocompatibility is better than that of artificial tissue substitutes, foreign bodies and heterogeneous materials. Although autologous fat transplantation has many advantages, the low retention rate of adipose tissue limits its clinical application. Here, we identified a secretory glycoprotein, leucine‐rich‐alpha‐2‐glycoprotein 1 (LRG‐1), that could promote fat graft survival through RAB31‐mediated inhibition of hypoxia‐induced apoptosis. We showed that LRG‐1 injection significantly increased the maintenance of fat volume and weight compared with the control. In addition, higher fat integrity, more viable adipocytes and fewer apoptotic cells were observed in the LRG‐1‐treated groups. Furthermore, we discovered that LRG‐1 could reduce the ADSC apoptosis induced by hypoxic conditions. The mechanism underlying the LRG‐1‐mediated suppression of the ADSC apoptosis induced by hypoxia was mediated by the upregulation of RAB31 expression. Using LRG‐1 for fat grafts may prove to be clinically successful for increasing the retention rate of transplanted fat.

Long-Term Effects of Platelet-Rich Fibrin on Fat Graft Survival and Their Optimal Mixing Ratio

BACKGROUND

Platelet-rich fibrin (PRF) can promote fat graft survival, but the reported mixing ratio of PRF to fat ranges from 1:25 to 1:2, lacking a clear standard for clinical application.

OBJECTIVES

The authors sought to explore the long-term effects of PRF on grafted fat and their optimal mixing ratio.

METHODS

Nude mice were randomly divided into a control group (receiving subcutaneous injection of fat granules) and 4 PRF groups (receiving subcutaneous injection of PRF and fat granules at volume ratios of 1:5, 1:10, 1:15, and 1:20, respectively). The graft samples (n = 12) were obtained in weeks 4, 8, and 12 to (1) calculate retention rates; (2) evaluate gene and protein expression of vascular endothelial growth factor A (VEGF-A), peroxisome proliferator-activated receptor-γ (PPAR-γ), type I collagen A1 (COL1-A1), and B-cell lymphoma-2 associated X protein (BAX); (3) perform hematoxylin and eosin, Masson's trichrome, α-smooth muscle action, and periplipin-1 stainings; and (4) count the microvessels and viable adipocytes.

RESULTS

Compared with the control group, PRF groups had higher retention rates, a higher gene/protein expression of VEGF-A, a lower gene/protein expression of COL1-A1 and BAX, less fibrosis, and more microvessels and viable adipocytes. Group 1:10 was superior to other groups in terms of retention rates and other evaluation indexes. The expression of PPAR-γ did not significantly differ among groups.

CONCLUSIONS

PRF may not play a long-term effect on adipogenesis, but it can still promote fat graft survival through facilitating vascularization, regulating collagen production, and inhibiting apoptosis. PRF can achieve the best promoting effect when the mixing ratio of PRF to fat is 1:10, which is recommended as the optimal ratio for clinical application.