Shenqi Fuzheng injection alleviates chemotherapy-induced cachexia by restoring glucocorticoid signaling in hypothalamus.

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Energy preservation for skeletal muscles: Shenqi Fuzheng injection prevents tissue wasting and restores bioenergetic profiles in a mouse model of chemotherapy-induced cachexia.

BACKGROUND: Energy deficiency is the characteristic of chemotherapy-induced cachexia (CIC) which is manifested by muscle wasting. glycolysis, tricarboxylic acid (TCA) cycle, and lipid metabolism are central to muscle bioenergy production, which is vulnerable to chemotherapy during cancer treatment. Recent investigations have spotlighted the potential of Shenqi Fuzheng injection (SQ), a Chinese proprietary medicine comprising Radix Codonopsis and Radix Astragali, in alleviating CIC. However, the specific effects of SQ on muscle energy metabolism remains less explored. PURPOSE AND METHODS: Here, we integrated transcriptomics, spatial metabolomics, gas chromatography-mass spectrometry targeted quantitative analysis, and transmission electron microscopy techniques, combined with Seahorse live-cell metabolic analysis to reveal the changes in genes and pathways related to energy metabolism in the CIC model and SQ's protective effects at molecular and functional levels. RESULTS: Our data showed that chemotherapeutic agents caused glycolysis imbalance, which further leads to metabolic derangements of TCA cycle intermediates. SQ maintained glycolysis balance by facilitating pyruvate fluxing to mitochondria for more efficient bioenergy production, which involved a dual effect on promoting functions of mitochondrial pyruvate dehydrogenase complexes and inhibiting lactate dehydrogenase for lactate production. As a result of the sustained pyruvate level achieved by SQ administration, glycolysis balance was maintained, which further led to the preservation of mitochondrial integrity and function of electron transport chain, thereby, ensuring the normal operation of the TCA cycle and the proper synthesis of adenosine triphosphate (ATP). The above results were further validated using the Seahorse live-cell assay. CONCLUSION: In conclusion, our study highlights SQ as a promising strategy for CIC management, emphasizing its ability to harmonize the homeostasis of the muscle bioenergetic profile. Beyond its therapeutic implications, this study also offers a novel perspective for the development of innovative treatments in the realm of herbal medicine.

Discovery of a pyrrole-pyridinimidazole derivative as novel SIRT6 inhibitor for sensitizing pancreatic cancer to gemcitabine.

Pancreatic cancer is a highly aggressive cancer, and is primarily treated with gemcitabine, with increasing resistance. SIRT6 as a member of sirtuin family plays important roles in lifespan and diverse diseases, such as cancer, diabetes, inflammation and neurodegenerative diseases. Considering the role of SIRT6 in the cytoprotective effect, it might be a potential anticancer drug target, and is associated with resistance to anticancer therapy. However, very few SIRT6 inhibitors have been reported. Here, we reported the discovery of a pyrrole-pyridinimidazole derivative, 8a, as a new non-competitive SIRT6 inhibitor, and studied its roles and mechanisms in the antitumor activity and sensitization of pancreatic cancer to gemcitabine. Firstly, we found a potent SIRT6 inhibitor compound 8a by virtual screening and identified by molecular and cellular SIRT6 activity assays. 8a could effectively inhibit SIRT6 deacetylation activity with IC50 values of 7.46 ± 0.79 µM in FLUOR DE LYS assay, and 8a significantly increased the acetylation levels of H3 in cells. Then, we found that 8a could inhibit the cell proliferation and induce cell apoptosis in pancreatic cancer cells. We further demonstrate that 8a sensitize pancreatic cancer cells to gemcitabine via reversing the activation of PI3K/AKT/mTOR and ERK signaling pathways induced by gemcitabine and blocking the DNA damage repair pathway. Moreover, combination of 8a and gemcitabine induces cooperative antitumor activity in pancreatic cancer xenograft model in vivo. Overall, we demonstrate that 8a, a novel SIRT6 inhibitor, could be a promising potential drug candidate for pancreatic cancer treatment.

A novel shark single-domain antibody targeting OGT as a tool for detection and intracellular localization.

Introduction: O-GlcNAcylation is a type of reversible post-translational modification on Ser/Thr residues of intracellular proteins in eukaryotic cells, which is generated by the sole O-GlcNAc transferase (OGT) and removed by O-GlcNAcase (OGA). Thousands of proteins, that are involved in various physiological and pathological processes, have been found to be O-GlcNAcylated. However, due to the lack of favorable tools, studies of the O-GlcNAcylation and OGT were impeded. Immunoglobulin new antigen receptor (IgNAR) derived from shark is attractive to research tools, diagnosis and therapeutics. The variable domain of IgNARs (VNARs) have several advantages, such as small size, good stability, low-cost manufacture, and peculiar paratope structure. Methods: We obtained shark single domain antibodies targeting OGT by shark immunization, phage display library construction and panning. ELISA and BIACORE were used to assess the affinity of the antibodies to the antigen and three shark single-domain antibodies with high affinity were successfully screened. The three antibodies were assessed for intracellular function by flow cytometry and immunofluorescence co-localization. Results: In this study, three anti-OGT VNARs (2D9, 3F7 and 4G2) were obtained by phage display panning. The affinity values were measured using surface plasmon resonance (SPR) that 2D9, 3F7 and 4G2 bound to OGT with KD values of 35.5 nM, 53.4 nM and 89.7 nM, respectively. Then, the VNARs were biotinylated and used for the detection and localization of OGT by ELISA, flow cytometry and immunofluorescence. 2D9, 3F7 and 4G2 were exhibited the EC50 values of 102.1 nM, 40.75 nM and 120.7 nM respectively. VNAR 3F7 was predicted to bind the amino acid residues of Ser375, Phe377, Cys379 and Tyr 380 on OGT. Discussion: Our results show that shark single-domain antibodies targeting OGT can be used for in vitro detection and intracellular co-localization of OGT, providing a powerful tool for the study of OGT and O-GlcNAcylation.