bims-amsmem 2023-07-09 papers

Issue of 2023–07–09
four papers selected by
Dipsikha Biswas, Københavns Universitet

bioRxiv. 2023 Jun 13. pii: 2023.06.12.544686. [Epub ahead of print]

AMPK Drives Both Glycolytic and Oxidative Metabolism in T Cells During Graft-versus-host Disease.

Archana Ramgopal, Erica L Braverman, Lee-Kai Sun, Darlene Monlish, Christopher Wittmann, Manda J Ramsey, Richard Caitley, William Hawse, Craig A Byersdorfer.

Allogeneic T cells reprogram their metabolism during acute graft-versus-host disease (GVHD) in a process reliant on the cellular energy sensor AMP-activated protein kinase (AMPK). Deletion of AMPK in donor T cells limits GVHD but still preserves homeostatic reconstitution and graft-versus-leukemia (GVL) effects. In the current studies, murine T cells lacking AMPK decreased oxidative metabolism at early timepoints post-transplant and were also unable to mediate a compensatory increase in glycolysis following inhibition of the electron transport chain. Human T cells lacking AMPK gave similar results, with glycolytic compensation impaired both in vitro and following expansion in vivo in a modified model of GVHD. Immunoprecipitation of proteins from day 7 allogeneic T cells, using an antibody specific to phosphorylated AMPK targets, recovered lower levels of multiple glycolysis-related proteins including the glycolytic enzymes aldolase, enolase, pyruvate kinase M (PKM), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Functionally, murine T cells lacking AMPK exhibited impaired aldolase activity following anti-CD3/CD28 stimulation and a decrease in GAPDH activity on day 7 post-transplant. Importantly, these changes in glycolysis correlated with an impaired ability of AMPK KO T cells to produce significant amounts of interferon gamma (IFNγ) upon antigenic re-stimulation. Together these data highlight a significant role for AMPK in controlling oxidative and glycolytic metabolism in both murine and human T cells during GVHD and endorse further study of AMPK inhibition as a potential target for future clinical therapies.
KEY POINTS: AMPK plays a key role in driving both and oxidative and glycolytic metabolism in T cells during graft-versus-host disease (GVHD)Absence of AMPK simultaneously impairs both glycolytic enzyme activity, most notably by aldolase, and interferon gamma (IFNγ) production.

DOI: https://doi.org/10.1101/2023.06.12.544686

Exp Cell Res. 2023 Jul 01. pii: S0014-4827(23)00239-2. [Epub ahead of print] 113691

Lower dose of metformin combined with artesunate induced autophagy-dependent apoptosis of glioblastoma by activating ROS-AMPK-mTOR axis.

Wencong Ding, Lingxiao Liao, Jia Liu, Jiaxing Zhao, Qiongyan Tang, Yongshi Liao.

Glioblastoma multiform (GBM), one of the most common, aggressive primary brain tumours, demonstrates resistance to radiotherapy and chemotherapy after surgical resection and treatment failure. Metformin (MET) has been shown to suppress the proliferative capacity and invasion ability of GBM cells by activating AMPK and inhibiting mTOR, but the effective dose exceeded the maximum tolerated dose. Artesunate (ART) can exert certain anti-tumour effects by activating the AMPK-mTOR axis and inducing autophagy in tumour cells. Therefore, this study investigated the effects of MET combined with ART combination therapy on autophagy and apoptosis in GBM cells. MET combined with ART treatment effectively suppressed the viability, mono-cloning ability, migration and invasion capacities, as well as metastatic ability of GBM cells. The underlying mechanism involved modulation of the ROS-AMPK-mTOR axis, which was confirmed using 3-methyladenine and rapamycin to inhibit or promote the effects of MET combined with ART, respectively. The study findings suggest that MET used in combination with ART can induce autophagy-dependent apoptosis in GBM cells by activating the ROS-AMPK-mTOR pathway, providing a potential new treatment for GBM.

Keywords: Artesunate; Autophagy; Autophagy-dependent apoptosis; Glioblastoma; Metformin

DOI: https://doi.org/10.1016/j.yexcr.2023.113691

Mol Ther. 2023 Jul 04. pii: S1525-0016(23)00380-5. [Epub ahead of print]

Development of a peptide drug restoring AMPK and adipose tissue functionality in cancer cachexia.

Honglei Ji, Felix Englmaier, Pauline Morigny, Maude Giroud, Pamina Gräsle, Sebastian Brings, Julia Szendrödi, Mauricio Berriel Diaz, Oliver Plettenburg, Stephan Herzig, Maria Rohm.

Cancer cachexia is a severe systemic wasting disease that negatively affects quality of life and survival in patients with cancer. To date, treating cancer cachexia is still a major unmet clinical need. We recently discovered the destabilization of the AMPK complex in adipose tissue as a key event in cachexia-related adipose tissue dysfunction and developed an AAV-based approach to prevent AMPK degradation and prolong cachexia-free survival. Here, we show the development and optimization of a prototypic peptide, Pen-X-ACIP, where the AMPK stabilizing peptide ACIP is fused to the cell-penetrating peptide moiety penetratin via a propargylic glycine linker to enable late-stage functionalization using click chemistry. Pen-X-ACIP was efficiently taken up by adipocytes, inhibited lipolysis and restored AMPK signaling. Tissue uptake assays showed a favorable uptake profile into adipose tissue upon intraperitoneal injection. Systemic delivery of Pen-X-ACIP into tumor-bearing animals prevented the progression of cancer cachexia without affecting tumor growth, and preserved body weight and adipose tissue mass with no discernable side effects in other peripheral organs, thereby achieving proof-of-concept. As Pen-X-ACIP also exerted its anti-lipolytic activity in human adipocytes, it now provides a promising platform for further (pre)clinical development towards a novel, first-in-class approach against cancer cachexia.

DOI: https://doi.org/10.1016/j.ymthe.2023.06.020

Transl Res. 2023 Jul 05. pii: S1931-5244(23)00108-1. [Epub ahead of print]

Depleted Hexokinase1 and lack of AMPKα activation favor OXPHOS-dependent energetics in Retinoblastoma tumors.

Vishnu Suresh Babu, Ashwin Mallipatna, Gagan Dudeja, Rohit Shetty, Archana Padmanabhan Nair, Sai Bo Bo Tun, Candice Ee Hua Ho, Shyam S Chaurasia, Shomi S Bhattacharya, Navin Kumar Verma, Rajamani Lakshminarayanan, Nilanjan Guha, Stephane Heymans, Veluchamy Amutha Barathi, Arkasubhra Ghosh.

Lack of retinoblastoma protein (Rb) causes aggressive intraocular retinal tumors in children. Recently, Rb tumors have been shown to have a distinctly altered metabolic phenotype, such as reduced expression of glycolytic pathway proteins alongside altered pyruvate and fatty acid levels. In this study, we demonstrate that loss of Hexokinase 1(HK1) in tumor cells rewires their metabolism allowing enhanced oxidative phosphorylation-dependent energy production. We show that rescuing HK1 or RB1 in these retinoblastoma cells reduced cancer hallmarks such as proliferation, invasion, spheroid formation and increased their sensitivity to chemotherapy drugs. Induction of HK1 was accompanied by a metabolic shift of the cells to glycolysis and a reduction in mitochondrial mass. Cytoplasmic HK1 bound Liver Kinase B1 (LKB1) and phosphorylated AMP-activated kinase-α (AMPKα Thr172), thereby reducing mitochondria-dependent energy production. We validated these findings in tumor samples from Rb patients compared to age-matched healthy retinae. HK1 or RB1 expression in Rb-/- cells led to a reduction in their respiratory capacity and glycolytic proton flux. HK1 overexpression reduced tumor burden in an intraocular tumor xenograft model. AMPKα activation by AICAR also enhanced the tumoricidal effects of the chemotherapeutic drug topotecan in vivo. Therefore, enhancing HK1 or AMPKα activity can reprogram cancer metabolism and sensitize retinoblastoma tumors to lower doses of existing treatments, a potential therapeutic modality for retinoblastoma.

Keywords: AMPKα; Hexokinase-1; Retinoblastoma; cancer; glycolysis; oxidative phosphorylation

DOI: https://doi.org/10.1016/j.trsl.2023.07.001