Cells Free Full-Text AICAr, a Widely Used AMPK Activator with Important AMPK-Independent Effects: A Systematic Review
Cells Free Full-Text AICAr, a Widely Used AMPK Activator with Important AMPK-Independent Effects: A Systematic Review
Collectively, these results suggest that AMPK regulates SIRT1 activity by modulating the quantity of the NAMPT protein, followed by PGC-1α deacetylation and transcriptional activation. Even though previous studies support AICAR’s treatment in leukaemia, hepatocarcinoma, and prostate cancer, our cell-based screening of cytotoxicity of AICAR was limited to its relatively smaller scale in lung cancer. Our data calls for high-throughput screening of various cancer cell lines in combination treatment with AICAR, JAK, or EGFR inhibitors.
۱. Animals
After normalisation, protein samples were separated via sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis and transferred onto Immobilon-FL polyvinylidene fluoride membranes. The membranes were blocked with BSA for 1 h and then incubated overnight with primary antibodies https://enjoyspa.fr/the-effects-of-steroids-on-the-longevity-and-2/ in a cold room. Then the membranes were incubated with either goat anti-rabbit IgG conjugated with HRP (Invitrogen) or goat anti-mouse IgG conjugated with HRP (Invitrogen) for 1 h at room temperature. Followed by incubation in ECL Western Blotting Substrate (Pierce) for 5 min and visualised on ChemiDoc Imaging System (BioRad). All incubations were performed under continuous gassing with 95% O2/5% CO2 at 30°C in a shaking water bath.
LPS induces an early and potent transcriptional response, which is largely dependent on the activity of NFκB and interferon response factor 3 (IRF3) transcription factors as well as the mitogen-activated protein kinase (MAPK) signalling cascade25. AICAR also lowered transcriptional activation of an anti-inflammatory cytokine IL-10 by LPS (Fig.1C). Blocking the LPS transcriptional response in the presence of AICAR strongly inhibited secretion of IL-6 and IL-10 into the culture medium of LPS-treated macrophages (Fig. 1D). Interestingly, TNFα secretion was only partly reduced by AICAR, which can be explained by the LPS-stimulated release of already pre-formed TNFα (Fig. 1D)27. In this study, we demonstrated that chronic AICAR treatment significantly decreased the mass of abdominal fat pads with concomitant increases in the expression of metabolic regulator proteins and mitochondrial components. Although the reasons for such reductions currently remain unclear, it is possible that increases in fatty acid oxidation and oxidative capacity in skeletal muscle induced by AICAR enhanced whole-body energy expenditure.
- To further determine the roles of AICAR in PALI, we next investigated whether replenishment of AICAR can rescue the damaged antioxidant system in sodium taurocholate-induced SAP rats.
- To further visualise the subcellular localisation of MUC1-CT, we performed immunofluorescence staining for MUC1-CT in H441 cells.
- It is worth noting that the AMPK-dependent effect on T cell survival is not prominent when T cells are activated with anti-CD3/CD28 signals, which may be attributed to the weak activation of AMPK under the anti-CD3 stimulation (Figure (Figure1B1B).
- We also believe that these effects would be more prominent in type II(B) fibers than in type I fibers.
- We next determined whether AICAR or Compound C affects T cell function by measurement of cytokine production in activated T cells.
The distance traveled in the center by the animals treated with HFD (except animals from group 4 (HFD + AC 1)) significantly decreased (2 ± ۱ m in group 3, 2 ± ۱ m in group 5 and 2 ± ۲ m in group 6 versus 5 ± ۱ m in group 2). The decrease in the distance traveled in the center by the animals treated with HFD indirectly indicates a higher level of anxiety compared to the animals kept on an STD. The absence of a difference in the distance traveled in the center from the animals treated with STD in the animals treated with HFD + AC 1 indirectly indicates some protective function of AICAR in relation to HFD-depending anxiety. Surface and intracellular staining were performed as what we previously described [38, 39]. The following antibodies were used for surface staining, which included anti-CD4 (clone RM4-5), anti-CD8 (clone 53-6.7), anti-CD69 (clone H1.2F3), anti-CD25 (clone PC61), anti-CD71 (clone RI7217).
Histopathological Analysis
So, in all the animals treated with HFD, as well as in the animals treated with AICAR on the background of a standard diet, glucose tolerance was observed. The animals treated with AICAR from week 7 alone (group 5) or in combination with Methotrexate (group 6) did not improve the glucose tolerance. Some improvement in glucose tolerance can be seen in the case of AICAR against the background of HFD from the first day of the study (group 4) (Table 6). AICAr-induced apoptosis and concurrent activation of AMPK were described in childhood acute lymphoblastic leukemia (ALL) cell lines [110], as well as in B cells isolated from patients with mantle cell lymphoma and splenic marginal zone lymphoma [7].
New insights into activation and function of the AMPK
Whereas induction of STAT3-dependent SOCS3 mRNA by IL-6 or IL-10 was inhibited by AICAR in the presence of ABT-702 (Fig. 4A), IL-4-induced expression of the typical STAT6-dependent target gene CCL18 was unaltered (Fig. 4B). Similarly, HIF-dependent SLC2A1 mRNA expression was not affected by AICAR either in the absence, or in the presence of ABT-702 (Fig. 4C). Obviously, AICAR does not generally inhibit transcriptional activation, rather acting in a stimulus- and transcription factor-specific manner.
Researchers and clinicians are increasingly turning to this peptide to help prevent or battle the effects of diabetes, auto-immune disorders, and other inflammatory conditions. Through its mechanism of activating AMP kinase, AICAR has been shown to reduce inflammation, aid in fat burning, and boost energy and endurance in a variety of research contexts. Furthermore, current management of hematological malignancies is extremely complex, well-developed, highly regulated, and specialized to the particular clinical situation. New treatments, including potential adjuvant treatments, thus have a long, uphill path to travel before they could be worked into current clinical protocol. Following decades of research into AMPK, the scientific community began to take interest in AICAR as “exercise in a pill.” Animal studies showed that AICAR treatment could enhance running endurance without subjecting the test subjects to any additional exercise [3].
In group 4, treated with HFD + AC 1, on the 35th day of the study (week 5), food intake was significantly higher compared to animals from group 3 (HFD + vehicle). In group 5 (HFD + AC 7), food intake was higher compared to group 3 (HFD + vehicle) on the 49th day (seventh week) (Table 4). Additionally, intragroup differences were observed in all the groups relative to the 7th and 21st days of the study, except for group 4 (HFD + AC 1) (Table 2).
Herein, using T cells from AMPK conditional knockout mice and their wild type littermates, we demonstrate that AICAR and Compound C can, indeed, activate or inhibit AMPK activity in T cells, respectively. Specifically, AICAR inhibits, but Compound C promotes, Ca2+-induced T cell death in an AMPK-dependent manner. In contrast, our data also demonstrate that AICAR and Compound C inhibit T cell activation and cytokine production in an AMPK-independent manner. Moreover, we find that the AMPK-independent activity of AICAR and Compound Cis mediated via the mTOR signaling pathway in activated T cells. Our results not only reveal the critical role of AMPK in regulating T cell survival and function, but also demonstrate AMPK-dependent and independent rolesof AICAR/Compound C in regulating T cell responses, thus suggesting a context-dependent effect of these “AMPK regulators”.