Metformin & AMPK Link Nobel Prize-winning Telomeres & Jumping Genes with Learning, HIV, & the Creation of Human Life

Nobel Prize winners, from left to right: Elizabeth Blackburn (discovered telomerase), Barbara McClintock (discovered “jumping genes”), and Françoise Barré-Sinoussi (discovered HIV). By Science History Institute, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=30112731; By Smithsonian Institution/Science Service; Restored by Adam Cuerden - Flickr: Barbara McClintock (1902-1992), Public Domain, https://commons.wikimedia.org/w/index.php?curid=25629182; By Prolineserver (talk) - Own work, GFDL 1.2, https://commons.wikimedia.org/w/index.php?curid=5395403

A recently published study in the journal Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease in 2018 demonstrated for the first time that chronic treatment with the anti-diabetic drug metformin activated human telomerase in human aortic endothelial cells (HAECs) and significantly delayed endothelial senescence in an AMPK-dependent manner [11]. Telomeres are specialized regions of repetitive nucleotide sequences located at the ends of eukaryotic chromosomes that protect chromosomal ends from deterioration [63]. However, continuous cell division leads to telomere shortening, impeding the replenishment of tissues and triggering cellular senescence (i.e. cells cease to divide). Although human telomeres shorten with age, telomeres may be lengthened by the enzyme telomerase [64].

This study substantiates and confirms several novel proposals in a recently published paper I authored in April of 2018 in which I first proposed that because telomerase is derived from a “jumping gene” (see below for discussion), metformin would activate telomerase via AMPK [6]. My paper also highlights a novel link between hippocampal long-term potentiation (essential for learning and memory), alleviation of accelerated cellular aging in Hutchinson-Gilford progeria syndrome, oocyte activation and the sperm acrosome reaction (prerequisites for human life creation), and transposable element (i.e. “jumping genes”)-mediated promotion of learning, memory, and the creation of human life [1-7]. Indeed, these novel proposals also link several Nobel Prize-winning discoveries, including the discovery of telomerase by Elizabeth Blackburn (photo-left), the discovery of “jumping genes” by Barbara McClintock (photo-middle), and the discovery of HIV by Françoise Barré-Sinoussi (photo-right).
 
The link between such disparate physiological and pathophysiological phenomena is cellular stress-induced modulation of energy metabolism, leading to the activation of the master metabolic regulator AMPK, a kinase that increases lifespan and healthspan in several model organisms [12]. I was the first to propose and publish (2014) that an increase in beneficial levels of cellular stress (e.g. increases in the levels reactive oxygen species [ROS], calcium [Ca2+], and/or an AMP(ADP)/ATP ratio increase, etc.) and activation of AMPK by compounds including metformin would alleviate accelerated cellular aging defects in children diagnosed with the genetic disorder Hutchinson-Gilford progeria syndrome (HGPS), a disease characterized by an accelerated aging phenotype and death at ~14.6 years of age [1]. This hypothesis was substantiated in 2016 and 2017, with metformin activating AMPK in cells taken from HGPS kids and ameliorating accelerated cellular aging defects (e.g. correcting nuclear morphology, decrease in senescence markers, etc.) [8,9]. Additionally, transfection of telomerase been shown to reverse senescence in HGPS cells [65]. As metformin activates telomerase and normal humans make the same toxic protein (called progerin) that leads to accelerated aging in HGPS kids (just at lower amounts that accumulate with age), AMPK activation may also play a significant role in ameliorating diseases associated with physiological aging [10,11].

AMPK also links HGPS with potential virus eradication. I first proposed in 2015 that AMPK activation links alleviation of accelerated aging in HGPS with the potential eradication of HIV-1 via the “shock and kill” approach, a method currently being pursued by HIV cure researchers to possibly eradicate HIV-1 [2,13]. The same gene splicing factor that promotes accelerated aging in HGPS (called SRSF1 or ASF/SF2) also inhibits reactivation of latent HIV-1 (i.e. “shock”), preventing immune system detection and virus destruction (i.e. “kill”) [8,14]. Metformin was shown to slow aging in HGPS cells by decreasing this splicing factor, as I originally predicted in 2014, and several compounds that potently induce latent HIV-1 reactivation in T cells from infected patients, including PMA (a phorbol ester) combined with ionomycin, each activate AMPK [1,8,15-17]. AMPKα1 deletion leads to a decrease in primary T cell responses to bacterial and viral infections in vivo, AMPK knockdown leads to cell death on T cell activation, and metformin has recently been shown to inhibit Zika and Dengue viruses, the malaria parasite, and Legionella pneumophila [18-23]. Intriguingly, early data presented at the International AIDS Conference in 2017 demonstrated that metformin destabilized the latent HIV-1 reservoir in chronically-infected HIV patients and decreased the percentage of CD4+ T cells expressing the immune checkpoint receptors PD-1, TIGIT, and TIM-3, each markers associated with T cells latently infected with HIV-1, indicating that AMPK activation may indeed contribute to a cure for HIV-1 [24,25].

As I first proposed in 2016 and 2017, the induction of cellular stress and AMPK activation also links HGPS and potential HIV-1 eradication with oocyte activation and the sperm acrosome reaction, prerequisites for the creation of human life [3,4]. Increases in both ROS and Ca2+ are critical for T cell activation (and hence latent HIV-1 reactivation) and ROS is transiently increased in HGPS cells when treated with a rapamycin analog to alleviate accelerated aging [26-28]. Stress-induced activation of AMPK by AICAR and other compounds promotes oocyte maturation, which precedes and is essential for efficient oocyte activation [29,30]. Oocyte activation is indispensable for the creation of all human life and PMA and ionomycin, which collectively reactivates latent HIV-1, activates mouse and human oocytes, respectively [31,32]. AMPK is also found in the acrosome of the human sperm head and ionomycin induces the acrosome reaction in human sperm, a process necessary for oocyte penetration and fertilization [33,34]. Ionomycin is also used extensively during fertility procedures to activate human oocytes (i.e. “shock”), creating normal, healthy children (i.e. “live”) [32]. Interestingly, ionomycin is a narrow spectrum antibiotic produced by certain species within the bacterial genus Streptomyces, from which ~70 percent of clinically useful antibiotics are derived [35,36]. Cellular stress, mediated by increases in ROS, Ca2+, and/or an AMP(ADP)/ATP ratio increase, etc. also enhances antibiotic production in many Streptomyces strains, reinforcing the notion that the beneficial effects of cellular stress induction crosses species boundaries [37,38].

Cellular stress induction and AMPK activation also link HGPS, potential HIV-1 eradication, and human life creation with learning and memory, a hypothesis I originally proposed in 2018 [6]. Hippocampal long-term potentiation (LTP) is considered the cellular correlate of learning and memory and AMPK has been found localized in hippocampal CA1 dendrites and is activated in neurons by metformin, AICAR, ionomycin, and glutamate, a neurotransmitter essential for hippocampal LTP induction [39-41]. The glutamate receptors AMPAR and NMDAR are found on and modulate T cell activation, AMPK activation increases synthesis and membrane insertion of AMPARs (critical for LTP expression), PMA enhances hippocampal CA1 LTP, and inhibition of ROS significantly impairs hippocampal CA1 LTP [42-46]. Also, neuronal depolarization decreases the recruitment efficiency of SRSF1 to nascent RNAs and promotes SRSF1 nuclear speckle accumulation [6]. SRSF1, a gene splicing factor that is inhibited by metformin, enhances progerin production in HGPS cells and prevents latent HIV-1 reactivation [2,8]. Metformin also significantly reduces pathology-associated reductions in LTP in animal models in vivo, indicating that learning and memory are linked to HGPS, potential HIV-1 eradication, and human life creation via the induction of beneficial levels of cellular stress [47].

Lastly, cellular stress and AMPK activation also links the activation and mobilization of transposable elements (i.e. “jumping genes”) with telomerase activation, potential HIV-1 eradication, learning and memory, and the creation of human life, a hypothesis I originally proposed in 2018 [6]. Transposable elements (TEs) are DNA sequences first described by Nobel laureate Barbara McClintock that comprise nearly half of the human genome, are able to transpose or move from one genomic location to another, and have played an extensive role in human genome evolution [48-50]. Strikingly, McClintock also described in her Nobel Prize speech that a genome “shock” seemed to promote TE activation and mobilization [50]. As first noted in my recently published paper, this “shock” is the same “shock” that HIV cure researchers are using during the “shock and kill” approach to reactivate latent HIV-1 to potentially effectuate a cure [6]. Indeed, several forms of cellular stress, including heat shock and radiation, have been convincingly shown to activate and enhance TE mobilization in several model organisms and in human cells [51-53]. This same “shock” McClintock referred to, mediated by increases in ROS, Ca2+, and/or an AMP(ADP)/ATP ratio, etc. is also what leads to the creation of human life, as the antibiotic ionomycin activates AMPK, promotes TE activation, and induces human oocyte activation [17,32,54]. LINE-1 (L1), a member of the retrotransposon class of TEs, is active and capable of mobilization in human oocytes, human sperm, and in human neural progenitor cells [55-57]. Inhibition of L1 impairs both oocyte maturation in vitro and long-term memory formation in vivo in mice [58,59]. L1 has also been detected in the human brain and is capable of mobilization in human neurons [57]. As noted above, AMPK is critical for oocyte maturation and metformin promotes hippocampal neurogenesis and spatial memory formation [29,60]. The landmark initial sequencing of the human genome also noted that both telomerase and RAG1 (promotes DNA cleavage and transposition in human cells) are derived from TEs [49]. Because metformin activates both telomerase and RAG1 via AMPK, it is likely that cellular stress-induced AMPK activation facilitates beneficial TE activation and mobilization (i.e. learning and memory associated with L1 mobilization), linking human genome evolution and the creation of human life with hippocampal LTP, HGPS, and potential HIV-1 eradication [61,62].

https://www.linkedin.com/pulse/metformin-ampk-link-nobel-prize-winning-telomeres-jumping-finley/

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