Identification of a novel de novo mutation associated with PRKAG2 cardiac syndrome and early onset of heart failure

Current RNA strategies in treating cardiovascular diseases

Cardiovascular disease (CVD) continues to impose a significant global health burden, necessitating the exploration of innovative treatment strategies. Ribonucleic acid (RNA)-based therapeutics have emerged as a promising avenue to address the complex molecular mechanisms underlying CVD pathogenesis. We present a comprehensive review of the current state of RNA therapeutics in the context of CVD, focusing on the diverse modalities that bring about transient or permanent modifications by targeting the different stages of the molecular biology central dogma. Considering the immense potential of RNA therapeutics, we have identified common gene targets that could serve as potential interventions for prevalent Mendelian CVD caused by single gene mutations, as well as acquired CVDs developed over time due to various factors. These gene targets offer opportunities to develop RNA-based treatments tailored to specific genetic and molecular pathways, presenting a novel and precise approach to address the complex pathogenesis of both types of cardiovascular conditions. Additionally, we discuss the challenges and opportunities associated with delivery strategies to achieve targeted delivery of RNA therapeutics to the cardiovascular system. This review highlights the immense potential of RNA-based interventions as a novel and precise approach to combat CVD, paving the way for future advancements in cardiovascular therapeutics.

Cardiomyopathies in children: An overview

Paediatric cardiomyopathies form a heterogeneous group of disorders characterized by structural and electrical abnormalities of the heart muscle, commonly due to a gene variant of the myocardial cell structure. Mostly inherited as a dominant or occasionally recessive trait, they might be part of a syndromic disorder of underlying metabolic or neuromuscular defects or combine early developing extracardiac abnormalities (i.e., Naxos disease). The annual incidence of 1 per 100,000 children appears higher during the first two years of life. Dilated and hypertrophic cardiomyopathy phenotypes share an incidence of 60% and 25%, respectively. Arrhythmogenic right ventricular cardiomyopathy (ARVC), restrictive cardiomyopathy, and left ventricular noncompaction are less commonly diagnosed. Adverse events such as severe heart failure, heart transplantation, or death usually appear early after the initial presentation. In ARVC patients, high-intensity aerobic exercise has been associated with worse clinical outcomes and increased penetrance in at-risk genotype-positive relatives. Acute myocarditis in children has an incidence of 1.4-2.1 cases/per 100,000 children per year, with a 6-14% mortality rate during the acute phase. A genetic defect is considered responsible for the progression to dilated cardiomyopathy phenotype. Similarly, a dilated or arrhythmogenic cardiomyopathy phenotype might emerge with an episode of acute myocarditis in childhood or adolescence. This review provides an overview of childhood cardiomyopathies focusing on clinical presentation, outcome, and pathology.

Intrafamilial Phenotypical Variability Linked to PRKAG2 Mutation-Family Case Report and Review of the Literature

PRKAG2 syndrome (PS) is a rare, early-onset autosomal dominant phenocopy of sarcomeric hypertrophic cardiomyopathy (HCM), that mainly presents with ventricular pre-excitation, cardiac hypertrophy and progressive conduction system degeneration. Its natural course, treatment and prognosis are significantly different from sarcomeric HCM. The clinical phenotypes of PRKAG2 syndrome often overlap with HCM due to sarcomere protein mutations, causing this condition to be frequently misdiagnosed. The syndrome is caused by mutations in the gene encoding for the γ2 regulatory subunit (PRKAG2) of 5′ Adenosine Monophosphate-Activated Protein Kinase (AMPK), an enzyme that modulates glucose uptake and glycolysis. PRKAG2 mutations (OMIM#602743) are responsible for structural changes of AMPK, leading to an impaired myocyte glucidic uptake, and finally causing storage cardiomyopathy. We describe the clinical and investigative findings in a family with several affected members (NM_016203.4:c.905G>A or p.(Arg302Gln), heterozygous), highlighting the various phenotypes even in the same family, and the utility of genetic testing in diagnosing PS. The particularity of this family case is represented by the fact that the index patient was diagnosed at age 16 with cardiac hypertrophy and ventricular pre-excitation while his mother, by age 42, only had Wolff−Parkinson−White syndrome, without left ventricle hypertrophy. Both the grandmother and the great-grandmother underwent pacemaker implantation at a young age because of conduction abnormalities. Making the distinction between PS and sarcomeric HCM is actionable, given the early-onset of the disease, the numerous life-threatening consequences and the high rate of conduction disorders. In patients who exhibit cardiac hypertrophy coexisting with ventricular pre-excitation, genetic screening for PRKAG2 mutations should be considered.

Left ventricular non-compaction cardiomyopathy associated with the PRKAG2 mutation

Left ventricular non-compaction cardiomyopathy (LVNC) is one of the most common inherited cardiovascular diseases. The genetic backgrounds of most LVNC patients are not fully understood. We collected clinical data, family histories, and blood samples and performed genetic analysis using next-generation sequencing (NGS) from a Chinese family of 15 subjects. Clinically LVNC affected subjects showed marked cardiac phenotype heterogeneity. We found that these subjects with LVNC carried a missense heterozygous genetic mutation c.905G>A (p.R302Q) in γ2 subunit of AMP-activated protein kinase (PRKAG2) gene through NGS. Individuals without this mutation showed no symptoms or cardiac structural abnormalities related to LVNC. One subject was the victim of sudden cardiac death. To sum up, PRKAG2 mutation c.905G>A (p.R302Q) caused familial LVNC. Our results described a potentially pathogenic mutation associated with LVNC, which may further extend the spectrum of LVNC phenotypes related to PRKAG2 gene mutations.

Controversial molecular functions of CBS versus non-CBS domain variants of PRKAG2 in arrhythmia and cardiomyopathy: A case report and literature review

Background

PRKAG2 cardiac syndrome is a rare autosomal dominant genetic disorder caused by a PRKAG2 gene variant. There are several major adverse cardiac presentations, including hypertrophic cardiomyopathy (HCM) and life‐threatening arrhythmia. Two cases with pathogenic variants in the PRKAG2 gene are reported here who presents different cardiac phenotypes.

Methods

Exome sequencing and variant analysis of PRKAG2 were performed to obtain genetic data, and clinical characteristics were determined.

Results

The first proband was a 9‐month‐old female infant (Case 1), and was identified with severe DCM and resistant heart failure. The second proband was a 10‐year‐old female infant (Case 2), and presented with HCM and ventricular preexcitation. Exome sequencing identified a de novo c.425C > T (p.T142I) heterozygous variant in the PRKAG2 gene for Case 1, and a c.869A > T (p.K290I) for Case 2. The mutated sites in the protein were labeled and identified as p.K290 in the CBS domain and p.T142 in the non‐CBS domain. Differences in the molecular functions of CBS and non‐CBS domains have not been resolved, and variants might lead to the different cardiomyopathy phenotypes. Single‐cell RNA analysis demonstrated similar expression levels of PRKAG2 in cardiomyocytes and conductive tissues. These results suggest that the arrhythmia induced by the PRKAG2 variant was the primary change, and not secondary to cardiomyopathy.

Conclusion

In summary, this is the first case report to describe a DCM phenotype with early onset in patients possessing a PRKAG2 c.425C > T (p.T142I) pathogenic variant. Our results aid in understanding the molecular function of non‐CBS variants in terms of the disordered sequence of transcripts. Moreover, we used scRNA‐seq to show that electrically conductive cells express a higher level of PRKAG2 than do cardiomyocytes. Therefore, variants in PRKAG2 are expected to also alter the biological function of the conduction system.

Development of the Cardiac Conduction System

The cardiac conduction system initiates and propagates each heartbeat. Specialized conducting cells are a well-conserved phenomenon across vertebrate evolution, although mammalian and avian species harbor specific components unique to organisms with four-chamber hearts. Early histological studies in mammals provided evidence for a dominant pacemaker within the right atrium and clarified the existence of the specialized muscular axis responsible for atrioventricular conduction. Building on these seminal observations, contemporary genetic techniques in a multitude of model organisms has characterized the developmental ontogeny, gene regulatory networks, and functional importance of individual anatomical compartments within the cardiac conduction system. This review describes in detail the transcriptional and regulatory networks that act during cardiac conduction system development and homeostasis with a particular emphasis on networks implicated in human electrical variation by large genome-wide association studies. We conclude with a discussion of the clinical implications of these studies and describe some future directions.

Familial Atrial Enlargement, Conduction Disorder and Symmetric Cardiac Hypertrophy Are Early Signs of PRKAG2 R302Q

PRKAG2 cardiac syndrome (PS) is a rare inherited disease due to PRKAG2 gene mutation and characterized by Wolff-Parkinson-White syndrome (WPWs), conduction system lesions and myocardial hypertrophy. It can also lead to serious consequences, such as sudden death. But the genetic and clinical heterogeneity makes the early diagnosis of PS difficult. Here we studied a family with familial hypertrophic cardiomyopathy and other diverse manifestations. Gene analysis identified a missense mutation (Arg302Gln) in the five affected subjects of the family. The electrocardiograph performance of the five was composed of sinus bradycardia (SB), WPWs, right bundle branch block (RBBB), atrioventricular block (AVB), left bundle branch block (LBBB), supraventricular tachycardia (SVT) and atrial premature beat (APB). Among them, the youngest one began to show paroxysmal palpitation at the age of nine and was confirmed to have WPWs at 17 years old; two members progressed over time to serious conduction damage, and the proband received a pacemaker at the age of 27 due to AVB. Besides, according to cardiac magnetic resonance and echocardiography, the youngest one showed symmetric hypertrophy; three older members showed asymmetric myocardial hypertrophy characterized with a diffuse pattern of middle-anterior-lateral-inferior wall hypertrophy and especially interventricular septal hypertrophy; all five affected patients showed atrial enlargement regardless of myocardial hypertrophy at an earlier stage. In conclusion, the conduction system disorder, familial atrial enlargement and symmetric cardiac hypertrophy may occur in the early stage of PRKAG2 R302Q mutation.

Identification, clinical manifestation and structural mechanisms of mutations in AMPK associated cardiac glycogen storage disease

Background

Although 21 causative mutations have been associated with PRKAG2 syndrome, our understanding of the syndrome remains incomplete. The aim of this project is to further investigate its unique genetic background, clinical manifestations, and underlying structural changes.

Methods

We recruited 885 hypertrophic cardiomyopathy (HCM) probands and their families internationally. Targeted next-generation sequencing of sudden cardiac death (SCD) genes was performed. The role of the identified variants was assessed using histological techniques and computational modeling.

Findings

Twelve PRKAG2 syndrome kindreds harboring 5 distinct variants were identified. The clinical penetrance of 25 carriers was 100.0%. Twenty-two family members died of SCD or heart failure (HF). All probands developed bradycardia (HRmin, 36.3 ± 9.8 bpm) and cardiac conduction defects, and 33% had evidence of atrial fibrillation/paroxysmal supraventricular tachycardia (PSVT) and 67% had ventricular preexcitation, respectively. Some carriers presented with apical hypertrophy, hypertension, hyperlipidemia, and renal insufficiency. Histological study revealed reduced AMPK activity and major cardiac channels in the heart tissue with K485E mutation. Computational modelling suggests that K485E disrupts the salt bridge connecting the β and γ subunits of AMPK, R302Q/P decreases the binding affinity for ATP, T400N and H401D alter the orientation of H383 and R531 residues, thus altering nucleotide binding, and N488I and L341S lead to structural instability in the Bateman domain, which disrupts the intramolecular regulation.

Interpretation

Including 4 families with 3 new mutations, we describe a cohort of 12 kindreds with PRKAG2 syndrome with novel pathogenic mechanisms by computational modelling. Severe clinical cardiac phenotypes may be developed, including HF, requiring close follow-up.

Analysis of De Novo Mutations in Sporadic Cardiomyopathies Emphasizes Their Clinical Relevance and Points to Novel Candidate Genes

The vast majority of cardiomyopathies have an autosomal dominant inheritance; hence, genetic testing is typically offered to patients with a positive family history. A de novo mutation is a new germline mutation not inherited from either parent. The purpose of our study was to search for de novo mutations in patients with cardiomyopathy and no evidence of the disease in the family. Using next-generation sequencing, we analyzed cardiomyopathy genes in 12 probands. In 8 (66.7%), we found de novo variants in known cardiomyopathy genes (TTN, DSP, SCN5A, TNNC1, TPM1, CRYAB, MYH7). In the remaining probands, the analysis was extended to whole exome sequencing in a trio (proband and parents). We found de novo variants in genes that, so far, were not associated with any disease (TRIB3, SLC2A6), a possible disease-causing biallelic genotype (APOBEC gene family), and a de novo mosaic variant without strong evidence of pathogenicity (UNC45A). The high prevalence of de novo mutations emphasizes that genetic screening is also indicated in cases of sporadic cardiomyopathy. Moreover, we have identified novel cardiomyopathy candidate genes that are likely to affect immunological function and/or reaction to stress that could be especially relevant in patients with disease onset associated with infection/infestation.

Molecular Pathogenesis of Familial Wolff-Parkinson-White Syndrome

Familial Wolff-Parkinson-White (WPW) syndrome is an autosomal dominant inherited disease and consists of a small percentage of WPW syndrome which exhibits ventricular pre-excitation by development of accessory atrioventricular pathway. A series of mutations in PRKAG2 gene encoding gamma2 subunit of 5'AMP-activated protein kinase (AMPK) has been identified as the cause of familial WPW syndrome. AMPK is one of the most important metabolic regulators of carbohydrates and lipids in many types of tissues including cardiac and skeletal muscles. Patients and animals with the mutation in PRKAG2 gene exhibit aberrant atrioventricular conduction associated with cardiac glycogen overload. Recent studies have revealed "novel" significance of canonical pathways leading to glycogen synthesis and provided us profound insights into molecular mechanism of the regulation of glycogen metabolism by AMPK. This review focuses on the molecular basis of the pathogenesis of cardiac abnormality due to PRKAG2 mutation and will provide current overviews of the mechanism of glycogen regulation by AMPK. J. Med. Invest. 65:1-8, February, 2018.

Human γ2-AMPK Mutations

In humans, dominant mutations in the gene encoding the regulatory γ2-subunit of AMP-activated protein kinase (PRKAG2) result in a highly penetrant phenotype dominated by cardiac features: left ventricular hypertrophy, ventricular pre-excitation, atrial tachyarrhythmia, cardiac conduction disease, and myocardial glycogen storage. The discovery of a link between the cell's fundamental energy sensor, AMPK, and inherited cardiac disease catalyzed intense interest into the biological role of AMPK in the heart. In this chapter, we provide an introduction to the spectrum of human disease resulting from pathogenic variants in PRKAG2, outlining its discovery, clinical genetics, and current perspectives on its pathogenesis and highlighting mechanistic insights derived through the evaluation of disease models. We also present a clinical perspective on the major components of the cardiomyopathy associated with mutations in PRKAG2, together with less commonly described extracardiac features, its prognosis, and principles of management.

Identification of de novo germline mutations and causal genes for sporadic diseases using trio-based whole-exome/genome sequencing

Whole-genome or whole-exome sequencing (WGS/WES) of the affected proband together with normal parents (trio) is commonly adopted to identify de novo germline mutations (DNMs) underlying sporadic cases of various genetic disorders. However, our current knowledge of the occurrence and functional effects of DNMs remains limited and accurately identifying the disease-causing DNM from a group of irrelevant DNMs is complicated. Herein, we provide a general-purpose discussion of important issues related to pathogenic gene identification based on trio-based WGS/WES data. Specifically, the relevance of DNMs to human sporadic diseases, current knowledge of DNM biogenesis mechanisms, and common strategies or software tools used for DNM detection are reviewed, followed by a discussion of pathogenic gene prioritization. In addition, several key factors that may affect DNM identification accuracy and causal gene prioritization are reviewed. Based on recent major advances, this review both sheds light on how trio-based WGS/WES technologies can play a significant role in the identification of DNMs and causal genes for sporadic diseases, and also discusses existing challenges.

A novel, de novo mutation in the PRKAG2 gene: infantile-onset phenotype and the signaling pathway involved

PRKAG2 encodes the γ2-subunit isoform of 5'-AMP-activated protein kinase (AMPK), a heterotrimeric enzyme with major roles in the regulation of energy metabolism in response to cellular stress. Mutations in PRKAG2 have been implicated in a unique hypertrophic cardiomyopathy (HCM) characterized by cardiac glycogen overload, ventricular preexcitation, and hypertrophy. We identified a novel, de novo PRKAG2 mutation (K475E) in a neonate with prenatal onset of HCM. We aimed to investigate the cellular impact, signaling pathways involved, and therapeutic options for K475E mutation using cells stably expressing human wild-type (WT) or the K475E mutant. In human embryonic kidney-293 cells, the K475E mutation induced a marked increase in the basal phosphorylation of T172 and AMPK activity, reduced sensitivity to AMP in allosteric activation, and a loss of response to phenformin. In H9c2 cardiomyocytes, the K475E mutation induced inhibition of AMPK and reduced the response to phenformin and increases in the phosphorylation of p70S6 kinase (p70S6K) and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1). Primary fibroblasts from the patient with the K475E mutation also showed marked increases in the phosphorylation of p70S6K and 4E-BP1 compared with those from age-matched, nondiseased controls. Moreover, overexpression of K475E induced hypertrophy in H9c2 cells, which was effectively reversed by treatment with rapamycin. Taken together, we have identified a novel, de novo infantile-onset PRKAG2 mutation causing HCM. Our study suggests the K475E mutation induces alteration in basal AMPK activity and results in a hypertrophy phenotype involving the mechanistic target of rapamycin signaling pathway, which can be reversed with rapamycin.NEW & NOTEWORTHY We identified a novel, de novo PRKAG2 mutation (K475E) in the cystathionine β-synthase 3 repeat, a region critical for AMP binding but with no previous reported mutation. Our data suggest the mutation affects AMP-activated protein kinase activity, activates cell growth pathways, and results in cardiac hypertrophy, which can be reversed with rapamycin.

A novel PRKAG2 mutation in a Chinese family with cardiac hypertrophy and ventricular pre-excitation

PRKAG2 syndrome is a rare autosomal dominant inherited disorder that is characterized by cardiac hypertrophy, ventricular pre-excitation and conduction system abnormalities. There is little knowledge in cardiovascular magnetic resonance (CMR) characteristics of PRKAG2 cardiomyopathy. This study investigated the genetic defect in a three-generation Chinese family with cardiac hypertrophy and ventricular pre-excitation using whole-exome sequencing. A novel missense mutation, c.1006 G > T (p.V336L), was identified in PRKAG2. This mutation had not been identified in the ExAC database, and the prediction result of MutationTaster indicated a deleterious effect. Furthermore, it cosegregated with the disease in the present family and was absent in unrelated 300 healthy controls. cDNA analysis did not detect any splicing defects, although the variant occurred in the first base of exon 9. CMR evaluation in five affected members showed diffuse hypertrophy in a concentric pattern, with markedly increased left ventricular mass above age and gender limits (median 151.3 g/m², range 108.4–233.4 g/m²). Two patients in progressive stage and one patient with sudden cardiac death exhibited extensive subendocardial late gadolinium enhancement. In conclusion, molecular screening for PRKAG2 mutations should be considered in patients who exhibit cardiac hypertrophy coexisting with ventricular pre-excitation. CMR offers promising advantages for evaluation of PRKAG2 cardiomyopathy.

Targeting the energy guardian AMPK: another avenue for treating cardiomyopathy?

5'-AMP-activated protein kinase (AMPK) is a pivotal regulator of endogenous defensive molecules in various pathological processes. The AMPK signaling regulates a variety of intracellular intermedial molecules involved in biological reactions, including glycogen metabolism, protein synthesis, and cardiac fibrosis, in response to hypertrophic stimuli. Studies have revealed that the activation of AMPK performs a protective role in cardiovascular diseases, whereas its function in cardiac hypertrophy and cardiomyopathy remains elusive and poorly understood. In view of the current evidence of AMPK, we introduce the biological information of AMPK and cardiac hypertrophy as well as some upstream activators of AMPK. Next, we discuss two important types of cardiomyopathy involving AMPK, RKAG2 cardiomyopathy, and hypertrophic cardiomyopathy. Eventually, therapeutic research, genetic screening, conflicts, obstacles, challenges, and potential directions are also highlighted in this review, aimed at providing a comprehensive understanding of AMPK for readers.

High prevalence of arrhythmic and myocardial complications in patients with cardiac glycogenosis due to PRKAG2 mutations

AIMS

Mutations in PRKAG2, the gene encoding for the γ2 subunit of 5'-AMP-activated protein kinase (AMPK), are responsible for an autosomal dominant glycogenosis with a cardiac presentation, associating hypertrophic cardiomyopathy (HCM), ventricular pre-excitation (VPE), and progressive heart block. The aim of this study was to perform a retrospective time-to-event study of the clinical manifestations associated with PRKAG2 mutations.

METHODS AND RESULTS

A cohort of 34 patients from 9 families was recruited between 2001 and 2010. DNA were sequenced on all exons and flanking sequences of the PRKAG2 gene using Sanger sequencing. Overall, four families carried the recurrent p.Arg302Gln mutation, and the five others carried private mutations among which three had never been reported. In the total cohort, at 40 years of age, the risk of developing HCM was 61%, VPE 70%, conduction block 22%, and sudden cardiac death (SCD) 20%. The global survival at 60 years of age was 66%. Thirty-two per cent of patients (N = 10) required a device implantation (5 pacemakers and 5 defibrillators) at a median age of 66 years, and two patients required heart transplant. Only one patient presented with significant skeletal muscle symptoms. No significant differences regarding the occurrence of VPE, ablation complications, or death incidence were observed between different mutations.

CONCLUSION

This study of patients with PRKAG2 mutations provides a more comprehensive view of the natural history of this disease and demonstrates a high risk of cardiac complications. Early recognition of this disease appears important to allow an appropriate management.

The Role of AMPK in Drosophila melanogaster

In the fruit fly, Drosophila melanogaster, mono-allelic expression of AMPK-α, -β, and -γ yields a single heterotrimeric energy sensor that regulates cellular and whole-body energetic homeostasis. The genetic simplicity of Drosophila, with only a single gene for each subunit, makes the fruit fly an appealing organism for elucidating the effects of AMPK mutations on signaling pathways and phenotypes. In addition, Drosophila presents researchers with an opportunity to use straightforward genetic approaches to elucidate metabolic signaling pathways that contain a level of complexity similar to that observed in mammalian pathways. Just as in mammals, however, the regulatory realm of AMPK function extends beyond metabolic rates and lipid metabolism. Indeed, experiments using Drosophila have shown that AMPK may exert protective effects with regard to life span and neurodegeneration. This chapter addresses a few of the research areas in which Drosophila has been used to elucidate the physiological functions of AMPK. In doing so, this chapter provides a primer for basic Drosophila nomenclature, thereby eliminating a communication barrier that persists for AMPK researchers trained in mammalian genetics.

The genetic basis for inherited forms of sinoatrial dysfunction and atrioventricular node dysfunction

The sinoatrial node (SAN) and the atrioventricular node (AVN) are the anatomical and functional regions of the heart which play critical roles in the generation and conduction of the electrical impulse. Their functions are ensured by peculiar structural cytological properties and specific collections of ion channels. Impairment of SAN and AVN activity is generally acquired,but in some cases familial inheritance has been established and therefore a genetic cause is involved. In recent years, combined efforts of clinical practice and experimental basic science studies have identified and characterized several causative gene mutations associated with the nodal syndromes. Channelopathies, i.e., diseases associated with defective ion channels, remain the major cause of genetically determined nodal arrhythmias; however, it is becoming increasingly evident that mutations in other classes of regulatory and structural proteins also have profound pathophysiological roles. In this review, we will present some aspects of the genetic identification of the molecular mechanism underlying both SAN and AVN dysfunctions with a particular focus on mutations of the Na, pacemaker (HCN), and Ca channels. Genetic defects in regulatory proteins and calcium-handling proteins will be also considered. In conclusion, the identification of the genetic defects associated with familial nodal dysfunction is an essential step for implementing an appropriate therapeutic treatment.

MicroRNAs in heart failure: Small molecules with major impact

MicroRNAs (miRNAs) have emerged as potent modulators of mammalian gene expression, thereby broadening the spectrum of molecular mechanisms orchestrating human physiological and pathological cellular functions. Growing evidence suggests that these small non-coding RNA molecules are pivotal regulators of cardiovascular development and disease. Importantly, multiple miRNAs have been specifically implicated in the onset and progression of heart failure, thus providing a new platform for battling this multi-faceted disease. This review introduces the basic concepts of miRNA biology, describes representative examples of miRNAs associated with multiple aspects of HF pathogenesis, and explores the prognostic, diagnostic and therapeutic potential of miRNAs in the cardiology clinic.

Past strategies and future directions for identifying AMP-activated protein kinase (AMPK) modulators

AMP-activated protein kinase (AMPK) is a promising therapeutic target for cancer, type II diabetes, and other illnesses characterized by abnormal energy utilization. During the last decade, numerous labs have published a range of methods for identifying novel AMPK modulators. The current understanding of AMPK structure and regulation, however, has propelled a paradigm shift in which many researchers now consider ADP to be an additional regulatory nucleotide of AMPK. How can the AMPK community apply this new understanding of AMPK signaling to translational research? Recent insights into AMPK structure, regulation, and holoenzyme-sensitive signaling may provide the hindsight needed to clearly evaluate the strengths and weaknesses of past AMPK drug discovery efforts. Improving future strategies for AMPK drug discovery will require pairing the current understanding of AMPK signaling with improved experimental designs.