Research & Bioactivity
AICAR (5-aminoimidazole-4-carboxamide ribonucleotide) is a naturally occurring intermediate in purine biosynthesis that researchers have widely studied as a pharmacological activator of AMP-activated protein kinase (AMPK), a central regulator of cellular energy sensing. Studies have examined its role in metabolic processes including fatty acid oxidation, glucose uptake, and lipid metabolism, often using animal models and cell-based in vitro systems to probe how AMPK signaling influences these pathways. Research has investigated AICAR in the context of reproductive biology, with studies in goat and porcine models exploring how AMPK activation affects steroidogenesis in Leydig cells, spermatogenesis, and ovarian granulosa cell function. Researchers have also studied AICAR in relation to hepatic metabolism, particularly how AMPK pathway activation intersects with regulators such as SIRT1 and PGC-1α in models relevant to fatty liver and metabolic dysfunction. More recently, research has investigated the role of purine metabolism — the biochemical network in which AICAR is a key intermediate — in kidney physiology, including studies examining how disruptions to this metabolic network may influence nephropathy severity in genetic risk models.
Published Research
MiR-27b-3p suppresses proliferation and testosterone synthesis in goat Leydig cells by activating the AMPK pathway through PPARG targeting.
An P, Cao M, Tang W, Wang Q, Ji Q, et al. — 2026
Leydig cells (LCs) are the primary sites for testosterone synthesis in male animals, with their proliferation and steroidogenic capacity directly affecting reproductive system development. Understanding the molecular regulation of testicular development in male goats supports semen quality improvement and treatment of testicular dysfunction, while also informing strategies to enhance reproductive efficiency in goat breeding. Although microRNAs (miRNAs) are known to influence LC function by targeting key genes, the specific role of miR-27b-3p remains unclear. Our study in Qianbei Ma goats identified a critical regulatory axis during testicular development, where miR-27b-3p expression decreased while PPARG and AMPK signaling increased. Functionally, overexpressing miR-27b-3p significantly inhibited LC proliferation-shown by reduced Cyclin B1/E2 levels (P < 0.05)-and testosterone synthesis, indicated by lower HSD3B1 and STAR protein levels (P < 0.05), while also downregulating PPARG (P < 0.05). Inhibiting miR-27b-3p produced opposite effects. Further mechanistic studies confirmed that PPARG acts upstream of AMPK signaling to regulate LC proliferation and steroidogenesis (P < 0.05-0.005). AMPK activation via AICAR partially rescued the defects caused by PPARG silencing (P < 0.05). These findings demonstrate that miR-27b-3p suppresses Leydig cell proliferation and testosterone production by targeting PPARG, thereby modulating AMPK signaling. This regulatory mechanism offers new insights for developing therapeutic strategies targeting male goat reproductive dysfunction.
Berberine Regulates Hepatic Fatty Acid Metabolism via AMPK/SIRT1/PGC-1α Pathway.
Guo YJ, Wu F, Gong MM, Wu WB, Lu FE, et al. — 2026
OBJECTIVE: To investigate the therapeutic effects and molecular mechanisms of berberine (BBR) for non-alcoholic fatty liver disease (NAFLD) concomitant with type 2 diabetes mellitus (T2DM). METHODS: In vivo, 16 db/db mice were randomly assigned to the model group and the BBR group by a random number table method (n=8), with db/m mice serving as the control group. Mice were given BBR [100 mg/(kg·d)] or distilled water via gavage for 4 weeks. In vitro, 5-aminoimidazole-4-carboxyamide ribonucleoside (AICAR) and compound C were introduced as a AMP-activated protein kinase (AMPK) agonist and an inhibitor, respectively. HepG2 cells were induced with palmitic acid (PA) and high glucose, and the treatment cells received BBR (5 µmol/L), AICAR (0.8 mmol/L) or compound C (10 µmol/L) or a combination of BBR and compound C for 24 h additionally. Biochemical assays and pathological staining were performed to assess lipid and glucose metabolism. qPCR and Western blot analysis were used to evaluate the mRNA and protein expressions related to fatty acids (FA) translation [including FA transport proteins (FATP) 2, FATP5, CD36], FA synthesis [including stearoyl-CoA desaturase 1 (SCD1), sterol regulatory element-binding proteins-1c (SREBP-1c), fatty acid synthase (FASN)], and FA β-oxidation [acyl-CoA synthetase long-chain family member 1 (ACSL1), carnitine palmitoyltransferase (CPT)1A, CPT1B, CPT2, short-chain-acyl-CoA dehydrogenase(SCAD), medium-chain-acyl-CoA dehydrogenase (MCAD), long-chain-acyl-CoA dehydrogenase (LCAD), and very-long-chain-acyl-CoA dehydrogenase (VLCAD), as well as AMPK/Sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) pathway. RESULTS: In vivo, compared with the model group, the mice in the BBR group showed lower TG, TC, LDL-C, fasting blood glucose levels and improved insulin sensitivity, as well as reduced lipid accumulation in liver tissues (P<0.05 or P<0.01). In the molecules related to fatty acid metabolism, the mice in the BBR group showed decreased protein expression of FASN and increased expressions of ACSL1 and CPT1A (P<0.05). Additionally, the mRNA expressions of fatp5 and CD36 were decreased, and CPT1A, CPT2, SCAD, LCAD, and VLCAD were increased (P<0.05). AMPK/SIRT1/PGC-1α pathway was activated in the liver of BBR-treated mice (P<0.05 or P<0.01). In vitro, BBR reduced lipid accumulation in HepG2 cells and activated the AMPK/SIRT1/PGC-1α pathway, and these effects were blocked by compound C (P<0.05 or P<0.01). CONCLUSION: Berberine activates AMPK/SIRT1/PGC-1α pathway, thereby improving fatty acid metabolism, and ultimately exerts therapeutic effects on NAFLD accompanied by T2DM.
Targeting AMPK Networks for Male Reproductive Health: Mechanisms and Emerging Therapies.
Rahman MA, Harrath AH, Jalouli M, Choi J, Choi M, et al. — 2026
Male infertility is an escalating global health issue, frequently associated with metabolic problems like obesity, diabetes, and age. Recent evidence designates AMP-activated protein kinase (AMPK) as a pivotal regulator linking energy balance to male reproductive function. AMPK regulates essential activities such as spermatogenesis, metabolic support of Sertoli cells, and steroidogenesis in Leydig cells, as well as sperm motility, capacitation, and the acrosome reaction. At the molecular level, AMPK coordinates signaling networks that include mTOR, SIRT1, PGC-1α, and FOXO to modulate mitochondrial function, oxidative stress, and autophagy-related quality control. Dysregulation of AMPK during metabolic and environmental stress results in compromised spermatogenesis, diminished sperm quality, mitochondrial malfunction, and reduced testosterone synthesis. Targeting AMPK signaling constitutes a possible therapeutic approach for enhancing male reproductive health. Pharmacological agents like metformin and AICAR, together with natural bioactive substances, lifestyle modifications, and exercise mimetics, have shown promise in reestablishing metabolic equilibrium and improving reproductive results. Moreover, combinatorial strategies that integrate antioxidants and autophagy modulators may yield synergistic advantages. Nonetheless, obstacles concerning tissue selectivity, optimum dose, and clinical translation persist. Future perspectives highlight precision medicine, biomarker-directed therapies, and the incorporation of metabolic health into fertility treatment. AMPK-targeted treatments collectively provide a novel and mechanistically sound method for addressing male infertility.
Gonadotropin-inhibitory hormone (GnIH) induces glycolipid metabolic dysfunction in porcine ovarian granulosa cells via Wnt and AMPK signaling pathways.
Peng K, Zhang X, Lu M, Zhu H, Song X, et al. — 2026
Animal reproduction is closely linked to energy metabolism, and ovarian glycolipid metabolism disorders can lead to follicular abnormalities, reduced fertility, and infertility. Granulosa cells (GCs), as key energy suppliers in the ovary, directly influence oocyte development, hormone secretion, and reproductive function. However, the interaction between reproductive regulatory factors and ovarian energy metabolism is unclear. Our prior studies showed that gonadotropin-inhibitory hormone (GnIH) causes ovarian degeneration and glycolipid metabolism disorders in female piglets, but its ovarian-level mechanism remains unknown. We explored GnIH's effects on porcine ovarian and GC glycolipid metabolism via in vivo and in vitro experiments. In vivo, intraperitoneal GnIH (0.1, 1 mg/mL) administered for 14 days inhibited glucose transport and gluconeogenesis, but promoted glycolysis, fatty acid synthesis, and β-oxidation. It inhibited the AKT-GSK-3β pathway and activated AMPK, causing abnormal glucose to use and ATP deficiency. Metabolomics showed increased adenosine and D-glyceroldehyde 3-phosphate, and decreased citrate, glucuronic acid, and testosterone. In vitro, transcriptomics revealed 5253 differentially expressed genes (956 glycolipid-related) in GnIH-treated GCs, enriched in Wnt and AMPK pathways. GnIH promoted glucose transport, glycolysis, and glycogen synthesis while simultaneously inhibiting mitochondrial ATP synthesis - effects that were closely associated with the activation of the Wnt signaling pathway and the inhibition of the AMPK pathway. GnIH inhibited AMPK and activated Wnt, promoting glucose transport and glycolysis but suppressing mitochondrial ATP synthesis. Furthermore, functional intervention experiments demonstrated that GnIH effectively reversed the metabolic effects induced by either the AMPK activator AICAR or the Wnt inhibitor IWP2 in GCs, reinforcing that GnIH acts as a dominant regulator upstream of both pathways. In addition, GnIH exacerbated oxidative stress, induced insulin resistance, and disrupted mitochondrial dynamics. In conclusion, GnIH disrupts energy metabolism via Wnt and AMPK pathways, causing GC glycolipid disorders and dysfunction, offering new targets for reproductive disorder interventions.
Purine Metabolism Regulates the Severity of APOL1 Nephropathy.
Huang H, Tattersfield C, Jacas S, Karreci ES, Rumde A, et al. — 2026
BACKGROUND: 13% of African Americans have a high risk APOL1 genotype, carrying two risk alleles (G1/G1, G1/G2 or G2/G2). The mechanisms underlying nephropathy caused by these APOL1 risk variant genotypes are not fully understood. Downstream of gene function, homeostatic maintenance of a complex and interconnected network of metabolites is essential for normal kidney function. However, this metabolic network can be rerouted by genetic changes or environmental insults, both of which can contribute to development and/or progression of kidney diseases. APOL1 nephropathy exhibits both genetic and environmental triggers, but how APOL1 might alter metabolic homeostasis and how such changes may contribute to disease progression remains unclear. METHODS: APOL1 nephropathy was induced in human BAC transgenic APOL1 mice by IFN-γ adenovirus. Non-targeted metabolomics was performed on glomeruli from risk variant (G1/G1 and G2/G2) and non-risk variant (G0/G0) mice as well as on tetracycline-inducible cell lines expressing risk or non-risk variants. Metabolic signaling pathways in risk or non-risk groups were compared and transcriptional changes driving these metabolic differences were identified. Metabolic interventions were performed in both APOL1 risk and non-risk variant-expressing cells and in mice. The effect of metabolic intervention was evaluated by cytotoxicity assays and urine albumin-to-creatinine ratios for cellular and in vivo responses, respectively. RESULTS: Perturbed purine metabolism was the strongest metabolite differentiator between high- and low-risk APOL1 genotypes in cultured cells and in whole glomeruli. Expression of APOL1 G2/G2 downregulated the rate-limiting enzymes of purine biosynthesis and induced ATP depletion. In APOL1 G2/G2-expressing cells, supplementation with the purine biosynthesis precursor AICAr rescued purine biosynthesis, reduced cytotoxicity and boosted ATP. In interferon-γ treated APOL1 G2/G2 transgenic mice, AICAr administration boosted purine biosynthesis, decreased kidney pAMPK, and reduced albuminuria levels. AICAr treatment rescued G2 mouse podocyte death induced by the inflammatory stimuli of combined interferon-γ and Toll-like receptor 1/2 agonist. CONCLUSIONS: Increasing purine biosynthesis mitigated APOL1 risk-variant induced injury in cell and transgenic mouse models of APOL1 kidney disease.