Papandreou ME et al. (2017) Methods Enzymol "Monitoring Autophagic Responses in Caenorhabditis elegans."

Tavernarakis N, Papandreou ME

[Methods Enzymol, 2017]

Autophagy, from the Greek auto (self) and phagy (eating), is a self-degradative process critical for eukaryotic cell homeostasis. Its rapidly responsive, highly dynamic nature renders this process essential for adapting to and offsetting acute/harsh conditions such as starvation, organelle dysfunction, and deoxyribonucleic acid (DNA) damage. Autophagy involves an intricate network of interacting factors with multiple levels of control. Importantly, dysregulation of autophagy has been linked to numerous debilitating pathologies, including cancer and neurodegenerative conditions in humans. Methods to monitor and quantify autophagic activity reliably are essential both for studying the basic mechanisms of autophagy and for dissecting its involvement in disease. The nematode Caenorhabditis elegans is a particularly suitable model organism to effectively visualize and study autophagy, in vivo, in a physiological and pathological context due to its optical transparency, experimental malleability, and precise developmental and anatomical characterization. Here, we outline the main tools and approaches to monitor and measure autophagic responses in C. elegans.

Papandreou ME et al. (2023) Nat Aging "Nucleophagy delays aging and preserves germline immortality."

Papandreou ME, Konstantinidis G, Tavernarakis N

[Nat Aging, 2023]

Marked alterations in nuclear ultrastructure are a universal hallmark of aging, progeroid syndromes and other age-related pathologies. Here we show that autophagy of nuclear proteins is an important determinant of fertility and aging. Impairment of nucleophagy diminishes stress resistance, germline immortality and longevity. We found that the nematode Caenorhabditis elegans nuclear envelope anchor protein, nuclear anchorage protein 1 (ANC-1) and its mammalian ortholog nesprin-2 are cleared out by autophagy and restrict nucleolar size, a biomarker of aging. We further uncovered a germline immortality assurance mechanism, which involves nucleolar degradation at the most proximal oocyte by ANC-1 and key autophagic components. Perturbation of this clearance pathway causes tumor-like structures in C. elegans, and genetic ablation of nesprin-2 causes ovarian carcinomas in mice. Thus, autophagic recycling of nuclear components is a conserved soma longevity and germline immortality mechanism that promotes youthfulness and delays aging under conditions of stress.

Papandreou ME et al. (2020) J Vis Exp "Assessment of de novo Protein Synthesis Rates in Caenorhabditis elegans."

Palikaras K, Tavernarakis N, Papandreou ME

[J Vis Exp, 2020]

Maintaining a healthy proteome is essential for cell and organismal homeostasis. Perturbation of the balance between protein translational control and degradation instigates a multitude of age-related diseases. Decline of proteostasis quality control mechanisms is a hallmark of ageing. Biochemical methods to detect de novo protein synthesis are still limited, have several disadvantages and cannot be performed in live cells or animals. Caenorhabditis elegans, being transparent and easily genetically modified, is an excellent model to monitor protein synthesis rates by using imaging techniques. Here, we introduce and describe a method to measure de novo protein synthesis in vivo utilizing fluorescence recovery after photobleaching (FRAP). Transgenic animals expressing fluorescent proteins in specific cells or tissues are irradiated by a powerful light source resulting in fluorescence photobleaching. In turn, assessment of fluorescence recovery signifies new protein synthesis in cells and/or tissues of interest. Hence, the combination of transgenic nematodes, genetic and/or pharmacological interventions together with live imaging of protein synthesis rates can shed light on mechanisms mediating age-dependent proteostasis collapse.