Dataset Information

Neuronal HLH-30 regulates glp-1 longevity independent of neuronal MML-1/MXL-2

ABSTRACT: Accumulating evidence has demonstrated the presence of inter-tissue communication regulating systemic aging, but the underlying molecular network has not been fully explored. We and others previously showed that two basic helix-loop-helix transcription factors, MML-1 and HLH-30, are required for lifespan extension in several longevity paradigms, including germline-less Caenorhabditis elegans. However, it is unknown what tissues these factors target to promote longevity. Here, using tissue-specific knockdown experiments, we found that MML-1 and its heterodimer partners MXL-2 and HLH-30 act primarily in neurons to extend longevity in germline-less animals. Neuronal functions of MML-1/MXL-2 and HLH-30 are also essential to prevent aging in non-neuronal tissues, including muscle and the intestine. Interestingly, however, both the temporal requirement and the downstream function of MML-1 in neurons were distinct from those of HLH-30. MML-1 was active early, while HLH-30 functioned later in life to sustain longevity in germline-less animals. Moreover, neuronal RNA interference (RNAi)-based transcriptome analysis revealed that the glutamate transporter GLT-5 is a novel downstream target of MML-1 but not HLH-30. Furthermore, the MML-1–GTL-5 axis in neurons is critical to prevent an age-dependent collapse of proteostasis and increased oxidative stress through autophagy and peroxidase MLT-7, respectively, in long-lived animals. Collectively, our study revealed that systemic aging is regulated by a novel molecular network involving neuronal MML-1 function in both neural and peripheral tissues.

ORGANISM(S): Caenorhabditis elegans

PROVIDER: GSE234429 | GEO | 2023/09/18

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Dietary restriction (DR), the process of decreasing overall food consumption over an extended period of time, has been shown to increase longevity across evolutionarily diverse species and delay the onset of age-associated diseases in humans. In Caenorhabditis elegans, the Myc-family transcription factors (TFs) MXL-2 (Mlx) and MML-1 (MondoA/ChREBP), which function as obligate heterodimers, and the forkhead box transcription factor A ortholog (PHA-4) are both necessary for the full physiological benefits of DR. However, the adaptive transcriptional response to DR and the role of MML-1::MXL-2 and PHA-4 remains elusive. We identified the transcriptional signature of C. elegans DR, using the eat-2 genetic model, and demonstrate broad changes in metabolic gene expression in eat-2 DR animals, which requires both mxl-2 and pha-4. While the requirement for these factors in DR gene expression overlaps, we found many of the DR genes exhibit an opposing change in relative gene expression in eat-2;mxl-2 animals compared to wild-type, which was not observed in eat-2 animals with pha-4 loss. We further show functional deficiencies of the mxl-2 loss in DR outside of lifespan, as eat-2;mxl-2 animals exhibit substantially smaller brood sizes and lay a proportion of dead eggs, indicating that MML-1::MXL-2 has a role in maintaining the balance between resource allocation to the soma and to reproduction under conditions of chronic food scarcity. While eat-2 animals do not show a significantly different metabolic rate compared to wild-type, we also find that loss of mxl-2 in DR does not affect the rate of oxygen consumption in young animals. The gene expression signature of eat-2 mutant animals is consistent with optimization of energy utilization and resource allocation, rather than induction of canonical gene expression changes associated with acute metabolic stress -such as induction of autophagy after TORC1 inhibition. Consistently, eat-2 animals are not substantially resistant to stress, providing further support to the idea that chronic DR may benefit healthspan and lifespan through efficient use of limited resources rather than broad upregulation of stress responses, and also indicates that MML-1::MXL-2 and PHA-4 may have different roles in promotion of benefits in response to different pro-longevity stimuli.

Dataset Information

Neuronal HLH-30 regulates glp-1 longevity independent of neuronal MML-1/MXL-2

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure