scholarly journals Relevance of NAC-2, an Na+-coupled citrate transporter, to life span, body size and fat content in Caenorhabditis elegans

2004 ◽  
Vol 379 (1) ◽  
pp. 191-198 ◽  
Author(s):  
You-Jun FEI ◽  
Jin-Cai LIU ◽  
Katsuhisa INOUE ◽  
Lina ZHUANG ◽  
Katsuya MIYAKE ◽  
...  

We have cloned and functionally characterized an Na+-coupled citrate transporter from Caenorhabditis elegans (ceNAC-2). This transporter shows significant sequence homology to Drosophila Indy and the mammalian Na+-coupled citrate transporter NaCT (now known as NaC2). When heterologously expressed in a mammalian cell line or in Xenopus oocytes, the cloned ceNAC-2 mediates the Na+-coupled transport of various intermediates of the citric acid cycle. However, it transports the tricarboxylate citrate more efficiently than dicarboxylates such as succinate, a feature different from that of ceNAC-1 (formerly known as ceNaDC1) and ceNAC-3 (formerly known as ceNaDC2). The transport process is electrogenic, as evidenced from the substrate-induced inward currents in oocytes expressing the transporter under voltage-clamp conditions. Expression studies using a reporter-gene fusion method in transgenic C. elegans show that the gene is expressed in the intestinal tract, the organ responsible for not only the digestion and absorption of nutrients but also for the storage of energy in this organism. Functional knockdown of the transporter by RNAi (RNA interference) not only leads to a significant increase in life span, but also causes a significant decrease in body size and fat content. The substrates of ceNAC-2 play a critical role in metabolic energy production and in the biosynthesis of cholesterol and fatty acids. The present studies suggest that the knockdown of these metabolic functions by RNAi is linked to an extension of life span and a decrease in fat content and body size.

2021 ◽  
Author(s):  
Chayki Charar ◽  
Sally Metsuyanim-Cohen ◽  
Daniel Z. Bar

Animals subjected to dietary restriction (DR) have reduced body size, low fecundity, slower development, lower fat content and longer life span. We identified lamin as a regulator of multiple dietary restriction phenotypes. Downregulation of lmn-1, the single Caenorhabditis elegans lamin gene, increased animal size and fat content, specifically in DR animals. The LMN-1 protein acts in the mTOR pathway, upstream to RAPTOR and S6K, key component and target of mTOR complex 1 (mTORC1), respectively. DR excludes the mTORC1 activator RAGC-1 from the nucleus. Downregulation of lmn-1 restores RAGC-1 to the nucleus, a necessary step for the activation of the mTOR pathway. These findings further link lamin to metabolic regulation.


2020 ◽  
Author(s):  
Chayki Charar ◽  
Sally Metsuyanim-Cohen ◽  
Yosef Gruenbaum ◽  
Daniel Z Bar

AbstractAnimals subjected to dietary restriction (DR) have reduced body size, low fecundity, slower development, lower fat content and longer life span. We identified lamin as a regulator of multiple dietary restriction phenotypes. Downregulation of lmn-1, the single Caenorhabditis elegans lamin gene, increased animal size and fat content, specifically in DR animals. The LMN-1 protein acts in the mTOR pathway, upstream to RAPTOR and S6K, key component and target of mTOR complex 1 (mTORC1), respectively. DR excludes the mTORC1 activator RAGC-1 from the nucleus. Downregulation of lmn-1 restores RAGC-1 to the nucleus, a necessary step for the activation of the mTOR pathway. These findings further link lamin to metabolic regulation.


Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1597-1610 ◽  
Author(s):  
David Gems ◽  
Donald L Riddle

Abstract Males of the nematode Caenorhabditis elegans are shorter lived than hermaphrodites when maintained in single-sex groups. We observed that groups of young males form clumps and that solitary males live longer, indicating that male-male interactions reduce life span. By contrast, grouped or isolated hermaphrodites exhibited the same longevity. In one wild isolate of C. elegans, AB2, there was evidence of copulation between males. Nine uncoordinated (unc) mutations were used to block clumping behavior. These mutations had little effect on hermaphrodite life span in most cases, yet many increased male longevity even beyond that of solitary wild-type males. In one case, the neuronal function mutant unc-64(e246), hermaphrodite life span was also increased by up to 60%. The longevity of unc-4(e120), unc-13(e51), and unc-32(e189) males exceeded that of hermaphrodites by 70–120%. This difference appears to reflect a difference in sex-specific life span potential revealed in the absence of male behavior that is detrimental to survival. The greater longevity of males appears not to be affected by daf-2, but is influenced by daf-16. In the absence of male-male interactions, median (but not maximum) male life span was variable. This variability was reduced when dead bacteria were used as food. Maintenance on dead bacteria extended both male and hermaphrodite longevity.


Author(s):  
Joshua D. Brycki ◽  
Jeremy R. Chen See ◽  
Gillian R. Letson ◽  
Cade S. Emlet ◽  
Lavinia V. Unverdorben ◽  
...  

Previous research has reported effects of the microbiome on health span and life span of Caenorhabditis elegans , including interactions with evolutionarily conserved pathways in humans. We build on this literature by reporting the gene expression of Escherichia coli OP50 in wild-type (N2) and three long-lived mutants of C. elegans .


2018 ◽  
Vol 293 (43) ◽  
pp. 16912-16922 ◽  
Author(s):  
Shanqing Zheng ◽  
Hilton Chiu ◽  
Jeffrey Boudreau ◽  
Tony Papanicolaou ◽  
William Bendena ◽  
...  

The human genome encodes 10 insulin-like genes, whereas the Caenorhabditis elegans genome remarkably encodes 40 insulin-like genes. Knockout strategies to determine the roles of all the insulin/insulin-like peptide ligands (INS) in C. elegans has been challenging due to functional redundancy. Here, we individually overexpressed each of the 40 ins genes pan-neuronally, and monitored multiple phenotypes including: L1 arrest life span, neuroblast divisions under L1 arrest, dauer formation, and fat accumulation, as readouts to characterize the functions of each INS in vivo. Of the 40 INS peptides, we found functions for 35 INS peptides and functionally categorized each as agonists, antagonists, or of pleiotropic function. In particular, we found that 9 of 16 agonistic INS peptides shortened L1 arrest life span and promoted neuroblast divisions during L1 arrest. Our study revealed that a subset of β-class INS peptides that contain a distinct F peptide sequence are agonists. Our work is the first to categorize the structures of INS peptides and relate these structures to the functions of all 40 INS peptides in vivo. Our findings will promote the study of insulin function on development, metabolism, and aging-related diseases.


2020 ◽  
Vol 15 (4) ◽  
pp. 1934578X2091728
Author(s):  
Yoshihiko Nishioka ◽  
Seiya Nishikawa ◽  
Toshiyuki Shibata

Sideritis scardica is a Lamiaceae plant that is endemic to the alpine zone of the Balkan Peninsula. The tea of S. scardica has been handed down as a “tea of longevity” in the Rhodope region of Bulgaria for an unknown amount of time. In this study, we prepared a hot water extract of S. scardica (SHWE) and examined its effects on both life span and stress response in living tissue using Caenorhabditis elegans and its transgenic mutants. The life span of wild-type N2 worms was prolonged by approximately 15% at the SHWE concentration of 5 µg/mL and approximately 22% at the SHWE concentration of 50 µg/mL, as compared with the control group. The effect of SHWE on the expression of heat shock protein 16.2 (HSP-16.2) under heat stress was investigated using TJ375 worms, a transgenic mutant of C. elegans. In the TJ375 worms pretreated with SHWE, the fluorescence intensity of green fluorescent protein fluorescence, which indicates the expression of HSP-16.2, was significantly increased. In the assay using TJ356 worms, the worms pretreated with SHWE did not show the translocation of DAF-16, a forkhead transcription factor class O homolog, from the cytoplasm to nucleus under heat stress. Additionally, under heat stress, the pretreatment of SHWE improved the survival rate of GR1307 worms, a knockout mutant of daf-16. These results indicate that SHWE enhances HSP-16.2 expression through a stress-response pathway (eg, HSF-1 pathway) other than the DAF-16 pathway, resulting in a prolonged life span of C. elegans under heat stress.


2017 ◽  
Vol 74 (8) ◽  
pp. 1173-1179 ◽  
Author(s):  
Joshua Coulter Russell ◽  
Nikolay Burnaevskiy ◽  
Bridget Ma ◽  
Miguel Arenas Mailig ◽  
Franklin Faust ◽  
...  

Abstract The function of the pharynx, an organ in the model system Caenorhabditis elegans, has been correlated with life span and motility (another measure of health) since 1980. In this study, in order to further understand the relationship between organ function and life span, we measured the age-related decline of the pharynx using an electrophysiological approach. We measured and analyzed electropharyngeograms (EPG) of wild type animals, short-lived hsf-1 mutants, and long-lived animals with genetically decreased insulin signaling or increased heat shock pathway signaling; we recorded a total of 2,478 EPGs from 1,374 individuals. As expected, the long-lived daf-2(e1370) and hsf-1OE(uthIs235) animals maintained pharynx function relatively closer to the youthful state during aging, whereas the hsf-1(sy441) and wild type animals’ pharynx function deviated significantly further from the youthful state at advanced age. Measures of the amount of variation in organ function can act as biomarkers of youthful physiology as well. Intriguingly, the long-lived animals had greater variation in the duration of pharynx contraction at older ages.


2016 ◽  
Vol 113 (32) ◽  
pp. E4620-E4629 ◽  
Author(s):  
Daniel Z. Bar ◽  
Chayki Charar ◽  
Jehudith Dorfman ◽  
Tam Yadid ◽  
Lionel Tafforeau ◽  
...  

Dietary restriction (DR) is a metabolic intervention that extends the lifespan of multiple species, including yeast, flies, nematodes, rodents, and, arguably, rhesus monkeys and humans. Hallmarks of lifelong DR are reductions in body size, fecundity, and fat accumulation, as well as slower development. We have identified atx-2, the Caenorhabditis elegans homolog of the human ATXN2L and ATXN2 genes, as the regulator of these multiple DR phenotypes. Down-regulation of atx-2 increases the body size, cell size, and fat content of dietary-restricted animals and speeds animal development, whereas overexpression of atx-2 is sufficient to reduce the body size and brood size of wild-type animals. atx-2 regulates the mechanistic target of rapamycin (mTOR) pathway, downstream of AMP-activated protein kinase (AMPK) and upstream of ribosomal protein S6 kinase and mTOR complex 1 (TORC1), by its direct association with Rab GDP dissociation inhibitor β, which likely regulates RHEB shuttling between GDP-bound and GTP-bound forms. Taken together, this work identifies a previously unknown mechanism regulating multiple aspects of DR, as well as unknown regulators of the mTOR pathway. They also extend our understanding of diet-dependent growth retardation, and offers a potential mechanism to treat obesity.


2012 ◽  
Vol 23 (4) ◽  
pp. 543-552 ◽  
Author(s):  
Rachel Barkan ◽  
Adam J. Zahand ◽  
Kfir Sharabi ◽  
Ayelet T. Lamm ◽  
Naomi Feinstein ◽  
...  

Emerin and LEM2 are ubiquitous inner nuclear membrane proteins conserved from humans to Caenorhabditis elegans. Loss of human emerin causes Emery-Dreifuss muscular dystrophy (EDMD). To test the roles of emerin and LEM2 in somatic cells, we used null alleles of both genes to generate C. elegans animals that were either hypomorphic (LEM-2–null and heterozygous for Ce-emerin) or null for both proteins. Single-null and hypomorphic animals were viable and fertile. Double-null animals used the maternal pool of Ce-emerin to develop to the larval L2 stage, then arrested. Nondividing somatic cell nuclei appeared normal, whereas dividing cells had abnormal nuclear envelope and chromatin organization and severe defects in postembryonic cell divisions, including the mesodermal lineage. Life span was unaffected by loss of Ce-emerin alone but was significantly reduced in LEM-2–null animals, and double-null animals had an even shorter life span. In addition to striated muscle defects, double-null animals and LEM-2–null animals showed unexpected defects in smooth muscle activity. These findings implicate human LEM2 mutations as a potential cause of EDMD and further suggest human LEM2 mutations might cause distinct disorders of greater severity, since C. elegans lacking only LEM-2 had significantly reduced life span and smooth muscle activity.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 84-84
Author(s):  
Chongwu Yang ◽  
Moussa Diarra ◽  
Muhammad Attiq Rehman ◽  
Linyan Li ◽  
Hai Yu ◽  
...  

Abstract This study investigated virulence potential of poultry antimicrobial resistant extraintestinal pathogenic E. coli (ExPEC). A total of 46 E. coli isolates from poultry meat, feces, or humans were sequenced and identified as ExPEC. Based on their characteristics, eight of these ExPEC isolates were evaluated for their potentials using a Caenorhabditis elegans infection model. The life-span of C. elegans in response to these eight isolates was examined in three life-span experiments: 1) E. coli OP 50 (negative control), K88+ enterotoxigenic E. coli strain JG280 (positive control), and an ExPEC isolate from human urinal tract infection; 2) three ExPEC isolates from chicken and turkey retail meats; 3) four ExPEC isolates from chicken feces with different antimicrobial resistance (AMR) profiles or a various number of virulence genes (VGs). All 46 isolates belonged to 24 serotypes among which 6 were of serotype O25:H4 Sequence Type 131 (ST131). Interestingly, all ST 131 isolates from chicken or turkey retail meats clustered with a human UTI isolate belonging to the similar serotype and ST type. The types and numbers of AGRs and VGs varied among the eight selected isolates for C. elegans model. The human ExPEC induced a similar effect as the JG280 on reducing (P < 0.05) survival of C. elegans. Interestingly, chicken and turkey meat ExPEC isolates, caused similar negative impacts on the survival of worms as the human ExPEC. Additionally, fecal ExPEC isolates reduced (P < 0.05) the survival of C. elegans compared to OP50. However, the survival of C. elegans was not reduced with an increasing number of VGs and did not seem to be affected by AMR profiles. This study indicated the virulence potential of ExPEC isolates from retail poultry meat or feces. The relationship between specific AMR profiles and/or numbers of VGs with pathogenicity in these E. coli isolates deserves further investigations.


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