CECAD

Environment/organism interactions in aging and age-associated diseases

The organism constantly has to integrate information about the internal state with external environmental cues to adapt behavioral and autonomic responses to ensure the correct, optimal physiological homeostasis. Therefore, the integrated coordination of internal state signals of   the organism with external environmental cues critically determines lifespan and the onset and development of age-associated diseases. Key neuronal networks in the hypothalamus provide an ideal integration point where neurons are specialized to sense fuel-state-communicating hormones and nutrients as well as to respond to external environmental cues such as sensory food perception, smell, and temperature. In turn, these neurons coordinate a broad spectrum of physiological responses, such as control of feeding, drinking, and circadian rhythm, as well as the regulation of systemic glucose homeostasis. Impairments of these responses and processes can lead to a variety of major health problems, especially during aging. Interestingly, recent studies have linked the diversity of the gut microbiota with host immune, metabolic, as well as neurological conditions. The production of microbial metabolites as well as the sensing of microbes by the immune system has been proposed as key functions in host-microbiota crosstalk regulating host physiology. The key objectives of RA-3 are to investigate:

  1. the neurocircuitry underlying the integration of internal state signals and external environmental cues,
  2. age- and diet-related changes in the activity of homeostatic hypothalamic neurocircuits,
  3. the function of non-neuronal cell types in hypothalamic control of age-associated diseases,
  4. the temperature-dependent regulation of physiological homeostasis,
  5. the circuitry integration and functional regulation of peripheral tissue function upon sensory food perception,
  6. microbiota-dependent modulation of age-related functional decline and organismal lifespan.

 

 

Dr. Tatiana Korotkova
Head of Research Area 3, Principal Investigator, Research Group Leader, MPI for Metabolism Research
 0221-4726-253
tatiana.korotkova[at]sf.mpg.de


MPI für Stoffwechselforschung
Gleueler Str. 50
50931 Köln

 

Prof. Dr. Manolis Pasparakis
Head of Research Area 3, Principal Investigator, Institute for Genetics
 +49 221 478 84351
pasparakis[at]uni-koeln.de

Institut für Genetik
CECAD Forschungszentrum
Joseph-Stelzmann-Str. 26


50931 Köln
Profile

Figures

Figure 1: (Above) Age-dependent changes in gut microbiota composition are characterised by decreased overall taxonomic diversity and overproliferation of potentially pathogenic Gammaproteobacteria and Betaproteobacteria. Changes in bacterial composition in older individuals are associated with gut dysfunction, consisting in increased fibrosis and inflammation.
(Below) Eterochronic microbiota transfer from young to middle-age killifish leads to life span extension, higher taxonomic diversity of the microbiota of older individuals, and remodelling of gut extracellular matrix.

Figure 2: (Above) Laboratory killifish have higher gut bacterial taxonomic richness (alpha diversity) compared to laboratory C. elegans and flies, of the same order of magnitude of mice and humans.
(Below) Being very short-lived vertebrates, killifish are an optimal vertebrate system to study the impact of a complex microbiota on host ageing and lifespan.

Figure 3: Evolutionary and ecological community changes during host ageing may play fundamental roles in shaping age-specific microbial communities. (AboveDe novo mutations (asterisk) or horizontal gene transfer in young-associated commensal bacterial species may lead to the evolution of highly fit bacterial strains that become more abundant in aged individuals, eventually leading to age-related pathogenicity. (Middle) Species-species bacterial ecological interactions could affect community dynamics that shape microbiota composition throughout host life span, ultimately affecting host physiology during ageing. (Bottom) An age-dependent decline in immune function may cause decreased surveillance over microbial communities over time, leading to age-dependent dysbiosis. On the other hand, a healthy microbiota itself could be necessary to preserve a healthy immune function during aging.

Figure 4: Eterochronic microbiota transfer from young to middle-age killifish extends life span and delays behavioural ageing (inset: swimming velocity) in killifish. Fish Experimental group legend, Abx: fish receiving only antibiotic treatment at 9.5 weeks without direct recolonization. Omt: fish receiving same-age GM transfer after antibiotic treatment at 9.5 weeks. Wt: wild-type, untreated fish. Ymt: fish receiving 6-week-old fish GM transfer after antibiotic treatment at 9.5 weeks. VMNA: antibiotic cocktail of vancomycin, metronidazole, neomycin and ampicillin.