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Leal H, Carvalhas-Almeida C, Álvaro AR, Cavadas C. Modeling hypothalamic pathophysiology in vitro for metabolic, circadian, and sleep disorders. Trends Endocrinol Metab 2024; 35:505-517. [PMID: 38307813 DOI: 10.1016/j.tem.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 02/04/2024]
Abstract
The hypothalamus, a small and intricate brain structure, orchestrates numerous neuroendocrine functions through specialized neurons and nuclei. Disruption of this complex circuitry can result in various diseases, including metabolic, circadian, and sleep disorders. Advances in in vitro models and their integration with new technologies have significantly benefited research on hypothalamic function and pathophysiology. We explore existing in vitro hypothalamic models and address their challenges and limitations as well as translational findings. We also highlight how collaborative efforts among multidisciplinary teams are essential to develop relevant and translational experimental models capable of replicating intricate neural circuits and neuroendocrine pathways, thereby advancing our understanding of therapeutic targets and drug discovery in hypothalamus-related disorders.
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Affiliation(s)
- Helena Leal
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Center for Innovation in Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Catarina Carvalhas-Almeida
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Center for Innovation in Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Ana Rita Álvaro
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Center for Innovation in Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal
| | - Cláudia Cavadas
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal; Center for Innovation in Biomedicine and Biotechnology (CIBB), University of Coimbra, Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal.
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Mercadante S, Bellastella A. Chrono-Endocrinology in Clinical Practice: A Journey from Pathophysiological to Therapeutic Aspects. Life (Basel) 2024; 14:546. [PMID: 38792568 PMCID: PMC11121809 DOI: 10.3390/life14050546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/26/2024] Open
Abstract
This review was aimed at collecting the knowledge on the pathophysiological and clinical aspects of endocrine rhythms and their implications in clinical practice, derived from the published literature and from some personal experiences on this topic. We chose to review, according to the PRISMA guidelines, the results of original and observational studies, reviews, meta-analyses and case reports published up to March 2024. Thus, after summarizing the general aspects of biological rhythms, we will describe the characteristics of several endocrine rhythms and the consequences of their disruption, paying particular attention to the implications in clinical practice. Rhythmic endocrine secretions, like other physiological rhythms, are genetically determined and regulated by a central hypothalamic CLOCK located in the suprachiasmatic nucleus, which links the timing of the rhythms to independent clocks, in a hierarchical organization for the regulation of physiology and behavior. However, some environmental factors, such as daily cycles of light/darkness, sleep/wake, and timing of food intake, may influence the rhythm characteristics. Endocrine rhythms are involved in important physiological processes and their disruption may cause several disorders and also cancer. Thus, it is very important to prevent disruptions of endocrine rhythms and to restore a previously altered rhythm by an early corrective chronotherapy.
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Affiliation(s)
| | - Antonio Bellastella
- Department of Cardiothoracic and Respiratory Sciences, University of Campania “Luigi Vanvitelli”, 80131 Naples, Italy;
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Schlaeger L, Olejniczak I, Lehmann M, Schmidt CX, Astiz M, Oster H, Pilorz V. Estrogen-mediated coupling via gap junctions in the suprachiasmatic nucleus. Eur J Neurosci 2024; 59:1723-1742. [PMID: 38326974 DOI: 10.1111/ejn.16270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 01/11/2024] [Accepted: 01/22/2024] [Indexed: 02/09/2024]
Abstract
The circadian clock orchestrates many physiological and behavioural rhythms in mammals with 24-h periodicity, through a hierarchical organisation, with the central clock located in the suprachiasmatic nucleus (SCN) in the hypothalamus. The circuits of the SCN generate circadian rhythms with precision, relying on intrinsic coupling mechanisms, for example, neurotransmitters like arginine vasopressin (AVP), vasoactive intestinal peptide (VIP), neuronal gamma-aminobutyric acid (GABA) signalling and astrocytes connected by gap junctions composed of connexins (Cx). In female rodents, the presence of estrogen receptors (ERs) in the dorsal SCN suggests an influence of estrogen (E2) on the circuit timekeeping that could regulate circadian rhythm and coupling. To investigate this, we used SCN explants together with hypothalamic neurons and astrocytes. First, we showed that E2 stabilised the circadian amplitude in the SCN when rAVPs (receptor-associated vasopressin peptides) were inhibited. However, the phase delay induced by VIPAC2 (VIP receptors) inhibition remained unaffected by E2. We then showed that E2 exerted its effects in the SCN via ERβ (estrogen receptor beta), resulting in increased expression of Cx36 and Cx43. Notably, specific inhibition of both connexins resulted in a significant reduction in circadian amplitude within the SCN. Remarkably, E2 restored the period with inhibited Cx36 but not with Cx43 inhibition. This implies that the network between astrocytes and neurons, responsible for coupling in the SCN, can be reinforced through E2. In conclusion, these findings provide new insights into how E2 regulates circadian rhythms ex vivo in an ERβ-dependent manner, underscoring its crucial role in fortifying the SCN's rhythm.
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Affiliation(s)
- Lina Schlaeger
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Iwona Olejniczak
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Marianne Lehmann
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Cosima Xenia Schmidt
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Mariana Astiz
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Henrik Oster
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
| | - Violetta Pilorz
- Institute of Neurobiology, Center of Brain, Behaviour and Metabolism, Marie-Curie-Strasse, University of Lübeck, Lübeck, Germany
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