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Pérez-Núñez R, González MF, Avalos AM, Leyton L. Impacts of PI3K/protein kinase B pathway activation in reactive astrocytes: from detrimental effects to protective functions. Neural Regen Res 2025; 20:1031-1041. [PMID: 38845231 DOI: 10.4103/nrr.nrr-d-23-01756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 05/06/2024] [Indexed: 07/12/2024] Open
Abstract
Astrocytes are the most abundant type of glial cell in the central nervous system. Upon injury and inflammation, astrocytes become reactive and undergo morphological and functional changes. Depending on their phenotypic classification as A1 or A2, reactive astrocytes contribute to both neurotoxic and neuroprotective responses, respectively. However, this binary classification does not fully capture the diversity of astrocyte responses observed across different diseases and injuries. Transcriptomic analysis has revealed that reactive astrocytes have a complex landscape of gene expression profiles, which emphasizes the heterogeneous nature of their reactivity. Astrocytes actively participate in regulating central nervous system inflammation by interacting with microglia and other cell types, releasing cytokines, and influencing the immune response. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway is a central player in astrocyte reactivity and impacts various aspects of astrocyte behavior, as evidenced by in silico , in vitro , and in vivo results. In astrocytes, inflammatory cues trigger a cascade of molecular events, where nuclear factor-κB serves as a central mediator of the pro-inflammatory responses. Here, we review the heterogeneity of reactive astrocytes and the molecular mechanisms underlying their activation. We highlight the involvement of various signaling pathways that regulate astrocyte reactivity, including the PI3K/AKT/mammalian target of rapamycin (mTOR), α v β 3 integrin/PI3K/AKT/connexin 43, and Notch/PI3K/AKT pathways. While targeting the inactivation of the PI3K/AKT cellular signaling pathway to control reactive astrocytes and prevent central nervous system damage, evidence suggests that activating this pathway could also yield beneficial outcomes. This dual function of the PI3K/AKT pathway underscores its complexity in astrocyte reactivity and brain function modulation. The review emphasizes the importance of employing astrocyte-exclusive models to understand their functions accurately and these models are essential for clarifying astrocyte behavior. The findings should then be validated using in vivo models to ensure real-life relevance. The review also highlights the significance of PI3K/AKT pathway modulation in preventing central nervous system damage, although further studies are required to fully comprehend its role due to varying factors such as different cell types, astrocyte responses to inflammation, and disease contexts. Specific strategies are clearly necessary to address these variables effectively.
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Affiliation(s)
- Ramón Pérez-Núñez
- Cellular Communication Laboratory, Programa de Biología Celular y Molecular, Center for Studies on Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - María Fernanda González
- Cellular Communication Laboratory, Programa de Biología Celular y Molecular, Center for Studies on Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Ana María Avalos
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Lisette Leyton
- Cellular Communication Laboratory, Programa de Biología Celular y Molecular, Center for Studies on Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
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Zhang Y, Yang YS, Chen WC, Wang CM, He HF. Constructing and Validating a Network of Potential Olfactory Sheathing Cell Transplants Regulating Spinal Cord Injury Progression. Mol Neurobiol 2023; 60:6883-6895. [PMID: 37515671 DOI: 10.1007/s12035-023-03510-9] [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: 04/14/2023] [Accepted: 07/10/2023] [Indexed: 07/31/2023]
Abstract
The pathology of spinal cord injury (SCI), including primary and secondary injuries, primarily involves hemorrhage, ischemia, edema, and inflammatory responses. Cell transplantation has been the most promising treatment for SCI in recent years; however, its specific molecular mechanism remains unclear. In this study, bioinformatics analysis verified by experiment was used to elucidate the hub genes associated with SCI and to discover the underlying molecular mechanisms of cell intervention. GSE46988 data were downloaded from the Gene Expression Omnibus dataset. In our study, differentially expressed genes (DEGs) were reanalyzed using the "R" software (R v4.2.1). Functional enrichment and protein-protein interaction network analyses were performed, and key modules and hub genes were identified. Network construction was performed for the hub genes and their associated miRNAs. Finally, a semi-quantitative analysis of hub genes and pathways was performed using quantitative real-time polymerase chain reaction. In total, 718 DEGs were identified, mainly enriched in immune and inflammation-related functions. We found that Cd4, Tp53, Rac2, and Akt3 differed between vehicle and transplanted groups, suggesting that these genes may play an essential role in the transplantation of olfactory ensheathing cells, while a toll-like receptor signaling pathway was significantly enriched in Gene set enrichment analysis, and then, the differences were statistically significant by experimentally verifying the expression of their associated molecules (Tlr4, Nf-κb, Ikkβ, Cxcl2, and Tnf-α). In addition, we searched for upstream regulatory molecules of these four central genes and constructed a regulatory network. This study is the first to construct a regulatory network for olfactory ensheathing cell transplantation in treating SCI, providing a new idea for SCI cell therapy.
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Affiliation(s)
- Yan Zhang
- Department of Anesthesiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province, China
| | - Yu-Shen Yang
- Department of Anesthesiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province, China
| | - Wei-Can Chen
- Department of Anesthesiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province, China
| | - Cong-Mei Wang
- Department of Anesthesiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province, China
| | - He-Fan He
- Department of Anesthesiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian Province, China.
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Medina-Vera D, Zambrana-Infantes EN, López-Gambero AJ, Verheul-Campos J, Santín LJ, Baixeras E, Suarez J, Pavon FJ, Rosell-Valle C, de Fonseca FR. Transcending the amyloid-beta dominance paradigm in Alzheimer's disease: An exploration of behavioural, metabolic, and gut microbiota phenotypes in 5xFAD mice. Neurobiol Dis 2023; 187:106295. [PMID: 37717663 DOI: 10.1016/j.nbd.2023.106295] [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: 05/31/2023] [Revised: 08/18/2023] [Accepted: 09/13/2023] [Indexed: 09/19/2023] Open
Abstract
The amyloid cascade hypothesis is widely accepted as an explanation for the neuropathological changes in Alzheimer's disease (AD). However, the role of amyloid-beta (Aβ) as the sole cause of these changes is being questioned. Using the 5xFAD mouse model of AD, we investigated various factors contributing to neuropathology, including genetic load (heterozygous (HTZ) versus homozygous (HZ) condition), behavioural phenotype, neuropathology markers, metabolic physiology, and gut microbiota composition at early (5 months of age) and late (12 months of age) stages of disease onset, and considering both sexes. At 5 months of age, both HTZ and HZ mice exhibited hippocampal alterations associated with Aβ accumulation, leading to increased neuroinflammation and disrupted PI3K-Akt pathway. However, only HZ mice showed cognitive impairment in the Y-maze and Morris water maze tests, worsening with age. Dysregulation of both insulin and insulin secretion-regulating GIP peptide were observed at 5 months of age, disappearing later. Circulating levels of metabolic-regulating hormones, such as Ghrelin and resisting helped to differentiates HTZ mice from HZ mice. Differences between HTZ and HZ mice were also observed in gut microbiota composition, disrupted intestinal barrier proteins, and increased proinflammatory products in the intestine. These findings suggest that cognitive impairment in 5xFAD mice may not solely result from Aβ aggregation. Other factors, including altered PI3K-Akt signalling, disrupted insulin-linked metabolic pathways, and changes in gut microbiota, contribute to disease progression. Targeting Aβ deposition alone may not suffice. Understanding AD pathogenesis and its multiple contributing factors is vital for effective therapies.
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Affiliation(s)
- Dina Medina-Vera
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, 29010 Málaga, Spain; Facultad de Ciencias, Campus de Teatinos s/n, Universidad de Málaga, 29010 Málaga, Spain; Facultad de Medicina, Campus de Teatinos s/n, Universidad de Málaga, 29010 Málaga, Spain; Unidad de Gestión Clínica del Corazón-CIBERCV (Enfermedades Cardiovasculares), Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
| | - Emma N Zambrana-Infantes
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Facultad de Psicología, Universidad de Málaga, 29010 Málaga, Spain
| | - Antonio J López-Gambero
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, 29010 Málaga, Spain; University of Bordeaux, INSERM, Neurocentre Magendie, U1215, 33000 Bordeaux, France
| | - Julia Verheul-Campos
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, 29010 Málaga, Spain
| | - Luis J Santín
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Facultad de Psicología, Universidad de Málaga, 29010 Málaga, Spain
| | - Elena Baixeras
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Málaga, 29010 Málaga, Spain
| | - Juan Suarez
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, 29010 Málaga, Spain; Departamento de Anatomía Humana, Medicina Legal e Historia de la Ciencia, Facultad de Medicina, Universidad de Málaga, 29010 Málaga, Spain
| | - Francisco J Pavon
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, 29010 Málaga, Spain; Unidad de Gestión Clínica del Corazón-CIBERCV (Enfermedades Cardiovasculares), Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
| | - Cristina Rosell-Valle
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, 29010 Málaga, Spain.
| | - Fernando Rodríguez de Fonseca
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, 29010 Málaga, Spain.
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Yu L, Qi S, Wei G, Rao X, Luo D, Zou M, Mi Y, Zhang C, Li J. Krüppel-like factor 5 activates chick intestinal stem cell and promotes mucosal repair after impairment. Cell Cycle 2023; 22:2142-2160. [PMID: 37950881 PMCID: PMC10732631 DOI: 10.1080/15384101.2023.2278938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 10/30/2023] [Indexed: 11/13/2023] Open
Abstract
The mucosal renewal, which depends on the intestinal stem cell (ISC) activity, is the foundation of mucosal repairment. Importantly, activation of reserve ISCs (rISCs) plays a vital role in initiating mucosal repair after injury. However, the underlying regulatory mechanism of rISCs activation in chickens remains unclear. In this study, immediately after lipopolysaccharide (LPS) challenge, mitochondrial morphological destruction and dysfunction appeared in the crypt, accompanied by decreased epithelial secretion (decreased Muc2 mRNA abundance and LYSOZYME protein level). However, immediately after mucosal injury, the mucosal renewal accelerated, as indicated by the increased BrdU positive rate, proliferating cell nuclear antigen (PCNA) protein level and mRNA abundance of cell cycle markers (Ccnd1, Cdk2). Concerning the ISCs activity, during the early period of injury, there appeared a reduction of active ISCs (aISCs) marker Lgr5 mRNA and protein, and an increasing of rISCs marker Hopx mRNA and protein. Strikingly, upon LPS challenge, increased mRNA transcriptional level of Krüppel-like factor 5 (Klf5) was detected in the crypt. Moreover, under LPS treatment in organoids, the KLF5 inhibitor (ML264) would decrease the mRNA and protein levels of Stat5a and Hopx, the STAT5A inhibitor (AC-4-130) would suppress the Lgr5 mRNA and protein levels. Furthermore, the Dual-Luciferase Reporter assay confirmed that, KLF5 would bind to Hopx promoter and activate the rISCs, STAT5A would trigger Lgr5 promoter and activate the aISCs. Collectively, KLF5 was upregulated during the early period of injury, further activate the rISCs directly and activate aISCs via STAT5A indirectly, thus initiate mucosal repair after injury.
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Affiliation(s)
- Lingzi Yu
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Sichao Qi
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
- Hainan Institute of Zhejiang University, Sanya, P.R. China
| | - Guozhen Wei
- Qingliu Animal Husbandry, Veterinary and Aquatic Products Center, Sanming, P.R. China
| | - Xi Rao
- Qingliu Animal Husbandry, Veterinary and Aquatic Products Center, Sanming, P.R. China
| | - Danni Luo
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Minyao Zou
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
- Hainan Institute of Zhejiang University, Sanya, P.R. China
| | - Yuling Mi
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Caiqiao Zhang
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Jian Li
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
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The role of PI3K/Akt signalling pathway in spinal cord injury. Biomed Pharmacother 2022; 156:113881. [DOI: 10.1016/j.biopha.2022.113881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 10/13/2022] [Accepted: 10/13/2022] [Indexed: 11/18/2022] Open
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