A role of the subdiaphragmatic vagus nerve in depression-like phenotypes in mice after fecal microbiota transplantation from Chrna7 knock-out mice with depression-like phenotypes

The gut microbiota (GM) represents a diverse and dynamic population of microorganisms and about 100 trillion symbiotic microbial cells that dwell in the gastrointestinal tract. Studies suggest that the GM can influence the health of the host, and several factors can modify the GM composition, such as diet, drug intake, lifestyle, and geographical locations. Gut dysbiosis can affect brain immune homeostasis through the microbiota–gut–brain axis and can play a key role in the pathogenesis of neurodegenerative diseases, including dementia and Alzheimer’s disease (AD). The relationship between gut dysbiosis and AD is still elusive, but emerging evidence suggests that it can enhance the secretion of lipopolysaccharides and amyloids that may disturb intestinal permeability and the blood–brain barrier. In addition, it can promote the hallmarks of AD, such as oxidative stress, neuroinflammation, amyloid-beta formation, insulin resistance, and ultimately the causation of neural death. Poor dietary habits and aging, along with inflammatory responses due to dysbiosis, may contribute to the pathogenesis of AD. Thus, GM modulation through diet, probiotics, or fecal microbiota transplantation could represent potential therapeutics in AD. In this review, we discuss the role of GM dysbiosis in AD and potential therapeutic strategies to modulate GM in AD.

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Loss of microglial SIRPα promotes synaptic pruning in preclinical models of neurodegeneration

Nature Communications ◽

10.1038/s41467-021-22301-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Xin Ding ◽

Jin Wang ◽

Miaoxin Huang ◽

Zhangpeng Chen ◽

Jing Liu ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Knock Out ◽

Classical Complement Pathway ◽

Synaptic Remodeling ◽

The Central Nervous System ◽

System Activation ◽

Knock Out Mice ◽

Synaptic Pruning

AbstractMicroglia play a key role in regulating synaptic remodeling in the central nervous system. Activation of classical complement pathway promotes microglia-mediated synaptic pruning during development and disease. CD47 protects synapses from excessive pruning during development, implicating microglial SIRPα, a CD47 receptor, in synaptic remodeling. However, the role of microglial SIRPα in synaptic pruning in disease remains unclear. Here, using conditional knock-out mice, we show that microglia-specific deletion of SIRPα results in decreased synaptic density. In human tissue, we observe that microglial SIRPα expression declines alongside the progression of Alzheimer’s disease. To investigate the role of SIRPα in neurodegeneration, we modulate the expression of microglial SIRPα in mouse models of Alzheimer’s disease. Loss of microglial SIRPα results in increased synaptic loss mediated by microglia engulfment and enhanced cognitive impairment. Together, these results suggest that microglial SIRPα regulates synaptic pruning in neurodegeneration.

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Insights into the Impact of Microbiota in the Treatment of NAFLD/NASH and Its Potential as a Biomarker for Prognosis and Diagnosis

Biomedicines ◽

10.3390/biomedicines9020145 ◽

2021 ◽

Vol 9 (2) ◽

pp. 145

Author(s):

Julio Plaza-Díaz ◽

Patricio Solis-Urra ◽

Jerónimo Aragón-Vela ◽

Fernando Rodríguez-Rodríguez ◽

Jorge Olivares-Arancibia ◽

...

Keyword(s):

Gut Microbiota ◽

Fecal Microbiota Transplantation ◽

Liver Steatosis ◽

Intestinal Barrier ◽

Fecal Microbiota ◽

Current Treatment ◽

Immune Defense ◽

Alcoholic Fatty Liver ◽

The Impact

Non-alcoholic fatty liver disease (NAFLD) is an increasing cause of chronic liver illness associated with obesity and metabolic disorders, such as hypertension, dyslipidemia, or type 2 diabetes mellitus. A more severe type of NAFLD, non-alcoholic steatohepatitis (NASH), is considered an ongoing global health threat and dramatically increases the risks of cirrhosis, liver failure, and hepatocellular carcinoma. Several reports have demonstrated that liver steatosis is associated with the elevation of certain clinical and biochemical markers but with low predictive potential. In addition, current imaging methods are inaccurate and inadequate for quantification of liver steatosis and do not distinguish clearly between the microvesicular and the macrovesicular types. On the other hand, an unhealthy status usually presents an altered gut microbiota, associated with the loss of its functions. Indeed, NAFLD pathophysiology has been linked to lower microbial diversity and a weakened intestinal barrier, exposing the host to bacterial components and stimulating pathways of immune defense and inflammation via toll-like receptor signaling. Moreover, this activation of inflammation in hepatocytes induces progression from simple steatosis to NASH. In the present review, we aim to: (a) summarize studies on both human and animals addressed to determine the impact of alterations in gut microbiota in NASH; (b) evaluate the potential role of such alterations as biomarkers for prognosis and diagnosis of this disorder; and (c) discuss the involvement of microbiota in the current treatment for NAFLD/NASH (i.e., bariatric surgery, physical exercise and lifestyle, diet, probiotics and prebiotics, and fecal microbiota transplantation).

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Excess of Serotonin (5-HT) Alters the Segregation of Ispilateral and Contralateral Retinal Projections in Monoamine Oxidase A Knock-Out Mice: Possible Role of 5-HT Uptake in Retinal Ganglion Cells During Development

Journal of Neuroscience ◽

10.1523/jneurosci.19-16-07007.1999 ◽

1999 ◽

Vol 19 (16) ◽

pp. 7007-7024 ◽

Cited By ~ 121

Author(s):

A. L. Upton ◽

N. Salichon ◽

C. Lebrand ◽

A. Ravary ◽

R. Blakely ◽

...

Keyword(s):

Monoamine Oxidase ◽

Retinal Ganglion Cells ◽

Ganglion Cells ◽

Monoamine Oxidase A ◽

Retinal Ganglion ◽

Knock Out ◽

Retinal Projections ◽

5 Ht Uptake ◽

Knock Out Mice

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The Role of Fecal Microbiota Transplantation in Neurological Diseases

The Microbiome and the Brain ◽

10.1201/9781351235709-11 ◽

2019 ◽

pp. 161-177

Author(s):

Thomas Borody ◽

John Bienenstock

Keyword(s):

Fecal Microbiota Transplantation ◽

Neurological Diseases ◽

Fecal Microbiota

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REST is a major negative regulator of endocrine differentiation during pancreas organogenesis

10.1101/2021.03.17.435876 ◽

2021 ◽

Author(s):

Meritxell Rovira ◽

Goutham Atla ◽

Miguel Angel Maestro ◽

Vane Grau ◽

Javier García-Hurtado ◽

...

Keyword(s):

Endocrine Cells ◽

Negative Regulator ◽

Β Cell ◽

Knock Out ◽

Endocrine Differentiation ◽

Conditional Allele ◽

Embryonic Pancreas ◽

Pancreatic Endocrine Cells ◽

Knock Out Mice

SUMMARYUnderstanding genomic regulatory mechanisms of pancreas differentiation is relevant to the pathophysiology of diabetes mellitus, and to the development of replacement therapies. Numerous transcription factors promote β cell differentiation, although less is known about negative regulators. Earlier epigenomic studies suggested that the transcriptional repressor REST could be a suppressor of endocrine gene programs in the embryonic pancreas. However, pancreaticRestknock-out mice failed to show increased numbers of endocrine cells, suggesting that REST is not a major regulator of endocrine differentiation. Using a different conditional allele that enables profound REST inactivation, we now observe a marked increase in the formation of pancreatic endocrine cells. REST inhibition also promoted endocrinogenesis in zebrafish and mouse early postnatal ducts, and induced β-cell specific genes in human adult duct-derived organoids. Finally, we define REST genomic programs that suppress pancreatic endocrine differentiation. These results establish a crucial role of REST as a negative regulator of pancreatic endocrine differentiation.

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Lupus Gut Microbiota Transplants Cause Autoimmunity and Inflammation

10.1101/2021.08.15.456375 ◽

2021 ◽

Author(s):

Yiyangzi Ma ◽

Ruru Guo ◽

Yiduo Sun ◽

Xin Li ◽

Lun He ◽

...

Keyword(s):

Gut Microbiota ◽

Lupus Erythematosus ◽

Fecal Microbiota Transplantation ◽

Fecal Microbiota ◽

Healthy Controls ◽

Germ Free ◽

Autoimmune Antibodies ◽

Expression Of Genes ◽

Rdna Sequencing

Background: The etiology of systemic lupus erythematosus (SLE) is multifactorial. Recently, growing evidence suggests that the microbiota plays a role in SLE, yet whether gut microbiota participates in the development of SLE remains largely unknown. To investigate this issue, we carried out 16s rDNA sequencing analyses in a cohort of 18 female un-treated active SLE patients and 7 female healthy controls, and performed fecal microbiota transplantation from patients and healthy controls to germ-free mice. Results: Compared to the healthy controls, we found no significant different microbial diversity but some significantly different species in SLE patients including Turicibacter genus and other 5 species. Fecal transfer from SLE patients to germ free (GF) C57BL/6 mice caused GF mice to develop a series of lupus-like phenotyptic features, which including an increased serum autoimmune antibodies, and imbalanced cytokines, altered distribution of immune cells in mucosal and peripheral immune response, and upregulated expression of genes related to SLE in recipient mice that received SLE fecal microbiota transplantation (FMT). Moreover, the metabolism of histidine was significantly altered in GF mice treated with SLE patient feces, as compared to those which received healthy fecal transplants. Conclusions: Overall, our results describe a causal role of aberrant gut microbiota in contributing to the pathogenesis of SLE. The interplay of gut microbial and histidine metabolism may be one of the mechanisms intertwined with autoimmune activation in SLE.

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