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Sahu B, Nookala S, Floden AM, Ambhore NS, Sathish V, Klug MG, Combs CK. House dust mite-induced asthma exacerbates Alzheimer's disease changes in the brain of the App NL-G-F mouse model of disease. Brain Behav Immun 2024; 121:365-383. [PMID: 39084541 DOI: 10.1016/j.bbi.2024.07.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 07/19/2024] [Accepted: 07/28/2024] [Indexed: 08/02/2024] Open
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ) plaques, neuroinflammation, and neuronal death. Besides aging, various comorbidities increase the risk of AD, including obesity, diabetes, and allergic asthma. Epidemiological studies have reported a 2.17-fold higher risk of dementia in asthmatic patients. However, the molecular mechanism(s) underlying this asthma-associated AD exacerbation is unknown. This study was designed to explore house dust mite (HDM)-induced asthma effects on AD-related brain changes using the AppNL-G-F transgenic mouse model of disease. Male and female 8-9 months old C57BL/6J wild type and AppNL-G-F mice were exposed to no treatment, saline sham, or HDM extract every alternate day for 16 weeks for comparison across genotypes and treatment. Mice were euthanized at the end of the experiment, and broncho-alveolar lavage fluid (BALF), blood, lungs, and brains were collected. BALF was used to quantify immune cell phenotype, cytokine levels, total protein content, lactate dehydrogenase (LDH) activity, and total IgE. Lungs were sectioned and stained with hematoxylin and eosin, Alcian blue, and Masson's trichrome. Serum levels of cytokines and soluble Aβ1-40/42 were quantified. Brains were sectioned and immunostained for Aβ, GFAP, CD68, and collagen IV. Finally, frozen hippocampi and temporal cortices were used to perform Aβ ELISAs and cytokine arrays, respectively. HDM exposure led to increased levels of inflammatory cells, cytokines, total protein content, LDH activity, and total IgE in the BALF, as well as increased pulmonary mucus and collagen staining in both sexes and genotypes. Levels of serum cytokines increased in all HDM-exposed groups. Serum from the AppNL-G-F HDM-induced asthma group also had significantly increased soluble Aβ1-42 levels in both sexes. In agreement with this peripheral change, hippocampi from asthma-induced male and female AppNL-G-F mice demonstrated elevated Aβ plaque load and increased soluble Aβ 1-40/42 and insoluble Aβ 1-40 levels. HDM exposure also increased astrogliosis and microgliosis in both sexes of AppNL-G-F mice, as indicated by GFAP and CD68 immunoreactivity, respectively. Additionally, HDM exposure elevated cortical levels of several cytokines in both sexes and genotypes. Finally, HDM-exposed groups also showed a disturbed blood-brain-barrier (BBB) integrity in the hippocampus of AppNL-G-F mice, as indicated by decreased collagen IV immunoreactivity. HDM exposure was responsible for an asthma-like condition in the lungs that exacerbated Aβ pathology, astrogliosis, microgliosis, and cytokine changes in the brains of male and female AppNL-G-F mice that correlated with reduced BBB integrity. Defining mechanisms of asthma effects on the brain may identify novel therapeutic targets for asthma and AD.
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Affiliation(s)
- Bijayani Sahu
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA
| | - Suba Nookala
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA
| | - Angela M Floden
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA
| | - Nilesh S Ambhore
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health and Human Sciences, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Venkatachalem Sathish
- Department of Pharmaceutical Sciences, School of Pharmacy, College of Health and Human Sciences, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Marilyn G Klug
- Department of Population health, School of Medicine and Health Sciences, USA
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA.
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Nwafor DC, Benkovic SA, Clary BL, Brichacek AL, Lambert HW, Zdilla MJ, Brown CM. A Scalable Histological Method to Embed and Section Multiple Brains Simultaneously. Cells 2024; 13:860. [PMID: 38786081 PMCID: PMC11119749 DOI: 10.3390/cells13100860] [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: 04/27/2024] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024] Open
Abstract
The preparation and processing of rodent brains for evaluation by immunohistochemistry is time-consuming. A large number of mouse brains are routinely used in experiments in neuroscience laboratories to evaluate several models of human diseases. Thus, methods are needed to reduce the time associated with processing brains for histology. A scalable method was developed to embed, section, and stain multiple mouse brains using supplies found in any common histology laboratory. Section collection schemes can be scaled to provide identical bregma locations between adjacent sections for immunohistochemistry, facilitating comprehensive, high-quality immunohistochemistry. As a result, sectioning and staining times are considerably reduced as sections from multiple blocks are stained simultaneously. This method improves on previous procedures and allows multiple embedding and subsequent immunostaining of brains easily with a dramatically reduced time requirement. Furthermore, we expand this method for use in numerous mouse tissues, rat brain tissue, and post-mortem human brain and arterial tissues. In summary, this procedure allows the processing of many rodent or human tissues from perfusion through microscopy in 10 days or less.
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Affiliation(s)
- Divine C. Nwafor
- Department of Neurosurgery, University of Virginia, Charlottesville, VA 22903, USA;
| | - Stanley A. Benkovic
- Department of Neuroscience, School of Medicine, West Virginia University, Morgantown, WV 26506, USA (B.L.C.)
| | - Briana L. Clary
- Department of Neuroscience, School of Medicine, West Virginia University, Morgantown, WV 26506, USA (B.L.C.)
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA
| | - Allison L. Brichacek
- Department of Microbiology, Immunology, and Cell Biology, School of Medicine, West Virginia University, Morgantown, WV 26506, USA;
| | - H. Wayne Lambert
- Department of Pathology, Anatomy and Laboratory Medicine, School of Medicine, West Virginia University, Morgantown, WV 26506, USA; (H.W.L.); (M.J.Z.)
| | - Matthew J. Zdilla
- Department of Pathology, Anatomy and Laboratory Medicine, School of Medicine, West Virginia University, Morgantown, WV 26506, USA; (H.W.L.); (M.J.Z.)
| | - Candice M. Brown
- Department of Neuroscience, School of Medicine, West Virginia University, Morgantown, WV 26506, USA (B.L.C.)
- Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA
- Department of Microbiology, Immunology, and Cell Biology, School of Medicine, West Virginia University, Morgantown, WV 26506, USA;
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Cooper CP, Cheng L, Bhatti J, Melendez ER, Huell D, Banuelos C, Perez E, Long JM, Rapp PR. Cerebellum Purkinje cell vulnerability in aged rats with memory impairment. J Comp Neurol 2024; 532:e25610. [PMID: 38605461 PMCID: PMC11027960 DOI: 10.1002/cne.25610] [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: 11/06/2023] [Revised: 01/22/2024] [Accepted: 03/24/2024] [Indexed: 04/13/2024]
Abstract
The cerebellum is involved in higher order cognitive function and is susceptible to age-related atrophy. However, limited evidence has directly examined the cerebellum's role in cognitive aging. To interrogate potential substrates of the relationship between cerebellar structure and memory in aging, here we target the Purkinje cells (PCs). The sole output neurons of the cerebellum, PC loss and/or degeneration underlie a variety of behavioral abnormalities. Using a rat model of normal cognitive aging, we immunostained sections through the cerebellum for the PC-specific protein, calbindin-D28k. Although morphometric quantification revealed no significant difference in total PC number as a function of age or cognitive status, regional cell number was a more robust correlate of memory performance in the young cerebellum than in aged animals. Parallel biochemical analysis of PC-specific protein levels in whole cerebellum additionally revealed that calbindin-D28k and Purkinje cell protein-2 (pcp-2) levels were lower selectively in aged rats with spatial memory impairment compared to both young animals and aged rats with intact memory. These results suggest that cognitive aging is associated with cerebellum vulnerability, potentially reflecting disruption of the cerebellum-medial temporal lobe network.
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Affiliation(s)
- C’iana P. Cooper
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Liam Cheng
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Jafar Bhatti
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Edward R. Melendez
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Derek Huell
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Cristina Banuelos
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Evelyn Perez
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Jeffrey M. Long
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Peter R. Rapp
- Neurocognitive Aging Section, Laboratory of Behavioral
Neuroscience, National Institute on Aging, Baltimore, Maryland
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Ambigapathy G, Mukundan S, Nagamoto-Combs K, Combs CK, Nookala S. HLA-II-Dependent Neuroimmune Changes in Group A Streptococcal Necrotizing Fasciitis. Pathogens 2023; 12:1000. [PMID: 37623960 PMCID: PMC10459635 DOI: 10.3390/pathogens12081000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/26/2023] [Accepted: 07/26/2023] [Indexed: 08/26/2023] Open
Abstract
Streptococcus pyogenes (Group A Streptococcus, GAS) bacteria cause a spectrum of human diseases ranging from self-limiting pharyngitis and mild, uncomplicated skin infections (impetigo, erysipelas, and cellulitis) to highly morbid and rapidly invasive, life-threatening infections such as streptococcal toxic shock syndrome and necrotizing fasciitis (NF). HLA class II allelic polymorphisms are linked with differential outcomes and severity of GAS infections. The dysregulated immune response and peripheral cytokine storm elicited due to invasive GAS infections increase the risk for toxic shock and multiple organ failure in genetically susceptible individuals. We hypothesized that, while the host immune mediators regulate the immune responses against peripheral GAS infections, these interactions may simultaneously trigger neuropathology and, in some cases, induce persistent alterations in the glial phenotypes. Here, we studied the consequences of peripheral GAS skin infection on the brain in an HLA-II transgenic mouse model of GAS NF with and without treatment with an antibiotic, clindamycin (CLN). Mice expressing the human HLA-II DR3 (DR3) or the HLA-II DR4 (DR4) allele were divided into three groups: (i) uninfected controls, (ii) subcutaneously infected with a clinical GAS strain isolated from a patient with GAS NF, and (iii) GAS-infected with CLN treatment (10 mg/kg/5 days, intraperitoneal). The groups were monitored for 15 days post-infection. Skin GAS burden and lesion area, splenic and hippocampal mRNA levels of inflammatory markers, and immunohistochemical changes in hippocampal GFAP and Iba-1 immunoreactivity were assessed. Skin GAS burden and hippocampal mRNA levels of the inflammatory markers S100A8/A9, IL-1β, IL-33, inflammasome-related caspase-1 (Casp1), and NLRP6 were elevated in infected DR3 but not DR4 mice. The levels of these markers were significantly reduced following CLN treatment in DR3 mice. Although GAS was not detectable in the brain, astrocyte (GFAP) and microglia (Iba-1) activation were evident from increased GFAP and Iba-1 mRNA levels in DR3 and DR4 mice. However, CLN treatment significantly reduced GFAP mRNA levels in DR3 mice, not DR4 mice. Our data suggest a skin-brain axis during GAS NF, demonstrating that peripherally induced pathological conditions regulate neuroimmune changes and gliotic events in the brain.
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Affiliation(s)
| | | | | | | | - Suba Nookala
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (G.A.); (S.M.); (K.N.-C.); (C.K.C.)
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Sahu B, Johnson LM, Sohrabi M, Usatii AA, Craig RMJ, Kaelberer JB, Chandrasekaran SP, Kaur H, Nookala S, Combs CK. Effects of Probiotics on Colitis-Induced Exacerbation of Alzheimer's Disease in AppNL-G-F Mice. Int J Mol Sci 2023; 24:11551. [PMID: 37511312 PMCID: PMC10381012 DOI: 10.3390/ijms241411551] [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: 06/14/2023] [Revised: 07/09/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Alzheimer's disease (AD) is characterized by progressive cognitive decline and is a leading cause of death in the United States. Neuroinflammation has been implicated in the progression of AD, and several recent studies suggest that peripheral immune dysfunction may influence the disease. Continuing evidence indicates that intestinal dysbiosis is an attribute of AD, and inflammatory bowel disease (IBD) has been shown to aggravate cognitive impairment. Previously, we separately demonstrated that an IBD-like condition exacerbates AD-related changes in the brains of the AppNL-G-F mouse model of AD, while probiotic intervention has an attenuating effect. In this study, we investigated the combination of a dietary probiotic and an IBD-like condition for effects on the brains of mice. Male C57BL/6 wild type (WT) and AppNL-G-F mice were randomly divided into four groups: vehicle control, oral probiotic, dextran sulfate sodium (DSS), and DSS given with probiotics. As anticipated, probiotic treatment attenuated the DSS-induced colitis disease activity index in WT and AppNL-G-F mice. Although probiotic feeding significantly attenuated the DSS-mediated increase in WT colonic lipocalin levels, it was less protective in the AppNL-G-F DSS-treated group. In parallel with the intestinal changes, combined probiotic and DSS treatment increased microglial, neutrophil elastase, and 5hmC immunoreactivity while decreasing c-Fos staining compared to DSS treatment alone in the brains of WT mice. Although less abundant, probiotic combined with DSS treatment demonstrated a few similar changes in AppNL-G-F brains with increased microglial and decreased c-Fos immunoreactivity in addition to a slight increase in Aβ plaque staining. Both probiotic and DSS treatment also altered the levels of several cytokines in WT and AppNL-G-F brains, with a unique increase in the levels of TNFα and IL-2 being observed in only AppNL-G-F mice following combined DSS and probiotic treatment. Our data indicate that, while dietary probiotic intervention provides protection against the colitis-like condition, it also influences numerous glial, cytokine, and neuronal changes in the brain that may regulate brain function and the progression of AD.
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Affiliation(s)
- Bijayani Sahu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
| | - Lauren M. Johnson
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
| | - Mona Sohrabi
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
| | - Anastasia A. Usatii
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
| | - Rachel M. J. Craig
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
| | - Joshua B. Kaelberer
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
| | - Sathiya Priya Chandrasekaran
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
| | | | - Suba Nookala
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
| | - Colin K. Combs
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA; (B.S.); (L.M.J.); (M.S.); (A.A.U.); (R.M.J.C.); (J.B.K.); (S.P.C.); (S.N.)
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6
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Ren H, Zhang X, Li Y, Zhang D, Huang F, Zhang Z. Preparation of Cross-Sectional Membrane Samples for Scanning Electron Microscopy Characterizations Using a New Frozen Section Technique. MEMBRANES 2023; 13:634. [PMID: 37505000 PMCID: PMC10383886 DOI: 10.3390/membranes13070634] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023]
Abstract
Characterization of the cross-sectional morphologies of polymeric membranes are critical in understanding the relationship of structure and membrane separation performances. However, preparation of cross-sectional samples with flat surfaces for scanning electron microscopy (SEM) characterizations is challenging due to the toughness of the non-woven fabric support. In this work, a new frozen section technique was developed to prepare the cross-sectional membrane samples. A special mold was self-designed to embed membranes orientationally. The frozen section parameters, including the embedding medium, cryostat working temperature, and sectioning thickness were optimized. The SEM characterizations demonstrated that the frozen section technique, using ultrapure water as the embedding medium at a working temperature of -30 °C and a sectioning thickness of 0.5 µm, was efficient for the preparation of the membrane samples. Three methods of preparation for the cross-sectional polymeric membranes, including the conventional liquid nitrogen cryogenic fracture, the broad ion beam (BIB) polishing, and the frozen section technique were compared, which showed that the modified frozen section method was efficient and low cost. This developed method could not only accelerate the development of membrane technology but also has great potential for applications in preparation of other solid samples.
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Affiliation(s)
- Hongyun Ren
- Center of Analytical Instrument, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xian Zhang
- Center of Analytical Instrument, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Yi Li
- School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, China
| | - Dandan Zhang
- Center of Analytical Instrument, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Fuyi Huang
- Center of Analytical Instrument, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Zixing Zhang
- Center of Analytical Instrument, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
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Mai L, Inada H, Osumi N. Whole-brain mapping of neuronal activity evoked by maternal separation in neonatal mice: An association with ultrasound vocalization. Neuropsychopharmacol Rep 2023. [PMID: 37128179 DOI: 10.1002/npr2.12337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 03/01/2023] [Accepted: 03/17/2023] [Indexed: 05/03/2023] Open
Abstract
Neonatal mice emit ultrasonic vocalizations (USVs) when separated from their mothers. Since the USVs attract their mothers' attention and trigger maternal retrieval, they are considered to serve as social signals for communication. We have modeled paternal aging effects on the vocal communication of offspring in mice. However, little is known about the neural basis underlying neonatal USV production. To identify responsible brain regions driving the vocal behavior, we comprehensively mapped the neuronal activity associated with USV production in the entire brain of mice at postnatal day 6 (P6). Using an expression of immediate-early gene c-Fos as a neuronal activity marker, correlations between the numbers of USVs and c-Fos positive neurons were analyzed. We identified 23 candidate brain regions associated with USV production in the mice at P6. Our study would be a first step toward comprehensively understanding the neuronal mechanisms that regulate and develop vocal behaviors in neonatal mice.
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Affiliation(s)
- Lingling Mai
- Department of Developmental Neuroscience, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan
| | - Hitoshi Inada
- Department of Developmental Neuroscience, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan
- Laboratory of Health and Sports Sciences, Division of Biomedical Engineering for Health and Welfare, Tohoku University Graduate School of Biomedical Engineering, Sendai, 980-8575, Japan
| | - Noriko Osumi
- Department of Developmental Neuroscience, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan
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Smiley JF, Bleiwas C, Marino BM, Vaddi P, Canals-Baker S, Wilson DA, Saito M. Estimates of total neuron number show that neonatal ethanol causes immediate and lasting neuron loss in cortical and subcortical areas. Front Neurosci 2023; 17:1186529. [PMID: 37205048 PMCID: PMC10185770 DOI: 10.3389/fnins.2023.1186529] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 04/13/2023] [Indexed: 05/21/2023] Open
Abstract
In neonatal brain development there is a period of normal apoptotic cell death that regulates adult neuron number. At approximately the same period, ethanol exposure can cause a dramatic spike in apoptotic cell death. While ethanol-induced apoptosis has been shown to reduce adult neuron number, questions remain about the regional selectivity of the ethanol effect, and whether the brain might have some capacity to overcome the initial neuron loss. The present study used stereological cell counting to compare cumulative neuron loss 8 h after postnatal day 7 (P7) ethanol treatment to that of animals left to mature to adulthood (P70). Across several brain regions we found that the reduction of total neuron number after 8 h was as large as that of adult animals. Comparison between regions revealed that some areas are more vulnerable, with neuron loss in the anterior thalamic nuclei > the medial septum/vertical diagonal band, dorsal subiculum, and dorsal lateral geniculate nucleus > the mammillary bodies and cingulate cortex > whole neocortex. In contrast to estimates of total neuron number, estimates of apoptotic cell number in Nissl-stained sections at 8 h after ethanol treatment provided a less reliable predictor of adult neuron loss. The findings show that ethanol-induced neonatal apoptosis often causes immediate neuron deficits that persist in adulthood, and furthermore suggests that the brain may have limited capacity to compensate for ethanol-induced neuron loss.
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Affiliation(s)
- John F. Smiley
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
- Department of Psychiatry, School of Medicine, New York University, New York, NY, United States
- *Correspondence: John F. Smiley,
| | - Cynthia Bleiwas
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
| | - Brandon M. Marino
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
| | - Prerana Vaddi
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
| | | | - Donald A. Wilson
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
- Department of Child and Adolescent Psychiatry, School of Medicine, New York University, New York, NY, United States
- Department of Neuroscience and Physiology, School of Medicine, New York University, New York, NY, United States
| | - Mariko Saito
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
- Department of Psychiatry, School of Medicine, New York University, New York, NY, United States
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Brishti A, Germundson-Hermanson DL, Smith NA, Kearney AE, Warda Y, Nagamoto-Combs K. Asymptomatic sensitization to a cow's milk protein induces sustained neuroinflammation and behavioral changes with chronic allergen exposure. FRONTIERS IN ALLERGY 2022; 3:870628. [PMID: 36157272 PMCID: PMC9490182 DOI: 10.3389/falgy.2022.870628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 08/22/2022] [Indexed: 12/04/2022] Open
Abstract
Mouse models of food allergy have contributed to our understanding of various aspects of the disease, including susceptibilities, symptom spectra, cellular mechanisms, and therapeutic approaches. Previously, we used a mouse model of non-anaphylactic cow's milk allergy (CMA) and investigated sex- and strain-dependent differences in immunological, neurological, and behavioral sequelae. We showed that male C57BL/6J mice sensitized to a bovine whey protein, β-lactoglobulin (BLG; Bos d 5), exhibited anxiety- and depression-like behavior upon acute allergen challenge. Systemic levels of BLG-specific immunoglobulins, cytokines and chemokines were also elevated in the sensitized mice. Furthermore, neuroinflammation and intestinal dysbiosis were evident as the possible causes of the altered behavior. To assess whether frequent allergen exposure influences CMA-associated pathologies over an extended period in this subclinical model, we placed BLG-sensitized mice on a whey protein (WP)-containing or whey-free control (CTL) diet for 3 months. As expected, allergen-specific IgE was significantly elevated in the plasma after completing the 5-week sensitization phase. However, the IgE levels declined in both diet groups after 3 months. In contrast, allergen-specific IgG1 stayed elevated in sensitized mice with the CTL diet, and the WP diet to a lesser extent. Interestingly, BLG-sensitized mice on the WP diet exhibited anxiety-like behavior and a trend toward spatial memory decline compared to the sham or the sensitized mice on the CTL diet. Moreover, increased immunoreactivities for GFAP and Iba1 and elevated levels of CXCL13 and CCL12, the chemokines involved in central leukocyte recruitment and other neurological diseases, were also observed in the brain. We demonstrated that sensitization to the whey protein, particularly with continuous allergen exposure, resulted in persistent neuroinflammation and associated behavioral changes despite lowered allergen-specific immunoglobulin levels. These results suggested that continuous consumption of the offending allergen may lead to adverse consequences in the brain even after desensitization.
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Affiliation(s)
- Afrina Brishti
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND, United States
| | - Danielle L. Germundson-Hermanson
- Clinical and Translational Science Graduate Program, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND, United States
| | - Nicholas A. Smith
- Clinical and Translational Science Graduate Program, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND, United States
| | - Angela E. Kearney
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND, United States
| | - Yassmine Warda
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND, United States
| | - Kumi Nagamoto-Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND, United States
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10
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Germundson DL, Nagamoto-Combs K. Potential Role of Intracranial Mast Cells in Neuroinflammation and Neuropathology Associated with Food Allergy. Cells 2022; 11:cells11040738. [PMID: 35203387 PMCID: PMC8870724 DOI: 10.3390/cells11040738] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/15/2022] [Accepted: 02/16/2022] [Indexed: 12/29/2022] Open
Abstract
Mast cells (MCs) are the major effector cells of allergic responses and reside throughout the body, including in the brain and meninges. Previously, we showed in a mouse model of subclinical cow's milk allergy that brain MC numbers were elevated in sensitized mice. However, the neurophysiological consequences of intracranial MC accumulation and activation are unclear. We hypothesized that centrally recruited MCs in sensitized mice could be activated by the allergen via the IgE/FcεRI mechanism and increase the blood-brain barrier (BBB) permeability to promote neuroinflammation. Furthermore, we suspected that repeated allergen exposure could sustain MC activation. To investigate our hypothesis, we sensitized C57BL6/J mice to a bovine whey allergen, β-lactoglobulin (BLG), and subsequently placed them on a whey-containing diet for two weeks. MC activity and associated changes in the brain were examined. BLG-sensitized mice showed mobility changes and depression-like behavior with significantly increased MC numbers and histamine levels in select brain regions. IgG extravasation and perivascular astrogliosis were also evident. Importantly, myelin staining revealed cortical demyelination in the BLG-sensitized mice, suggesting a potential neural substrate for their behavioral changes. Our findings support the ability of brain MCs to release histamine and other mediators to increase BBB permeability and facilitate neuroinflammatory responses in the brain.
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Affiliation(s)
- Danielle L. Germundson
- Clinical and Translational Sciences Graduate Program, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND 58202-9037, USA;
| | - Kumi Nagamoto-Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND 58202-9037, USA
- Correspondence: ; Tel.: +1-701-777-2559
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11
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Vanický I, Blaško J, Končeková J, Dzurjašková Z, Michalová Z, Székiová E. Formaldehyde-hardened albumin as a non-penetrating embedding matrix for frozen and vibratome sectioning. Acta Histochem 2022; 124:151838. [PMID: 34979375 DOI: 10.1016/j.acthis.2021.151838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 12/25/2021] [Indexed: 11/19/2022]
Abstract
In this paper, we describe a protocol for a non-penetrating embedding matrix that can be used for frozen or vibratome sectioning of various formaldehyde-fixed tissue specimens. In our experiments, we wanted to prepare thin frozen sections from miniature specimens for fluorescent staining. As we could not achieve satisfactory results with any of the previously published methods, we have tried to modify the existing protocols, and systematically evaluated the effect of these modifications on the properties of the embedding matrix. The resulting protocol is simple, the matrix gets firmly attached to the tissues, does not cause autofluorescence and enables preparing extremely thin frozen sections. The matrix can be used for 1, embedding miniature specimens from problematic tissues to enable cutting very thin frozen sections, 2, grouping multiple specimens into one large block for simultaneous processing, and 3, dispersing single cells and preparing cell blocks for frozen sectioning.
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Affiliation(s)
- Ivo Vanický
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, Košice 040 01 Slovak Republic.
| | - Juraj Blaško
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, Košice 040 01 Slovak Republic
| | - Jana Končeková
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, Košice 040 01 Slovak Republic
| | - Zuzana Dzurjašková
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, Košice 040 01 Slovak Republic
| | - Zuzana Michalová
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, Košice 040 01 Slovak Republic
| | - Eva Székiová
- Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Šoltésovej 4, Košice 040 01 Slovak Republic
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Smiley JF, Bleiwas C, Canals-Baker S, Williams SZ, Sears R, Teixeira CM, Wilson DA, Saito M. Neonatal ethanol causes profound reduction of cholinergic cell number in the basal forebrain of adult animals. Alcohol 2021; 97:1-11. [PMID: 34464696 DOI: 10.1016/j.alcohol.2021.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 05/24/2021] [Accepted: 08/12/2021] [Indexed: 11/26/2022]
Abstract
In animal models that mimic human third-trimester fetal development, ethanol causes substantial cellular apoptosis in the brain, but for most brain structures, the extent of permanent neuron loss that persists into adulthood is unknown. We injected ethanol into C57BL/6J mouse pups at postnatal day 7 (P7) to model human late-gestation ethanol toxicity, and then used stereological methods to investigate adult cell numbers in several subcortical neurotransmitter systems that project extensively in the forebrain to regulate arousal states. Ethanol treatment caused especially large reductions (34-42%) in the cholinergic cells of the basal forebrain, including cholinergic cells in the medial septal/vertical diagonal band nuclei (Ch1/Ch2) and in the horizontal diagonal band/substantia innominata/nucleus basalis nuclei (Ch3/Ch4). Cell loss was also present in non-cholinergic basal forebrain cells, as demonstrated by 34% reduction of parvalbumin-immunolabeled GABA cells and 25% reduction of total Nissl-stained neurons in the Ch1/Ch2 region. In contrast, cholinergic cells in the striatum were reduced only 12% by ethanol, and those of the brainstem pedunculopontine/lateral dorsal tegmental nuclei (Ch5/Ch6) were not significantly reduced. Similarly, ethanol did not significantly reduce dopamine cells of the ventral tegmental area/substantia nigra or serotonin cells in the dorsal raphe nucleus. Orexin (hypocretin) cells in the hypothalamus showed a modest reduction (14%). Our findings indicate that the basal forebrain is especially vulnerable to alcohol exposure in the late gestational period. Reduction of cholinergic and GABAergic projection neurons from the basal forebrain that regulate forebrain arousal may contribute to the behavioral and cognitive deficits associated with neonatal ethanol exposure.
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13
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Kaur H, Nookala S, Singh S, Mukundan S, Nagamoto-Combs K, Combs CK. Sex-Dependent Effects of Intestinal Microbiome Manipulation in a Mouse Model of Alzheimer's Disease. Cells 2021; 10:2370. [PMID: 34572019 PMCID: PMC8469717 DOI: 10.3390/cells10092370] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/04/2021] [Accepted: 09/06/2021] [Indexed: 12/21/2022] Open
Abstract
Mechanisms linking intestinal bacteria and neurodegenerative diseases such as Alzheimer's disease (AD) are still unclear. We hypothesized that intestinal dysbiosis might potentiate AD, and manipulating the microbiome to promote intestinal eubiosis and immune homeostasis may improve AD-related brain changes. This study assessed sex differences in the effects of oral probiotic, antibiotics, and synbiotic treatments in the AppNL-G-F mouse model of AD. The fecal microbiome demonstrated significant correlations between bacterial genera in AppNL-G-F mice and Aβ plaque load, gliosis, and memory performance. Female and not male AppNL-G-F mice fed probiotic but not synbiotic exhibited a decrease in Aβ plaques, microgliosis, brain TNF-α, and memory improvement compared to no treatment controls. Although antibiotics treatment did not produce these multiple changes in brain cytokines, memory, or gliosis, it did decrease Aβ plaque load and colon cytokines in AppNL-G-F males. The intestinal cytokine milieu and splenocyte phenotype of female but not male AppNL-G-F mice indicated a modest proinflammatory innate response following probiotic treatment compared to controls, with an adaptive response following antibiotics treatment in male AppNL-G-F mice. Overall, these results demonstrate the beneficial effects of probiotic only in AppNL-G-F females, with minimal benefits of antibiotics or synbiotic feeding in male or female mice.
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Affiliation(s)
- Harpreet Kaur
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA; (S.N.); (S.M.); (K.N.-C.)
| | - Suba Nookala
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA; (S.N.); (S.M.); (K.N.-C.)
| | - Surjeet Singh
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience (CCBN), University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 3M4, Canada;
| | - Santhosh Mukundan
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA; (S.N.); (S.M.); (K.N.-C.)
| | - Kumi Nagamoto-Combs
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA; (S.N.); (S.M.); (K.N.-C.)
| | - Colin Kelly Combs
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037, USA; (S.N.); (S.M.); (K.N.-C.)
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Züchner M, Escalona MJ, Teige LH, Balafas E, Zhang L, Kostomitsopoulos N, Boulland JL. How to generate graded spinal cord injuries in swine - tools and procedures. Dis Model Mech 2021; 14:dmm049053. [PMID: 34464444 PMCID: PMC8419714 DOI: 10.1242/dmm.049053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/07/2021] [Indexed: 12/13/2022] Open
Abstract
Spinal cord injury (SCI) is a medically, psychologically and socially disabling condition. A large body of our knowledge on the basic mechanisms of SCI has been gathered in rodents. For preclinical validation of promising therapies, the use of animal models that are closer to humans has several advantages. This has promoted the more-intensive development of large-animal models for SCI during the past decade. We recently developed a multimodal SCI apparatus for large animals that generated biomechanically reproducible impacts in vivo. It is composed of a spring-load impactor and support systems for the spinal cord and the vertebral column. We now present the functional outcome of farm pigs and minipigs injured with different lesion strengths. There was a correlation between the biomechanical characteristics of the impact, the functional outcome and the tissue damage observed several weeks after injury. We also provide a detailed description of the procedure to generate such a SCI in both farm pigs and minipigs, in the hope to ease the adoption of the swine model by other research groups.
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Affiliation(s)
- Mark Züchner
- Department of Neurosurgery, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
| | - Manuel J. Escalona
- Department for Immunology, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
| | - Lena Hammerlund Teige
- Department for Immunology, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
| | - Evangelos Balafas
- Center of Clinical Experimental Surgery and Translational Research, Biomedical Research Foundation of Academy of Athens, 11527 Athens, Greece
| | - Lili Zhang
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway
| | - Nikolaos Kostomitsopoulos
- Center of Clinical Experimental Surgery and Translational Research, Biomedical Research Foundation of Academy of Athens, 11527 Athens, Greece
| | - Jean-Luc Boulland
- Department for Immunology, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
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15
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Kaur H, Golovko S, Golovko MY, Singh S, Darland DC, Combs CK. Effects of Probiotic Supplementation on Short Chain Fatty Acids in the AppNL-G-F Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2021; 76:1083-1102. [PMID: 32623399 PMCID: PMC8104916 DOI: 10.3233/jad-200436] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The intestinal microbiota and its metabolites, particularly short-chain fatty acids (SCFAs), have been implicated in immune function, host metabolism, and even behavior. OBJECTIVE This study was performed to investigate whether probiotic administration influences levels of intestinal microbiota and their metabolites in a fashion that may attenuate brain changes in a mouse model of Alzheimer's disease (AD). METHODS C57BL/6 wild-type (WT) mice were compared to AppNL-G-Fmice. The animals were treated with either vehicle or probiotic (VSL#3) for 8 weeks. Fecal microbiome analysis along with Aβ, GFAP, Iba-1, c-Fos, and Ki-67 immunohistochemistry was done. SCFAs were analyzed in serum and brains using UPLC-MS/MS. RESULTS Probiotic (VSL#3) supplementation for 2 months resulted in altered microbiota in both WT and AppNL-G-Fmice. An increase in serum SCFAs acetate, butyrate, and lactate were found in both genotypes following VSL#3 treatment. Propionate and isobutyrate were only increased in AppNL-G-Fmice. Surprisingly, VSL#3 only increased lactate and acetate in brains of AppNL-G-Fmice. No significant differences were observed between vehicle and VSL#3 fed AppNL-G-Fhippocampal immunoreactivities of Aβ, GFAP, Iba-1, and Ki-67. However, hippocampal c-Fos staining increased in VSL#3 fed AppNL-G-Fmice. CONCLUSION These data demonstrate intestinal dysbiosis in the AppNL-G-Fmouse model of AD. Probiotic VSL#3 feeding altered both serum and brain levels of lactate and acetate in AppNL-G-Fmice correlating with increased expression of the neuronal activity marker, c-Fos.
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Affiliation(s)
- Harpreet Kaur
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Svetlana Golovko
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Mikhail Y Golovko
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Surjeet Singh
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience (CCBN), University of Lethbridge, Lethbridge, AB, Canada
| | - Diane C Darland
- Department of Biology, University of North Dakota, College of Arts & Sciences, Grand Forks, ND, USA
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, ND, USA
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16
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Struzyna LA, Watt ML. The Emerging Role of Neuronal Organoid Models in Drug Discovery: Potential Applications and Hurdles to Implementation. Mol Pharmacol 2021; 99:256-265. [PMID: 33547249 DOI: 10.1124/molpharm.120.000142] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/15/2021] [Indexed: 12/20/2022] Open
Abstract
The high failure rate of drugs in the clinical pipeline is likely in part the result of inadequate preclinical models, particularly those for neurologic disorders and neurodegenerative disease. Such preclinical animal models often suffer from fundamental species differences and rarely recapitulate all facets of neurologic conditions, whereas conventional two-dimensional (2D) in vitro models fail to capture the three-dimensional spatial organization and cell-to-cell interactions of brain tissue that are presumed to be critical to the function of the central nervous system. Recent studies have suggested that stem cell-derived neuronal organoids are more physiologically relevant than 2D neuronal cultures because of their cytoarchitecture, electrophysiological properties, human origin, and gene expression. Hence there is interest in incorporating such physiologically relevant models into compound screening and lead optimization efforts within drug discovery. However, despite their perceived relevance, compared with previously used preclinical models, little is known regarding their predictive value. In fact, some have been wary to broadly adopt organoid technology for drug discovery because of the low-throughput and tedious generation protocols, inherent variability, and lack of compatible moderate-to-high-throughput screening assays. Consequently, microfluidic platforms, specialized bioreactors, and automated assays have been and are being developed to address these deficits. This mini review provides an overview of the gaps to broader implementation of neuronal organoids in a drug discovery setting as well as emerging technologies that may better enable their utilization. SIGNIFICANCE STATEMENT: Neuronal organoid models offer the potential for a more physiological system in which to study neurological diseases, and efforts are being made to employ them not only in mechanistic studies but also in profiling/screening purposes within drug discovery. In addition to exploring the utility of neuronal organoid models within this context, efforts in the field aim to standardize such models for consistency and adaptation to screening platforms for throughput evaluation. This review covers potential impact of and hurdles to implementation.
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17
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Sohrabi M, Pecoraro HL, Combs CK. Gut Inflammation Induced by Dextran Sulfate Sodium Exacerbates Amyloid-β Plaque Deposition in the AppNL-G-F Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2021; 79:1235-1255. [PMID: 33427741 PMCID: PMC8122495 DOI: 10.3233/jad-201099] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Although it is known that the brain communicates with the gastrointestinal (GI) tract via the well-established gut-brain axis, the influence exerted by chronic intestinal inflammation on brain changes in Alzheimer's disease (AD) is not fully understood. We hypothesized that increased gut inflammation would alter brain pathology of a mouse model of AD. OBJECTIVE Determine whether colitis exacerbates AD-related brain changes. METHODS To test this idea, 2% dextran sulfate sodium (DSS) was dissolved in the drinking water and fed ad libitum to male C57BL/6 wild type and AppNL-G-F mice at 6-10 months of age for two cycles of three days each. DSS is a negatively charged sulfated polysaccharide which results in bloody diarrhea and weight loss, changes similar to human inflammatory bowel disease (IBD). RESULTS Both wild type and AppNL-G-F mice developed an IBD-like condition. Brain histologic and biochemical assessments demonstrated increased insoluble Aβ1-40/42 levels along with the decreased microglial CD68 immunoreactivity in DSS treated AppNL-G-F mice compared to vehicle treated AppNL-G-F mice. CONCLUSION These data demonstrate that intestinal dysfunction is capable of altering plaque deposition and glial immunoreactivity in the brain. This study increases our knowledge of the impact of peripheral inflammation on Aβ deposition via an IBD-like model system.
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Affiliation(s)
- Mona Sohrabi
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND
| | - Heidi L. Pecoraro
- Veterinary Diagnostic Laboratory, North Dakota State University, Fargo ND
| | - Colin K. Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND
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18
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Sahu B, Mackos AR, Floden AM, Wold LE, Combs CK. Particulate Matter Exposure Exacerbates Amyloid-β Plaque Deposition and Gliosis in APP/PS1 Mice. J Alzheimers Dis 2021; 80:761-774. [PMID: 33554902 PMCID: PMC8100996 DOI: 10.3233/jad-200919] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ) plaques, neuroinflammation, and neuronal death. There are several well-established genetic and environmental factors hypothesized to contribute to AD progression including air pollution. However, the molecular mechanisms by which air pollution exacerbates AD are unclear. OBJECTIVE This study explored the effects of particulate matter exposure on AD-related brain changes using the APP/PS1 transgenic model of disease. METHODS Male C57BL/6;C3H wild type and APP/PS1 mice were exposed to either filtered air (FA) or particulate matter sized under 2.5μm (PM2.5) for 6 h/day, 5 days/week for 3 months and brains were collected. Immunohistochemistry for Aβ, GFAP, Iba1, and CD68 and western blot analysis for PS1, BACE, APP, GFAP, and Iba1 were performed. Aβ ELISAs and cytokine arrays were performed on frozen hippocampal and cortical lysates, respectively. RESULTS The Aβ plaque load was significantly increased in the hippocampus of PM2.5-exposed APP/PS1 mice compared to their respective FA controls. Additionally, in the PM2.5-exposed APP/PS1 group, increased astrocytosis and microgliosis were observed as indicated by elevated GFAP, Iba1, and CD68 immunoreactivities. PM2.5 exposure also led to an elevation in the levels of PS1 and BACE in APP/PS1 mice. The cytokines TNF-α, IL-6, IL-1β, IFN-γ, and MIP-3α were also elevated in the cortices of PM2.5-exposed APP/PS1 mice compared to FA controls. CONCLUSION Our data suggest that chronic particulate matter exposure exacerbates AD by increasing Aβ plaque load, gliosis, and the brain inflammatory status.
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Affiliation(s)
- Bijayani Sahu
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037
| | - Amy R. Mackos
- College of Nursing, The Ohio State University, Columbus, OH
| | - Angela M. Floden
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037
| | - Loren E. Wold
- College of Nursing, The Ohio State University, Columbus, OH
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH
| | - Colin K. Combs
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, 1301 N Columbia Road, Grand Forks, ND 58202-9037
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19
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Germundson DL, Vendsel LP, Nagamoto-Combs K. Region-specific regulation of central histaminergic H3 receptor expression in a mouse model of cow's milk allergy. Brain Res 2020; 1749:147148. [PMID: 33035498 DOI: 10.1016/j.brainres.2020.147148] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 01/04/2023]
Abstract
Central histaminergic H3 receptor (H3R) has been extensively investigated as a potential therapeutic target for various neurological and neurodegenerative disorders. Despite promising results in preclinical rodent models, clinical trials have not provided conclusive evidence for the benefit of H3R antagonists to alleviate cognitive and behavioral symptoms of these disorders. Inconsistent pharmacological efficacies may arise from aberrant changes in H3R over time during disease development. Because H3R is involved in feedback inhibition of histamine synthesis and secretion, the expression of the autoreceptor may also be reciprocally regulated by altered histamine levels in a pathological condition. Thus, we investigated H3R expression in a mouse model of cow's milk allergy, a condition associated with increased histamine levels. Mice were sensitized to bovine whey proteins (WP) over 5 weeks and H3R protein and transcript levels were examined in the brain. Substantially increased H3R immunoreactivity was observed in various brain regions of WP-sensitized mice compared to sham mice. Elevated H3R expression was also found in the thalamic/hypothalamic region. The expression of histaminergic H1, but not H2, receptor subtype was also increased in this and the midbrain regions. Unlike the brain, all three histaminergic receptors were increased in the small intestine. These results indicated that the central histaminergic receptors were altered in WP-sensitized mice in a subtype- and region-specific manner, which likely contributed to behavioral changes we observed in these mice. Our study also suggests that altered levels of H3R could be considered during a pharmacological intervention of a neurological disease.
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Affiliation(s)
- Danielle L Germundson
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 N. Columbia Rd, Grand Forks, ND, United States
| | - Lane P Vendsel
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 N. Columbia Rd, Grand Forks, ND, United States
| | - Kumi Nagamoto-Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 N. Columbia Rd, Grand Forks, ND, United States.
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20
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Sohrabi M, Floden AM, Manocha GD, Klug MG, Combs CK. IGF-1R Inhibitor Ameliorates Neuroinflammation in an Alzheimer's Disease Transgenic Mouse Model. Front Cell Neurosci 2020; 14:200. [PMID: 32719587 PMCID: PMC7348663 DOI: 10.3389/fncel.2020.00200] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 06/08/2020] [Indexed: 01/01/2023] Open
Abstract
Aging is a major risk factor for Alzheimer's disease (AD). Insulin-like growth factor-1 receptor (IGF-1R) regulates general aging and lifespan. However, the contribution of IGF-1 to age-related AD pathology and progression is highly controversial. Based on our previous work, AβPP/PS1 double transgenic mice, which express human mutant amyloid precursor protein (APP) and presenilin-1 (PS-1), demonstrated a decrease in brain IGF-1 levels when they were crossed with IGF-1 deficient Ames dwarf mice (df/df). Subsequently, a reduction in gliosis, amyloid-β (Aβ) plaque deposition, and Aβ1-40/42 concentrations were observed in this mouse model. This supported the hypothesis that IGF-1 may contribute to the progression of the disease. To assess the role of IGF-1 in AD, 9-10-month-old male littermate control wild type and AβPP/PS1 mice were randomly divided into two treatment groups including control vehicle (DMSO) and picropodophyllin (PPP), a selective, competitive, and reversible IGF-1R inhibitor. The brain penetrant inhibitor was given ip. at 1 mg/kg/day. Mice were sacrificed after 7 days of daily injection and the brains, spleens, and livers were collected to quantify histologic and biochemical changes. The PPP-treated AβPP/PS1 mice demonstrated attenuated insoluble Aβ1-40/42. Additionally, an attenuation in microgliosis and protein p-tyrosine levels was observed due to drug treatment in the hippocampus. Our data suggest IGF-1R signaling is associated with disease progression in this mouse model. More importantly, modulation of the brain IGF-1R signaling pathway, even at mid-life, was enough to attenuate aspects of the disease phenotype. This suggests that small molecule therapy targeting the IGF-1R pathway may be viable for late-stage disease treatment.
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Affiliation(s)
- Mona Sohrabi
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Angela M Floden
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Gunjan D Manocha
- Department of Geriatrics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Marilyn G Klug
- Department of Population Health, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States
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21
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Kaur H, Nagamoto-Combs K, Golovko S, Golovko MY, Klug MG, Combs CK. Probiotics ameliorate intestinal pathophysiology in a mouse model of Alzheimer's disease. Neurobiol Aging 2020; 92:114-134. [PMID: 32417748 DOI: 10.1016/j.neurobiolaging.2020.04.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 02/06/2023]
Abstract
Evidence suggests that changes in intestinal microbiota may affect the central nervous system. However, it is unclear whether alteration of intestinal microbiota affects progression of Alzheimer's disease (AD). To understand this, wild-type control (C57BL/6) mice were compared with the AppNL-G-F model of disease. We used probiotic supplementation to manipulate the gut microbiota. Fecal samples were collected for microbiota profiling. To study brain and intestinal inflammation, biochemical and histological analyses were performed. Altered metabolic pathways were examined by quantifying eicosanoid and bile acid profiles in the brain and serum using ultraperformance liquid chromatography-tandem mass spectrometry. We observed that brain pathology was associated with intestinal dysbiosis and increased intestinal inflammation and leakiness in AppNL-G-F mice. Probiotic supplementation significantly decreased intestinal inflammation and gut permeability with minimal effect on amyloid-β, cytokine, or gliosis levels in the brain. Concentrations of several bile acids and prostaglandins were altered in the serum and brain because of AD or probiotic supplementation. Our study characterizes intestinal dysfunction in an AD mouse model and the potential of probiotic intervention to ameliorate this condition.
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Affiliation(s)
- Harpreet Kaur
- Department of Biomedical Sciences, University of North Dakota, School of Medicine & Health Sciences, Grand Forks, ND, USA
| | - Kumi Nagamoto-Combs
- Department of Pathology, University of North Dakota, School of Medicine & Health Sciences, Grand Forks, ND, USA
| | - Svetlana Golovko
- Department of Biomedical Sciences, University of North Dakota, School of Medicine & Health Sciences, Grand Forks, ND, USA
| | - Mikhail Y Golovko
- Department of Biomedical Sciences, University of North Dakota, School of Medicine & Health Sciences, Grand Forks, ND, USA
| | - Marilyn G Klug
- Department of Population Health, University of North Dakota, School of Medicine & Health Sciences, Grand Forks, ND, USA
| | - Colin Kelly Combs
- Department of Biomedical Sciences, University of North Dakota, School of Medicine & Health Sciences, Grand Forks, ND, USA.
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Manocha G, Ghatak A, Puig K, Combs C. Anti-α4β1 Integrin Antibodies Attenuated Brain Inflammatory Changes in a Mouse Model of Alzheimer's Disease. Curr Alzheimer Res 2019; 15:1123-1135. [PMID: 30068274 PMCID: PMC6302348 DOI: 10.2174/1567205015666180801111033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 07/11/2018] [Accepted: 07/23/2018] [Indexed: 01/04/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is associated with age-associated central nervous system degeneration and dementia. This decline in the function correlates with deposition of Aβ peptide containing plaques and associated reactive gliosis. The inflammatory phenotype of microglia, in particular, is often considered detrimental to cognitive function in AD. In addition to the changes in the CNS, altered immune changes in the periphery have recently been observed in AD suggesting a critical immune- related communication between the periphery and the brain. OBJECTIVE We hypothesized that modulating the peripheral immune system may alter the proinflammatory gliosis associated with AD. Therapeutic antibodies against the α4β1 integrin receptor have been used clinically to attenuate the ability of various immune cells to adhere to endothelium and migrate into target tissues such as the intestines (Crohn's disease) or brain (multiple sclerosis). We hypothesized that a similar peripheral antibody-based therapy would attenuate gliosis by altering immune cell infiltration or phenotype in peripheral organs and the brain using an APP/PS1 mouse model of Alzheimer's disease. METHOD Littermate control wild-type and APP/PS1 mice were tail vein injected with either saline, isotype control (IgG2b), or an antibody recognizing α4-integrin, anti-CD49d, once a week for 4 consecutive weeks. To understand CNS and peripheral immune changes, brains and spleen were used. RESULTS/CONCLUSION Our data suggests that the antibody therapy was able to reduce microgliosis, astrogliosis, and synaptic changes in the APP/PS1 mice compared to isotype control injections without changing amyloid-β plaque load. Interestingly, both isotype control and antibody therapy also reduced the number of proinflammatory cytokines in the spleen although changes in the brain were less robust. The anti-CD49d and isotype control treatments also reduced CD4 immunoreactivity in the brains, suggesting a possible mechanism for attenuation of inflammation in the brain. This data suggests that it is indeed feasible to alter the immune component of AD brain changes using a clinically feasible strategy of delivering a particular subtype of IgG or epitope selective antibodies that target infiltration of the peripheral immune system.
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Affiliation(s)
- Gunjan Manocha
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, ND 58202, United States
| | - Atreyi Ghatak
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, ND 58202, United States
| | - Kendra Puig
- Presentation College Aberdeen, South Dakota, ND 58202, United States
| | - Colin Combs
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, North Dakota, ND 58202, United States
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23
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A protocol for making and sectioning multiple embedded Swiss-rolls in a gelatin matrix. MethodsX 2019; 6:2028-2036. [PMID: 31667100 PMCID: PMC6812402 DOI: 10.1016/j.mex.2019.08.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 08/22/2019] [Indexed: 11/22/2022] Open
Abstract
The appropriate methodological approach for intestinal preparation enables researchers to create representative histological and immunostaining images which validate their biochemical data. The Swiss-roll technique was first introduced by Reilly and Kirsner in 1965. Later, Moolenbeek and Ruitenberg described a detailed procedure to longitudinally study the rodent intestine in 1981 [1]. In this publication, our slightly different approach for co-embedding four different Swiss-rolls in a gelatin block provides a full-length overview of cross-sectional colons on a single slide. This protocol allows for longitudinal histologic examination of multiple tissue samples on a single slide simultaneously. In this method, antigenicity is retained for immunohistology. In addition, the accessibility of samples during the prolonged hardening time required of the gelatin matrix allows the tissue samples to be adjusted/re-adjusted to provide the desired orientation and spatial arrangement for ideal cross sections with similar planes of section and optimum space utilization for slide mounting. Although not the focus of this protocol, the room temperature stability of the gelatin matrix and the ability to contain numerous tissue samples in a block allows the flexibility of performing thicker sections for free-floating tissue staining and ease of mounting a single gelatin sheet rather than individual tissue sections. This is a convenient approach for allowing precise preparation of multi-tissue blocks and simultaneous sectioning, staining, and slide mounting of tissue for subsequent comparisons. A single gelatin block is prepared by simultaneously embedding at least four different intestinal Swiss-rolls. The tissue orientation can be adjusted for each sample as desired which facilitates the comparison of different colon samples on a single gelatin section. The gelatin sections containing tissue samples are stable at least overnight at room temperature for staining.
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Manocha GD, Floden AM, Miller NM, Smith AJ, Nagamoto-Combs K, Saito T, Saido TC, Combs CK. Temporal progression of Alzheimer's disease in brains and intestines of transgenic mice. Neurobiol Aging 2019; 81:166-176. [PMID: 31284126 DOI: 10.1016/j.neurobiolaging.2019.05.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 05/21/2019] [Accepted: 05/30/2019] [Indexed: 12/14/2022]
Abstract
The amyloid beta (Aβ) peptide is associated with the neurodegenerative and inflammatory changes in brains affected by Alzheimer's disease (AD). We hypothesized that the enteric nervous system also produces Aβ in an intestinal component of disease. To test this idea, we compared C57BL/6 wild-type (WT) male and female mice to two models of Alzheimer's disease, amyloid precursor protein (APP)/presenilin 1 (PS1) mice and amyloid precursor protein NL-G-F (AppNL-G-F) mice, at 3, 6, and 12 months of age. Brain Aβ plaque deposition in AppNL-G-F mice preceded that in the APP/PS1 mice, observable by 3 months. Three-month-old female AppNL-G-F mice had decreased intestinal motility compared with WT and APP/PS1 mice. However, 3-month-old female APP/PS1 mice demonstrated increased intestinal permeability compared with WT and AppNL-G-F mice. Both sexes of APP/PS1 and AppNL-G-F mice demonstrated increased colon lipocalin 2 mRNA and insoluble Aβ 1-42 levels at 3 months. These data demonstrate an unrecognized enteric aspect of disease in 2 different mouse models correlating with the earliest brain changes.
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Affiliation(s)
- Gunjan D Manocha
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Angela M Floden
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Nicole M Miller
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Abbie J Smith
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Kumi Nagamoto-Combs
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA.
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Effects of neonatal ethanol on cerebral cortex development through adolescence. Brain Struct Funct 2019; 224:1871-1884. [PMID: 31049690 DOI: 10.1007/s00429-019-01881-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 04/19/2019] [Indexed: 02/03/2023]
Abstract
Neonatal brain lesions cause deficits in structure and function of the cerebral cortex that sometimes are not fully expressed until adolescence. To better understand the onset and persistence of changes caused by postnatal day 7 (P7) ethanol treatment, we examined neocortical cell numbers, volume, surface area and thickness from neonatal to post-adolescent ages. In control mice, total neuron number decreased from P8 to reach approximately stable levels at about P30, as expected from normal programmed cell death. Cortical thickness reached adult levels by P14, but cortical volume and surface area continued to increase from juvenile (P20-30) to post-adolescent (P54-93) ages. P7 ethanol caused a reduction of total neurons by P14, but this deficit was transient, with later ages having only small and non-significant reductions. Previous studies also reported transient neuron loss after neonatal lesions that might be partially explained by an acute acceleration of normally occurring programmed cell death. GABAergic neurons expressing parvalbumin, calretinin, or somatostatin were reduced by P14, but unlike total neurons the reductions persisted or increased in later ages. Cortical volume, surface area and thickness were also reduced by P7 ethanol. Cortical volume showed evidence of a transient reduction at P14, and then was reduced again in post-adolescent ages. The results show a developmental sequence of neonatal ethanol effects. By juvenile ages the cortex overcomes the P14 deficit of total neurons, whereas P14 GABA cell deficits persist. Cortical volume reductions were present at P14, and again in post-adolescent ages.
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Habbal O, Farhat A, Khalil R. A mechanized device for mounting histological tissue sections. J Neurosci Methods 2019; 320:72-78. [DOI: 10.1016/j.jneumeth.2019.03.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/16/2019] [Accepted: 03/19/2019] [Indexed: 11/16/2022]
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Kulas JA, Franklin WF, Smith NA, Manocha GD, Puig KL, Nagamoto-Combs K, Hendrix RD, Taglialatela G, Barger SW, Combs CK. Ablation of amyloid precursor protein increases insulin-degrading enzyme levels and activity in brain and peripheral tissues. Am J Physiol Endocrinol Metab 2019; 316:E106-E120. [PMID: 30422705 PMCID: PMC6417684 DOI: 10.1152/ajpendo.00279.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The amyloid precursor protein (APP) is a type I transmembrane glycoprotein widely studied for its role as the source of β-amyloid peptide, accumulation of which is causal in at least some cases of Alzheimer's disease (AD). APP is expressed ubiquitously and is involved in diverse biological processes. Growing bodies of evidence indicate connections between AD and somatic metabolic disorders related to type 2 diabetes, and App-/- mice show alterations in glycemic regulation. We find that App-/- mice have higher levels of insulin-degrading enzyme (IDE) mRNA, protein, and activity compared with wild-type controls. This regulation of IDE by APP was widespread across numerous tissues, including liver, skeletal muscle, and brain as well as cell types within neural tissue, including neurons, astrocytes, and microglia. RNA interference-mediated knockdown of APP in the SIM-A9 microglia cell line elevated IDE levels. Fasting levels of blood insulin were lower in App-/- than App+/+ mice, but the former showed a larger increase in response to glucose. These low basal levels may enhance peripheral insulin sensitivity, as App-/- mice failed to develop impairment of glucose tolerance on a high-fat, high-sucrose ("Western") diet. Insulin levels and insulin signaling were also lower in the App-/- brain; synaptosomes prepared from App-/- hippocampus showed diminished insulin receptor phosphorylation compared with App+/+ mice when stimulated ex vivo. These findings represent a new molecular link connecting APP to metabolic homeostasis and demonstrate a novel role for APP as an upstream regulator of IDE in vivo.
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Affiliation(s)
- Joshua A Kulas
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Whitney F Franklin
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch , Galveston, Texas
| | - Nicholas A Smith
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Gunjan D Manocha
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Kendra L Puig
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Kumi Nagamoto-Combs
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
| | - Rachel D Hendrix
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences , Little Rock Arkansas
| | - Giulio Taglialatela
- Department of Neurology, University of Texas Medical Branch , Galveston, Texas
| | - Steven W Barger
- Department of Geriatrics, University of Arkansas for Medical Sciences , Little Rock Arkansas
- Geriatric Research, Education and Clinical Center, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Colin K Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences , Grand Forks, North Dakota
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Germundson DL, Smith NA, Vendsel LP, Kelsch AV, Combs CK, Nagamoto-Combs K. Oral sensitization to whey proteins induces age- and sex-dependent behavioral abnormality and neuroinflammatory responses in a mouse model of food allergy: a potential role of mast cells. J Neuroinflammation 2018; 15:120. [PMID: 29685134 PMCID: PMC5913881 DOI: 10.1186/s12974-018-1146-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/03/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Growing evidence has strengthened the association of food allergy with neuropsychiatric symptoms such as depression, anxiety, and autism. However, underlying mechanisms by which peripheral allergic responses lead to behavioral dysfunction are yet to be determined. Allergen-activated mast cells may serve as mediators by releasing histamine and other inflammatory factors that could adversely affect brain function. We hypothesized that eliciting food allergy in experimental animals would result in behavioral changes accompanied by mast cell accumulation in the brain. Our hypothesis was tested in a mouse model of milk allergy using bovine milk whey proteins (WP) as the allergen. METHODS Male and female C57BL/6 mice at 4 weeks (young) and 10 months (old) of age underwent 5-week WP sensitization with weekly intragastric administration of 20 mg WP and 10 μg cholera toxin as an adjuvant. Age-matched sham animals were given the vehicle containing only the adjuvant. All animals were orally challenged with 50 mg WP in week 6 and their intrinsic digging behavior was assessed the next day. Animals were sacrificed 3 days after the challenge, and WP-specific serum IgE, intestinal and brain mast cells, glial activation, and epigenetic DNA modification in the brain were examined. RESULTS WP-sensitized males showed significantly less digging activity than the sham males in both age groups while no apparent difference was observed in females. Mast cells and their activities were evident in the intestines in an age- and sex-dependent manner. Brain mast cells were predominantly located in the region between the lateral midbrain and medial hippocampus, and their number increased in the WP-sensitized young, but not old, male brains. Noticeable differences in for 5-hydroxymethylcytosine immunoreactivity were observed in WP mice of both age groups in the amygdala, suggesting epigenetic regulation. Increased microglial Iba1 immunoreactivity and perivascular astrocytes hypertrophy were also observed in the WP-sensitized old male mice. CONCLUSIONS Our results demonstrated that food allergy induced behavioral abnormality, increases in the number of mast cells, epigenetic DNA modification in the brain, microgliosis, and astrocyte hypertrophy in a sex- and age-dependent manner, providing a potential mechanism by which peripheral allergic responses evoke behavioral dysfunction.
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Affiliation(s)
- Danielle L Germundson
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Nicholas A Smith
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Lane P Vendsel
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Andrea V Kelsch
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Colin K Combs
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA
| | - Kumi Nagamoto-Combs
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Stop 9037, Grand Forks, ND, 58202-9037, USA.
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