Tag: mouse model

Olmesartan alleviates symptoms of chronic fatigue syndrome in mice

Abstract:

Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) is a lifestyle-related ailment that affects physical and mental abilities.

The etiology is largely unidentified but there are certain multifactorial mechanisms responsible such as mitochondrial aerobic pathways aberrations, hypothalamic-pituitary-adrenal (HPA) axis deregulation, immune hyperactivation, free radicals, pathogen infections, and central neurohumoral alterations.

Olmesartan is an antihypertensive drug that acts on the angiotensin 1 (AT1 ) receptor. The present research evaluated the efficiency of Olmesartanagainst CFS.

CFS was induced by lipopolysaccharide (LPS, 1mg/kg, i.p.) once on day 1 trailed by a forced swim (10 minutes) continued for 21 consecutive times once each day. Olmesartan (1and 3mg/kg, p.o.) and dexamethasone (standard drug, 0.5mg/kg, i.p.) were given from the 1 st to 21 st day.

Immobility time was noted in the forced swim test (FST). Elevated plus maze, raised zero maze, and open field tests were employed to assess animal behavior. Plasma glucose and cortisol, lipid peroxidation, and GSH levels were determined in the whole brain. LPS and repeated forced swim sessions instigated symptoms of CFS such as memory deficit and depression and anxiety-like symptoms.

Findings suggested that Olmesartan shortened the immobility period of mice against CFS in FST. Olmesartan reduced memory deficits, increased ambulation, and exerted an anxiolytic effect. Olmesartan treatment reduced blood cortisol levels, brain TBARS, and enhanced brain GSHin the CFS mouse model.

Hence, Olmesartan may prove to be an effective treatment for CFS and related behavioral discrepancies.

Source:

Mild respiratory SARS-CoV-2 infection can cause multi-lineage cellular dysregulation and myelin loss in the brain

Abstract:

Survivors of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection frequently experience lingering neurological symptoms, including impairment in attention, concentration, speed of information processing and memory. This long-COVID cognitive syndrome shares many features with the syndrome of cancer therapy-related cognitive impairment (CRCI). Neuroinflammation, particularly microglial reactivity and consequent dysregulation of hippocampal neurogenesis and oligodendrocyte lineage cells, is central to CRCI. We hypothesized that similar cellular mechanisms may contribute to the persistent neurological symptoms associated with even mild SARS-CoV-2 respiratory infection.

Here, we explored neuroinflammation caused by mild respiratory SARS-CoV-2 infection – without neuroinvasion – and effects on hippocampal neurogenesis and the oligodendroglial lineage. Using a mouse model of mild respiratory SARS-CoV-2 infection induced by intranasal SARS-CoV-2 delivery, we found white matter-selective microglial reactivity, a pattern observed in CRCI. Human brain tissue from 9 individuals with COVID-19 or SARS-CoV-2 infection exhibits the same pattern of prominent white matter-selective microglial reactivity. In mice, pro-inflammatory CSF cytokines/chemokines were elevated for at least 7-weeks post-infection; among the chemokines demonstrating persistent elevation is CCL11, which is associated with impairments in neurogenesis and cognitive function.

Humans experiencing long-COVID with cognitive symptoms (48 subjects) similarly demonstrate elevated CCL11 levels compared to those with long-COVID who lack cognitive symptoms (15 subjects). Impaired hippocampal neurogenesis, decreased oligodendrocytes and myelin loss in subcortical white matter were evident at 1 week, and persisted until at least 7 weeks, following mild respiratory SARS-CoV-2 infection in mice. Taken together, the findings presented here illustrate striking similarities between neuropathophysiology after cancer therapy and after SARS-CoV-2 infection, and elucidate cellular deficits that may contribute to lasting neurological symptoms following even mild SARS-CoV-2 infection.

Source: Fernández-Castañeda A, Lu P, Geraghty AC, Song E, Lee MH, Wood J, Yalçın B, Taylor KR, Dutton S, Acosta-Alvarez L, Ni L, Contreras-Esquivel D, Gehlhausen JR, Klein J, Lucas C, Mao T, Silva J, Peña-Hernández MA, Tabachnikova A, Takahashi T, Tabacof L, Tosto-Mancuso J, Breyman E, Kontorovich A, McCarthy D, Quezado M, Hefti M, Perl D, Folkerth R, Putrino D, Nath A, Iwasaki A, Monje M. Mild respiratory SARS-CoV-2 infection can cause multi-lineage cellular dysregulation and myelin loss in the brain. bioRxiv [Preprint]. 2022 Jan 10:2022.01.07.475453. doi: 10.1101/2022.01.07.475453. PMID: 35043113; PMCID: PMC8764721.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8764721/ (Full text)

Animal Models for Neuroinflammation and Potential Treatment Methods

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease of unknown etiology and without effective treatment options. The onset of ME/CFS is often associated with neuroinflammation following bacterial or viral infection.

A positron emission tomography imaging study revealed that the degree of neuroinflammation was correlated with the severity of several symptoms in patients with ME/CFS. In animal studies, lipopolysaccharide- and polyinosinic-polycytidylic acid-induced models are thought to mimic the pathological features of ME/CFS and provoke neuroinflammation, characterized by increased levels of proinflammatory cytokines and activation of microglia.

In this review, we described the anti-inflammatory effects of three compounds on neuroinflammatory responses utilizing animal models. The findings of the included studies suggest that anti-inflammatory substances may be used as effective therapies to ameliorate disease symptoms in patients with ME/CFS.

Source: Tamura Y, Yamato M, Kataoka Y. Animal Models for Neuroinflammation and Potential Treatment Methods. Front Neurol. 2022 Jun 27;13:890217. doi: 10.3389/fneur.2022.890217. PMID: 35832182; PMCID: PMC9271866. https://pubmed.ncbi.nlm.nih.gov/35832182/  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9271866/ (Full study)

Mild respiratory COVID can cause multi-lineage neural cell and myelin dysregulation

Summary:

COVID survivors frequently experience lingering neurological symptoms that resemble cancer therapy-related cognitive impairment, a syndrome for which white-matter microglial reactivity and consequent neural dysregulation is central. Here, we explored the neurobiological effects of respiratory SARS-CoV-2 infection and found white-matter-selective microglial reactivity in mice and humans.
Following mild respiratory COVID in mice, persistently impaired hippocampal neurogenesis, decreased oligodendrocytes and myelin loss were evident together with elevated CSF cytokines/chemokines including CCL11. Systemic CCL11 administration specifically caused hippocampal microglial reactivity and impaired neurogenesis. Concordantly, humans with lasting cognitive symptoms post-COVID exhibit elevated CCL11 levels. Compared to SARS-CoV-2, mild respiratory influenza in mice caused similar patterns of white matter-selective microglial reactivity, oligodendrocyte loss, impaired neurogenesis and elevated CCL11 at early timepoints, but after influenza only elevated CCL11 and hippocampal pathology persisted. These findings illustrate similar neuropathophysiology after cancer therapy and respiratory SARS-CoV-2 infection which may contribute to cognitive impairment following even mild COVID.
Source: Anthony Fernández-Castañeda, Peiwen Lu, Anna C. Geraghty, Eric Song, MyoungHwa Lee, Jamie Wood, Michael R. O’Dea, Selena Dutton, Kiarash Shamardani, Kamsi Nwangwu, Rebecca Mancusi, Belgin Yalçın, Kathryn R. Taylor, Lehi AcostaAlvarez, Karen Malacon, Michael B. Keough, Lijun Ni, Pamelyn J. Woo, Daniel Contreras-Esquivel, Angus Martin Shaw Toland, Jeff R. Gehlhausen, Jon Klein, Takehiro Takahashi, Julio Silva, Benjamin Israelow, Carolina Lucas, Tianyang Mao, Mario A. Peña-Hernández, Alexandra Tabachnikova, Robert J. Homer, Laura Tabacof, Jenna Tosto-Mancuso, Erica Breyman, Amy Kontorovich, Dayna McCarthy, Martha Quezado, Hannes Vogel, Marco M. Hefti, Daniel P. Perl, Shane Liddelow, Rebecca Folkerth, David Putrino, Avindra Nath, Akiko Iwasaki, Michelle Monje. Mild respiratory COVID can cause multi-lineage neural cell and myelin dysregulation.  Cell (2022). Published: June 12, 2022 DOI:https://doi.org/10.1016/j.cell.2022.06.008 https://www.sciencedirect.com/science/article/pii/S0092867422007139 (Full text available as PDF file)

Electroacupuncture at BL15 attenuates chronic fatigue syndrome by downregulating iNOS/NO signaling in C57BL/6 mice

Abstract:

in English, Chinese

Chronic fatigue syndrome (CFS) has a high incidence due to the increased pressure of daily life and work in modern society. Our previous clinical studies have found the effects of electroacupuncture (EA) on CFS patients, however, the mechanism of EA on CFS is still unknown. In this study, we investigated the effects of EA on cardiac function in a CFS mouse model to explore its underlying mechanism.

The mice were randomly divided into three groups: control, CFS, and CFS mice receiving EA (CFS + EA). After behavioral assessments and echocardiographic measurement, blood and heart tissue of the mice were collected for biochemical tests, and then we evaluated the effects of EA on the CFS mouse model when nitric oxide (NO) levels were enhanced by l-arginine.

The results showed that EA ameliorated the injured motor and cardiac function. Meanwhile, EA also inhibited increased expression of inducible nitric oxide synthase (iNOS) at heart tissue and the serum NO levels in mice subjected to sustained forced swimming stress. Furthermore, the NO level in serum increased with l-arginine administration, which blocked the effects of EA on CFS mice. This study suggested that EA could improve the motor function and cardiac function in CFS mice and its effects may be associated with the down-regulation of iNOS/NO signaling.

Source: Zhu Y, Wang J, Yao L, Huang Y, Yang H, Yu X, Chen X, Chen Y. Electroacupuncture at BL15 attenuates chronic fatigue syndrome by downregulating iNOS/NO signaling in C57BL/6 mice. Anat Rec (Hoboken). 2022 May 24. doi: 10.1002/ar.24953. Epub ahead of print. PMID: 35608198. https://pubmed.ncbi.nlm.nih.gov/35608198/

Development of a Mouse Model for Chronic Fatigue Syndrome

Abstract:

The purpose of this study was to develop a clinically relevant mouse model of CFS to allow for the testing of underlying mechanisms and development of novel treatment interventions.

Mice were injected with either lipopolysaccharide (LPS) or Poly I:C systemically (0.1- 1.0 mg/kg LPS, i.p. or 0.6-6mg/kg Poly I:C) and compared to a vehicle control injection.

To test for fatigue-like behaviors, we examined voluntary wheel running (VWR) and open field activity.

To test for pain-like behaviors, muscle withdrawal thresholds (MWT) and mechanical sensitivity of the paw.

Measurements were assessed before and up to 1 week after injection of LPS or Poly I:C.

Differences in voluntary running wheel data were assessed using mixed model analysis for differences between dose, time and an interaction between dose and time.

Differences in open field parameters, MWT, and paw sensitivity between groups were assessed using repeated measures ANOVAs.

Running wheel activity was reduced after injection of either LPS or Poly I:C (χ2=15.4; p=0.003).

LPS reduced running wheel activity on days 1-3 for the 1.0 mg/kg dose of LPS and on Day 1 for Poly I:C when compared to vehicle (p<0.001).

Lower doses of LPS showed faster recovery to baseline.

For the open field testing, LPS reduced in distance travelled (F=9.1; p<0.001), increase in time standing still (F=6.5, p=0.001) but not time in center (F= 1.1, p=0.36) 24h after infection.

Post-hoc testing (Tukey’s test) showed a significant difference between the vehicle and the 1.0 mg/kg group of LPS (p=0.001).

Similar reductions were observed for the 6 mg/kg group of Poly I:C (p<0.001). For pain behaviors, there was no difference between groups in the MWT or paw sensitivity (p>0.05) for either LPS or Poly I:C.

These results show that a single injection of an infectious agent reduces physical activity and exploratory behavior, but does not produce pain behaviors.

Source: Adam Janowski, Joseph Lesnak, Ashley Plumb, Lynn Rasmussen, Kathleen Sluka. Development of a Mouse Model for Chronic Fatigue Syndrome. The Journal of Pain 23 (5): 12. https://www.sciencedirect.com/science/article/abs/pii/S152659002200092X

TLR Antagonism by Sparstolonin B Alters Microbial Signature and Modulates Gastrointestinal and Neuronal Inflammation in Gulf War Illness Preclinical Model

Abstract:

The 1991 Persian Gulf War veterans presented a myriad of symptoms that ranged from chronic pain, fatigue, gastrointestinal disturbances, and cognitive deficits. Currently, no therapeutic regimen exists to treat the plethora of chronic symptoms though newer pharmacological targets such as microbiome have been identified recently. Toll-like receptor 4 (TLR4) antagonism in systemic inflammatory diseases have been tried before with limited success, but strategies with broad-spectrum TLR4 antagonists and their ability to modulate the host-microbiome have been elusive.

Using a mouse model of Gulf War Illness, we show that a nutraceutical, derived from a Chinese herb Sparstolonin B (SsnB) presented a unique microbiome signature with an increased abundance of butyrogenic bacteria. SsnB administration restored a normal tight junction protein profile with an increase in Occludin and a parallel decrease in Claudin 2 and inflammatory mediators high mobility group box 1 (HMGB1), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in the distal intestine. SsnB also decreased neuronal inflammation by decreasing IL-1β and HMGB1, while increasing brain-derived neurotrophic factor (BDNF), with a parallel decrease in astrocyte activation in vitro.

Mechanistically, SsnB inhibited the binding of HMGB1 and myeloid differentiation primary response protein (MyD88) to TLR4 in the intestine, thus attenuating TLR4 downstream signaling. Studies also showed that SsnB was effective in suppressing TLR4-induced nod-like receptor protein 3 (NLRP3) inflammasome activation, a prominent inflammatory disease pathway. SsnB significantly decreased astrocyte activation by decreasing colocalization of glial fibrillary acid protein (GFAP) and S100 calcium-binding protein B (S100B), a crucial event in neuronal inflammation. Inactivation of SsnB by treating the parent molecule by acetate reversed the deactivation of NLRP3 inflammasome and astrocytes in vitro, suggesting that SsnB molecular motifs may be responsible for its anti-inflammatory activity.

Source: Bose D, Mondal A, Saha P, Kimono D, Sarkar S, Seth RK, Janulewicz P, Sullivan K, Horner R, Klimas N, Nagarkatti M, Nagarkatti P, Chatterjee S. TLR Antagonism by Sparstolonin B Alters Microbial Signature and Modulates Gastrointestinal and Neuronal Inflammation in Gulf War Illness Preclinical Model. Brain Sci. 2020 Aug 8;10(8):532. doi: 10.3390/brainsci10080532. PMID: 32784362; PMCID: PMC7463890. https://www.mdpi.com/2076-3425/10/8/532 (Full text)

Improvement Effects of Myelophil on Symptoms of Chronic Fatigue Syndrome in a Reserpine-Induced Mouse Model

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is associated with various symptoms, such as depression, pain, and fatigue. To date, the pathological mechanisms and therapeutics remain uncertain. The purpose of this study was to investigate the effect of myelophil (MYP), composed of Astragali Radix and Salviaemiltiorrhizae Radix, on depression, pain, and fatigue behaviors and its underlying mechanisms.

Reserpine (2 mg/kg for 10 days, intraperitoneally) induced depression, pain, and fatigue behaviors in mice. MYP treatment (100 mg/kg for 10 days, intragastrically) significantly improved depression behaviors, mechanical and thermal hypersensitivity, and fatigue behavior. MYP treatment regulated the expression of c-Fos, 5-HT1A/B receptors, and transforming growth factor β (TGF-β) in the brain, especially in the motor cortex, hippocampus, and nucleus of the solitary tract. MYP treatment decreased ionized calcium binding adapter molecule 1 (Iba1) expression in the hippocampus and increased tyrosine hydroxylase (TH) expression and the levels of dopamine and serotonin in the striatum. MYP treatment altered inflammatory and anti-oxidative-related mRNA expression in the spleen and liver.

In conclusion, MYP was effective in recovering major symptoms of ME/CFS and was associated with the regulation of dopaminergic and serotonergic pathways and TGF-β expression in the brain, as well as anti-inflammatory and anti-oxidant mechanisms in internal organs.

Source: Song JH, Won SK, Eom GH, Lee DS, Park BJ, Lee JS, Son CG, Park JY. Improvement Effects of Myelophil on Symptoms of Chronic Fatigue Syndrome in a Reserpine-Induced Mouse Model. Int J Mol Sci. 2021 Sep 22;22(19):10199. doi: 10.3390/ijms221910199. PMID: 34638540. https://pubmed.ncbi.nlm.nih.gov/34638540/

Inflammation plays a causal role in fatigue-like behavior induced by pelvic irradiation in mice

Abstract:

Fatigue is a persistent and debilitating symptom following radiation therapy for prostate cancer. However, it is not well-understood how radiation targeted to a small region of the body can lead to broad changes in behavior. In this study, we used targeted pelvic irradiation of healthy male mice to test whether inflammatory signaling mediates changes in voluntary physical activity levels.

First, we tested the relationship between radiation dose, blood cell counts, and fatigue-like behavior measured as voluntary wheel-running activity. Next, we used oral minocycline treatments to reduce inflammation and found that minocycline reduces, but does not eliminate, the fatigue-like behavioral changes induced by radiation. We also used a strain of mice lacking the MyD88 adaptor protein and found that these mice also showed less fatigue-like behavior than the wild-type controls. Finally, using serum and brain tissue samples, we determined changes in inflammatory signaling induced by irradiation in wild-type, minocycline treated, and MyD88 knockout mice.

We found that irradiation increased serum levels of IL-6, a change that was partially reversed in mice treated with minocycline or lacking MyD88. Overall, our results suggest that inflammation plays a causal role in radiation-induced fatigue and that IL-6 may be an important mediator.

Source: Wolff BS, Alshawi SA, Feng LR, Juneau PL, Saligan LN. Inflammation plays a causal role in fatigue-like behavior induced by pelvic irradiation in mice. Brain Behav Immun Health. 2021 May 19;15:100264. doi: 10.1016/j.bbih.2021.100264. PMID: 34589770; PMCID: PMC8474574. https://pubmed.ncbi.nlm.nih.gov/34589770/

Passive transfer of fibromyalgia symptoms from patients to mice

Abstract:

Fibromyalgia syndrome (FMS) is characterized by widespread pain and tenderness, and patients typically experience fatigue and emotional distress. The etiology and pathophysiology of fibromyalgia are not fully explained and there are no effective drug treatments. Here we show that IgG from FMS patients produced sensory hypersensitivity by sensitizing nociceptive neurons. Mice treated with IgG from FMS patients displayed increased sensitivity to noxious mechanical and cold stimulation, and nociceptive fibers in skin-nerve preparations from mice treated with FMS IgG displayed an increased responsiveness to cold and mechanical stimulation.

These mice also displayed reduced locomotor activity, reduced paw grip strength, and a loss of intraepidermal innervation. In contrast, transfer of IgG-depleted serum from FMS patients or IgG from healthy control subjects had no effect. Patient IgG did not activate naive sensory neurons directly. IgG from FMS patients labeled satellite glial cells and neurons in vivo and in vitro, as well as myelinated fiber tracts and a small number of macrophages and endothelial cells in mouse dorsal root ganglia (DRG), but no cells in the spinal cord. Furthermore, FMS IgG bound to human DRG. Our results demonstrate that IgG from FMS patients produces painful sensory hypersensitivities by sensitizing peripheral nociceptive afferents and suggest that therapies reducing patient IgG titers may be effective for fibromyalgia.

Source: Andreas Goebel, … , Camilla I. Svensson, David A. Andersson. Passive transfer of fibromyalgia symptoms from patients to mice. J Clin Invest. 2021;131(13):e144201. https://doi.org/10.1172/JCI144201. Published July 1, 2021 https://www.jci.org/articles/view/144201?key=51bf6d85e305f6b62f87 (Full text)