Category: Animals

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

Neuropathology and virus in brain of SARS-CoV-2 infected non-human primates

Abstract:

Neurological manifestations are a significant complication of coronavirus disease (COVID-19), but underlying mechanisms aren’t well understood. The development of animal models that recapitulate the neuropathological findings of autopsied brain tissue from patients who died from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are critical for elucidating the neuropathogenesis of infection and disease.

Here, we show neuroinflammation, microhemorrhages, brain hypoxia, and neuropathology that is consistent with hypoxic-ischemic injury in SARS-CoV-2 infected non-human primates (NHPs), including evidence of neuron degeneration and apoptosis. Importantly, this is seen among infected animals that do not develop severe respiratory disease, which may provide insight into neurological symptoms associated with “long COVID”. Sparse virus is detected in brain endothelial cells but does not associate with the severity of central nervous system (CNS) injury.

We anticipate our findings will advance our current understanding of the neuropathogenesis of SARS-CoV-2 infection and demonstrate SARS-CoV-2 infected NHPs are a highly relevant animal model for investigating COVID-19 neuropathogenesis among human subjects.

Source: Rutkai I, Mayer MG, Hellmers LM, Ning B, Huang Z, Monjure CJ, Coyne C, Silvestri R, Golden N, Hensley K, Chandler K, Lehmicke G, Bix GJ, Maness NJ, Russell-Lodrigue K, Hu TY, Roy CJ, Blair RV, Bohm R, Doyle-Meyers LA, Rappaport J, Fischer T. Neuropathology and virus in brain of SARS-CoV-2 infected non-human primates. Nat Commun. 2022 Apr 1;13(1):1745. doi: 10.1038/s41467-022-29440-z. PMID: 35365631. https://www.nature.com/articles/s41467-022-29440-z (Full text)

Metabolomics study of the effect of Danggui Buxue Tang on rats with chronic fatigue syndrome

Abstract:

Danggui Buxue Tang (DBT), a traditional Chinese medicine formula for “invigorating qi and enriching blood”, has been reported to produce a good effect on chronic fatigue syndrome (CFS). However, the related mechanism remains largely unresolved. In this study, a metabolomics approach with gas chromatography coupled to mass spectrometry combined with pattern recognition was devised to estimate the extent to which DBT alleviated CFS induced by food restriction and force swimming in rats.

After four weeks of treatment, the endurance capability of rats was significantly better and the motionless time was significantly shorter in the DBT group than in CFS model group. Moreover, the activities of SOD and GSH-Px were increased, while the levels of MDA, IL-6 and TNF-α were decreased in the DBT treatment group. Fifteen significantly changed metabolites were observed in the serum of rats with CFS, which was reversed markedly by DBT treatment. Metabolic pathway analysis showed that DBT could possibly alleviate CFS in rats by regulating phenylalanine, tyrosine and tryptophan biosynthesis, glycine, serine and the metabolism of threonine, glycerolipid, glyoxylate, dicarboxylate and tyrosine. It was observed that the metabolism of glycine, serine and threonine was most closely related to the improvement of CFS by DBT treatment. This study showed that DBT could improve CFS effectively and metabolomics was a powerful means to gain insights into the traditional Chinese medicine formulas against CFS.

Source: Miao X, Li S, Xiao B, Yang J, Huang R. Metabolomics study of the effect of Danggui Buxue Tang on rats with chronic fatigue syndrome. Biomed Chromatogr. 2022 Apr 4:e5379. doi: 10.1002/bmc.5379. Epub ahead of print. PMID: 35373377.  https://pubmed.ncbi.nlm.nih.gov/35373377/

Changes in TCA cycle and TCA cycle-related metabolites in plasma upon citric acid administration in rats

Abstract:

Recent studies have reported that plasma levels of tricarboxylic acid (TCA) cycle metabolites and TCA cycle-related metabolite change in patients with chronic fatigue syndrome (CFS) and in healthy humans after exercise. Exogenous dietary citric acid has been reported to alleviate fatigue during daily activities and after exercise. However, it is unknown whether dietary citric acid affects the plasma levels of these metabolites. Therefore, the present study aimed to investigate the effects of exogenously administered citric acid on TCA cycle metabolites and TCA cycle-related metabolites in plasma.

Sprague-Dawley rats were divided into control and citric acid groups. We evaluated the effect of exogenous dietary citric acid on the plasma TCA cycle and TCA cycle-related metabolites by metabolome analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). TCA cycle metabolites, including plasma citrate, cis-aconitate, and isocitrate, were significantly elevated after exogenous administration of citric acid. Anaplerotic amino acids, which are converted to TCA cycle metabolites, such as serine, glycine, tryptophan, lysine, leucine, histidine, glutamine, arginine, isoleucine, methionine, valine, and phenylalanine, also showed significantly elevated levels.

Citric acid administration significantly increased the levels of initial TCA cycle metabolites in the plasma. This increase after administration of citric acid was shown to be opposite to the metabolic changes observed in patients with CFS. These results contribute novel insight into the fatigue alleviation mechanism of citric acid.

Source: Hara Y, Kume S, Kataoka Y, Watanabe N. Changes in TCA cycle and TCA cycle-related metabolites in plasma upon citric acid administration in rats. Heliyon. 2021 Dec 4;7(12):e08501. doi: 10.1016/j.heliyon.2021.e08501. PMID: 34934832; PMCID: PMC8654791. https://pubmed.ncbi.nlm.nih.gov/34934832/

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/

Electroacupuncture improves cognitive function by inhibiting NF-κB activity in rats with chronic fatigue syndrome

Abstract:

in English, Chinese

Objective: To observe the effect of electroacupuncture (EA) on the expression of NF-κB p65 in hippocampus and the morphology of hippocampus in rats with chronic fatigue syndrome (CFS), so as to explore its mechanism in improving cognitive dysfunction of CFS.

Methods: Forty-eight SD rats were randomly divided into control, model, EA and inhibitor groups (n=12 in each group). The CFS model was established by multi-factor compound stress stimulation method. Rats of the EA group received EA (50 Hz, 1 mA) at “Baihui” (GV20), Emotional Area I and bilateral Sensory Area for 30 min, once daily for 15 days. For rats in the inhibitor group, pyrrolidine dithiocarbamate (100 mg·kg-1·d-1) was injected intraperitoneally, once a day for 15 days. Learning and memory ability was evaluated by Morris water maze test. HE staining was used to observe the morphology of hippocampus. Western blot was used to determine the expression level of NF-κB p65 in hippocampus.

Results: After mode-ling, the general status score was increased （P<0.01）, the escape latency was prolonged(P<0.01), the times of crossing the platform was decreased(P<0.01), and the expression level of NF-κB p65 in hippocampus tissue was significantly increased (P<0.05) in the model group compared with the control group. Compared with the model group, the general status score was decreased （P<0.01）, the escape latency was shortened(P<0.01), the times of crossing the platform was increased(P<0.01), and the expression level of NF-κB p65 in hippocampus tissue was significantly decreased (P<0.05) in the EA and inhibitor groups. HE staining showed that in the model group, the hippocampal nerve cells were arranged disorderly, the structure was loose, and the number of apoptotic bodies and inflammatory cells was significantly increased. The degree of tissue damage of the EA and inhibitor groups was milder than that of the model group.

Conclusion: EA can improve the cognitive function in CFS rats, which may be associated with its effect in inhibiting the expression of NF-κB and reducing the inflammation response in hippocampus.

Source: Feng CW, Qu YY, Sun ZR, Wang YL, Zhang P, Wang QY, Lin WJ, Zhang L, Yang TS. [Electroacupuncture improves cognitive function by inhibiting NF-κB activity in rats with chronic fatigue syndrome]. Zhen Ci Yan Jiu. 2021 Sep 25;46(9):775-81. Chinese. doi: 10.13702/j.1000-0607.200827. PMID: 34558244. https://pubmed.ncbi.nlm.nih.gov/34558244/ [Article in Chinese]

A proprietary herbal drug Young Yum Pill ameliorates chronic fatigue syndrome in mice

Abstract:

Background: Chronic fatigue syndrome (CFS) is a complex disease with few effective and safe therapies. Young Yum Pill (YYP), a proprietary herbal drug, has been used to relieve CFS-like symptoms. The pharmacological basis of this application of YYP is unknown.

Purpose: This study aimed to investigate the pharmacological effects and mechanisms of action of YYP in a mouse model of CFS.

Study design and methods: A food restriction and exhaustive swimming-induced mouse CFS model was used to evaluate the effects of YYP. Lymphocyte proliferation was assessed by MTT assays. T-lymphocyte subsets were analyzed by flow cytometry. Serum biochemical parameters were determined using commercial kits. Protein levels were measured by immunoblotting.

Results: Intragastric administration of YYP (2.85, 5.70, 11.40 g/kg) daily for 21 consecutive days significantly prolonged swimming time and diminished body weight loss of CFS mice. Mechanistic investigations revealed that YYP increased thymus and spleen indices of CFS mice, enhanced proliferation of lipopolysaccharide- or concanavalin A-stimulated spleen lymphocytes, and increased CD3+CD4+ and CD3+CD8+ T-cells in the spleen. YYP increased glycogen content in gastrocnemius muscle and liver, and lowered levels of triglyceride, lactic acid and urea nitrogen in sera of CFS mice. YYP suppressed the elevation of serum level of malondialdehyde, the increase of activities of lactic dehydrogenase and creatine phosphokinase, and the decrease of activity of the serum antioxidant enzyme superoxide dismutase in CFS mice. Moreover, YYP upregulated protein level of activated AMPK in gastrocnemius muscle and liver of CFS mice.

Conclusions: YYP ameliorates CFS by reversing metabolic changes, reducing oxidative damage, and improving some immune function parameters in mice. This study provides pharmacological justifications for the use of YYP in treating fatigue, including CFS.

Source: Yin C, Fu X, Chou J, Li J, Chen Y, Bai J, Wu J, Wu Y, Wang X, Yu ZL. A proprietary herbal drug Young Yum Pill ameliorates chronic fatigue syndrome in mice. Phytomedicine. 2021 May 25;88:153602. doi: 10.1016/j.phymed.2021.153602. Epub ahead of print. PMID: 34102522. https://pubmed.ncbi.nlm.nih.gov/34102522/