TGF-β1 – American ME and CFS Society

Exogenous Transforming Growth Factor-β in Brain-Induced Symptoms of Central Fatigue and Suppressed Dopamine Production in Mice

Abstract:

Myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) is one of the most refractory diseases in humans and is characterized by severe central fatigue accompanied with various symptoms that affect daily life, such as impaired memory, depression, and somatic pain. However, the etiology and pathophysiological mechanisms of CFS remain unknown. To investigate the pathophysiological role of transforming growth factor (TGF)-β1, we injected a cytokine into the lateral ventricle of a C57BL/6 mouse. The intracranial injection of TGF-β1 increased the immobility duration in a forced swimming test (FST) and time spent at the closed arm in elevated plus maze (EPM) analysis.

The mice injected with TGF-β1 into their brain showed increased sensitivity to pain in a von Frey test, and had a decreased retention time on rotarod and latency time in a bright box in a passive avoidance test. In addition, the serum levels of muscle fatigue biomarkers, lactate dehydrogenase (LDH) and creatine kinase (CK), were significantly increased after administration of TGF-β1. Intracranial injection of TGF-β1 significantly reduced the production of tyrosine hydroxylase (TH) in the ventral tegmental area, accompanied by a decreased level of dopamine in the striatum. The suppression of TH expression by TGF-β1 was confirmed in the human neuroblastoma cell line, SH-SY5Y. These results, which show that TGF-β1 induced fatigue-like behaviors by suppressing dopamine production, suggest that TGF-β1 plays a critical role in the development of central fatigue and is, therefore, a potential therapeutic target of the disease.

Source: Lee WK, Kim Y, Jang H, Sim JH, Choi HJ, Shin Y, Choi JJ. Exogenous Transforming Growth Factor-β in Brain-Induced Symptoms of Central Fatigue and Suppressed Dopamine Production in Mice. Int J Mol Sci. 2021 Mar 4;22(5):2580. doi: 10.3390/ijms22052580. PMID: 33806649. https://pubmed.ncbi.nlm.nih.gov/33806649/

Pitfalls in cytokine measurements – Plasma TGF-β1 in chronic fatigue syndrome

Abstract:

BACKGROUND: Serum TGF-β1 concentrations are reported to be elevated in chronic fatigue syndrome (CFS). However, measurement of circulating cytokines is a complex procedure and control of pre-analytical procedures is essential. The objective of the current study was to measure circulating TGF-β1 concentrations in CFS patients compared to healthy controls, taking into account differences in pre-analytical procedures.

METHODS: Two cohorts of female CFS patients were included. In both studies patients were asked to bring a healthy, age-matched control. At baseline, TGF-β1 levels were measured in plasma and additionally P-selectin, a marker of platelet activity, was determined in a subgroup of participants.

RESULTS: 50 patients and 48 controls were included in cohort I, and 90 patients and 29 controls in cohort II. Within the cohorts there were no differences in TGF-β1 concentrations. However, between the cohorts there was a large discrepancy, which appeared to be caused by differences in g-force of the centrifuges used. The lower g-force used in cohort II (1361 g) caused more platelet activation, reflected by higher p-selectin concentrations, compared to cohort I (p < 0.0001), which was confirmed in a second independent experiment. There was a correlation between TGF-β1 and p-selectin concentrations (r 0.79, p < 0.0001).

CONCLUSION: These results demonstrate that control of pre-analytical procedures is an essential aspect when measuring circulating cytokines. No evidence for enhanced TGF-β1 in patients with CFS was found.

Source: Roerink ME, van der Schaaf ME, Hawinkels LJAC, Raijmakers RPH, Knoop H, Joosten LAB, van der Meer JWM. Pitfalls in cytokine measurements – Plasma TGF-β1 in chronic fatigue syndrome. Neth J Med. 2018 Sep;76(7):310-313. https://www.ncbi.nlm.nih.gov/pubmed/30220655

Up-regulation of TGF-β1 mRNA expression in peripheral blood mononuclear cells of patients with chronic fatigue syndrome

Abstract:

BACKGROUND/PURPOSE: It has been shown that the abnormality in immune cells in chronic fatigue syndrome (CFS) patients is closely associated with the participation of TGF-β. In order to study the relationship between TGF-β1 and CFS, we investigated the mRNA levels of TGF-β1 in peripheral blood mononuclear cells (PBMCs) in patients with CFS.

METHODS: Fluorescent quantitative real time reverse-transcription polymerase chain reaction (FQ-RT-PCR) was performed to test TGF-β1 mRNA expression in PBMCs in 63 cases of CFS, 50 cases of disease controls, and 50 cases of healthy controls.

RESULTS: The mean value of TGF-β1 mRNA expression in CFS patients was ΔΔCt=1.17±0.58, which was significantly higher than the disease controls (ΔΔCt=0.07±1.08, df=111, p < 0.01) and the healthy controls (ΔΔCt=0.00±1.63, df=111, p < 0.01). No significant difference was detected between disease and healthy controls (p > 0.05).

CONCLUSION: The expression of TGF-β1 in PBMCs is significantly elevated in patients with CFS. It might be correlated to the pathogenesis of the disease.

Source: Zhang HY, Liu ZD, Hu CJ, Wang DX, Zhang YB, Li YZ. Up-regulation of TGF-β1 mRNA expression in peripheral blood mononuclear cells of patients with chronic fatigue syndrome. J Formos Med Assoc. 2011 Nov;110(11):701-4. doi: 10.1016/j.jfma.2011.09.006. Epub 2011 Oct 22. http://www.jfma-online.com/article/S0929-6646(11)00070-2/fulltext (Full article)