Tag: AMPK

Effect of herbal cake-separated moxibustion on behavioral stress reactions and blood lactic acid level and muscular AMPK/PGC-1α signaling in rats with chronic fatigue syndrome

Abstract:

in English, Chinese

Objective: To observe the effect of herbal cake-separated moxibustion (HCSM) on serum lactic acid (BLA) level and AMPK/PGC-1α signaling pathway in the quadriceps femoris in chronic fatigue syndrome (CFS) rats, so as to explore its mechanisms underlying improvement of CFS.

Methods: According to the random number table, 50 SD rats were divided into blank control, model, HCSM, sham HCSM and medication (herbal medicine gavage) groups, with 10 rats in each group. The CFS model was established by using chronic restraint and exhaustive swimming, alternately, once daily for 21 days. The herbal cake was made of Xiaoyao Powder (Mental Ease Powder, composed of [Danggui (Radix Angelicae Sinensis), Baishao (Radix Paeoniae Alba), Chaihu (Radix Bupleuri), Fuling (Poria), Baizhu (Rhizoma Atractylodis, Macrocephalae), etc.]. The HCSM was applied to “Shenque” (CV8), “Guanyuan “(CV4), bilateral “Zusanli” (ST36) and “Qimen” (LR14), 5 moxa-cones for each acupoint, once daily for 10 days. For sham HCSM, the excipient was instead of herbal cake, and the same 5 moxa-cones was given as the HCSM group. Rats of the medication group received gavage of Xiaoyao Powder suspension (60 mg·kg-1), once daily for 10 days. The open field test and tail suspension test were conducted for determining the animals’ locomotor activity. The blood sample was taken from the abdominal aorta under anesthesia for assaying the levels of serum BLA, chemokine ligand CXCL9 and β-endorphin (EP) by ELISA. Bilateral quadriceps femoris were sampled for observing histopathological changes after staining with conventional H.E. technique, and for detecting the expression levels of phosphorylated AMP-activated protein kinase (p-AMPK) and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) by using immunohistochemistry.

Results: Compared with the blank control group, the number of rearing and horizontal grid-crossing times, struggling times of tail suspension test were significantly decreased (P<0.05), and the immobility time was obviously prolonged (P<0.05) in the model group. Compared with the model group, both HCSM and medication groups had a significant increase of rearing, horizontal grid-crossing times and struggling times (P<0.05), and the immobility time had a significant decrease (P<0.05). But there were no significant differences in the total movement distance among the 5 groups (P>0.05), and in the 5 indexes of behavioral measurements between the HCSM and medication groups (P>0.05). The sham HCSM could also evidently increase the struggling times and reduce the immobility time (P<0.05). The contents of serum BLA, CXCL9 and β-EP were obviously higher in the model group than in the blank control group (P<0.05), as well as remarkably lower in the HCSM and medication groups than in the model group (P<0.05). Whereas the expression levels of muscular p-AMPK and PGC-1α were considerably lower in the model group than in the blank control group (P<0.05), and significantly increased in both HCSM and medication groups relevant to the model group (P<0.05). Compared with the sham HCSM group, the contents of BLA, CXCL9 and β-EP in serum of the HCSM group and contents of CXCL9, β-EP in medication group were significantly decreased (P<0.05), and the protein expressions of p-AMPK and PGC-1α in quadriceps femoris in both HCSM and medication groups were significantly increased (P<0.05). H.E. staining showed smaller intercellular space, uneven cytoplasmic staining in some muscle fibers, nucleus pyknosis and condensation, and inflammatory cell infiltration in the model group, which was milder in both HCSM and medication groups.

Conclusion: HCSM can mitigate the stress behavioral state in CFS rats, which may be related with its functions in lowering the levels of serum BLA, CXCL9 and β-EP, and activating AMPK/PGC-1α signaling pathway (balancing energy metabolism) in the quadriceps femoris.

Source: Xu XS, Ma W, Xiong LJ, Zhai CT, Li W, Tian YF. [Effect of herbal cake-separated moxibustion on behavioral stress reactions and blood lactic acid level and muscular AMPK/PGC-1α signaling in rats with chronic fatigue syndrome]. Zhen Ci Yan Jiu. 2022 Oct 25;47(10):878-84. Chinese. doi: 10.13702/j.1000-0607.20220017. PMID: 36301164. https://pubmed.ncbi.nlm.nih.gov/36301164/

CD24 expression and B cell maturation shows a novel link with energy metabolism: potential implications for patients with Myalgic Encephalomyelitis / Chronic Fatigue Syndrome

Abstract:

CD24 expression on pro-B cells plays a role in B cell selection and development in the bone marrow. We previously detected higher CD24 expression and frequency within IgD+ naïve and memory B cells in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) compared with age-matched healthy controls (HC). Here, we investigated the relationship between CD24 expression and B cell maturation.

In vitro stimulation of isolated B cells in response to conventional agonists were used to follow the dynamics of CD24 positivity during proliferation and differentiation (or maturation). The relationship between CD24 expression to cycles of proliferation and metabolism in purified B cells from HC was also investigated using phospho-flow (phosphorylation of AMPK-pAMPK), 1proton nuclear magnetic resonance and Mitotracker Far-red (Mitochondrial mass-MM).

In vitro, in the absence of stimulation, there was an increased percentage of CD24+ viable B cells in ME/CFS patients compared to HC (p< 0.05) following 5 days culture. Following stimulation with B cell agonists, percentage of CD24+B cells in both naïve and memory B cell populations decreased. p< 0.01). There was a negative relationship between percentage of CD24+B cells with MM (R2=0.76; p< 0.01), which was subsequently lost over sequential cycles of proliferation. There was a significant correlation between CD24 expression on B cells and the usage of glucose and secretion of lactate in vitro. Short term ligation of the B cell receptor with anti-IgM antibody significantly reduced the viability of CD24+ memory B cells compared to those cross-linked by anti-IgD or anti-IgG antibody.

A clear difference was found between naïve and memory B cells with respect to CD24 expression and pAMPK, most notably a strong positive association in IgD+IgM+ memory B cells. In vitro findings confirmed dysregulation of CD24-expressing B cells from ME/CFS patients previously suggested by immunophenotype studies of B cells from peripheral blood. CD24-negative B cells underwent productive proliferation whereas CD24+ B cells were either unresponsive or susceptible to cell death upon BCR-engagement alone. We suggest that CD24 expression may reflect variations in energy metabolism on different B cell subsets.

Source: Fane K. Mensah, Christopher W. Armstrong, Venkat Reddy, Amolak S. Bansal, Saul Berkovitz, Maria Leandro and Geraldine Cambridge. CD24 expression and B cell maturation shows a novel link with energy metabolism: potential implications for patients with Myalgic
Encephalomyelitis / Chronic Fatigue Syndrome. Front. Immunol. | doi: 10.3389/fimmu.2018.02421 https://www.frontiersin.org/articles/10.3389/fimmu.2018.02421/abstract

Pharmacological activation of AMPK and glucose uptake in cultured human skeletal muscle cells from patients with ME/CFS

Abstract:

Background: Skeletal muscle fatigue and post-exertional malaise are key symptoms of Myalgic Encephalomyelitis (ME/CFS). We have previously shown that AMPK activation and glucose uptake are impaired in primary human skeletal muscle cell cultures derived from patients with ME/CFS in response to electrical pulse stimulation, a method which induces contraction of muscle cells in vitro. The aim of this study was to assess if AMPK could be activated pharmacologically in ME/CFS.

Methods: Primary skeletal muscle cell cultures from patients with ME/CFS and healthy controls were treated with either metformin or 991. AMPK activation was assessed by Western blot and glucose uptake measured.

Results: Both metformin and 991 treatment significantly increased AMPK activation and glucose uptake in muscle cell cultures from both controls and ME/CFS. Cellular ATP content was unaffected by treatment although ATP content was significantly decreased in ME/CFS compared to controls.

Conclusions: Pharmacological activation of AMPK can improve glucose uptake in muscle cell cultures from patients with ME/CFS. This suggests that the failure of electrical pulse stimulation to activate AMPK in these muscle cultures is due to a defect proximal to AMPK. Further work is required to delineate the defect and determine whether pharmacological activation of AMPK improves muscle function in patients with ME/CFS.

Source: Brown AE, Dibnah B, Fisher E, Newton JL, Walker M. Pharmacological activation of AMPK and glucose uptake in cultured human skeletal muscle cells from patients with ME/CFS. Biosci Rep. 2018 Apr 13. pii: BSR20180242. doi: 10.1042/BSR20180242. [Epub ahead of print]  https://www.ncbi.nlm.nih.gov/pubmed/29654166/

 

Abnormalities of AMPK activation and glucose uptake in cultured skeletal muscle cells from individuals with chronic fatigue syndrome

Abstract:

BACKGROUND: Post exertional muscle fatigue is a key feature in Chronic Fatigue Syndrome (CFS). Abnormalities of skeletal muscle function have been identified in some but not all patients with CFS. To try to limit potential confounders that might contribute to this clinical heterogeneity, we developed a novel in vitro system that allows comparison of AMP kinase (AMPK) activation and metabolic responses to exercise in cultured skeletal muscle cells from CFS patients and control subjects.

METHODS: Skeletal muscle cell cultures were established from 10 subjects with CFS and 7 age-matched controls, subjected to electrical pulse stimulation (EPS) for up to 24h and examined for changes associated with exercise.

RESULTS: In the basal state, CFS cultures showed increased myogenin expression but decreased IL6 secretion during differentiation compared with control cultures. Control cultures subjected to 16 h EPS showed a significant increase in both AMPK phosphorylation and glucose uptake compared with unstimulated cells. In contrast, CFS cultures showed no increase in AMPK phosphorylation or glucose uptake after 16 h EPS. However, glucose uptake remained responsive to insulin in the CFS cells pointing to an exercise-related defect. IL6 secretion in response to EPS was significantly reduced in CFS compared with control cultures at all time points measured.

CONCLUSION: EPS is an effective model for eliciting muscle contraction and the metabolic changes associated with exercise in cultured skeletal muscle cells. We found four main differences in cultured skeletal muscle cells from subjects with CFS; increased myogenin expression in the basal state, impaired activation of AMPK, impaired stimulation of glucose uptake and diminished release of IL6. The retention of these differences in cultured muscle cells from CFS subjects points to a genetic/epigenetic mechanism, and provides a system to identify novel therapeutic targets.

 

Source: Brown AE, Jones DE, Walker M, Newton JL. Abnormalities of AMPK activation and glucose uptake in cultured skeletal muscle cells from individuals with chronic fatigue syndrome. PLoS One. 2015 Apr 2;10(4):e0122982. doi: 10.1371/journal.pone.0122982. ECollection 2015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4383615/ (Full article)