Transient receptor potential melastatin 3 dysfunction in post COVID-19 condition and myalgic encephalomyelitis/chronic fatigue… (Sasso et al, 2022)

[Consul]

Transient receptor potential melastatin 3 dysfunction in post COVID-19 condition and myalgic encephalomyelitis/chronic fatigue syndrome patients


Abstract

Background
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe multisystemic condition associated with post-infectious onset, impaired natural killer (NK) cell cytotoxicity and impaired ion channel function, namely Transient Receptor Potential Melastatin 3 (TRPM3). Long-term effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has resulted in neurocognitive, immunological, gastrointestinal, and cardiovascular manifestations recently recognised as post coronavirus disease 2019 (COVID-19) condition. The symptomatology of ME/CFS overlaps significantly with post COVID-19; therefore, this research aimed to investigate TRPM3 ion channel function in post COVID-19 condition patients.

Methods
Whole-cell patch-clamp technique was used to measure TRPM3 ion channel activity in isolated NK cells of N = 5 ME/CFS patients, N = 5 post COVID-19 patients, and N = 5 healthy controls (HC). The TRPM3 agonist, pregnenolone sulfate (PregS) was used to activate TRPM3 function, while ononetin was used as a TRPM3 antagonist.

Results
As reported in previous research, PregS-induced TRPM3 currents were significantly reduced in ME/CFS patients compared with HC (p = 0.0048). PregS-induced TRPM3 amplitude was significantly reduced in post COVID-19 condition compared with HC (p = 0.0039). Importantly, no significant difference was reported in ME/CFS patients compared with post COVID-19 condition as PregS-induced TRPM3 currents of post COVID-19 condition patients were similar of ME/CFS patients currents (p > 0.9999). Isolated NK cells from post COVID-19 condition and ME/CFS patients were resistant to ononetin and differed significantly with HC (p < 0.0001).

Conclusion
The results of this investigation suggest that post COVID-19 condition patients may have impaired TRPM3 ion channel function and provide further evidence regarding the similarities between post COVID-19 condition and ME/CFS. Impaired TRPM3 channel activity in post COVID-19 condition patients suggest impaired ion mobilisation which may consequently impede cell function resulting in chronic post-infectious symptoms. Further investigation into TRPM3 function may elucidate the pathomechanism, provide a diagnostic and therapeutic target for post COVID-19 condition patients and commonalities with ME/CFS patients.

The study: https://molmed.biomedcentral.com/articles/10.1186/s10020-022-00528-y

 

[MonkeyMan]

Excellent. I really think Long COVID is our ticket out of this nightmare, and this study is just one example of why. As hard as they've tried to find answers, the woefully under-funded researchers who've worked for years and years on ME/CFS seem absolutely flummoxed. Whereas, with millions upon millions of dollars now being allocated for Long COVID research, and the increasing pressure from the Long COVID community for answers (like their excellent "How Long" campaign), we finally have reason to hope that answers will be forthcoming shortly.

 

[pattismith]

same team

Impaired TRPM3-dependent calcium influx and restoration using Naltrexone in natural killer cells of myalgic encephalomyelitis/chronic fatigue syndrome patients (springer.com)

Validation of impaired Transient Receptor Potential Melastatin 3 ion channel activity in natural killer cells from Chronic Fatigue Syndrome/ Myalgic Encephalomyelitis patients | SpringerLink

The effect of IL-2 stimulation and treatment of TRPM3 on channel co-localisation with PIP2 and NK cell function in myalgic encephalomyelitis/chronic fatigue syndrome patients | Journal of Translational Medicine | Full Text (biomedcentral.com)

Frontiers | Potential Therapeutic Benefit of Low Dose Naltrexone in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Role of Transient Receptor Potential Melastatin 3 Ion Channels in Pathophysiology and Treatment (frontiersin.org)

 

[Consul]

Im speculating the problem in mecfs could be general second messenger dysfunction.

Staines and Gradisniks research on problems in these calcium ion channels are pretty convincing to me. Also there is the Petter et al 2022 study which could imply elevated calcium levels in the cells (elevated sodium could reverse the sodium/calcium transporter).

And now there is also the genetic finding mentioned in Dibble et al 2022 where male patients with SNPs in PDE10A are more likely to get mecfs. This enzyme is supposed to break down cAMP and cGMP in the cells so their signalling effects doesnt last forever.

So calcium, cAMP and cGMP are all second messengers and if they dont come and go into the cytosol in timely fashion and in correct amounts the cells are probably going to be a complete mess.