VEGF - Vascular Endothelial Growth Factor

By popular demand, a thread on VEGF, Vascular Endothelial Growth Factor. As the name suggests, it's involved in the growth of blood vessels, e.g. after wounding or hypoxia.

 

So, if a cell doesn't have enough oxygen, all other things being equal, it sends a signal that releases VEGF-A. VEGF-A binds to endothelial cells, triggering angiogenesis, the development of new blood vessels.

We have this paper related to this:
The Emerging Role of Pericyte-Derived Extracellular Vesicles in Vascular and Neurological Health 2022 Sharma et al


The development of new blood vessels and higher levels of endothelial permeability isn't always good. High levels of VEGF are associated with some diseases e.g. tumours, and in diabetic retinopathy.

 

Ebola
Ebola virus disrupts the inner blood-retinal barrier by induction of vascular endothelial growth factor in pericytes 2023 Gao et al
Ebola virus particles have been found to stimulate pericytes to secrete VEGF, causing a weaker blood-retinal barrier. They give examples of viruses affecting the integrity of the vascular endothelium. They report that anti-VEGF medication can restore barrier function.

Covid and Long Covid
Case series: Maraviroc and pravastatin as a therapeutic option to treat long COVID/Post-acute sequelae of COVID (PASC), Patterson et al 2023
Patterson's team reported finding that VEGF levels reduced as symptoms of Long Covid reduced. That might just be a natural reduction of levels that were high during the Covid-19 infection and not related to reductions in post-Covid symptoms over time. More on this thread too.

Clinical and biochemical characteristics of people experiencing post-coronavirus disease 2019-related symptoms:... 2022 Alfadda et al. This team reported higher levels of VEGF in people reporting the greatest severity of post-Covid symptoms.

Elevated vascular transformation blood biomarkers in Long-COVID indicate angiogenesis as a key pathophysiological mechanism 2022, Patel et al. This paper reported higher levels of various sorts of VEGF in people with Long Covid symptoms compared to healthy controls. However, they didn't have controls that had had Covid-19 but didn't have persistent symptoms. So, we don't know if the raised levels are just a product of a recent viral infection.


Gender differences
Sex differences in the blood-brain barrier: Implications for mental health, 2022, Dion-Albert et al
It is notes that VEGF increases during pregnancy, as there is a lot of blood vessel creation going on. Therefore, pregnancy might be a natural experiment if levels of VEGF are relevant to ME/CFS.

 

Fibromyalgia
CGRP, VEGF, and Clinical Manifestations in Women with Fibromyalgia, 2022, Rus et al. That study looked at levels of VEGF in women with fibromyalgia; they did not find any differences from healthy controls.

Conversion disorder/motor FND
Assessment of cytokines, microRNA and patient related outcome measures in conversion disorder/[FND], 2021, van der Feltz-Cornelis et al. In this small sample, people with motor FND and a range of other symptoms had VEGF at the low end of the normal range.

 

Exercise intolerance and ME/CFS
Rather than high levels, there are some papers suggesting that low levels of VEGF might be relevant to ME/CFS.

..effect of VEGF gene inactivation ... on muscle enzyme activity, capillary supply & endurance exercise, 2020, Breen et al
In mice.

That thread has links to a couple of papers that found low levels of VEGF in ME/CFS. It might be worth making threads for them, to have a closer look.

There is other interesting discussion there, including a link to a paper suggesting that VEGF is protective against neurodegeneration.

 

There's some relevant discussion here:
Snow Leopard's cornucopia of wonder!
Including this paper:
Beyond the Matrix: The Many Non-ECM Ligands for Integrins
Some pathogens can disrupt the VEGF mechanisms e.g. increasing vascular permeability for a given level of VEGF

The impact of a certain level of VEGF depends on the integrins binding to it (so it probably won't be as simple as a straight line between VEGF levels and symptoms)

 

From a member, thank you for this:

According to a German laboratory called IMD Berlin, Bartonella are the only (currently) known bacteria to induce VEGF in infected cells.

Deepl translation from their pdf - attached below (page 2):

Differential diagnosis of Bartonellosis - the 2nd indication for VEGF determination in blood.

Elevated serum VEGF levels are a differential diagnostic indication of Bartonella henselae co-infection in patients with tick-borne diseases. Bartonella are aerobic gram-negative rod-shaped bacteria. The reservoir of Bartonella is the domestic cat. Transmission to humans occurs through scratch or bite wounds of infected cats, but also through ticks. In the acute infection stage, they induce cat scratch disease. In the chronic infection stage, they can induce permanent immune activations. There is much evidence that co-infection limits therapeutic success in patients with Lyme disease.

Elevated VEGF blood levels are an indication of infection

Bartonella is the only human pathogenic bacterium described to date that induces VEGF in the infected cells. Fig. 3 shows the mechanism why the induction of VEGF confers a survival advantage to the bacteria. The proliferating bartonellae induce an energy deficit in the affected cells, i.e., they trigger an ATP deficiency. This deficit would reduce the probability of survival not only for the cells but also for the bartonellae themselves. The induction of VEGF and the resulting improved blood flow and nutrient supply to the infected tissue leads to a survival advantage for the bartonellae and thus to pathogen persistence. Whether increased VEGF levels are also associated with greater resistance to therapy and whether therapeutic reduction of VEGF levels can accelerate the success of pathogen-specific therapies can be assumed, but remains to be confirmed by clinical studies.

- - - - - - - - -
IMD Berlin cite only one source for this (Kempf et al.)attached as a pdf (in German).
There is a thesis about this (also in German), which can be found here: https://edoc.ub.uni-muenchen.de/1697/1/Volkmann_Bettina.pdf

 

Yes, VEGF certainly is a molecule that is involved with a number of the things that come up often in ME/CFS research and theories. It would be good to have a close look at the papers reporting low levels in ME/CFS (mentioned in post #5) to see how reliable they look.

It's a bit hard to make a coherent story as yet, with the reports of high levels in some relevant conditions such as Long Covid. As I mentioned, as @Snow Leopard I think has said, things may be more complicated, with it not being so much about VEGF levels, but how effective the molecules can be. That might require looking at integrins and other things.

It might even be as complicated as an ongoing battle with an intracellular pathogen that tries to increase VEGF in order to increase nutrient supply as hypothesised by IMD Berlin above, but where the host (i.e. us) dials down the VEGF (and turns on the itaconate shunt) to try to essentially starve the pathogen to keep it under control. Clearly, I'm just tossing ideas around.

Anyway, it's good to 'put faces to the names' of these molecules, to start to understand what they do and how they work, and have possibilities to look at. It can help us make better sense of new research and maybe allow us to connect the dots.

On Bartonella, I find it an interesting pathogen, I posted about it on PR. We might need a thread on that too.