From cellular function to global impact: the vascular perspective on COVID-19

Portal-splenic-mesenteric venous thrombosis in COVID-19 patients: a systematic review

The COVID-19 pandemic affected millions of people worldwide. In addition to respiratory impairment, this viral infection can also provoke gastrointestinal symptoms caused by vascular disorders, such as portal-splenic-mesenteric venous thrombosis (PSMVT). This systematic review aimed to investigate the profile of patients who developed PSMVT concomitant with or after viral infection and its predominant outcomes. The database searches returned 214 articles. Of these, 40 case reports were included in the review, presenting a total of 41 cases of PSMVT addressed. Males were more prevalent (n=27; 65.85%), mean age was 51.54 years, and 19.57% had a previous history of endocrine diseases. Statistically significant relationships (p<0.05) were found between patient death and tachypnea at hospital admission (p=0.043) and between patient death and age (p=0.019). It was therefore possible to identify the main profiles and risk factors for PSMVT development and mortality of COVID-19 infected patients.

Ovarian function after COVID-19: long-term effects and vaccine safety in ART patients

PURPOSE

This study aimed to evaluate the long-term impact of mild COVID-19 infection and COVID-19 vaccination on ovarian function in patients undergoing assisted reproductive technology (ART). Specifically, we assessed ovarian outcomes between 9 and 18 months post-infection and investigated the effects of COVID-19 vaccines (inactivated virus and adenovirus) on reproductive parameters.

METHODS

The study included two objectives: (a) examining ovarian function in post-COVID-19 patients (9-18 months post-infection) compared to a control group and (b) comparing reproductive outcomes in vaccinated versus unvaccinated patients. According to the study objectives, ART patients were divided into the following groups: a control group (n = 30), a post-COVID-19 group (n = 55), an unvaccinated group (n = 70), and a vaccinated group (n = 55). Findings revealed a reduction in the number of retrieved and mature oocytes in patients over 36 years in the post-COVID-19 group. Lower IL-1β levels were found in follicular fluid (FF) of post-COVID-19 patients, while VEGF levels were reestablished between 9 and 18 months post-infection. Although cell migration was reduced in endothelial cells incubated with post-COVID-19 FF, angiogenic factor levels and DNA integrity remained stable. No significant differences in retrieved or mature oocytes were observed between vaccinated and unvaccinated patients.

CONCLUSIONS

VEGF levels and DNA integrity in FF from post-COVID-19 patients were normalized between 9 and 18 months post-infection. Additionally, COVID-19 vaccination did not negatively impact ovarian response in ART patients, supporting vaccine safety in reproductive contexts.

Endogenous humoral determinants of vascular endothelial dysfunction as triggers of acute poisoning complications

The vascular endothelium is not only the semipermeable membrane that separates tissue from blood but also an organ that regulates inflammation, vascular tone, blood clotting, angiogenesis and synthesis of connective tissue proteins. It is susceptible to the direct cytotoxic action of numerous xenobiotics and to the acute hypoxia that accompanies acute poisoning. This damage is superimposed on the preformed state of the vascular endothelium, which, in turn, depends on many humoral factors. The probability that an exogenous toxicant will cause life-threatening dysfunction of the vascular endothelium, thereby complicating the course of acute poisoning, increases with an increase in the content of endogenous substances in the blood that disrupt endothelial function. These include ammonia, bacterial endotoxin, indoxyl sulfate, para-cresyl sulfate, trimethylamine N-oxide, asymmetric dimethylarginine, glucose, homocysteine, low-density and very-low-density lipoproteins, free fatty acids and products of intravascular haemolysis. Some other endogenous substances (albumin, haptoglobin, haemopexin, biliverdin, bilirubin, tetrahydrobiopterin) or food-derived compounds (ascorbic acid, rutin, omega-3 polyunsaturated fatty acids, etc.) reduce the risk of lethal vascular endothelial dysfunction. The individual variability of the content of these substances in the blood contributes to the stochasticity of the complications of acute poisoning and is a promising target for the risk reduction measures. Another feasible option may be the repositioning of drugs that affect the function of the vascular endothelium while being currently used for other indications.

Vascular dysfunction in COVID-19 patients: update on SARS-CoV-2 infection of endothelial cells and the role of long non-coding RNAs

Although COVID-19 is primarily a respiratory disease, it may affect also the cardiovascular system. COVID-19 patients with cardiovascular disorder (CVD) develop a more severe disease course with a significantly higher mortality rate than non-CVD patients. A common denominator of CVD is the dysfunction of endothelial cells (ECs), increased vascular permeability, endothelial-to-mesenchymal transition, coagulation, and inflammation. It has been assumed that clinical complications in COVID-19 patients suffering from CVD are caused by SARS-CoV-2 infection of ECs through the angiotensin-converting enzyme 2 (ACE2) receptor and the cellular transmembrane protease serine 2 (TMPRSS2) and the consequent dysfunction of the infected vascular cells. Meanwhile, other factors associated with SARS-CoV-2 entry into the host cells have been described, including disintegrin and metalloproteinase domain-containing protein 17 (ADAM17), the C-type lectin CD209L or heparan sulfate proteoglycans (HSPG). Here, we discuss the current data about the putative entry of SARS-CoV-2 into endothelial and smooth muscle cells. Furthermore, we highlight the potential role of long non-coding RNAs (lncRNAs) affecting vascular permeability in CVD, a process that might exacerbate disease in COVID-19 patients.

SARS-CoV-2 infection negatively affects ovarian function in ART patients

Several organs, such as the heart, breasts, intestine, testes, and ovaries, have been reported to be target tissues of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To date, no studies have demonstrated SARS-CoV-2 infection in the female reproductive system. In the present study, we investigated the effects of SARS-CoV-2 infection on ovarian function by comparing follicular fluid (FF) from control and recovered coronavirus disease 2019 (COVID-19) patients and by evaluating the influence of these FF on human endothelial and non-luteinized granulosa cell cultures. Our results showed that most FFs (91.3%) from screened post COVID-19 patients were positive for IgG antibodies against SARS-CoV-2. Additionally, patients with higher levels of IgG against SARS-CoV-2 had lower numbers of retrieved oocytes. While VEGF and IL-1β were significantly lower in post COVID-19 FF, IL-10 did not differ from that in control FF. Moreover, in COV434 cells stimulated with FF from post COVID-19 patients, steroidogenic acute regulatory protein (StAR), estrogen-receptor β (Erβ), and vascular endothelial growth factor (VEGF) expression were significantly decreased, whereas estrogen-receptor α (ERα) and 3β-hydroxysteroid dehydrogenase (3β-HSD) did not change. In endothelial cells stimulated with post COVID-19 FF, we observed a decrease in cell migration without changes in protein expression of certain angiogenic factors. Both cell types showed a significantly higher γH2AX expression when exposed to post COVID-19 FF. In conclusion, our results describe for the first time that the SARS-CoV-2 infection adversely affects the follicular microenvironment, thus dysregulating ovarian function.