Gasdermin-D activation by SARS-CoV-2 triggers NET and mediate COVID-19 immunopathology

Background

The release of neutrophil extracellular traps (NETs) is associated with inflammation, coagulopathy, and organ damage found in severe cases of COVID-19. However, the molecular mechanisms underlying the release of NETs in COVID-19 remain unclear.

Objectives

We aim to investigate the role of the Gasdermin-D (GSDMD) pathway on NETs release and the development of organ damage during COVID-19.

Methods

We performed a single-cell transcriptome analysis in public data of bronchoalveolar lavage. Then, we enrolled 63 hospitalized patients with moderate and severe COVID-19. We analyze in blood and lung tissue samples the expression of GSDMD, presence of NETs, and signaling pathways upstreaming. Furthermore, we analyzed the treatment with disulfiram in a mouse model of SARS-CoV-2 infection.

Results

We found that the SARS-CoV-2 virus directly activates the pore-forming protein GSDMD that triggers NET production and organ damage in COVID-19. Single-cell transcriptome analysis revealed that the expression of GSDMD and inflammasome-related genes were increased in COVID-19 patients. High expression of active GSDMD associated with NETs structures was found in the lung tissue of COVID-19 patients. Furthermore, we showed that activation of GSDMD in neutrophils requires active caspase1/4 and live SARS-CoV-2, which infects neutrophils. In a mouse model of SARS-CoV-2 infection, the treatment with disulfiram inhibited NETs release and reduced organ damage.

Conclusion

These results demonstrated that GSDMD-dependent NETosis plays a critical role in COVID-19 immunopathology and suggests GSDMD as a novel potential target for improving the COVID-19 therapeutic strategy.

SARS-CoV-2-triggered neutrophil extracellular traps mediate COVID-19 pathology

Severe COVID-19 patients develop acute respiratory distress syndrome that may progress to cytokine storm syndrome, organ dysfunction, and death. Considering that neutrophil extracellular traps (NETs) have been described as important mediators of tissue damage in inflammatory diseases, we investigated whether NETs would be involved in COVID-19 pathophysiology. A cohort of 32 hospitalized patients with a confirmed diagnosis of COVID-19 and healthy controls were enrolled. The concentration of NETs was augmented in plasma, tracheal aspirate, and lung autopsies tissues from COVID-19 patients, and their neutrophils released higher levels of NETs. Notably, we found that viable SARS-CoV-2 can directly induce the release of NETs by healthy neutrophils. Mechanistically, NETs triggered by SARS-CoV-2 depend on angiotensin-converting enzyme 2, serine protease, virus replication, and PAD-4. Finally, NETs released by SARS-CoV-2-activated neutrophils promote lung epithelial cell death in vitro. These results unravel a possible detrimental role of NETs in the pathophysiology of COVID-19. Therefore, the inhibition of NETs represents a potential therapeutic target for COVID-19.

SARS-CoV-2-triggered neutrophil extracellular traps mediate COVID-19 pathology

Severe COVID-19 patients develop acute respiratory distress syndrome that may progress to cytokine storm syndrome, organ dysfunction, and death. Considering that neutrophil extracellular traps (NETs) have been described as important mediators of tissue damage in inflammatory diseases, we investigated whether NETs would be involved in COVID-19 pathophysiology. A cohort of 32 hospitalized patients with a confirmed diagnosis of COVID-19 and healthy controls were enrolled. The concentration of NETs was augmented in plasma, tracheal aspirate, and lung autopsies tissues from COVID-19 patients, and their neutrophils released higher levels of NETs. Notably, we found that viable SARS-CoV-2 can directly induce the release of NETs by healthy neutrophils. Mechanistically, NETs triggered by SARS-CoV-2 depend on angiotensin-converting enzyme 2, serine protease, virus replication, and PAD-4. Finally, NETs released by SARS-CoV-2–activated neutrophils promote lung epithelial cell death in vitro. These results unravel a possible detrimental role of NETs in the pathophysiology of COVID-19. Therefore, the inhibition of NETs represents a potential therapeutic target for COVID-19.

Depressed Men's Lower Ability to Interpret Nonverbal Cues: A Preliminary Study

The ability to interpret nonverbal facial cues was tested with 20 depressed males prior to treatment. Each subject and matched control was asked to interpret videotaped facial cues of individuals engaged in a gambling task. Interpretive ability was significantly lower for the nontreated depressed white men than for their matched controls.

Depressed men's lower ability to interpret nonverbal cues: a preliminary study

The ability to interpret nonverbal facial cues was tested with 20 depressed males prior to treatment. Each subject and matched control was asked to interpret videotaped facial cues of individuals engaged in a gambling task. Interpretive ability was significantly lower for the nontreated depressed white men than for their matched controls.

Augmentation of haloperidol by ascorbic acid in phencyclidine intoxication

The authors studied 40 white men with acute phencyclidine (PCP) intoxication. On a random basis, 10 were treated with ascorbic acid, 10 with placebo, 10 with haloperidol, and 10 with a combination of ascorbic acid and haloperidol. While haloperidol was significantly more effective than ascorbic acid, the combination was significantly more effective than either used alone. This combination may have a specific antipsychotic role in the emergency treatment of PCP psychosis.

Space-based abstinence: alleviation of withdrawal symptoms in combinative cocaine-phencyclidine abuse

Twenty male combinative cocaine free-base/phencyclidine (space-base) abusers were studied for forty-five days, in a double-blind design. Treatment with desipramine was significantly more effective than placebo in alleviating abstinence symptoms. This study tends to support the catecholamine-depletion hypothesis of cocaine and phencyclidine withdrawal.

Comparison of clonidine and lithium in the treatment of mania

The authors compared the antimanic effects of clonidine with lithium carbonate in a double-blind crossover design with 24 volunteers. Lithium was observed to be more effective than clonidine. Some patients reported experiencing hypotension (N=8) and depression (N=7) while taking clonidine.

Contemporary drugs of abuse

The physician needs to know the signs, symptoms and recommended treatments of drug overdoses. Overdose of hallucinogens usually does not require drug therapy. Overdose of amphetamines ("uppers") may be complicated by the presence of PCP, a dissociative substance. It is important for the physician to be familiar with the street terminology for contemporary drugs of abuse and to be aware of how users obtain these drugs.

Treatment of depression in chronic cocaine and phencyclidine abuse with desipramine

An open field trial was conducted comparing desipramine and an active placebo in separate populations of chronic cocaine and phencyclidine (PCP) abusers, who discontinued their abuse. Subjects who received desipramine showed a decrease in depressive symptoms after a 20-40 day period regardless of whether they abused PCP or cocaine.

Hyperphagia in premenstrual tension syndrome

The relationship between premenstrual tension syndrome and dietary intake was studied in a population of 20 young adult women. Caloric intake was measured during the 10 days preceding and following the menstrual cycle. Those women with more severe symptoms recorded a greater increase in caloric intake. Caloric intake during the premenstrual period also increased with age. It is hypothesized that this caloric intake may be due to increased beta-endorphin levels.

Pseudocholinesterase and trait anxiety in premenstrual tension syndrome

Volunteers (N=71) with premenstrual syndrome (PMS) were given the Peck-Abraham PMS Questionnaire and separated by resulting scores into mild, moderate, and severe groups. Fourteen subjects were randomly selected from each group. Pseudocholinesterase serum levels were measured on the first day of menses for all group members. Trait anxiety was measured by the State Trait Anxiety Inventory (STAI). Pseudocholinesterase, a possible marker for trait anxiety, was found elevated in 6 of 14 (43%) of the severe PMS subjects, in 2 of the 14 (14%) moderate PMS subjects, and in none of the mild PMS subjects. Trait anxiety was found in 8 of these subjects. None of the subjects with mild PMS showed trait anxiety, while 25% of those with moderate PMS and 75% of those with severe PMS showed trait anxiety. No subject with mild PMS had trait anxiety. In this study PMS is treated as a trait-dependent form of anxiety.

Antimanic effects of verapamil

When the authors compared the antimanic effects of verapamil, lithium carbonate, and placebo, no differences were seen between lithium and verapamil and both were more effective than placebo in reducing symptoms. No major side effects emerged during the study.

Comparison of haloperidol and chlorpromazine in the treatment of phencyclidine psychosis

Phencyclidine (PCP) is a widely abused drug inducing a psychosis relieved by such dopamine antagonists as the neuroleptics. In the current study we compared two neuroleptics which act at different dopamine receptor sites. Haloperidol, a DA-2 receptor antagonist, and chlorpromazine, a DA-1 antagonist, were used to treat a total of 20 patients who experienced a phencyclidine psychosis. Ten patients each received two doses of one or the other neuroleptic on an alternating basis. Haloperidol 5 mg i.m. was shown to be superior to chlorpromazine 50 mg i.m. in relieving all signs of psychosis. The authors hypothesize that the DA-2 receptor is site-specific for PCP.

Defective response to social cues in Möbius' syndrome

A case of Möbius' syndrome is presented, with the mask-like facies and poor social relationships consistent with this diagnosis. Previous thought has implicated the inability to transmit facial cues as a cause for impoverished social functioning. The authors hypothesize that the inability to transmit is related to an inability to receive cues. They repeated a paradigm used previously to test ability to interpret facial cues. The otherwise intelligent patient could not perform a task previously performed by approximately 300 other subjects. These findings suggest that the rehabilitation of Möbius patients should include education in interpreting social cues.

Reception of nonverbal communication in alcoholics

The ability to interpret nonverbal facial cues was tested in 21 young male, primary alcoholics and a group of matched controls. All Ss were asked to view videotapes of individuals gambling and to determine only on the basis of facial cues the amount of monetary reward offered to videotaped individuals during a specific trial. On the basis of accuracy, the alcoholic group was determined to be significantly better than the control group at receiving the nonverbal cues.