Gasdermin D pores are dynamically regulated by local phosphoinositide circuitry

Gasdermin D forms large, ~21 nm diameter pores in the plasma membrane to drive the cell death program pyroptosis. These pores are thought to be permanently open, and the resultant osmotic imbalance is thought to be highly damaging. Yet some cells mitigate and survive pore formation, suggesting an undiscovered layer of regulation over the function of these pores. However, no methods exist to directly reveal these mechanistic details. Here, we combine optogenetic tools, live cell fluorescence biosensing, and electrophysiology to demonstrate that gasdermin pores display phosphoinositide-dependent dynamics. We quantify repeated and fast opening-closing of these pores on the tens of seconds timescale, visualize the dynamic pore geometry, and identify the signaling that controls dynamic pore activity. The identification of this circuit allows pharmacological tuning of pyroptosis and control of inflammatory cytokine release by living cells.

Efficacy of Tocilizumab in COVID-19: Single-Center Experience

Background. Cytokine release syndrome can be observed during the course of COVID-19. Tocilizumab is used for treating this highly fatal syndrome. We think that the starting time of tocilizumab is important. In this article, we aimed to discuss the efficacy of tocilizumab and to review the necessity of starting it in the early period and the laboratory values that guide us in determining the time of this early period. Methods. This retrospective study includes a total of 308 patients with a diagnosis of COVID-19 who were treated with tocilizumab, who were hospitalized in the University of Health Sciences, Gazi Yaşargil Training and Research Hospital between July 2020 and December 2020. The data of the patients were recorded on the day of hospitalization, the day of taking tocilizumab (day 0), and the 1st day, 3rd day, 7th day, and 14th day after taking tocilizumab. Data included age, gender, underlying diseases, where the patient was followed, duration of symptoms before admission to the hospital, duration of oxygen demand before tocilizumab, fever, saturation, and laboratory values. Patients were divided into the mortality group (group 1) and the survival group (group 2), and all data were compared. Results. The study consisted of 308 COVID-19 patients divided into two groups: the mortality group (group 1, n = 135 ) and the survival group (group 2, n = 173 ). The median age of the patients was 60 (min–max: 50-70) years, 75.3% ( n = 232 ) were male, and 56.8% had at least one comorbidity. While 88.9% of group 1 was in the intensive care unit, 26.6% of group 2 received tocilizumab while in the intensive care unit, and there was a statistically significant difference. Median SpO2 values and lymphocyte counts were significantly lower in group 1 than in group 2, both on the day of hospitalization and on the day of the first dose of tocilizumab treatment ( p < 0.001 for both). C-reactive protein, d-dimer, and alanine aminotransferase values were higher in the mortal group on the first day of hospitalization, and this was significant ( p = 0.021 , p = 0.001 , and p = 0.036 , respectively). In our study, d-dimer was 766.5 ng/mL in the survivor group and 988.5 ng/mL in the mortal group. In our patient group, the mean lymphocyte count was 700 × 10 3 / m m 3 in the group that survived the first day of TCZ and 500 × 10 3 / m m 3 in the mortal group. In addition, the CRP value was 135.5 mg/L in the survivor group and 169 mg/L in the mortal group. There was no difference between ferritin values. Conclusions. Tocilizumab is still among the COVID-19 treatment options and appears to be effective. But the start time is important. In order to increase its effectiveness, it may be important to know a cut-off value of the laboratory findings required for the diagnosis of cytokine release syndrome. Further studies are needed for this.

Pathways of Renal Involvement in COVID-19 Infection

The causative agent of the highly infectious pandemic COVID-19 is SARS-CoV-2. According to WHO, as of August 18th 2020, the number of confirmed cases was and confirmed deaths was 771,635 from 216 countries. The most affected organ system in COVID-19 is the respiratory system. Later studies proved that the virus caused multiorgan infections. Several studies shows that SARS-CoV-2 causes damage to the renal system and; critically ill patients with associated renal damage show a higher mortality rate as compared to those patients with an unaffected renal system .This review article aims at updating the knowledge about associated kidney failure in covid-19 cases and its impact on the morbidity and mortality. The virus damages the renal system through two different mechanisms: Direct and Indirect pathway. The direct pathway explains how the virus damages the renal system by directly acting upon the target cells in the kidney.SARS-CoV-2 gains its entry by binding to the ACE2 receptors on the target cell. The SARS-CoV-2 progresses its journey and extensively spread the infection, damaging the kidneys leading to the failure of the renal system. The indirect pathway of damage speaks about the secondary damage caused to the renal system due to cytokine release syndrome caused by SARS-CoV-2.This pathway also points out the formation of microthrombi in the glomerular capillaries and also kidney hypoperfusion. AKI in covid-19 patients can occur secondary to multiorgan failure. This review aims to build a foundation concerning the direct pathway and indirect pathway by means of which SARS-Cov-2 infects the kidneys by summarizing the numerous researches carried out till date to update the knowledge gained thus far to aid in building better protocols for covid-19 management and decrease morbidity caused due to renal damage.

Three Component Composite Scaffolds Based on PCL, Hydroxyapatite, and L-Lysine Obtained in TIPS-SL: Bioactive Material for Bone Tissue Engineering

In this research, we describe the properties of three-component composite foam scaffolds based on poly(ε-caprolactone) (PCL) as a matrix and hydroxyapatite whiskers (HAP) and L-Lysine as fillers (PCL/HAP/Lys with wt% ratio 50/48/2). The scaffolds were prepared using a thermally induced phase separation technique supported by salt leaching (TIPS-SL). All materials were precisely characterized: porosity, density, water uptake, wettability, DSC, and TGA measurements and compression tests were carried out. The microstructure of the obtained scaffolds was analyzed via SEM. It was found that the PCL/HAP/Lys scaffold has a 45% higher Young’s modulus and better wettability compared to the PCL/HAP system. At the same time, the porosity of the system was ~90%. The osteoblast hFOB 1.19 cell response was also investigated in osteogenic conditions (39 °C) and the cytokine release profile of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α was determined. Modification of PCL scaffolds with HAP and L-Lysine significantly improved the proliferation of pre-osteoblasts cultured on such materials.

Case Report: Fatal Complications of BK Virus-Hemorrhagic Cystitis and Severe Cytokine Release Syndrome Following BK Virus-Specific T-Cells

BK virus (BKV)-hemorrhagic cystitis (HC) is a well-known and rarely fatal complication of hematopoietic stem cell transplantation (HSCT). Treatment for BKV-HC is limited, but virus-specific T-cells (VST) represent a promising therapeutic option feasible for use posttransplant. We report on the case of a 16-year-old male with dedicator of cytokinesis 8 (DOCK8) deficiency who underwent haploidentical HSCT complicated by severe BKV-HC, catastrophic renal hemorrhage, and VST-associated cytokine release syndrome (CRS). Gross hematuria refractory to multiple interventions began with initiation of posttransplant cyclophosphamide (PT/Cy). Complete left renal arterial embolization (day +43) was ultimately indicated to control intractable renal hemorrhage. Subsequent infusion of anti-BK VSTs was complicated by CRS and progressive multiorgan failure, with postmortem analysis confirming diagnosis of hepatic sinusoidal obstruction syndrome (SOS). This case illustrates opportunities for improvement in the management of severe BKV-HC posttransplant while highlighting rare and potentially life-threatening complications of BKV-HC and VST therapy.

Single-Agent Mosunetuzumab Shows Durable Complete Responses in Patients With Relapsed or Refractory B-Cell Lymphomas: Phase I Dose-Escalation Study

PURPOSE Mosunetuzumab is a bispecific antibody targeting CD20 and CD3 that redirects T cells to engage and eliminate malignant B cells and is being developed for relapsed or refractory (R/R) B-cell non-Hodgkin lymphomas (B-NHLs). METHODS This first-in-human trial (ClinicalTrials.gov identifier: NCT02500407 ) evaluated the safety and tolerability and efficacy of mosunetuzumab in patients with R/R B-NHL and established the recommended phase II dose. Data from dose escalation are presented. Single-agent mosunetuzumab was administered intravenously in 3-week cycles, at full dose in cycle 1 day 1 (group A) or with ascending (step-up) doses during cycle 1 on days 1, 8, and 15 (group B), for eight or 17 cycles on the basis of tumor response. RESULTS Two hundred thirty patients were enrolled. Doses up to 2.8 mg and 60 mg were assessed in groups A and B, respectively; maximum tolerated dose was not exceeded. In group B (n = 197), common adverse events (≥ 20% of patients) were neutropenia (28.4%), cytokine release syndrome (27.4%), hypophosphatemia (23.4%), fatigue (22.8%), and diarrhea (21.8%). Cytokine release syndrome was mostly low-grade (grade ≥ 3: 1.0%) and mainly confined to cycle 1. Across the doses investigated (group B), best overall response rates were 34.9% and 66.2% in patients with aggressive and indolent B-NHL, respectively, and complete response rates were 19.4% and 48.5%. Among patients with a complete response, the median duration of response was 22.8 months (95% CI, 7.6 to not estimable) and 20.4 (95% CI, 16 to not estimable) in patients with aggressive and indolent B-NHL, respectively. CONCLUSION Mosunetuzumab, administered with step-up dosing, has a manageable safety profile and induces durable complete responses in R/R B-NHL. The expansion stage of the study is ongoing at the dose level of 1/2/60/60/30 mg selected for further study.