Altered sphingolipid pathway in SARS-CoV-2 infected human lung tissue.

Introduction: The SARS-CoV-2 mediated COVID-19 pandemic has impacted millions worldwide. Hyper-inflammatory processes, including cytokine storm, contribute to long-standing tissue injury and damage in COVID-19. The metabolism of sphingolipids as regulators of cell survival, differentiation, and proliferation has been implicated in inflammatory signaling and cytokine responses. Sphingosine-kinase-1 (SK1) and ceramide-synthase-2 (CERS2) generate metabolites that regulate the anti- and pro-apoptotic processes, respectively. Alterations in SK1 and CERS2 expression may contribute to the inflammation and tissue damage during COVID-19. The central objective of this study is to evaluate structural changes in the lung post-SARS-CoV-2 infection and to investigate whether the sphingolipid rheostat is altered in response to SARS-CoV-2 infection. Methods: Central and peripheral lung tissues from COVID-19+ or control autopsies and resected lung tissue from COVID-19 convalescents were subjected to histologic evaluation of airspace and collagen deposisiton, and immunohistochemical evaluation of SK1 and CERS2. Results: Here, we report significant reduction in air space and increase in collagen deposition in lung autopsy tissues from patients who died from COVID-19 (COVID-19+) and COVID-19 convalescent individuals. SK1 expression increased in the lungs of COVID-19+ autopsies and COVID-19 convalescent lung tissue compared to controls and was mostly associated with Type II pneumocytes and alveolar macrophages. No significant difference in CERS2 expression was noted. SARS-CoV-2 infection upregulates SK1 and increases the ratio of SK1 to CERS2 expression in lung tissues of COVID-19 autopsies and COVID-19 convalescents. Discussion: These data suggest an alteration in the sphingolipid rheostat in lung tissue during COVID-19, suggesting a potential contribution to the inflammation and tissue damage associated with viral infection.

Bioactive Knee Sleeve for Osteoarthritis: A Small Cohort Study.

OBJECTIVES: Osteoarthritis (OA) is one of the most prevalent musculoskeletal ailments worldwide. Numerous conservative therapies exist, but evidence for such treatments remains conflicting. Recently, there has been growing interest surrounding bioactive sleeves for managing knee arthritis; however, the literature on their efficacy for relieving pain and improving function in the setting of knee OA is limited. As such, we sought to investigate the effect of a bioactive sleeve on patient-reported outcome measures in a small cohort of patients with OA. METHODS: Patients with knee OA were given a bioactive sleeve (Reparel, Chico, CA) and asked to refrain from lifestyle modifications and intraarticular corticosteroid injections. Lysholm Knee Score, Oxford Knee Score, Knee Injury and OA Outcome Score (KOOS), Single Assessment Numeric Evaluation, and Visual Analog Scale score were obtained at baseline, 2 weeks, 6 weeks, and 3 months. OA severity was evaluated using the Kellgren and Lawrence (KL) classification system. The Wilcoxon signed rank test was used to compare baseline patient-reported outcomes with 2-week, 6-week, and 3-month time points. Bivariate correlation was used to evaluate the relation between patient-reported outcome measures and KL classification. RESULTS: The cohort was composed of 14 participants-4 males and 10 females-with a mean age of 62.2 ± 13.2 years and a body mass index of 33.7 ± 5.8. The average KL grade was 2.9 (range 2-4). KOOS pain, symptoms, activities of daily living, and quality of life increased significantly at 2 weeks, 6 weeks, and 3 months. KOOS sport and recreation significantly increased at 3 months. The Oxford Knee Score was significantly greater at 2 weeks, 6 weeks, and 3 months. The Lysholm Knee Score was significantly greater at 6 weeks and 3 months. The Single Assessment Numeric Evaluation attained significant improvement at 3 months, and the Visual Analog Scale improvement was significant at 2 weeks. No statistically significant difference was attained with University of California at Los Angeles activity score. Outcome scores did not correlate with KL classification. CONCLUSIONS: These data suggest that a bioactive sleeve may improve patient-reported pain, symptoms, and function in the setting of knee OA. Further research is needed to better understand the role of bioactive sleeves for patients with knee arthritis.

Local SARS-CoV-2 Peptide-Specific Immune Responses in Lungs of Convalescent and Uninfected Human Subjects.

Multi-specific and long-lasting T cell immunity have been recognized as indicators for long term protection against pathogens including the novel coronavirus SARS-CoV-2, the causative agent of the COVID-19 pandemic. Functional significance of peripheral memory T cells in individuals recovering from COVID-19 (COVID-19 + ) are beginning to be appreciated; but little is known about lung resident memory T cells (lung TRM) in SARS-CoV-2 infection. Here, we utilize a perfused three dimensional (3D) human lung tissue model and identify pre-existing local T cell immunity against SARS-CoV-2 proteins in lung tissues. We report ex vivo maintenance of functional multi-specific IFN-γ secreting lung TRM in COVID-19 + and their induction in lung tissues of vaccinated COVID-19 + . Importantly, we identify SARS-CoV-2 peptide-responding B cells and IgA + plasma cells in lung tissues of COVID-19 + in ex vivo 3D-tissue models. Our study highlights the importance of balanced and local anti-viral immune response in the lung with persistent induction of TRM and IgA + plasma cells for future protection against SARS-CoV-2 infection. Further, our data suggest that inclusion of multiple viral antigens in vaccine approaches may broaden the functional profile of memory T cells to combat the severity of coronavirus infection.

Reactive carbon-chain molecules: synthesis of 1-diazo-2,4-pentadiyne and spectroscopic characterization of triplet pentadiynylidene (H-C[triple bond]C-:C-C[triple bond]C-H).

1-Diazo-2,4-pentadiyne (6a), along with both monodeuterio isotopomers 6b and 6c, has been synthesized via a route that proceeds through diacetylene, 2,4-pentadiynal, and 2,4-pentadiynal tosylhydrazone. Photolysis of diazo compounds 6a-c (lambda > 444 nm; Ar or N2, 10 K) generates triplet carbenes HC5H (1) and HC5D (1-d), which have been characterized by IR, EPR, and UV/vis spectroscopy. Although many resonance structures contribute to the resonance hybrid for this highly unsaturated carbon-chain molecule, experiment and theory reveal that the structure is best depicted in terms of the dominant resonance contributor of penta-1,4-diyn-3-ylidene (diethynylcarbene, H-C[triple bond]C-:C-C[triple bond]C-H). Theory predicts an axially symmetric (D(infinity h)) structure and a triplet electronic ground state for 1 (CCSD(T)/ANO). Experimental IR frequencies and isotope shifts are in good agreement with computed values. The triplet EPR spectrum of 1 (absolute value(D/hc) = 0.6157 cm(-1), absolute value(E/hc) = 0.0006 cm(-1)) is consistent with an axially symmetric structure, and the Curie law behavior confirms that the triplet state is the ground state. The electronic absorption spectrum of 1 exhibits a weak transition near 400 nm with extensive vibronic coupling. Chemical trapping of triplet HC5H (1) in an O2-doped matrix affords the carbonyl oxide 16 derived exclusively from attack at the central carbon.