Single-Cell Profiling of the Differential In Vivo Impact of Severe Acute Respiratory Syndrome Coronavirus 2 Infection Among Lung Tissue Cell Subtypes at the Protein Level.

The complexity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and its variants in lung cells can truly be characterized only at the tissue and protein levels among unique cell subtypes. However, in vivo data are limited due to lack of accessible human tissues. Using a transgenic mouse model of SARS-CoV-2 infection and flow cytometry, we provide in vivo novel insight at the protein level that the differential impact of SARS-CoV-2 (Wuhan strain) and its B.1.617.2 (Delta) and BA.1 (Omicron) variants on lung may be attributed to differential patterns of viral protein levels among ciliated airway cells, alveolar types 1 and 2 cells, immune cells, and endothelial lung cells.

Isolation and Enrichment of Major Primary Neuroglial Cells from Neonatal Mouse Brain.

The central nervous system (CNS) relies on the complex interaction of neuroglial cells to carry out vital physiological functions. To comprehensively understand the structural and functional interplay between these neuroglial cells, it is essential to establish an appropriate in vitro system that can be utilized for thorough investigation. Traditional protocols for establishing primary neuronal and mixed glial cultures from prenatal mice or neural stem cells require sacrificing pregnant mice and have the drawback of yielding only specific types of cells. Our current protocol overcomes these drawbacks by utilizing the brain from day-0 pups to isolate CNS resident neuroglial cells including astrocytes, microglia, oligodendrocytes [oligodendrocyte precursor cells (OPCs) and differentiated oligodendrocytes], and meningeal fibroblasts, as well as hippocampal neurons, avoiding sacrificing pregnant mice, which makes this procedure efficient and cost effective. Furthermore, through this protocol, we aim to provide step-by-step instructions for isolating and establishing different primary neuroglial cells and their characterization using cell-specific markers. This study presents an opportunity to isolate, culture, and establish all major CNS resident cells individually. These cells can be utilized in various cell-based and biochemical assays to comprehensively investigate the cell-specific roles and behaviors of brain resident cells in a reductionist approach. Key features • Efficient isolation of major neuroglial cells like meningeal fibroblasts, neurons, astrocytes, oligodendrocytes, and microglia from a single day-0 neonatal mouse pup's brain. • Circumvents the sacrifice of pregnant female mice. • Acts as a bridging experimental method between secondary cell lines and in vivo systems. • Isolated cells can be used for performing various cell-based and biochemical assays.

Severe Acute Respiratory Syndrome Coronavirus 2 Infection Alters Mediators of Lung Tissue Remodeling In Vitro and In Vivo.

BACKGROUND: Altered mediators of airway tissue remodeling such as matrix metalloproteinases (MMPs) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may contribute to morbidity in coronavirus disease 2019 (COVID-19); however, the differential impact of SARS-CoV-2 variants of concern (VOCs) on MMPs is unknown. METHODS: Using both in vitro human airway cell culture model and in vivo transgenic mouse model of SARS-CoV-2 infection, we studied the differential effect of SARS-CoV-2 VOCs on expression of key MMPs and inflammatory mediators in airway cells and tissues. RESULTS: The most consistent findings with all SARS-CoV-2 variants in infected compared to uninfected human bronchial epithelial cell air-liquid interface cultures were the SARS-CoV-2-induced increases in MMP-12 and tissue inhibitor of MMPs. Infection with both SARS-CoV-2 wild type and SARS-CoV-2 Delta variant over 3 days postinfection (dpi) and with Beta variant over 7 dpi increased lung tissue levels of MMP-9 compared to uninfected mice. Overall, SARS-CoV-2 variants had differential dose-dependent impact on secretion of MMP-1, MMP-2, MMP-9, and MMP-12 that varied at the protein versus the gene level and in the early noninflammatory compared to late inflammatory phase of infection. CONCLUSIONS: We provide novel mechanistic insight that the differential impact of SARS-CoV-2 variants on severity of COVID-19 may partially be attributed to unique changes in MMPs.

Connexin 43 mediated collective cell migration is independent of Golgi orientation.

Cell migration is vital for multiple physiological functions and is involved in the metastatic dissemination of tumour cells in various cancers. For effective directional migration, cells often reorient their Golgi apparatus and, therefore, the secretory traffic towards the leading edge. However, not much is understood about the regulation of Golgi's reorientation. Herein, we address the role of gap junction protein Connexin 43 (Cx43), which connects cells, allowing the direct exchange of molecules. We utilized HeLa WT cells lacking Cx43 and HeLa 43 cells, stably expressing Cx43, and found that functional Cx43 channels affected Golgi morphology and reduced the reorientation of Golgi during cell migration. Although the migration velocity of the front was reduced in HeLa 43, the front displayed enhanced coherence in movement, implying an augmented collective nature of migration. On BFA treatment, Golgi was dispersed and the high heterogeneity in inter-regional front velocity of HeLa WT cells was reduced to resemble the HeLa 43. HeLa 43 had higher vimentin expression and stronger basal F-actin. Furthermore, non-invasive measurement of basal membrane height fluctuations revealed a lower membrane tension. We, therefore, propose that reorientation of Golgi is not the major determinant of migration in the presence of Cx43, which induces collective-like coherent migration in cells.

Chronic Electronic Cigarette Use and Atherosclerosis Risk in Young People: A Cross-Sectional Study-Brief Report.

BACKGROUND: Little is known whether electronic cigarettes (ECIG) increase vulnerability to future atherosclerotic cardiovascular disease. We determined, using an ex vivo mechanistic atherogenesis assay, whether proatherogenic changes including monocyte transendothelial migration and monocyte-derived foam cell formation are increased in people who use ECIGs. METHODS: In a cross-sectional single-center study using plasma and peripheral blood mononuclear cells from healthy participants who are nonsmokers or with exclusive use of ECIGs or tobacco cigarettes (TCIGs), autologous peripheral blood mononuclear cells with patient plasma and pooled peripheral blood mononuclear cells from healthy nonsmokers with patient plasma were utilized to dissect patient-specific ex vivo proatherogenic circulating factors present in plasma and cellular factors present in monocytes. Our main outcomes were monocyte transendothelial migration (% of blood monocyte cells that undergo transendothelial migration through a collagen gel) and monocyte-derived foam cell formation as determined by flow cytometry and the median fluorescence intensity of the lipid-staining fluorochrome BODIPY in monocytes of participants in the setting of an ex vivo model of atherogenesis. RESULTS: Study participants (N=60) had median age of 24.0 years (interquartile range [IQR], 22.0-25.0 years), and 31 were females. Monocyte transendothelial migration was increased in people who exclusively used TCIGs (n=18; median [IQR], 2.30 [ 1.29-2.82]; P<0.001) and in people who exclusively used ECIGs (n=21; median [IQR], 1.42 [ 0.96-1.91]; P<0.01) compared with nonsmoking controls (n=21; median [IQR], 1.05 [0.66-1.24]). Monocyte-derived foam cell formation was increased in people who exclusively used TCIGs (median [IQR], 2.01 [ 1.59-2.49]; P<0.001) and in people who exclusively used ECIGs (median [IQR], 1.54 [ 1.10-1.86]; P<0.001) compared with nonsmoker controls (median [IQR], 0.97 [0.86-1.22]). Both monocyte transendothelial migration and monocyte-derived foam cell formation were higher in TCIG smokers compared with ECIG users and in ECIG users who were former smokers versus ECIG users who were never smokers (P<0.05 for all comparisons). CONCLUSIONS: The finding of alterations in proatherogenic properties of blood monocytes and plasma in TCIG smokers compared with nonsmokers validates this assay as a strong ex vivo mechanistic tool with which to measure proatherogenic changes in people who use ECIGs. Similar yet significantly less severe alterations in proatherogenic properties of monocytes and plasma were detected in the blood from ECIG users. Future studies are necessary to determine whether these findings are attributable to a residual effect of prior smoking or are a direct effect of current ECIG use.

Ifit2 restricts murine coronavirus spread to the spinal cord white matter and its associated myelin pathology.

Interferon-induced protein with tetratricopeptide repeats 2, Ifit2, is critical in restricting neurotropic murine-ß-coronavirus, RSA59 infection. RSA59 intracranial injection of Ifit2-deficient (-/-) compared to wild-type (WT) mice results in impaired acute microglial activation, reduced CX3CR1 expression, limited migration of peripheral lymphocytes into the brain, and impaired virus control followed by severe morbidity and mortality. While the protective role of Ifit2 is established for acute viral encephalitis, less is known about its influence during the chronic demyelinating phase of RSA59 infection. To understand this, RSA59 infected Ifit2-/- and Ifit2+/+ (WT) were observed for neuropathological outcomes at day 5 (acute phase) and 30 post-infection (chronic phase). Our study demonstrates that Ifit2 deficiency causes extensive RSA59 spread throughout the spinal cord gray and white matter, associated with impaired CD4+ T and CD8+ T cell infiltration. Further, the cervical lymph nodes of RSA59 infected Ifit2-/- mice showed reduced activation of CD4+ T cells and impaired IFNγ expression during acute encephalomyelitis. Interestingly, BBB integrity was better preserved in Ifit2-/- mice, as evidenced by tight junction protein Claudin-5 and adapter protein ZO-1 expression surrounding the meninges and blood vessels and decreased Texas red dye uptake, which may be responsible for reduced leukocyte infiltration. In contrast to sparse myelin loss in WT mice, the chronic disease phase in Ifit2-/- mice was associated with severe demyelination and persistent viral load, even at low inoculation doses. Overall, our study highlights that Ifit2 provides antiviral functions by promoting acute neuroinflammation and thereby aiding virus control and limiting severe chronic demyelination. IMPORTANCE Interferons execute their function by inducing specific genes collectively termed as interferon-stimulated genes (ISGs), among which interferon-induced protein with tetratricopeptide repeats 2, Ifit2, is known for restricting neurotropic viral replication and spread. However, little is known about its role in viral spread to the spinal cord and its associated myelin pathology. Toward this, our study using a neurotropic murine ß-coronavirus and Ifit2-deficient mice demonstrates that Ifit2 deficiency causes extensive viral spread throughout the gray and white matter of the spinal cord accompanied by impaired microglial activation and T cell infiltration. Furthermore, infected Ifit2-deficient mice showed impaired activation of T cells in the cervical lymph node and relatively intact blood-brain barrier integrity. Overall, Ifit2 plays a crucial role in mounting host immunity against neurotropic murine coronavirus in the acute phase while preventing mice from developing viral-induced severe chronic neuroinflammatory demyelination, the characteristic feature of human neurological disease multiple sclerosis (MS).

Mitoquinone Mesylate and Mitochondrial DNA in End Organs in Humanized Mouse Model of Chronic Treated Human Immunodeficiency Virus Infection.

No treatment exists for mitochondrial dysfunction, a contributor to end-organ disease in human immunodeficiency virus (HIV). The mitochondrial antioxidant mitoquinone mesylate (MitoQ) attenuates mitochondrial dysfunction in preclinical mouse models of various diseases but has not been used in HIV. We used a humanized murine model of chronic HIV infection and polymerase chain reaction to show that HIV-1-infected mice treated with antiretroviral therapy and MitoQ for 90 days had higher ratios of human and murine mitochondrial to nuclear DNA in end organs compared with HIV-1-infected mice on antiretroviral therapy. We offer translational evidence of MitoQ as treatment for mitochondrial dysfunction in HIV.

Blood immune cells from people with HIV on antiviral regimens that contain tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) have differential metabolic signatures.

BACKGROUND: Mitochondria regulate immune and organ function. It is unknown whether higher intracellular drug levels observed in peripheral blood mononuclear cells (PBMCs) treated with tenofovir alafenamide (TAF) compared to tenofovir disoproxil fumarate (TDF) may alter mitochondrial function and energy production in immune cells in HIV(+) patients. METHODS: Cellular bioenergetics were determined in PBMCs from HIV-1(-) participants exposed to TAF versus TDF in vitro, at a comparable concentration to a clinically relevant plasma exposure. A decrease in cellular oxygen consumption rate (OCR) at baseline (basal-OCR) and under cellular stress (max-OCR) may suggest mitochondrial dysfunction. We also assessed the in vivo impact of TAF vs TDF on OCR in PBMCs from 26 people with HIV (PWH) interchanged from TDF-based to TAF-based antiretroviral therapy (ART) over a 9-month period in the setting of an open label clinical trial. The Wilcoxon and Mann Whitney tests were used for comparison of continuous variables. RESULTS: PBMCs from HIV-1(-) participants exposed in vitro to a concentration of 0.12-3.3 µM for TAF and TDF at 2 and 24 h, reduced basal and maximal OCR compared to vehicle control. Switch studies of antivirals (TAF vs TDF) within the same PWH showed that TAF-based ART was associated with reduced OCR compared to TDF-based ART in PBMCs. We observed that TAF-treated PBMCs selectively relied more on glucose/pyruvate supply rather than fatty acid to fuel their mitochondria. CONCLUSIONS: Compared to TDF, TAF may alter bioenergetics in immune cells from PWH in vitro and in vivo. The clinical significance in terms of the differential impact caused by TAF versus TDF on mitochondrial function and energy production in immune cells, a regulator of immune function, requires further studied in HIV, preexposure prophylaxis and hepatitis B.

Ectodomain shedding of proteins important for SARS-CoV-2 pathogenesis in plasma of tobacco cigarette smokers compared to electronic cigarette vapers: a cross-sectional study.

The impact of tobacco cigarette (TCIG) smoking and electronic cigarette (ECIG) vaping on the risk of development of severe COVID-19 is controversial. The present study investigated levels of proteins important for SARS-CoV-2 pathogenesis present in plasma because of ectodomain shedding in smokers, ECIG vapers, and non-smokers (NSs). Protein levels of soluble angiotensin-converting enzyme 2 (ACE2), angiotensin (Ang) II (the ligand of ACE2), Ang 1-7 (the main peptide generated from Ang II by ACE2 activity), furin (a protease that increases the affinity of the SARS-CoV-2 spike protein for ACE2), and products of ADAM17 shedding activity that predict morbidity in COVID-19 (IL-6/IL-6R alpha (IL-6/IL-6Rα) complex, soluble CD163 (sCD163), L-selectin) were determined in plasma from 45 NSs, 30 ECIG vapers, and 29 TCIG smokers using ELISA. Baseline characteristics of study participants did not differ among groups. TCIG smokers had increased sCD163, L-selectin compared to NSs and ECIG vapers (p < 0.001 for all comparisons). ECIG vapers had higher plasma furin compared to both NSs (p < 0.001) and TCIG smokers (p < 0.05). ECIG vaping and TCIG smoking did not impact plasma ACE2, Ang 1-7, Ang II, and IL-6 levels compared to NSs (p > 0.1 for all comparisons). Further studies are needed to determine if increased furin activity and ADAM17 shedding activity that is associated with increased plasma levels of sCD163 and L-selectin in healthy young TCIG smokers may contribute to the future development of severe COVID-19 and cardiovascular complications of post-acute COVID-19 syndrome.

Mitoquinone mesylate targets SARS-CoV-2 infection in preclinical models.

To date, there is no effective oral antiviral against SARS-CoV-2 that is also anti-inflammatory. Herein, we show that the mitochondrial antioxidant mitoquinone/mitoquinol mesylate (Mito-MES), a dietary supplement, has potent antiviral activity against SARS-CoV-2 and its variants of concern in vitro and in vivo . Mito-MES had nanomolar in vitro antiviral potency against the Beta and Delta SARS-CoV-2 variants as well as the murine hepatitis virus (MHV-A59). Mito-MES given in SARS-CoV-2 infected K18-hACE2 mice through oral gavage reduced viral titer by nearly 4 log units relative to the vehicle group. We found in vitro that the antiviral effect of Mito-MES is attributable to its hydrophobic dTPP+ moiety and its combined effects scavenging reactive oxygen species (ROS), activating Nrf2 and increasing the host defense proteins TOM70 and MX1. Mito-MES was efficacious reducing increase in cleaved caspase-3 and inflammation induced by SARS-CoV2 infection both in lung epithelial cells and a transgenic mouse model of COVID-19. Mito-MES reduced production of IL-6 by SARS-CoV-2 infected epithelial cells through its antioxidant properties (Nrf2 agonist, coenzyme Q10 moiety) and the dTPP moiety. Given established safety of Mito-MES in humans, our results suggest that Mito-MES may represent a rapidly applicable therapeutic strategy that can be added in the therapeutic arsenal against COVID-19. Its potential long-term use by humans as diet supplement could help control the SARS-CoV-2 pandemic, especially in the setting of rapidly emerging SARS-CoV-2 variants that may compromise vaccine efficacy. One-Sentence Summary: Mitoquinone/mitoquinol mesylate has potent antiviral and anti-inflammatory activity in preclinical models of SARS-CoV-2 infection.

ApoA-I mimetics reduce systemic and gut inflammation in chronic treated HIV.

Novel therapeutic strategies are needed to attenuate increased systemic and gut inflammation that contribute to morbidity and mortality in chronic HIV infection despite potent antiretroviral therapy (ART). The goal of this study is to use preclinical models of chronic treated HIV to determine whether the antioxidant and anti-inflammatory apoA-I mimetic peptides 6F and 4F attenuate systemic and gut inflammation in chronic HIV. We used two humanized murine models of HIV infection and gut explants from 10 uninfected and 10 HIV infected persons on potent ART, to determine the in vivo and ex vivo impact of apoA-I mimetics on systemic and intestinal inflammation in HIV. When compared to HIV infected humanized mice treated with ART alone, mice on oral apoA-I mimetic peptide 6F with ART had consistently reduced plasma and gut tissue cytokines (TNF-α, IL-6) and chemokines (CX3CL1) that are products of ADAM17 sheddase activity. Oral 6F attenuated gut protein levels of ADAM17 that were increased in HIV-1 infected mice on potent ART compared to uninfected mice. Adding oxidized lipoproteins and endotoxin (LPS) ex vivo to gut explants from HIV infected persons increased levels of ADAM17 in myeloid and intestinal cells, which increased TNF-α and CX3CL1. Both 4F and 6F attenuated these changes. Our preclinical data suggest that apoA-I mimetic peptides provide a novel therapeutic strategy that can target increased protein levels of ADAM17 and its sheddase activity that contribute to intestinal and systemic inflammation in treated HIV. The large repertoire of inflammatory mediators involved in ADAM17 sheddase activity places it as a pivotal orchestrator of several inflammatory pathways associated with morbidity in chronic treated HIV that make it an attractive therapeutic target.

Imatinib-Resistant Gastrointestinal Stromal Tumor Presenting as a Large Abdominal Mass.

Gastrointestinal stromal tumors (GISTs) are the stromal or mesenchymal neoplasms affecting the gastrointestinal tract. Although they constitute 1% of primary gastrointestinal tumors, they are the most common nonepithelial tumors involving the gastrointestinal tract. They mostly present as overt or occult gastrointestinal bleeding. We present a case in which a 77-year-old female presented with a large abdominal mass. The origin of the mass was unclear on CT and MRI scan of the abdomen. Upper gastrointestinal endoscopic ultrasonography showed a cystic lesion in the perigastric region. A fine-needle biopsy of the lesion was performed, which was consistent with spindle type GIST. After the initial failure of imatinib therapy, the tumor was managed surgically.

Inhibition of the BTK-IDO-mTOR axis promotes differentiation of monocyte-lineage dendritic cells and enhances anti-tumor T cell immunity.

Monocytic-lineage inflammatory Ly6c+CD103+ dendritic cells (DCs) promote antitumor immunity, but these DCs are infrequent in tumors, even upon chemotherapy. Here, we examined how targeting pathways that inhibit the differentiation of inflammatory myeloid cells affect antitumor immunity. Pharmacologic inhibition of Bruton's tyrosine kinase (BTK) and the tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) or deletion of Btk or Ido1 allowed robust differentiation of inflammatory Ly6c+CD103+ DCs during chemotherapy, promoting antitumor T cell responses and inhibiting tumor growth. Immature Ly6c+c-kit+ precursor cells had epigenetic profiles similar to conventional DC precursors; deletion of Btk or Ido1 promoted differentiation of these cells. Mechanistically, a BTK-IDO axis inhibited a tryptophan-sensitive differentiation pathway driven by GATOR2 and mTORC1, and disruption of the GATOR2 in monocyte-lineage precursors prevented differentiation into inflammatory DCs in vivo. IDO-expressing DCs and monocytic cells were present across a range of human tumors. Thus, a BTK-IDO axis represses differentiation of inflammatory DCs during chemotherapy, with implications for targeted therapies.

The structurally conserved TELR region on shelterin protein TPP1 is essential for telomerase processivity but not recruitment.

The shelterin protein TPP1 is involved in both recruiting telomerase and stimulating telomerase processivity in human cells. Assessing the in vivo significance of the latter role of TPP1 has been difficult, because TPP1 mutations that perturb telomerase function tend to abolish both telomerase recruitment and processivity. The Saccharomyces cerevisiae telomerase-associated Est3 protein adopts a protein fold similar to the N-terminal region of TPP1. Interestingly, a previous structure-guided mutagenesis study of Est3 revealed a TELR surface region that regulates telomerase function via an unknown mechanism without affecting the interaction between Est3 and telomerase [T. Rao et al., Proc. Natl. Acad. Sci. U.S.A. 111, 214-218 (2014)]. Here, we show that mutations within the structurally conserved TELR region on human TPP1 impaired telomerase processivity while leaving telomerase recruitment unperturbed, hence uncoupling the two roles of TPP1 in regulating telomerase. Telomeres in cell lines containing homozygous TELR mutations progressively shortened to a critical length that caused cellular senescence, despite the presence of abundant telomerase in these cells. Our findings not only demonstrate that telomerase processivity can be regulated by TPP1 in a process separable from its role in recruiting telomerase, but also establish that the in vivo stimulation of telomerase processivity by TPP1 is critical for telomere length homeostasis and long-term viability of human cells.

Apolipoprotein A-I mimetics attenuate macrophage activation in chronic treated HIV.

OBJECTIVES: Despite antiretroviral therapy (ART), there is an unmet need for therapies to mitigate immune activation in HIV infection. The goal of this study is to determine whether the apoA-I mimetics 6F and 4F attenuate macrophage activation in chronic HIV. DESIGN: Preclinical assessment of the in-vivo impact of Tg6F and the ex-vivo impact of apoA-I mimetics on biomarkers of immune activation and gut barrier dysfunction in treated HIV. METHODS: We used two humanized murine models of HIV infection to determine the impact of oral Tg6F with ART (HIV+ART+Tg6F+) on innate immune activation (plasma human sCD14, sCD163) and gut barrier dysfunction [murine I-FABP, endotoxin (LPS), LPS-binding protein (LBP), murine sCD14]. We also used gut explants from 10 uninfected and 10 HIV-infected men on potent ART and no morbidity, to determine the impact of ex-vivo treatment with 4F for 72 h on secretion of sCD14, sCD163, and I-FABP from gut explants. RESULTS: When compared with mice treated with ART alone (HIV+ART+), HIV+ART+Tg6F+ mice attenuated macrophage activation (h-sCD14, h-sCD163), gut barrier dysfunction (m-IFABP, LPS, LBP, and m-sCD14), plasma and gut tissue oxidized lipoproteins. The results were consistent with independent mouse models and ART regimens. Both 4F and 6F attenuated shedding of I-FABP and sCD14 from gut explants from HIV-infected and uninfected participants. CONCLUSION: Given that gut barrier dysfunction and macrophage activation are contributors to comorbidities like cardiovascular disease in HIV, apoA-I mimetics should be tested as therapy for morbidity in chronic treated HIV.

Superior Mesenteric Artery Syndrome: A Forgotten Cause of Duodenal Obstruction.

Superior mesenteric artery (SMA) syndrome has been described in medical literature as a rare cause of duodenal occlusion. It has a varied presentation, with distressing gastrointestinal symptoms such as nausea, abdominal pain, and further weight loss. Several conditions contribute to duodenal obstruction in SMA syndrome. We present a case of SMA syndrome in a patient with malignant breast cancer who presented with sudden onset of severe nausea and voluminous vomiting. Various imaging studies revealed a distended proximal intestine with a transition point in the third part of the duodenum. The patient was managed conservatively with nasogastric decompression and fluid electrolyte management, leading to symptomatic relief.

Impact of High-Density Lipoprotein Levels on Cardiovascular Outcomes of Patients Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents.

Low levels of high-density lipoprotein (HDL) have been associated with adverse cardiovascular events in epidemiologic studies. Evidence regarding its role in patients who underwent percutaneous coronary intervention (PCI) is scarce. We evaluated consecutive patients who underwent PCI with drug-eluting stents from 2012 to 2017, excluding those with unavailable baseline HDL, age <18 years, presentation with ST-segment elevation myocardial infarction (MI) or shock, and coexisting neoplastic disease. The final population was stratified according to baseline HDL levels into reduced and nonreduced HDL cohorts, with cut-off value 40 mg/dl in males and 50 mg/dl in females. The primary end point was 1-year major adverse cardiovascular events (MACE), defined as the composite of death, MI, or target vessel revascularization (TVR). Among 10,843 patients included, 6,511 (60%) had reduced HDL, and 4,332 (40%) nonreduced HDL. The rate of 1-year MACE was similar between the 2 groups (7.5% vs 6.6%; p = 0.14). Although mortality and MI rates were comparable, reduced HDL was associated with significantly higher TVR 5.2% vs 4.0%; p = 0.02, a finding that attenuated after multivariable adjustment (adjusted hazard ratio 1.18, p = 0.14). Sex subgroup analysis included 7,718 (71.2%) males and 3,125 (28.8%) females. Among men, there was a trend toward higher MACE in those with reduced HDL (7.4% vs 6.0%; p = 0.08) mostly driven by TVR (5.4% vs 3.7%; p = 0.005). No association between HDL and 1-year outcomes was evident in females. Assessment for interaction between sex and reduced HDL did not reach statistical significance. In conclusion, reduced baseline HDL was not associated with increased risk of MACE in a contemporary PCI population.

Calculated Serum Osmolality, Acute Kidney Injury, and Relationship to Mortality after Percutaneous Coronary Intervention.

BACKGROUND: Data on the associations between serum osmolality (sOsmo) and acute kidney injury (AKI) as well as short- and long-term mortality in patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI) are limited. OBJECTIVES: To investigate the association between sOsmo and development of AKI and clinical outcomes in patients undergoing PCI. METHODS: We investigated 1,927 consecutive patients undergoing PCI from the registry of a single center. Patients were divided into quartiles according to sOsmo at admission (Q1-Q4). sOsmo was calculated using the following equation: (1.86 × serum sodium [mmol/L]) + (glucose [mg/dL] / 18) + (blood urea nitrogen [mg/dL] / 2.8) + 9. The primary endpoint was AKI, per Kidney Disease: Improving Global Outcomes (KDIGO) definition. The secondary endpoints were 30-day and 1-year all-cause mortality. RESULTS: Patients with the highest sOsmo (Q4) were older and more likely female, with significantly more cardiovascular risk factors and comorbidities compared to those with lower sOsmo (Q1-Q3). Incidence of AKI was highest in Q4 and lowest in Q2. In the multivariate logistic regression model, high sOsmo independently predicted the development of AKI (OR 2.00, 95% CI 1.26-3.19, p = 0.003). Patients with Q4 had a higher risk of 1-year mortality compared to patients with Q2 (HR 2.11, 95% CI 1.10-4.15; p = 0.031), but not after adding AKI to the multivariate model (HR 1.71, 95% CI 0.87-3.39; p = 0.12). CONCLUSION: sOsmo is a valid and easily obtainable predictor of AKI after PCI. High sOsmo is associated with increased risk of AKI and 1-year mortality in patients undergoing PCI. Further research is warranted to clarify whether the use of an sOsmo-directed hydration protocol might reduce the incidence of AKI in patients undergoing PCI.

An N-terminal Flag-tag impairs TPP1 regulation of telomerase function.

The shelterin protein complex protects natural chromosome ends from being recognized as DNA damage sites and also regulates the synthesis of telomeric repeats by telomerase. TPP1, a shelterin subunit that is essential for telomerase extension of telomeres, has been studied intensively in recent years. Many such studies utilize epitope tagged TPP1, but it is unclear how the tags may affect the multiple cellular functions of TPP1. Here we analyzed the effect of adding a 3x Flag epitope tag to the N- or C-terminus of TPP1. While the position of the tag did not affect TPP1's interaction within the shelterin complex or its localization to telomeres, the N-terminal Flag tag on TPP1 impaired telomerase function, resulting in reduced telomerase processivity in vitro and a failure to stimulate telomere elongation in vivo. The C-terminally Flag-tagged TPP1, in contrast, behaved similarly to untagged TPP1 in all functional aspects examined. These findings suggest that caution is required when utilizing epitope tagged TPP1 to study its regulation of telomerase function.