Peptidylarginine Deiminases 2 Mediates Caspase-1-Associated Lethality in Pseudomonas aeruginosa Pneumonia-Induced Sepsis.

BACKGROUND: Pseudomonas aeruginosa (PA) is a pathogenic bacterium that causes severe pneumonia in critically ill and immunocompromised patients. Peptidylarginine deiminase (PAD) 2, PAD4, and caspase-1 are important enzymes in mediating host response to infection. The goal of this study was to determine the interplay between PAD2, PAD4, and caspase-1 in PA pneumonia-induced sepsis. METHODS: Pneumonia was produced in wild-type, Pad2-/-, and Pad4-/- mice by intranasal inoculation of PA (2.5 × 106 colony-forming units per mouse), and survival (n = 15/group) was monitored for 10 days. Bone marrow-derived macrophages (BMDMs) were isolated for in vitro studies. Samples were collected at specific timepoints for Western blot, bacterial load determination, and flow cytometry analysis. RESULTS: Caspase-1-dependent inflammation was diminished in PA-inoculated Pad2-/- mice, contributing to reduced macrophage death and enhanced bacterial clearance. In addition, Pad2-/- mice exhibited improved survival and attenuated acute lung injury after PA infection. In contrast, Pad4-/- mice did not display diminished caspase-1 activation, altered bacterial loads, or improved survival. CONCLUSIONS: Peptidylarginine deiminase 2 plays an essential role in the pathogenesis of pulmonary sepsis by mediating caspase-1 activation. This goes against previous findings of PAD4 in sepsis. Our study suggests that PAD2 is a potential therapeutic target of PA pneumonia-induced sepsis.

Prognostic utility of quantitative image analysis of microvascular density in prostate cancer.

The walls of angiogenic blood vessel capillaries are composed of two principal cell types, blood vessel endothelial cells (BEC) and pericytes (PC), whereas the walls of lymphatic capillaries are composed of lymphatic endothelial cells (LEC). In this investigation we describe a practical application of NIH ImageJ software for quantitative image analysis for pericytes and endothelial cells in prostate cancer. We used a tissue microarray that contained 49 tissue cores (normal prostate tissue or prostatic carcinomas with Gleason scores of 6 through 10). These prostate cancer samples represented AJCC prognostic stages II, III, and IV. Slides were immunostained with anti-PDGFR-ß antibody for identification of PC, and quantified as microvascular pericyte density (MVPD); they were also immunostained with anti-CD34 antibody for identification of LEC and BEC simultaneously, and quantified as microvascular endothelial density (MVED). CD31 and D2-40 immunostains were used to quantify BEC and lymphatic endothelial cells, respectively. Our results showed higher MVPD and MVED in prostate cancers with higher Gleason scores and higher stages, suggesting the prognostic utility of vascular image analysis in prostate pathology. This investigation demonstrates the feasibility, versatility, and ease of use of ImageJ software and pericyte-specific and endothelial-specific immunohistochemistry for quantitative image analysis in prostate pathology.

Assessment of Residual Cancer Burden and Event-Free Survival in Neoadjuvant Treatment for High-risk Breast Cancer: An Analysis of Data From the I-SPY2 Randomized Clinical Trial.

IMPORTANCE: Residual cancer burden (RCB) distributions may improve the interpretation of efficacy in neoadjuvant breast cancer trials. OBJECTIVE: To compare RCB distributions between randomized control and investigational treatments within subtypes of breast cancer and explore the relationship with survival. DESIGN, SETTING, AND PARTICIPANTS: The I-SPY2 is a multicenter, platform adaptive, randomized clinical trial in the US that compares, by subtype, investigational agents in combination with chemotherapy vs chemotherapy alone in adult women with stage 2/3 breast cancer at high risk of early recurrence. Investigational treatments graduated in a prespecified subtype if there was 85% or greater predicted probability of higher rate of pathologic complete response (pCR) in a confirmatory, 300-patient, 1:1 randomized, neoadjuvant trial in that subtype. Evaluation of a secondary end point was reported from the 10 investigational agents tested in the I-SPY2 trial from March 200 through 2016, and analyzed as of September 9, 2020. The analysis plan included modeling of RCB within subtypes defined by hormone receptor (HR) and ERBB2 status and compared control treatments with investigational treatments that graduated and those that did not graduate. INTERVENTIONS: Neoadjuvant paclitaxel plus/minus 1 of several investigational agents for 12 weeks, then 12 weeks of cyclophosphamide/doxorubicin chemotherapy followed by surgery. MAIN OUTCOMES AND MEASURES: Residual cancer burden (pathological measure of residual disease) and event-free survival (EFS). RESULTS: A total of 938 women (mean [SD] age, 49 [11] years; 66 [7%] Asian, 103 [11%] Black, and 750 [80%] White individuals) from the first 10 investigational agents were included, with a median follow-up of 52 months (IQR, 29 months). Event-free survival worsened significantly per unit of RCB in every subtype of breast cancer (HR-positive/ERBB2-negative: hazard ratio [HZR], 1.75; 95% CI, 1.45-2.16; HR-positive/ERBB2-positive: HZR, 1.55; 95% CI, 1.18-2.05; HR-negative/ERBB2-positive: HZR, 2.39; 95% CI, 1.64-3.49; HR-negative/ERBB2-negative: HZR, 1.99; 95% CI, 1.71-2.31). Prognostic information from RCB was similar from treatments that graduated (HZR, 2.00; 95% CI, 1.57-2.55; 254 [27%]), did not graduate (HZR, 1.87; 95% CI, 1.61-2.17; 486 [52%]), or were control (HZR, 1.79; 95% CI, 1.42-2.26; 198 [21%]). Investigational treatments significantly lowered RCB in HR-negative/ERBB2-negative (graduated and nongraduated treatments) and ERBB2-positive subtypes (graduated treatments), with improved EFS (HZR, 0.61; 95% CI, 0.41-0.93) in the exploratory analysis. CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, the prognostic significance of RCB was consistent regardless of subtype and treatment. Effective neoadjuvant treatments shifted the distribution of RCB in addition to increasing pCR rate and appeared to improve EFS. Using a standardized quantitative method to measure response advances the interpretation of efficacy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01042379.

Peptidylarginine deiminase 2 has potential as both a biomarker and therapeutic target of sepsis.

Peptidylarginine deiminases (PADs) are a family of calcium-dependent enzymes that are involved in a variety of human disorders, including cancer and autoimmune diseases. Although targeting PAD4 has shown no benefit in sepsis, the role of PAD2 remains unknown. Here, we report that PAD2 is engaged in sepsis and sepsis-induced acute lung injury in both human patients and mice. Pad2-/- or selective inhibition of PAD2 by a small molecule inhibitor increased survival and improved overall outcomes in mouse models of sepsis. Pad2 deficiency decreased neutrophil extracellular trap (NET) formation. Importantly, Pad2 deficiency inhibited Caspase-11-dependent pyroptosis in vivo and in vitro. Suppression of PAD2 expression reduced inflammation and increased macrophage bactericidal activity. In contrast to Pad2-/-, Pad4 deficiency enhanced activation of Caspase-11-dependent pyroptosis in BM-derived macrophages and displayed no survival improvement in a mouse sepsis model. Collectively, our findings highlight the potential of PAD2 as an indicative marker and therapeutic target for sepsis.

Peptidylarginine Deiminase 2 Knockout Improves Survival in hemorrhagic shock.

BACKGROUND: The peptidylarginine deiminase (PAD) family converts arginine into citrulline through protein citrullination. PAD2 and PAD4 inhibitors can improve survival in hemorrhagic shock (HS). However, the impact of isoform-specific PAD inhibition in improving survival has not been studied. In this study, we utilize selective Pad2 knockout mice to elucidate loss of function of PAD2 leads to pro-survival effect in HS. METHODS: HS: Pad2 and wild-type (WT) mice (n = 5/group) were subjected to lethal HS (55% volume hemorrhage). Survival was monitored over 7 days. Myocardial infarction (MI): Pad2 and WT mice (n = 9/group) were subjected to MI by permanent LAD ligation to examine the effect of ischemia on the heart. After 24 h cardiac function and infarct size were measured. RESULTS: HS: Pad2 mice demonstrated 100% survival compared with 0% for WT mice (P = 0.002). In a sub-lethal HS model, cardiac ß-catenin levels were higher in Pad2 compared with WT after 24 h. MI: WT mice demonstrated larger MI (75%) compared with Pad2 (60%) (P < 0.05). Pad2 had significantly higher ejection fraction and fractional shortening compared with WT (P < 0.05). CONCLUSIONS: Pad2 improves survival in lethal HS. Possible mechanisms by which loss of PAD2 function improves survival include the activation of cell survival pathways, improved tolerance of cardiac ischemia, and improved cardiac function during ischemia. PAD2 is promising as a future therapeutic target for the treatment of HS and cardiac ischemia.

Citrullinated Histone H3 as a Therapeutic Target for Endotoxic Shock in Mice.

Sepsis results in millions of deaths every year, with acute lung injury (ALI) being one of the leading causes of mortality in septic patients. As neutrophil extracellular traps (NETs) are abundant in sepsis, neutralizing components of NETs may be a useful strategy to improve outcomes of sepsis. Citrullinated histone H3 (CitH3) has been recently shown to be involved in the NET formation. In this study, we demonstrate that CitH3 damages human umbilical vein endothelial cells (HUVECs) and potentiates NET formation through a positive feedback mechanism. We developed a novel CitH3 monoclonal antibody to target peptidylarginine deiminase (PAD) 2 and PAD 4 generated CitH3. In a mouse model of lethal lipopolysaccharide (LPS) induced shock, neutralizing CitH3 with the newly developed anti-CitH3 monoclonal antibody attenuates inflammatory responses, ameliorates ALI, and improves survival. Our study suggests that effectively blocking circulating CitH3 might be a potential therapeutic method for the treatment of endotoxemia.

Inhibition of peptidylarginine deiminase alleviates LPS-induced pulmonary dysfunction and improves survival in a mouse model of lethal endotoxemia.

Immune cell death caused by neutrophil extracellular traps (NETs), referred to as NETosis, can contribute to the pathogenesis of endotoxemia and organ damage. Although the mechanisms by which infection induces NETosis and how that leads to organ dysfunction remain largely unknown, NET formation is often found following citrullination of histone H3 (CitH3) by peptidylarginine deiminase (PAD). We hypothesized that lipopolysaccharide (LPS)-induced activation of PAD and subsequent CitH3-mediated NET formation increases endothelial permeability and pulmonary dysfunction and, therefore, that inhibition of PAD can mitigate damage and improve survival in lethal endotoxemia. Here, we showed that treatment with YW3-56, a PAD2/PAD4 inhibitor, significantly diminished PAD activation, blocked LPS-induced pulmonary vascular leakage, alleviated acute lung injury, and improved survival in a mouse model of lethal LPS-induced endotoxemia. We found CitH3 in the bloodstream 30 min after intraperitoneal injection of LPS (35 mg/kg) into mice. Additionally, CitH3 production was induced in cultured neutrophils exposed to LPS, and NETs derived from these LPS-treated neutrophils increased the permeability of endothelial cells. However, YW3-56 reduced CitH3 production and NET formation by neutrophils following LPS exposure. Moreover, treatment with YW3-56 decreased the levels of circulating CitH3 and abolished neutrophil activation and NET formation in the lungs of mice with endotoxemia. These data suggest a novel mechanism by which PAD-NET-CitH3 can play a pivotal role in pulmonary vascular dysfunction and the pathogenesis of lethal endotoxemia.

Protective Effect of Tubastatin A in CLP-Induced Lethal Sepsis.

We have found earlier that Tubastatin A (TubA), a selective inhibitor of histone deacetylase 6 (HDAC6), improves survival in a mouse model of lethal cecal ligation and puncture (CLP)-induced sepsis. However, the underlying mechanisms have not been fully established. This study sought to test the hypothesis that TubA could affect both lung and splenic functions. C57BL/6J mice were subjected to CLP, and randomized to receive either TubA (70 mg/kg) dissolved in dimethyl sulfoxide (DMSO), or DMSO alone, 1 h following CLP. Sham animals acted as control. Twenty-four hours later, lung tissue was harvested for pathological examination, and splenic tissue was harvested for bacterial colonization. In a parallel study, the spleen was collected 48 h following CLP, and single cell suspension was prepared. Splenocytes then underwent flow cytometry to analyze the immune cell population. RAW264.7 macrophages were treated with lipopolysaccharide (LPS) with or without the presence of TubA (10 µM) at 37 °C for 3 h to assess the effect on macrophage phagocytosis. We found that acute lung injury secondary to lethal sepsis was attenuated by TubA. Treatment with TubA restored the percentage of B lymphocytes, and significantly increased percentages of innate immune cells and macrophages compared to the vehicle-treated CLP group. Moreover, TubA significantly decreased the bacterial load in the spleen, and improved the phagocytic ability of RAW264.7 murine macrophages in vitro. Such findings may help to explain the beneficial effects of TubA treatment in a model of lethal sepsis, as previously reported.

Lung Protective Effects of Low-Volume Resuscitation and Pharmacologic Treatment of Swine Subjected to Polytrauma and Hemorrhagic Shock.

Hemorrhage is a common cause of death in the battlefield. Valproic acid (VPA) has been associated with improved outcomes in multiple models of trauma, when combined with isotonic fluid resuscitation. However, isotonic fluid administered in this setting is logistically impractical and may be associated with complications. In this study, we sought to evaluate the feasibility and immunologic impact of combining VPA treatment with low-volume hypertonic saline (HTS). In vivo: female Yorkshire swine were subjected to hemorrhage (40% total blood volume) and polytrauma (rib fracture and delayed liver injury). Animals were kept in shock for 30 minutes and resuscitated with (1) normal saline (NS, 3× hemorrhaged volume), (2) HTS (7.5% saline, 4 mL/kg), or (3) HTS + VPA (4 mg/kg; 150 mg/kg; n = 3/cohort). After 18 hours of observation, animals were euthanized and the lungs evaluated for acute injury and expression of myeloperoxidase (MPO) and caveolin-1 (Cav-1). In vitro: human umbilical vein endothelial cells (HUVECs) were exposed to anoxic conditions (5% CO2, 95% N2) for 16 hours in (1) normosmotic, (2) hyperosmotic (400 mOsm), or (3) hyperosmotic + VPA (4 mM) media. Immunohistochemistry and Western blots were performed to determine Cav-1 expression. Lungs from VPA-treated animals demonstrated decreased acute injury, MPO expression, and endothelial expression of Cav-1 when compared to lungs from animals resuscitated with NS or HTS alone. Similarly, HUVECs cultured in hyperosmotic media containing VPA demonstrated decreased expression of Cav-1. This study demonstrates that combined treatment with VPA and HTS is a viable strategy in hemorrhagic shock and polytrauma. Attenuation of lung injury following VPA treatment may be related to modulation of the inflammatory response.

Inhibition of histone deacetylase 6 restores intestinal tight junction in hemorrhagic shock.

BACKGROUND: We recently discovered that Tubastatin-A, a histone deacetylase (HDAC6) inhibitor, can improve survival in a rodent model of hemorrhagic shock (HS), but mechanisms remain poorly defined. In this study, we investigated whether Tubastatin-A could protect intestinal tight junction (TJ) in HS. METHODS: In an in-vivo study with Wistar-Kyoto rats, the rats underwent HS (40% blood loss) followed by Tubastatin-A (70 mg/kg) treatment, without fluid resuscitation. The experimental groups were (1) sham (no hemorrhage, no treatment), (2) control (hemorrhage, without treatment), and (3) treatment (hemorrhage with Tubastatin-A administration). Six hours after hemorrhage, ileum was harvested. Whole cell lysate were analyzed for acetylated α-tubulin (Ac-tubulin), total tubulin, acetylated histone 3 at lysine 9 (Ac-H3K9), ß-actin, claudin-3 and zonula occludens 1 (ZO-1) proteins by Western blot. Histological effects of Tubastatin-A on small bowel were examined. In an in-vitro study, human intestinal epithelial cells (Caco-2) were divided into three groups: (1) sham (normoxia), (2) control (anoxia, no treatment), and (3) treatment (anoxia, treatment with Tubastatin-A). After 12 hours in an anoxia chamber, the cells were examined for Ac-tubulin and Ac-H3K9, cellular viability, cytotoxicity, claudin-3 and ZO-1 protein expression, and transwell permeability study. RESULTS: Tubastatin-A treatment significantly attenuated HS-induced decreases of Ac-tubulin, Ac-H3K9, ZO-1 and claudin-3 proteins in small bowel in-vivo (p < 0.05). In cultured Caco-2 cells, anoxia significantly decreased cellular viability (p < 0.001) and increased cytotoxicity (p < 0.001) compared to the sham group, while Tubastatin-A treatment offered significant protection (p < 0.0001). Moreover, expression of claudin-3 was markedly decreased in vitro compared to the sham group, whereas this was significantly attenuated by Tubastatin-A (p < 0.05). Finally, anoxia markedly increased the permeability of Caco-2 monolayer cells (p < 0.05), while Tubastatin-A significantly attenuated the alteration (p < 0.05). CONCLUSION: Inhibition of HDAC6 can induce Ac-tubulin and Ac-H3K9, promote cellular viability, and prevent the loss of intestinal tight junction proteins during HS and anoxia.

Inhibition of histone deacetylase 6 improves long-term survival in a lethal septic model.

BACKGROUND: We recently demonstrated that suberoylanilide hydroxamic acid, a broad-spectrum histone deacetylase (HDAC) inhibitor that inhibits HDACs 1, 2, 3, and 6, improves survival in a mouse model of cecal ligation and puncture (CLP)-induced lethal sepsis. The current study was undertaken to determine the effect of selective inhibition of HDAC isoform on survival, key cytokine production, organ injury, bacteria clearance, and cell apoptosis. METHODS: In Experiment 1, C57BL/6J mice were subjected to CLP and, 1 hour later, given intraperitoneal injections of (1) Tubastatin A (inhibitor of HDAC6) dissolved in dimethyl sulfoxide (DMSO), (2) MS-275 (inhibitor of HDACs 1, 2, and 3) in DMSO, and (3) DMSO only. Survival was monitored for 10 days. In Experiment 2, 1 hour after CLP, animals were treated with DMSO vehicle or Tubastatin A. Sham-operated animals served as control. Peritoneal fluid and blood samples were collected for measurement of cytokines at 24 hours or 48 hours. Blood at 48 hours was also used to determine bacteria load. Liver was harvested to evaluate acute liver injury. In Experiment 3, Primary splenocytes were used to assess cytokine responses and phagocytosis. Macrophages were cultured and harvested 3 hours and 6 hours after lipopolysaccharide stimulation in the absence or presence of Tubastatin A to analyze cell apoptosis. RESULTS: Animals treated with Tubastatin A, but not MS-275, displayed a significant improvement in survival. Moreover, Tubastatin A significantly inhibited cytokine production in peritoneal fluid and plasma as well as in supernatant from splenocytes stimulated with lipopolysaccharide. Tubastatin A significantly attenuated acute liver injury, increased blood bacteria clearance and splenocyte phagocytosis, and decreased macrophage apoptosis. CONCLUSION: HDAC6 inhibition significantly improves survival, reduces "cytokine storm," attenuates acute livery injury, increases bacteria clearance and immune cell phagocytosis, and inhibits macrophage apoptosis in a lethal mouse CLP model.

Metastatic juxtaglomerular cell tumor in a 52-year-old man.

Juxtaglomerular cell tumor is a rare renal neoplasm arising from the juxtaglomerular apparatus. Approximately 70 cases have been reported in the English literature since it was first described by Robertson et al in 1967. This tumor has been considered benign and resection has so far been curative. In this paper, we report the first metastatic juxtaglomerular cell tumor. The 15-cm tumor occurred in the right kidney of a 46-year-old man. It invaded the renal vein, and was treated by radical nephrectomy in 1995. The diagnosis at that time was renal cell carcinoma. The patient was well for 6 years and then developed bilateral lung masses, which were resected. Microscopically, the tumors from the kidney and the lungs were similar, consisting of solid sheets of uniformly round-to-polygonal cells intermixed with abundant delicate vasculature. Both renal and pulmonary tumors were positive for vimentin, renin, and only focally to CD34. Electron microscopic studies performed on the paraffin-embedded renal tumor and formalin-fixed lung tumor revealed the typical rhomboid crystals of proto-renin. In consideration of the characteristic morphologic features, immunohistochemistry, and the presence of rhomboid crystals of proto-renin, the diagnosis was modified to malignant juxtaglomerular cell tumor.

Creating a prosurvival phenotype through a histone deacetylase inhibitor in a lethal two-hit model.

OBJECTIVES: Hemorrhagic shock (HS) can initiate an exaggerated systemic inflammatory response and multiple organ failure, especially if followed by a subsequent inflammatory insult ("second hit"). We have recently shown that histone deacetylase inhibitors can improve survival in rodent models of HS or septic shock, individually. In the present study, we examined whether valproic acid (VPA), a histone deacetylase inhibitor, could prolong survival in a rodent "two-hit" model: HS followed by septic shock from cecal ligation and puncture (CLP). METHODS: Male Sprague-Dawley rats (250-300 g) were subjected to sublethal HS (40% blood loss) and then randomly divided into two groups (n = 7/group): VPA and control. The VPA group was treated intraperitoneally with VPA (300 mg/kg in normal saline [NS], volume = 750 µL/kg). The control group was injected with 750 µL/kg NS. After 24 h, all rats received CLP followed immediately by injection of the same dose of VPA (VPA group) or NS (vehicle group). Survival was monitored for 10 days. In a parallel study, serum and peritoneal irrigation fluid from VPA- or vehicle-treated rats were collected 3, 6, and 24 h after CLP, and enzyme-linked immunosorbent assay was performed to analyze myeloperoxidase activity and determine tumor necrosis factor α and interleukin 6 concentrations. Hematoxylin-eosin staining of lungs at 24-h time point was performed to investigate the grade of acute lung injury. RESULTS: Rats treated with VPA (300 mg/kg) showed significantly higher survival rates (85.7%) compared with the control (14.3%). Moreover, VPA significantly suppressed myeloperoxidase activity (marker of neutrophil-mediated oxidative damage) and inhibited levels of proinflammatory cytokine tumor necrosis factor α and interleukin 6 in the serum and peritoneal cavity. Meanwhile, the severity of acute lung injury was significantly reduced in VPA-treated animals. CONCLUSIONS: We have demonstrated that VPA treatment improves survival and attenuates inflammation in a rodent two-hit model.

A practical application of quantitative vascular image analysis in breast pathology.

AIMS: Quantitative image analysis of histopathology slides is becoming an important technology in diagnostic pathology. To this end, it is essential to combine a robust image analysis software with the most commonly used immunohistochemical staining methods. In this investigation, we describe a practical application of NIH ImageJ software for quantitative vascular image analysis for diaminobenzene chromogen-based CD34 immunostain in breast cancer. CD34 immunostain is in a unique position to identify lymphangiogenesis and angiogenesis simultaneously in a given tumor tissue. This investigation aims at establishing a practical quantitative vascular image analysis solution for diagnostic pathologists by using ImageJ, and CD34 immunostain. METHODS AND RESULTS: Tissue microarray slides containing breast cancer tissue were immunostained for CD34 for simultaneous identification of lymphatic endothelial cells (LEC) and blood vessel endothelial cells (BEC). Digital images were analyzed using NIH ImageJ software. A CD34 score was quantified for each tissue core as a percentage (CD34-positive area/area of tissue core). The mean CD34 scores were 0.24%, 0.40%, 1.30%, 2.33%, 2.64%, and 3.44% for normal breast tissue, in stage IIA, IIB, IIIA, IIIB, and IIIC breast cancer tissue cores, respectively (p<0.0001). The mean CD34 scores were 0.70% and 2.21% for lymph node-negative and lymph node-positive breast cancer patients, respectively (p<0.0001). CONCLUSIONS: ImageJ software seems to be an attractive quantitative image analysis tool for diagnostic pathology for immunohistochemistry-based applications because of its capabilities, availability, and ease of use with most image formats. Our results show the feasibility, versatility, and ease of use of ImageJ and CD34 immunohistochemistry for vascular image analysis in breast pathology. Given the prospects of novel lymphatic and vascular endothelium-targeting therapeutics in breast oncology, the practical analysis of combined LEC and BEC density described in this report could enable diagnostic pathologists to apply quantitative vascular image analysis easily in their pathology practice and translational research.

Synergistic effects of hypertonic saline and valproic acid in a lethal rat two-hit model.

BACKGROUND: Hemorrhagic shock (HS) followed by an infection ("second hit") can lead to severe systemic inflammatory response and multiple-organ failure. Studies have shown that resuscitation with hypertonic saline (HTS) can blunt the inflammatory response. We demonstrated that large doses of valproic acid (VPA, 300 mg/kg), a histone deacetylase inhibitor, improves survival in a rodent two-hit model (HS followed by cecal ligation and puncture [CLP]). In the present study, we examined whether combination of HTS with VPA would allow us to achieve survival advantage at a lower dose of VPA (200 mg/kg). METHODS: Male Sprague-Dawley rats were subjected to HS (50% blood loss) and randomized into five groups (n = 7-8 per group) as follows: (1) isotonic sodium chloride solution (ISCS), (2) 7.5% saline, (3) VPA, (4) ISCS + VPA, and (5) HTS + VPA. After 24 hours, they underwent CLP, followed by the same doses of ISCS, HTS, and/or VPA and were monitored for 10 days. In a parallel experiment, blood, peritoneal irrigation fluid and lung homogenate were subjected to enzyme-linked immunosorbent assay 3 hours and 24 hours after CLP to measure myeloperoxidase activity and proinflammatory cytokines tumor necrosis factor α and interleukin 1ß levels. Western blotting was performed to investigate the expression of pentraxin 3 protein in the lung homogenate at 24 hours after CLP. Hematoxylin and eosin staining of lungs at the 24 hours were performed to quantify the degree of acute lung injury. RESULTS: HTS + VPA treatment significantly improved survival (87.5%), compared with the other groups (14.3%; p < 0.05), while attenuating peritoneal myeloperoxidase levels and proinflammatory cytokine tumor necrosis factor α and interleukin 1ß levels in the serum, peritoneal cavity, and lung. The degree of acute lung injury and expression of pentraxin 3 in the lung were significantly reduced in the HTS + VPA group. CONCLUSION: This is the first study to show that VPA and HTS can work synergistically to attenuate inflammation and improve survival in a lethal two-hit model.

Novel pharmacologic treatment attenuates septic shock and improves long-term survival.

BACKGROUND: We have demonstrated previously that suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, improves survival in a lipopolysaccharide-induced lethal model of endotoxemia. The goal of this study was to investigate the impact of SAHA on survival in a more clinically relevant model of cecal ligation and puncture (CLP)-induced septic shock and to elucidate changes in cytokine responses and organ injury. METHODS: C57BL/6J mice were subjected to CLP, and 1 hour later were given intraperitoneally either SAHA dissolved in dimethyl sulfoxide or dimethyl sulfoxide only. Survival was monitored for 10 days. In a second study, livers were harvested for evaluation of acute liver injury, and peritoneal fluid and blood samples were collected for cytokine assays. In addition, RAW264.7 and bone marrow-derived macrophages were used to assess effects of SAHA on cytokine responses. RESULTS: SAHA-treated animals displayed a substantial improvement in survival. In addition, SAHA also attenuated cytokine levels in blood and peritoneal fluid compared with vehicle animals, as well as in culture supernatant of macrophages stimulated with bacterial components (lipopolysaccharide or Pam3CSK4). Moreover, SAHA-treated animals showed a substantial decrease in acute liver injury. CONCLUSION: SAHA treatment improves survival, decreases "cytokine storm," and prevents distant organ damage in a lethal septic model.

Invasive paget disease of the breast: clinicopathologic study of an underrecognized entity in the breast.

Mammary Paget disease (MPD) is considered an intraepidermal manifestation of an underlying mammary carcinoma. In contrast to extramammary Paget disease, invasion of mammary Paget cells into the dermis (invMPD) has not been reported, except for 2 cases described in Rosen's textbook. Our study was designed to identify the presence of dermal invasion of mammary Paget cells and characterize the associated clinicopathologic features. Slides from 146 MPD patients were retrieved. Six cases of invMPD were identified. One case of invMPD was not associated with an underlying breast cancer, 1 was associated with invasive ductal carcinoma (IDC), 1 with ductal carcinoma in situ (DCIS) with microinvasion, and 3 with DCIS only. The underlying breast carcinomas was separate from the area of invMPD. The depth of invasion, measured from the dermal-epidermal junction to the focus of deepest invasion, ranged from 0.02 to 0.9 mm. The horizontal extent ranged from 0.01 to 4.0 mm. Lymph node with isolated tumor clusters was present in case 1, which had no underlying carcinoma but had the greatest extent of invasion, and in case 3, which had DCIS with microinvasion. One patient (case 1) died of unrelated causes 2 years later, and the remaining patients were alive without disease at last follow-up. In summary, we describe 6 cases of MPD with invasion of Paget cells into the dermis and provide histopathologic criteria for the diagnosis of this rare and underrecognized entity. Further studies are required to determine whether invasion in MPD has clinical significance.

Intravascular large B-cell lymphoma presenting as cholecystitis and pancytopenia: case report with literature review.

Intravascular large B-cell lymphoma (IVLBCL) is a rare variant of extranodal diffuse large Bcell lymphoma with only a few more than 300 cases reported. It is characterized as lymphoma cells confined to the lumina of small vessels, so patients usually do not present with masses or lymphadenopathy. Clinical presentations of these patients are non-specific and the pathologic changes may be subtle, which often leads to delayed diagnoses and, in many instances, a postmortem diagnosis. IVLBCL can essentially involve the vessels of any organ, but it is quite rare for the gallbladder to serve as the initial presenting site; there are only four such cases reported in the English literature. Furthermore, IVLBCL of the gallbladder with peripheral blood involvement is even less common. We report a recent case of IVLBCL presenting as acute cholecystitis and pancytopenia. The patient underwent a simple cholecystectomy. Examination of the gallbladder showed clusters of large lymphoma cells within lumina of small vessels in the gallbladder wall. These cells were positive for CD5/CD20 and negative for CD3, CD10, and TdT. Based on these findings, a diagnosis of IVLBCL was made. Coincidently, circulating lymphoma cells were identified in the peripheral blood and confirmed by flow cytometric analysis (positive for CD19/CD20/CD5, without light chain expression). The patient was started on chemotherapy but subsequently died of chemotherapy related multi-organ failure 10 days after the initial diagnosis.

Intravascular large B-cell lymphoma: report of three cases and analysis of the mTOR pathway.

Intravascular large B-cell lymphoma (IVLBCL) is a rare, aggressive and often fatal non-Hodgkin lymphoma characterized by preferential growth of malignant B-cells within the lumina of small vessels. Rituximab plus anthracycline-based chemotherapy is the current standard regimen for IVLBCL, however it has minimal efficacy in relapsed or refractory diseases. Recent clinical trials have shown a significant anti-lymphoma activity of mammalian target of rapamycin (mTOR) inhibitors in relapsed and refractory diffuse large B-cell lymphoma (DLBCL); however, the activation status of the mTOR pathway and the therapeutic potential of mTOR inhibitors in IVLBCL have not yet been studied. Here we described the clinicopathological features of 3 cases of IVLBCL diagnosed at our institutions, and evaluated the activation status of the mTOR signaling in these tumors. Our results showed that the mTOR complex 2 pathway was selectively upregulated in IVLBCL, as evidenced by a predominant nuclear localization of the activated form of mTOR (p-mTOR at Ser2448) with concomitant overexpression of nuclear p-Akt (Ser473) and vascular endothelial growth factor (VEGF)-A in the lymphoma cells. These data suggest that overactivation of mTOR pathway may play a role in lymphomagenesis of IVLBCL and mTORC2 inhibitors may be beneficial in treating IVLBCL.

Multicentric hepatic EBV-associated smooth muscle tumors in an AIDS patient: a case report, investigation of mTOR activation and review of the literature.

Epstein-Barr virus (EBV) - associated smooth muscle tumors (EBV-SMT) are a rare, recently recognized distinct group of mesenchymal tumors that develop exclusively in patients with immunosuppression. It is believed that tumorigenesis is, at least in part, through the activation of the Akt/mammalian target of rapamycin (mTOR) signal pathway. We describe the clinicopathologic and immunohistochemical features of a multifocal hepatic EBV-SMT in a 34-year-old acquired immunodeficiency syndrome (AIDS) patient and investigate the activation status of the mTOR signal pathway in this tumor. In addition, we provide a review of the literature on the clinicopathologic findings of hepatic EBV-SMT in adult AIDS patients, and discuss their biologies and possible therapeutic strategies.