Hepatocyte ß-catenin loss is compensated by Insulin-mTORC1 activation to promote liver regeneration.

BACKGROUND AND AIMS: Liver regeneration (LR) following partial hepatectomy (PH) occurs via activation of various signaling pathways. Disruption of a single pathway can be compensated by activation of another pathway to continue LR. The Wnt-ß-catenin pathway is activated early during LR and conditional hepatocyte loss of ß-catenin delays LR. Here, we study mechanism of LR in the absence of hepatocyte-ß-catenin. APPROACH AND RESULTS: Eight-week-old hepatocyte-specific Ctnnb1 knockout mice (ß-catenin ΔHC ) were subjected to PH. These animals exhibited decreased hepatocyte proliferation at 40-120 h and decreased cumulative 14-day BrdU labeling of <40%, but all mice survived, suggesting compensation. Insulin-mediated mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) activation was uniquely identified in the ß-catenin ΔHC mice at 72-96 h after PH. Deletion of hepatocyte regulatory-associated protein of mTOR (Raptor), a critical mTORC1 partner, in the ß-catenin ΔHC mice led to progressive hepatic injury and mortality by 30 dys. PH on early stage nonmorbid Raptor ΔHC -ß-catenin ΔHC mice led to lethality by 12 h. Raptor ΔHC mice showed progressive hepatic injury and spontaneous LR with ß-catenin activation but died by 40 days. PH on early stage nonmorbid Raptor ΔHC mice was lethal by 48 h. Temporal inhibition of insulin receptor and mTORC1 in ß-catenin ΔHC or controls after PH was achieved by administration of linsitinib at 48 h or rapamycin at 60 h post-PH and completely prevented LR leading to lethality by 12-14 days. CONCLUSIONS: Insulin-mTORC1 activation compensates for ß-catenin loss to enable LR after PH. mTORC1 signaling in hepatocytes itself is critical to both homeostasis and LR and is only partially compensated by ß-catenin activation. Dual inhibition of ß-catenin and mTOR may have notable untoward hepatotoxic side effects.

SOD2 V16A amplifies vascular dysfunction in sickle cell patients by curtailing mitochondria complex IV activity.

Superoxide dismutase 2 (SOD2) catalyzes the dismutation of superoxide to hydrogen peroxide in mitochondria, limiting mitochondrial damage. The SOD2 amino acid valine-to-alanine substitution at position 16 (V16A) in the mitochondrial leader sequence is a common genetic variant among patients with sickle cell disease (SCD). However, little is known about the cardiovascular consequences of SOD2V16A in SCD patients or its impact on endothelial cell function. Here, we show SOD2V16A associates with increased tricuspid regurgitant velocity (TRV), systolic blood pressure, right ventricle area at systole, and declined 6-minute walk distance in 410 SCD patients. Plasma lactate dehydrogenase, a marker of oxidative stress and hemolysis, significantly associated with higher TRV. To define the impact of SOD2V16A in the endothelium, we introduced the SOD2V16A variant into endothelial cells. SOD2V16A increases hydrogen peroxide and mitochondrial reactive oxygen species (ROS) production compared with controls. Unexpectedly, the increased ROS was not due to SOD2V16A mislocalization but was associated with mitochondrial complex IV and a concomitant decrease in basal respiration and complex IV activity. In sum, SOD2V16A is a novel clinical biomarker of cardiovascular dysfunction in SCD patients through its ability to decrease mitochondrial complex IV activity and amplify ROS production in the endothelium.

A Novel Method of Mouse RPE Explant Culture and Effective Introduction of Transgenes Using Adenoviral Transduction for In Vitro Studies in AMD.

Degeneration of retinal pigment epithelium (RPE) is one of the most critical phenotypic changes of age-related macular degeneration (AMD), the leading cause of vision loss in the elderly. While cultured polarized RPE cells with original properties are valuable in in vitro models to study RPE biology and the consequences of genetic and/or pharmacological manipulations, the procedure to establish mouse primary PRE cell culture or pluripotent stem cell-derived RPE cells is time-consuming and yields a limited number of cells. Thus, establishing a mouse in situ RPE culture system is highly desirable. Here we describe a novel and efficient method for RPE explant culture that allows for obtaining biologically relevant RPE cells in situ. These RPE explants (herein referred to as RPE flatmounts) are viable in culture for at least 7 days, can be efficiently transduced with adenoviral constructs, and/or treated with a variety of drugs/chemicals followed by downstream analysis of the signaling pathways/biological processes of interest, such as assessment of the autophagy flux, inflammatory response, and receptor tyrosine kinases stimulation. This method of RPE explant culture is highly beneficial for pharmacological and mechanistic studies in the field of RPE biology and AMD research.

ECSIT is a critical limiting factor for cardiac function.

Evolutionarily conserved signaling intermediate in Toll pathways (ECSIT) is a protein with roles in early development, activation of the transcription factor NF-κB, and production of mitochondrial reactive oxygen species (mROS) that facilitates clearance of intracellular bacteria like Salmonella. ECSIT is also an important assembly factor for mitochondrial complex I. Unlike the murine form of Ecsit (mEcsit), we demonstrate here that human ECSIT (hECSIT) is highly labile. To explore whether the instability of hECSIT affects functions previously ascribed to its murine counterpart, we created a potentially novel transgenic mouse in which the murine Ecsit gene is replaced by the human ECSIT gene. The humanized mouse has low levels of hECSIT protein, in keeping with its intrinsic instability. Whereas low-level expression of hECSIT was capable of fully compensating for mEcsit in its roles in early development and activation of the NF-κB pathway, macrophages from humanized mice showed impaired clearance of Salmonella that was associated with reduced production of mROS. Notably, severe cardiac hypertrophy was manifested in aging humanized mice, leading to premature death. The cellular and molecular basis of this phenotype was delineated by showing that low levels of human ECSIT protein led to a marked reduction in assembly and activity of mitochondrial complex I with impaired oxidative phosphorylation and reduced production of ATP. Cardiac tissue from humanized hECSIT mice also showed reduced mitochondrial fusion and more fission but impaired clearance of fragmented mitochondria. A cardiomyocyte-intrinsic role for Ecsit in mitochondrial function and cardioprotection is also demonstrated. We also show that cardiac fibrosis and damage in humans correlated with low expression of human ECSIT. In summary, our findings identify a role for ECSIT in cardioprotection, while generating a valuable experimental model to study mitochondrial dysfunction and cardiac pathophysiology.

Graft-derived extracellular vesicles transported across subcapsular sinus macrophages elicit B cell alloimmunity after transplantation.

Despite the role of donor-specific antibodies (DSAs) in recognizing major histocompatibility complex (MHC) antigens and mediating transplant rejection, how and where recipient B cells in lymphoid tissues encounter donor MHC antigens remains unclear. Contrary to the dogma, we demonstrated here that migration of donor leukocytes out of skin or heart allografts is not necessary for B or T cell allosensitization in mice. We found that mouse skin and cardiac allografts and human skin grafts release cell-free donor MHC antigens via extracellular vesicles (EVs) that are captured by subcapsular sinus (SCS) macrophages in lymph nodes or analog macrophages in the spleen. Donor EVs were transported across the SCS macrophages, and donor MHC molecules on the EVs were recognized by alloreactive B cells. This triggered B cell activation and DSA production, which were both prevented by SCS macrophage depletion. These results reveal an unexpected role for graft-derived EVs and open venues to interfere with EV biogenesis, trafficking, or function to restrain priming or reactivation of alloreactive B cells.

Profilin-1 deficiency leads to SMAD3 upregulation and impaired 3D outgrowth of breast cancer cells.

BACKGROUND: Adhesion-mediated activation of FAK/ERK signalling pathway, enabled by the formation of filopodial protrusions (FLP), has been shown to be an important event for triggering of dormancy-to-proliferation switch and metastatic outgrowth of breast cancer cells (BCC). We studied the role of actin-binding protein profilin1 (Pfn1) in these processes. METHODS: Quantitative immunohistochemistry (IHC) of BC tissue microarray (TMA) and survival analyses of curated transcriptome datasets of BC patients were performed to examine Pfn1's association with certain clinicopathological features. FLP formation and single cell outgrowth of BCC were assessed using a 3D matrigel culture that accurately predicts dormant vs metastatic outgrowth phenotypes of BCC in certain microenvironment. Gene expression studies were performed to identify potential biological pathways that are perturbed under Pfn1-depleted condition. RESULTS: Lower Pfn1 expression is correlated with lower nuclear grade of breast tumours and longer relapse-free survival of BC patients. Pfn1 depletion leads to defects in FLP and outgrowth of BCC but without impairing either FAK or ERK activation. Guided by transcriptome analyses, we further showed that Pfn1 depletion is associated with prominent SMAD3 upregulation. Although knockdown and overexpression experiments revealed that SMAD3 has an inhibitory effect on the outgrowth of breast cancer cells, SMAD3 knockdown alone was not sufficient to enhance the outgrowth potential of Pfn1-depleted BCC suggesting that other proliferation-regulatory pathways in conjunction with SMAD3 upregulation may underlie the outgrowth-deficient phenotype of BCC cells upon depletion of Pfn1. CONCLUSION: Overall, these data suggest that Pfn1 may be a novel biomarker for BC recurrence and a possible target to reduce metastatic outgrowth of BCC.

Compensatory increases of select proteostasis networks after Hsp70 inhibition in cancer cells.

Cancer cells thrive when challenged with proteotoxic stress by inducing components of the protein folding, proteasome, autophagy and unfolded protein response (UPR) pathways. Consequently, specific molecular chaperones have been validated as targets for anti-cancer therapies. For example, inhibition of Hsp70 family proteins (hereafter Hsp70) in rhabdomyosarcoma triggers UPR induction and apoptosis. To define how these cancer cells respond to compromised proteostasis, we compared rhabdomyosarcoma cells that were sensitive (RMS13) or resistant (RMS13-R) to the Hsp70 inhibitor MAL3-101. We discovered that endoplasmic reticulum-associated degradation (ERAD) and autophagy were activated in RMS13-R cells, suggesting that resistant cells overcome Hsp70 ablation by increasing misfolded protein degradation. Indeed, RMS13-R cells degraded ERAD substrates more rapidly than RMS cells and induced the autophagy pathway. Surprisingly, inhibition of the proteasome or ERAD had no effect on RMS13-R cell survival, but silencing of select autophagy components or treatment with autophagy inhibitors restored MAL3-101 sensitivity and led to apoptosis. These data indicate a route through which cancer cells overcome a chaperone-based therapy, define how cells can adapt to Hsp70 inhibition, and demonstrate the value of combined chaperone and autophagy-based therapies.This article has an associated First Person interview with the first author of the paper.

Support of bone mineral deposition by regulation of pH.

Osteoblasts secrete collagen and isolate bone matrix from extracellular space. In the matrix, alkaline phosphatase generates phosphate that combines with calcium to form mineral, liberating 8 H+ per 10 Ca+2 deposited. However, pH-dependent hydroxyapatite deposition on bone collagen had not been shown. We studied the dependency of hydroxyapatite deposition on type I collagen on pH and phosphate by surface plasmon resonance in 0-5 mM phosphate at pH 6.8-7.4. Mineral deposition saturated at <1 mM Ca2+ but was sensitive to phosphate. Mineral deposition was reversible, consistent with amorphous precipitation; stable deposition requiring EDTA removal appeared with time. At pH 6.8, little hydroxyapatite deposited on collagen; mineral accumulation increased 10-fold at pH 7.4. Previously, we showed high expression Na+/H+ exchanger (NHE) and ClC transporters in osteoblasts. We hypothesized that, in combination, these move protons across osteoblasts to the general extracellular space. We made osteoblast membrane vesicles by nitrogen cavitation and used acridine orange quenching to characterize proton transport. We found H+ transport dependent on gradients of chloride or sodium, consistent with apical osteoblast ClC family Cl-,H+ antiporters and basolateral osteoblast NHE family Na+/H+ exchangers. Little, if any, active H+ transport, supported by ATP, occurred. Major transporters include cariporide-sensitive NHE1 in basolateral membranes and ClC3 and ClC5 in apical osteoblast membranes. The mineralization inhibitor levamisole reduced bone formation and expression of alkaline phosphatase, NHE1, and ClC5. We conclude that mineral deposition in bone collagen is pH-dependent, in keeping with H+ removal by Cl-,H+ antiporters and Na+/H+-exchangers. Periodic orientation hydroxyapatite is organized on type I collagen-coiled coils.

Hierarchically aligned fibrous hydrogel films through microfluidic self-assembly of graphene and polysaccharides.

Despite significant interest in developing extracellular matrix (ECM)-inspired biomaterials to recreate native cell-instructive microenvironments, the major challenge in the biomaterial field is to recapitulate the complex structural and biophysical features of native ECM. These biophysical features include multiscale hierarchy, electrical conductivity, optimum wettability, and mechanical properties. These features are critical to the design of cell-instructive biomaterials for bioengineering applications such as skeletal muscle tissue engineering. In this study, we used a custom-designed film fabrication assembly, which consists of a microfluidic chamber to allow electrostatic charge-based self-assembly of oppositely charged polymer solutions forming a hydrogel fiber and eventually, a nanocomposite fibrous hydrogel film. The film recapitulates unidirectional hierarchical fibrous structure along with the conductive properties to guide initial alignment and myotube formation from cultured myoblasts. We combined high conductivity, and charge carrier mobility of graphene with biocompatibility of polysaccharides to develop graphene-polysaccharide nanocomposite fibrous hydrogel films. The incorporation of graphene in fibrous hydrogel films enhanced their wettability, electrical conductivity, tensile strength, and toughness without significantly altering their elastic properties (Young's modulus). In a proof-of-concept study, the mouse myoblast cells (C2C12) seeded on these nanocomposite fibrous hydrogel films showed improved spreading and enhanced myogenesis as evident by the formation of multinucleated myotubes, an early indicator of myogenesis. Overall, graphene-polysaccharide nanocomposite fibrous hydrogel films provide a potential biomaterial to promote skeletal muscle tissue regeneration.

Apical Cell-Cell Adhesions Reconcile Symmetry and Asymmetry in Zebrafish Neurulation.

The symmetric tissue and body plans of animals are paradoxically constructed with asymmetric cells. To understand how the yin-yang duality of symmetry and asymmetry are reconciled, we asked whether apical polarity proteins orchestrate the development of the mirror-symmetric zebrafish neural tube by hierarchically modulating apical cell-cell adhesions. We found that apical polarity proteins localize by a pioneer-intermediate-terminal order. Pioneer proteins establish the mirror symmetry of the neural rod by initiating two distinct types of apical adhesions: the parallel apical adhesions (PAAs) cohere cells of parallel orientation and the novel opposing apical adhesions (OAAs) cohere cells of opposing orientation. Subsequently, the intermediate proteins selectively augment the PAAs when the OAAs dissolve by endocytosis. Finally, terminal proteins are required to inflate the neural tube by generating osmotic pressure. Our findings suggest a general mechanism to construct mirror-symmetric tissues: tissue symmetry can be established by organizing asymmetric cells opposingly via adhesions.

Heme Oxygenase-2 Localizes to Mitochondria and Regulates Hypoxic Responses in Hepatocytes.

Hypoxia occurs as a part of multiple disease states, including hemorrhagic shock. Adaptive responses occur within the cell to limit the consequences of hypoxia. This includes changes in mitochondrial respiration, stress-induced cell signaling, and gene expression that is regulated by hypoxia inducible factor-1α (HIF-1α). Heme oxygenase-2 (HO-2) has been shown to be involved in oxygen sensing in several cell types. The purpose of these experiments was to test the hypothesis that HO-2 is a critical regulator of mitochondrial oxygen consumption and reactive oxygen species (ROS) production to influence hypoxia-adaptive responses such as HIF-1α protein levels and JNK signaling. Methods and Results. In vitro studies were performed in primary mouse hepatocytes. HO-2, but not HO-1, was expressed in mitochondria at baseline. Decreased oxygen consumption and increased mitochondrial ROS production in response to hypoxia were dependent upon HO-2 expression. HO-2 expression regulated HIF-1α and JNK signaling in a mitochondrial ROS-dependent manner. Furthermore, knockdown of HO-2 led to increased organ damage, systemic inflammation, tissue hypoxia, and shock in a murine model of hemorrhage and resuscitation. Conclusion. HO-2 signaling plays a role in hypoxic signaling and hemorrhagic shock. This pathway may be able to be harnessed for therapeutic effects.

Graft-infiltrating PD-L1hi cross-dressed dendritic cells regulate antidonor T cell responses in mouse liver transplant tolerance.

Although a key role of cross-dressing has been established in immunity to viral infection and more recently in the instigation of transplant rejection, its role in tolerance is unclear. We investigated the role of intragraft dendritic cells (DCs) and cross-dressing in mouse major histocompatibility complex (MHC)-mismatched liver transplant tolerance that occurs without therapeutic immunosuppression. Although donor interstitial DCs diminished rapidly after transplantation, they were replaced in the liver by host DCs that peaked on postoperative day (POD) 7 and persisted indefinitely. Approximately 60% of these recipient DCs displayed donor MHC class I, indicating cross-dressing. By contrast, only a very minor fraction (0%-2%) of cross-dressed DCs (CD-DCs) was evident in the spleen. CD-DCs sorted from liver grafts expressed much higher levels of T cell inhibitory programed death ligand 1 (PD-L1) and high levels of interleukin-10 compared with non-CD-DCs (nCD-DCs) isolated from the graft. Concomitantly, high incidences of programed death protein 1 (PD-1)hi T cell immunoglobulin and mucin domain containing 3 (TIM-3)+ exhausted graft-infiltrating CD8+ T cells were observed. Unlike nCD-DCs, the CD-DCs failed to stimulate proliferation of allogeneic T cells but markedly suppressed antidonor host T cell proliferation. CD-DCs were much less evident in allografts from DNAX-activating protein of 12 kDa (DAP12)-/- donors that were rejected acutely. CONCLUSION: These findings suggest that graft-infiltrating PD-L1hi CD-DCs may play a key role in the regulation of alloimmunity and in the induction of liver transplant tolerance. (Hepatology 2018;67:1499-1515).

Donor dendritic cell-derived exosomes promote allograft-targeting immune response.

The immune response against transplanted allografts is one of the most potent reactions mounted by the immune system. The acute rejection response has been attributed to donor dendritic cells (DCs), which migrate to recipient lymphoid tissues and directly activate alloreactive T cells against donor MHC molecules. Here, using a murine heart transplant model, we determined that only a small number of donor DCs reach lymphoid tissues and investigated how this limited population of donor DCs efficiently initiates the alloreactive T cell response that causes acute rejection. In our mouse model, efficient passage of donor MHC molecules to recipient conventional DCs (cDCs) was dependent on the transfer of extracellular vesicles (EVs) from donor DCs that migrated from the graft to lymphoid tissues. These EVs shared characteristics with exosomes and were internalized or remained attached to the recipient cDCs. Recipient cDCs that acquired exosomes became activated and triggered full activation of alloreactive T cells. Depletion of recipient cDCs after cardiac transplantation drastically decreased presentation of donor MHC molecules to directly alloreactive T cells and delayed graft rejection in mice. These findings support a key role for transfer of donor EVs in the generation of allograft-targeting immune responses and suggest that interrupting this process has potential to dampen the immune response to allografts.

Peroxisome Proliferator-activated Receptor-γ Coactivator 1-α (PGC1α) Protects against Experimental Murine Colitis.

Peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC1α) is the primary regulator of mitochondrial biogenesis and was recently found to be highly expressed within the intestinal epithelium. PGC1α is decreased in the intestinal epithelium of patients with inflammatory bowel disease, but its role in pathogenesis is uncertain. We now hypothesize that PGC1α protects against the development of colitis and helps to maintain the integrity of the intestinal barrier. We selectively deleted PGC1α from the intestinal epithelium of mice by breeding a PGC1α(loxP/loxP) mouse with a villin-cre mouse. Their progeny (PGC1α(ΔIEC) mice) were subjected to 2% dextran sodium sulfate (DSS) colitis for 7 days. The SIRT1 agonist SRT1720 was used to enhance PGC1α activation in wild-type mice during DSS exposure. Mice lacking PGC1α within the intestinal epithelium were more susceptible to DSS colitis than their wild-type littermates. Pharmacologic activation of PGC1α successfully ameliorated disease and restored mitochondrial integrity. These findings suggest that a depletion of PGC1α in the intestinal epithelium contributes to inflammatory changes through a failure of mitochondrial structure and function as well as a breakdown of the intestinal barrier, which leads to increased bacterial translocation. PGC1α induction helps to maintain mitochondrial integrity, enhance intestinal barrier function, and decrease inflammation.

FoxO1 integrates direct and indirect effects of insulin on hepatic glucose production and glucose utilization.

FoxO proteins are major targets of insulin action. To better define the role of FoxO1 in mediating insulin effects in the liver, we generated liver-specific insulin receptor knockout (LIRKO) and IR/FoxO1 double knockout (LIRFKO) mice. Here we show that LIRKO mice are severely insulin resistant based on glucose, insulin and C-peptide levels, and glucose and insulin tolerance tests, and genetic deletion of hepatic FoxO1 reverses these effects. (13)C-glucose and insulin clamp studies indicate that regulation of both hepatic glucose production (HGP) and glucose utilization is impaired in LIRKO mice, and these defects are also restored in LIRFKO mice corresponding to changes in gene expression. We conclude that (1) inhibition of FoxO1 is critical for both direct (hepatic) and indirect effects of insulin on HGP and utilization, and (2) extrahepatic effects of insulin are sufficient to maintain normal whole-body and hepatic glucose metabolism when liver FoxO1 activity is disrupted.

Identification of a candidate stem cell in human gallbladder.

There are currently no reports of identification of stem cells in human gallbladder. The differences between human gallbladder and intrahepatic bile duct (IHBD) cells have also not been explored. The goals of this study were to evaluate if human fetal gallbladder contains a candidate stem cell population and if fetal gallbladder cells are distinct from fetal IHBD cells. We found that EpCAM+CD44+CD13+ cells represent the cell population most enriched for clonal self-renewal from primary gallbladder. Primary EpCAM+CD44+CD13+ cells gave rise to EpCAM+CD44+CD13+ and EpCAM+CD44+CD13- cells in vitro, and gallbladder cells expanded in vitro exhibited short-term engraftment in vivo. Last, we found that CD13, CD227, CD66, CD26 and CD49b were differentially expressed between gallbladder and IHBD cells cultured in vitro indicating clear phenotypic differences between the two cell populations. Microarray analyses of expanded cultures confirmed that both cell types have unique transcriptional profiles with predicted functional differences in lipid, carbohydrate, nucleic acid and drug metabolism. In conclusion, we have isolated a distinct clonogenic population of epithelial cells from primary human fetal gallbladder with stem cell characteristics and found it to be unique compared to IHBD cells.

Unwrapping the origins and roles of the renal endothelium.

The renal vasculature, like all vessels, is lined by a thin layer of simple squamous epithelial cells called an endothelium. These endothelial-lined vessels can be subdivided into four major compartments: arteries, veins, capillaries and lymphatics. The renal vasculature is a highly integrated network that forms through the active processes of angiogenesis and vasculogenesis. Determination of the precise contribution of these two processes and of the molecular signaling that governs the differentiation, specification and maturation of these critical cell populations is the focus of an actively evolving field of research. Although much of the focus has concentrated on the origin of the glomerular capillaries, in this review we extend the investigation to the origins of the endothelial cells throughout the entire kidney and the signaling events that cause their distinct functional and molecular profiles. A thorough understanding of endothelial cell biology may play a critical role in a better understanding of renal vascular diseases.

Effects of intra-abdominal sepsis on atherosclerosis in mice.

INTRODUCTION: Sepsis and other infections are associated with late cardiovascular events. Although persistent inflammation is implicated, a causal relationship has not been established. We tested whether sepsis causes vascular inflammation and accelerates atherosclerosis. METHODS: We performed prospective, randomized animal studies at a university research laboratory involving adult male ApoE-deficient (ApoE-/-) and young C57B/L6 wild-type (WT) mice. In the primary study conducted to determine whether sepsis accelerates atherosclerosis, we fed ApoE-/- mice (N = 46) an atherogenic diet for 4 months and then performed cecal ligation and puncture (CLP), followed by antibiotic therapy and fluid resuscitation or a sham operation. We followed mice for up to an additional 5 months and assessed atheroma in the descending aorta and root of the aorta. We also exposed 32 young WT mice to CLP or sham operation and followed them for 5 days to determine the effects of sepsis on vascular inflammation. RESULTS: ApoE-/- mice that underwent CLP had reduced activity during the first 14 days (38% reduction compared to sham; P < 0.001) and sustained weight loss compared to the sham-operated mice (-6% versus +9% change in weight after CLP or sham surgery to 5 months; P < 0.001). Despite their weight loss, CLP mice had increased atheroma (46% by 3 months and 41% increase in aortic surface area by 5 months; P = 0.03 and P = 0.004, respectively) with increased macrophage infiltration into atheroma as assessed by immunofluorescence microscopy (0.52 relative fluorescence units (rfu) versus 0.97 rfu; P = 0.04). At 5 months, peritoneal cultures were negative; however, CLP mice had elevated serum levels of interleukin 6 (IL-6) and IL-10 (each at P < 0.05). WT mice that underwent CLP had increased expression of intercellular adhesion molecule 1 in the aortic lumen versus sham at 24 hours (P = 0.01) that persisted at 120 hours (P = 0.006). Inflammatory and adhesion genes (tumor necrosis factor α, chemokine (C-C motif) ligand 2 and vascular cell adhesion molecule 1) and the adhesion assay, a functional measure of endothelial activation, were elevated at 72 hours and 120 hours in mice that underwent CLP versus sham-operations (all at P <0.05). CONCLUSIONS: Using a combination of existing murine models for atherosclerosis and sepsis, we found that CLP, a model of intra-abdominal sepsis, accelerates atheroma development. Accelerated atheroma burden was associated with prolonged systemic, endothelial and intimal inflammation and was not explained by ongoing infection. These findings support observations in humans and demonstrate the feasibility of a long-term follow-up murine model of sepsis.

Chemoprevention of prostate cancer by d,l-sulforaphane is augmented by pharmacological inhibition of autophagy.

There is a preclinical evidence that the oral administration of d,l-sulforaphane (SFN) can decrease the incidence or burden of early-stage prostate cancer [prostatic intraepithelial neoplasia (PIN)] and well-differentiated cancer (WDC) but not late-stage poorly differentiated cancer (PDC). Because SFN treatment induces cytoprotective autophagy in cultured human prostate cancer cells, the present study tested the hypothesis that chemopreventive efficacy of SFN could be augmented by the pharmacologic inhibition of autophagy using chloroquine (CQ). Incidence of PDC characterized by prostate weight of more than 1 g was significantly lower in the SFN + CQ group than in control (P = 0.004), CQ group (P = 0.026), or SFN group (P = 0.002 by Fisher exact test). Average size of the metastatic lymph node was lower by about 42% in the SFN + CQ group than in control (P = 0.043 by Wilcoxon test). On the other hand, the SFN + CQ combination was not superior to SFN alone with respect to inhibition of incidence or burden of microscopic PIN or WDC. SFN treatment caused in vivo autophagy as evidenced by transmission electron microscopy. Mechanistic studies showed that prevention of prostate cancer and metastasis by the SFN + CQ combination was associated with decreased cell proliferation, increased apoptosis, alterations in protein levels of autophagy regulators Atg5 and phospho-mTOR, and suppression of biochemical features of epithelial-mesenchymal transition. Plasma proteomics identified protein expression signature that may serve as biomarker of SFN + CQ exposure/response. This study offers a novel combination regimen for future clinical investigations for prevention of prostate cancer in humans.