The tetraspanin transmembrane protein CD53 mediates dyslipidemia and integrates inflammatory and metabolic signaling in hepatocytes.

Tetraspanins are transmembrane signaling and proinflammatory proteins. Prior work demonstrates that the tetraspanin, CD53/TSPAN25/MOX44, mediates B-cell development and lymphocyte migration to lymph nodes and is implicated in various inflammatory diseases. However, CD53 is also expressed in highly metabolic tissues, including adipose and liver; yet its function outside the lymphoid compartment is not defined. Here, we show that CD53 demarcates the nutritional and inflammatory status of hepatocytes. High-fat exposure and inflammatory stimuli induced CD53 in vivo in liver and isolated primary hepatocytes. In contrast, restricting hepatocyte glucose flux through hepatocyte glucose transporter 8 deletion or through trehalose treatment blocked CD53 induction in fat- and fructose-exposed contexts. Furthermore, germline CD53 deletion in vivo blocked Western diet-induced dyslipidemia and hepatic inflammatory transcriptomic activation. Surprisingly, metabolic protection in CD53 KO mice was more pronounced in the presence of an inciting inflammatory event. CD53 deletion attenuated tumor necrosis factor alpha-induced and fatty acid + lipopolysaccharide-induced cytokine gene expression and hepatocyte triglyceride accumulation in isolated murine hepatocytes. In vivo, CD53 deletion in nonalcoholic steatohepatitis diet-fed mice blocked peripheral adipose accumulation and adipose inflammation, insulin tolerance, and liver lipid accumulation. We then defined a stabilized and trehalase-resistant trehalose polymer that blocks hepatocyte CD53 expression in basal and over-fed contexts. The data suggest that CD53 integrates inflammatory and metabolic signals in response to hepatocyte nutritional status and that CD53 blockade may provide a means by which to attenuate pathophysiology in diseases that integrate overnutrition and inflammation, such as nonalcoholic steatohepatitis and type 2 diabetes.

Sox9 Is a Modifier of the Liver Disease Severity in a Mouse Model of Alagille Syndrome.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is a multisystem developmental disorder characterized by bile duct (BD) paucity, caused primarily by haploinsufficiency of the Notch ligand jagged1. The course of the liver disease is highly variable in ALGS. However, the genetic basis for ALGS phenotypic variability is unknown. Previous studies have reported decreased expression of the transcription factor SOX9 (sex determining region Y-box 9) in late embryonic and neonatal livers of Jag1-deficient mice. Here, we investigated the effects of altering the Sox9 gene dosage on the severity of liver disease in an ALGS mouse model. APPROACH AND RESULTS: Conditional removal of one copy of Sox9 in Jag1+/- livers impairs the biliary commitment of cholangiocytes and enhances the inflammatory reaction and liver fibrosis. Loss of both copies of Sox9 in Jag1+/- livers further worsens the phenotypes and results in partial lethality. Ink injection experiments reveal impaired biliary tree formation in the periphery of P30 Jag1+/- livers, which is improved by 5 months of age. Sox9 heterozygosity worsens the P30 biliary tree phenotype and impairs the partial recovery in 5-month-old animals. Notably, Sox9 overexpression improves BD paucity and liver phenotypes in Jag1+/- mice without ectopic hepatocyte-to-cholangiocyte transdifferentiation or long-term liver abnormalities. Notch2 expression in the liver is increased following Sox9 overexpression, and SOX9 binds the Notch2 regulatory region in the liver. Histological analysis shows a correlation between the level and pattern of SOX9 expression in the liver and outcome of the liver disease in patients with ALGS. CONCLUSIONS: Our results establish Sox9 as a dosage-sensitive modifier of Jag1+/- liver phenotypes with a permissive role in biliary development. Our data further suggest that liver-specific increase in SOX9 levels is a potential therapeutic approach for BD paucity in ALGS.

Cp*Co(III)-Catalyzed Coupling of Benzamides with α,ß-Unsaturated Carbonyl Compounds: Preparation of Aliphatic Ketones and Azepinones.

A Cp*CoIII -catalyzed C-H functionalization of benzamide substrates with α,ß-unsaturated ketones has been optimized, providing a facile route towards aliphatic ketone products. When employing α,ß-unsaturated aldehydes as coupling partners, under the optimized protocol, a cascade reaction forming azepinones has also been developed. Finally, DFT studies have demonstrated how stabilization of a metallo-enol intermediate when employing α,ß-unsaturated ketones is the driving force leading to the observed aliphatic ketone product rather than olefinic products reported using α,ß-unsaturated esters as coupling partners.

Ag nanoparticles generated using bio-reduction and -coating cause microbial killing without cell lysis.

Cost-effective "green" methods of producing Ag nanoparticles (NPs) are being examined because of the potential of these NPs as antimicrobials. Ag NPs were generated from Ag ions using extracellular metabolites from a soil-borne Pythium species. The NPs were variable in size, but had one dimension less than 50 nm and were biocoated; aggregation and coating changed with acetone precipitation. They had dose-dependent lethal effects on a soil pseudomonad, Pseudomonas chlororaphis O6, and were about 30-fold more effective than Ag(+) ions. A role of reactive oxygen species in cell death was demonstrated by use of fluorescent dyes responsive to superoxide anion and peroxide accumulation. Also mutants of the pseudomonad, defective in enzymes that protect against oxidative stress, were more sensitive than the wild type strain; mutant sensitivity differed between exposure to Ag NPs and Ag(+) ions demonstrating a nano-effect. Imaging of bacterial cells treated with the biocoated Ag NPs revealed no cell lysis, but there were changes in surface properties and cell height. These findings support that biocoating the NPs results in limited Ag release and yet they retained potent antimicrobial activity.

FLOWERING LOCUS T duplication coordinates reproductive and vegetative growth in perennial poplar.

Annual plants grow vegetatively at early developmental stages and then transition to the reproductive stage, followed by senescence in the same year. In contrast, after successive years of vegetative growth at early ages, woody perennial shoot meristems begin repeated transitions between vegetative and reproductive growth at sexual maturity. However, it is unknown how these repeated transitions occur without a developmental conflict between vegetative and reproductive growth. We report that functionally diverged paralogs FLOWERING LOCUS T1 (FT1) and FLOWERING LOCUS T2 (FT2), products of whole-genome duplication and homologs of Arabidopsis thaliana gene FLOWERING LOCUS T (FT), coordinate the repeated cycles of vegetative and reproductive growth in woody perennial poplar (Populus spp.). Our manipulative physiological and genetic experiments coupled with field studies, expression profiling, and network analysis reveal that reproductive onset is determined by FT1 in response to winter temperatures, whereas vegetative growth and inhibition of bud set are promoted by FT2 in response to warm temperatures and long days in the growing season. The basis for functional differentiation between FT1 and FT2 appears to be expression pattern shifts, changes in proteins, and divergence in gene regulatory networks. Thus, temporal separation of reproductive onset and vegetative growth into different seasons via FT1 and FT2 provides seasonality and demonstrates the evolution of a complex perennial adaptive trait after genome duplication.

Polyamine-Mediated Sensitization of Klebsiella pneumoniae to Macrolides through a Dual Mode of Action.

Chemicals bacteria encounter at the infection site could shape their stress and antibiotic responses; such effects are typically undetected under standard lab conditions. Polyamines are small molecules typically overproduced by the host during infection and have been shown to alter bacterial stress responses. We sought to determine the effect of polyamines on the antibiotic response of Klebsiella pneumoniae, a Gram-negative priority pathogen. Interestingly, putrescine and other natural polyamines sensitized K. pneumoniae to azithromycin, a macrolide protein translation inhibitor typically used for Gram-positive bacteria. This synergy was further potentiated in the physiological buffer, bicarbonate. Chemical genomic screens suggested a dual mechanism, whereby putrescine acts at the membrane and ribosome levels. Putrescine permeabilized the outer membrane of K. pneumoniae (NPN and ß-lactamase assays) and the inner membrane (Escherichia coli ß-galactosidase assays). Chemically and genetically perturbing membranes led to a loss of putrescine-azithromycin synergy. Putrescine also inhibited protein synthesis in an E. coli-derived cell-free protein expression assay simultaneously monitoring transcription and translation. Profiling the putrescine-azithromycin synergy against a combinatorial array of antibiotics targeting various ribosomal sites suggested that putrescine acts as tetracyclines targeting the 30S ribosomal acceptor site. Next, exploiting the natural polyamine-azithromycin synergy, we screened a polyamine analogue library for azithromycin adjuvants, discovering four azithromycin synergists with activity starting from the low micromolar range and mechanisms similar to putrescine. This work sheds light on the bacterial antibiotic responses under conditions more reflective of those at the infection site and provides a new strategy to extend the macrolide spectrum to drug-resistant K. pneumoniae.

A Structure-function Analysis of Hepatocyte Arginase 2 Reveals Mitochondrial Ureahydrolysis as a Determinant of Glucose Oxidation.

BACKGROUND & AIMS: Restoring hepatic and peripheral insulin sensitivity is critical to prevent or reverse metabolic syndrome and type 2 diabetes. Glucose homeostasis comprises in part the complex regulation of hepatic glucose production and insulin-mediated glucose uptake and oxidation in peripheral tissues. We previously identified hepatocyte arginase 2 (Arg2) as an inducible ureahydrolase that improves glucose homeostasis and enhances glucose oxidation in multiple obese, insulin-resistant models. We therefore examined structure-function determinants through which hepatocyte Arg2 governs systemic insulin action and glucose oxidation. METHODS: To do this, we generated mice expressing wild-type murine Arg2, enzymatically inactive Arg2 (Arg2H160F) and Arg2 lacking its putative mitochondrial targeting sequence (Arg2Δ1-22). We expressed these hepatocyte-specific constructs in obese, diabetic (db/db) mice and performed genetic complementation analyses in hepatocyte-specific Arg2-deficent (Arg2LKO) mice. RESULTS: We show that Arg2 attenuates hepatic steatosis, independent of mitochondrial localization or ureahydrolase activity, and that enzymatic arginase activity is dispensable for Arg2 to augment total body energy expenditure. In contrast, mitochondrial localization and ureahydrolase activity were required for Arg2-mediated reductions in fasting glucose and insulin resistance indices. Mechanistically, Arg2Δ1-22 and Arg2H160F failed to suppress glucose appearance during hyperinsulinemic-euglycemic clamping. Quantification of heavy-isotope-labeled glucose oxidation further revealed that mistargeting or ablating Arg2 enzymatic function abrogates Arg2-induced peripheral glucose oxidation. CONCLUSION: We conclude that the metabolic effects of Arg2 extend beyond its enzymatic activity, yet hepatocyte mitochondrial ureahydrolysis drives hepatic and peripheral oxidative metabolism. The data define a structure-based mechanism mediating hepatocyte Arg2 function and nominate hepatocyte mitochondrial ureahydrolysis as a key determinant of glucose oxidative capacity in mammals.

One-Year Results of a Low-Profile Endograft in Acute, Complicated Type B Aortic Dissection.

BACKGROUND: The safety and effectiveness of the RelayPro endograft (Terumo Aortic) was assessed for the treatment of acute, complicated type B aortic dissection (TBAD). METHODS: A prospective pivotal trial analyzed a primary end point of all-cause mortality at 30 days. Secondary end points included technical success, major adverse events (disabling stroke, renal failure, and paraplegia/paralysis), endoleaks, patency, rupture, device integrity, false lumen perfusion, reinterventions, aortic expansion, and migration evaluated to 5 years. RESULTS: The study involved 22 United States centers and enrolled 56 patients (mean age, 59.5 ± 11.4 years) from 2017 to 2021; of whom, 73.2% were men and 53.6% were African American. TBAD was complicated by malperfusion of the kidneys (51.8%), lower extremities (35.7%), and viscera (33.9%), and rupture (10.7%). Dissection extended proximally to zones 1/2 (14.3%) and zone 3 (78.6%) and distally to the iliac arteries (67.3%). Most procedures were percutaneous (85.5%). Technical success was 100%. Median hospitalization was 7 days (interquartile range, 5-12 days). All-cause mortality at 30 days was 1.8% (1 of 56; upper 95% CI, 8.2%; P < .0001). Seven major adverse events occurred in 6 patients (10.7%), consisting of paraplegia (n = 3), paraparesis (n = 2), disabling stroke (n = 1), and renal failure (n = 1). All paraplegia/paraparesis resolved with lumbar drainage. Kaplan-Meier analysis estimated a freedom from major adverse events of 89.1% at each interval from 30 days to 3 years. There was 1 endoleak (Type Ia), 2 retrograde dissections, and aortic diameter growth occurred in 2. There has been no rupture, fistula, component separation, patency loss, stenosis, kinking, twisting, bird beak, loss of device integrity, or fracture. CONCLUSIONS: RelayPro is safe and effective in acute, complicated TBAD. Follow-up is ongoing to evaluate longer-term outcomes and durability.

The PML1-WDR5 axis regulates H3K4me3 marks and promotes stemness of estrogen receptor-positive breast cancer.

The alternative splicing of PML precursor mRNA gives rise to various PML isoforms, yet their expression profile in breast cancer cells remains uncharted. We discovered that PML1 is the most abundant isoform in all breast cancer subtypes, and its expression is associated with unfavorable prognosis in estrogen receptor-positive (ER+) breast cancers. PML depletion reduces cell proliferation, invasion, and stemness, while heterologous PML1 expression augments these processes and fuels tumor growth and resistance to fulvestrant, an FDA-approved drug for ER+ breast cancer, in a mouse model. Moreover, PML1, rather than the well-known tumor suppressor isoform PML4, rescues the proliferation of PML knockdown cells. ChIP-seq analysis reveals significant overlap between PML-, ER-, and Myc-bound promoters, suggesting their coordinated regulation of target gene expression, including genes involved in breast cancer stem cells (BCSCs), such as JAG1, KLF4, YAP1, SNAI1, and MYC. Loss of PML reduces BCSC-related gene expression, and exogenous PML1 expression elevates their expression. Consistently, PML1 restores the association of PML with these promoters in PML-depleted cells. We identified a novel association between PML1 and WDR5, a key component of H3K4 methyltransferase (HMTs) complexes that catalyze H3K4me1 and H3K4me3. ChIP-seq analyses showed that the loss of PML1 reduces H3K4me3 in numerous loci, including BCSC-associated gene promoters. Additionally, PML1, not PML4, re-establishes the H3K4me3 mark on these promoters in PML-depleted cells. Significantly, PML1 is essential for recruiting WDR5, MLL1, and MLL2 to these gene promoters. Inactivating WDR5 by knockdown or inhibitors phenocopies the effects of PML1 loss, reducing BCSC-related gene expression and tumorsphere formation and enhancing fulvestrant's anticancer activity. Our findings challenge the conventional understanding of PML as a tumor suppressor, redefine its role as a promoter of tumor growth in breast cancer, and offer new insights into the unique roles of PML isoforms in breast cancer.

The PML1-WDR5 axis regulates H3K4me3 marks and promotes stemness of estrogen receptor-positive breast cancer.

The alternative splicing of PML precursor mRNA gives rise to various PML isoforms, yet their expression profile in breast cancer cells remains uncharted. We discovered that PML1 is the most abundant isoform in all breast cancer subtypes, and its expression is associated with unfavorable prognosis in estrogen receptor-positive (ER+) breast cancers. PML depletion reduces cell proliferation, invasion, and stemness, while heterologous PML1 expression augments these processes and fuels tumor growth and resistance to fulvestrant, an FDA-approved drug for ER + breast cancer, in a mouse model. Moreover, PML1, rather than the well-known tumor suppressor isoform PML4, rescues the proliferation of PML knockdown cells. ChIP-seq analysis reveals significant overlap between PML-, ER-, and Myc-bound promoters, suggesting their coordinated regulation of target gene expression, including genes involved in breast cancer stem cells (BCSCs), such as JAG1, KLF4, YAP1, SNAI1, and MYC. Loss of PML reduces BCSC-related gene expression, and exogenous PML1 expression elevates their expression. Consistently, PML1 restores the association of PML with these promoters in PML-depleted cells. We identified a novel association between PML1 and WDR5, a key component of H3K4 methyltransferase (HMTs) complexes that catalyze H3K4me1 and H3K4me3. ChIP-seq analyses showed that the loss of PML1 reduces H3K4me3 in numerous loci, including BCSC-associated gene promoters. Additionally, PML1, not PML4, re-establishes the H3K4me3 mark on these promoters in PML-depleted cells. Significantly, PML1 is essential for recruiting WDR5, MLL1, and MLL2 to these gene promoters. Inactivating WDR5 by knockdown or inhibitors phenocopies the effects of PML1 loss, reducing BCSC-related gene expression and tumorsphere formation and enhancing fulvestrant's anticancer activity. Our findings challenge the conventional understanding of PML as a tumor suppressor, redefine its role as a promoter of tumor growth in breast cancer and offer new insights into the unique roles of PML isoforms in breast cancer.

Plant-based FRET biosensor discriminates environmental zinc levels.

Heavy metal accumulation in the environment poses great risks to flora and fauna. However, monitoring sites prone to accumulation poses scale and economic challenges. In this study, we present and test a method for monitoring these sites using fluorescent resonance energy transfer (FRET) change in response to zinc (Zn) accumulation in plants as a proxy for environmental health. We modified a plant Zn transport protein by adding flanking fluorescent proteins (FPs) and deploying the construct into two different species. In Arabidopsis thaliana, FRET was monitored by a confocal microscope and had a 1.4-fold increase in intensity as the metal concentration increased. This led to a 16.7% overall error-rate when discriminating between a control (1µm Zn) and high (10mm Zn) treatment after 96h. The second host plant (Populus tremula×Populu salba) also had greater FRET values (1.3-fold increase) when exposed to the higher concentration of Zn, while overall error-rates were greater at 22.4%. These results indicate that as plants accumulate Zn, protein conformational changes occur in response to Zn causing differing interaction between FPs. This results in greater FRET values when exposed to greater amounts of Zn and monitored with appropriate light sources and filters. We also demonstrate how this construct can be moved into different host plants effectively including one tree species. This chimeric protein potentially offers a method for monitoring large areas of land for Zn accumulation, is transferable among species, and could be modified to monitor other specific heavy metals that pose environmental risks.

Pulsed high-intensity-focused US and tissue plasminogen activator (TPA) versus TPA alone for thrombolysis of occluded bypass graft in swine.

PURPOSE: Prosthetic arteriovenous or arterial-arterial bypass grafts can thrombose and be resistant to revascularization. A thrombosed bypass graft model was created to evaluate the potential therapeutic enhancement and safety profile of pulsed high-intensity-focused ultrasound (pHIFU) on pharmaceutical thrombolysis. MATERIALS AND METHODS: In swine, a right carotid-carotid expanded polytetrafluoroethylene bypass graft was surgically constructed, containing a 40% stenosis at its distal end to induce graft thrombosis. The revascularization procedure was performed 7 days after surgery. After model development and dose response experiments (n = 11), two cohorts were studied: pHIFU with tissue plasminogen activator (TPA; n = 4) and sham pHIFU with TPA (n = 3). The experiments were identical in both groups except no energy was delivered in the sham pHIFU group. Serial angiograms were obtained in all cases. The area of graft opacified by contrast medium on angiograms was quantified with digital image processing software. A blinded reviewer calculated the change in the graft area opacified by contrast medium and expressed it as a percentage, representing percentage of thrombolysis. RESULTS: Combining pHIFU with 0.5 mg of TPA resulted in a 52% ± 4% increase in thrombolysis on angiograms obtained at 30 minutes, compared with a 9% ± 14% increase with sham pHIFU and 0.5 mg TPA (P = .003). Histopathologic examination demonstrated no differences between the groups. CONCLUSIONS: Thrombolysis of occluded bypass grafts was significantly increased when combining pHIFU and TPA versus sham pHIFU and TPA. These results suggest that application of pHIFU may augment thrombolysis with a reduced time and dose.

Tightrope Technique for facilitating complex endovascular aortic repair in patients with severely angulated neck.

An 84-year-old presented with a large, symptomatic juxtarenal abdominal aortic aneurysm. Owing to severe angulation of the infrarenal neck, advancement of the distal bifurcated component caused dramatic lateral movement of the proximal physician-modified endovascular graft (PMEG) fenestrated device. This procedure risked aneurysm sac perforation and possible PMEG device displacement. To avoid this complication, the distal aspect of the PMEG device was tethered in place using endoscopic forceps to provide countertraction, similar to pulling a tightrope. This technique allowed for the uneventful placement of the distal bifurcated component without complication. This technique can overcome device placement challenges within an angulated aorta caused by large aneurysms.

NGLY1 Deficiency, a Congenital Disorder of Deglycosylation: From Disease Gene Function to Pathophysiology.

N-Glycanase 1 (NGLY1) is a cytosolic enzyme involved in removing N-linked glycans of misfolded N-glycoproteins and is considered to be a component of endoplasmic reticulum-associated degradation (ERAD). The 2012 identification of recessive NGLY1 mutations in a rare multisystem disorder has led to intense research efforts on the roles of NGLY1 in animal development and physiology, as well as the pathophysiology of NGLY1 deficiency. Here, we present a review of the NGLY1-deficient patient phenotypes, along with insights into the function of this gene from studies in rodent and invertebrate animal models, as well as cell culture and biochemical experiments. We will discuss critical processes affected by the loss of NGLY1, including proteasome bounce-back response, mitochondrial function and homeostasis, and bone morphogenetic protein (BMP) signaling. We will also cover the biologically relevant targets of NGLY1 and the genetic modifiers of NGLY1 deficiency phenotypes in animal models. Together, these discoveries and disease models have provided a number of avenues for preclinical testing of potential therapeutic approaches for this disease.

Poplar maintains zinc homeostasis with heavy metal genes HMA4 and PCS1.

Perennial woody species, such as poplar (Populus spp.) must acquire necessary heavy metals like zinc (Zn) while avoiding potential toxicity. Poplar contains genes with sequence homology to genes HMA4 and PCS1 from other species which are involved in heavy metal regulation. While basic genomic conservation exists, poplar does not have a hyperaccumulating phenotype. Poplar has a common indicator phenotype in which heavy metal accumulation is proportional to environmental concentrations but excesses are prevented. Phenotype is partly affected by regulation of HMA4 and PCS1 transcriptional abundance. Wild-type poplar down-regulates several transcripts in its Zn-interacting pathway at high Zn levels. Also, overexpressed PtHMA4 and PtPCS1 genes result in varying Zn phenotypes in poplar; specifically, there is a doubling of Zn accumulation in leaf tissues in an overexpressed PtPCS1 line. The genomic complement and regulation of poplar highlighted in this study supports a role of HMA4 and PCS1 in Zn regulation dictating its phenotype. These genes can be altered in poplar to change its interaction with Zn. However, other poplar genes in the surrounding pathway may maintain the phenotype by inhibiting drastic changes in heavy metal accumulation with a single gene transformation.

Extracellular Matrix Patches for Endarterectomy Repair.

Patch repair is the preferred method for arteriotomy closure following femoral or carotid endarterectomy. Choosing among available patch options remains a clinical challenge, as current evidence suggests roughly comparable outcomes between autologous grafts and synthetic and biologic materials. Biologic patches have potential advantages over other materials, including reduced risk for infection, mitigation of an excessive foreign body response, and the potential to remodel into healthy, vascularized tissue. Here we review the use of decellularized extracellular matrix (ECM) for cardiovascular applications, particularly endarterectomy repair, and the capacity of these materials to remodel into native, site-appropriate tissues. Also presented are data from two post-market observational studies of patients undergoing iliofemoral and carotid endarterectomy patch repair as well as one histologic case report in a challenging iliofemoral endarterectomy repair, all with the use of small intestine submucosa (SIS)-ECM. In alignment with previously reported studies, high patency was maintained, and adverse event rates were comparable to previously reported rates of patch angioplasty. Histologic analysis from one case identified constructive remodeling of the SIS-ECM, consistent with the histologic characteristics of the endarterectomized vessel. These clinical and histologic results align with the biologic potential described in the academic ECM literature. To our knowledge, this is the first histologic demonstration of SIS-ECM remodeling into site-appropriate vascular tissues following endarterectomy. Together, these findings support the safety and efficacy of SIS-ECM for patch repair of femoral and carotid arteriotomy.

Apoplast proteome reveals that extracellular matrix contributes to multistress response in poplar.

BACKGROUND: Riverine ecosystems, highly sensitive to climate change and human activities, are characterized by rapid environmental change to fluctuating water levels and siltation, causing stress on their biological components. We have little understanding of mechanisms by which riverine plant species have developed adaptive strategies to cope with stress in dynamic environments while maintaining growth and development. RESULTS: We report that poplar (Populus spp.) has evolved a systems level "stress proteome" in the leaf-stem-root apoplast continuum to counter biotic and abiotic factors. To obtain apoplast proteins from P. deltoides, we developed pressure-chamber and water-displacement methods for leaves and stems, respectively. Analyses of 303 proteins and corresponding transcripts coupled with controlled experiments and bioinformatics demonstrate that poplar depends on constitutive and inducible factors to deal with water, pathogen, and oxidative stress. However, each apoplast possessed a unique set of proteins, indicating that response to stress is partly compartmentalized. Apoplast proteins that are involved in glycolysis, fermentation, and catabolism of sucrose and starch appear to enable poplar to grow normally under water stress. Pathogenesis-related proteins mediating water and pathogen stress in apoplast were particularly abundant and effective in suppressing growth of the most prevalent poplar pathogen Melampsora. Unexpectedly, we found diverse peroxidases that appear to be involved in stress-induced cell wall modification in apoplast, particularly during the growing season. Poplar developed a robust antioxidative system to buffer oxidation in stem apoplast. CONCLUSION: These findings suggest that multistress response in the apoplast constitutes an important adaptive trait for poplar to inhabit dynamic environments and is also a potential mechanism in other riverine plant species.

Role of chemokine and cytokine polymorphisms in the progression of HIV-1 disease.

Allelic variants of the genes for chemokine receptors and their natural ligands, the chemokines, and cytokines can affect HIV-1 disease progression. This study investigates the level of expression of the CCR5-Delta32, CCR2b-641, RANTES In1.1C, SDF-1 3'A, IL-10-5'-592A and IL-4-589T alleles in two unique HIV-1 infected patient cohorts that represent the two distinct stages of disease progression, namely rapid progressors (RPs) and long term non-progressors (LTNPs) (n=12/group) were recruited. Quantitation of the gene expression of CCR5-Delta32, CCR2b-641, RANTES In1.1C, SDF-1 3'A, IL-10-5'-592A and IL-4-589T in peripheral blood mononuclear leukocytes (PBML) isolated from patients was performed by real time, quantitative (Q)-PCR using DNA was isolated from PBML. We observed that expression of these HIV-protective alleles was generally greater in the LTNP cohort than the RP cohort. LTNPs expressed more of the protective chemokine, SDF-1alpha than RPs, and no statistically significant difference was observed in RANTES production between the LTNPs and RPs. The LTNPs expressed significantly less amounts of cytokines IL-10 and IL-4 as compared to the RPs. Our results demonstrate that gene polymorphisms for CCR5-Delta32, CCR2b-641, RANTES In1.1C, SDF-1 3'A, IL-10-5'-592A and IL-4-589T may be used as clinical markers to predict progression of HIV-1 infections.

Real-world experience with type I endoleaks after endovascular repair of the thoracic aorta.

Endoleaks are a frequent complication of thoracic endovascular aortic repair (TEVAR) and will likely increase in incidence with application of the technique to more complicated aortic anatomy and a wider range of thoracic aortic pathologies. Management generally consists of aggressive repair of Type I endoleaks; however, the natural history of Type I endoleaks after TEVAR remains largely unknown. The purpose of this study was to examine the incidence and characteristics of Type I endoleaks and to evaluate clinical outcomes of patients with Type I endoleaks after TEVAR. A single-center retrospective review was performed on all patients who underwent TEVAR over a 4-year period. Type I endoleaks were detected in 21 per cent (27 of 129) of patients on post-deployment aortography or CT angiography. During a mean follow-up of 750.63 +/- 483 days, 59 per cent (16 of 27) closed spontaneously; 30 per cent (eight of 27) required secondary endovascular intervention; and 11 per cent (three of 27) have persisted with no increase in maximum aortic diameter. No patients have died or required open surgical conversion as a result of their Type I endoleak. Although accurate predictors of spontaneous resolution of Type I endoleaks have yet to be definitively characterized, our initial results suggest that it may be safe to observe small Type I endoleaks given that a large percentage resolve spontaneously and no endoleak-related deaths have occurred.