Inflammation primes the kidney for recovery by activating AZIN1 A-to-I editing.

The progression of kidney disease varies among individuals, but a general methodology to quantify disease timelines is lacking. Particularly challenging is the task of determining the potential for recovery from acute kidney injury following various insults. Here, we report that quantitation of post-transcriptional adenosine-to-inosine (A-to-I) RNA editing offers a distinct genome-wide signature, enabling the delineation of disease trajectories in the kidney. A well-defined murine model of endotoxemia permitted the identification of the origin and extent of A-to-I editing, along with temporally discrete signatures of double-stranded RNA stress and Adenosine Deaminase isoform switching. We found that A-to-I editing of Antizyme Inhibitor 1 (AZIN1), a positive regulator of polyamine biosynthesis, serves as a particularly useful temporal landmark during endotoxemia. Our data indicate that AZIN1 A-to-I editing, triggered by preceding inflammation, primes the kidney and activates endogenous recovery mechanisms. By comparing genetically modified human cell lines and mice locked in either A-to-I edited or uneditable states, we uncovered that AZIN1 A-to-I editing not only enhances polyamine biosynthesis but also engages glycolysis and nicotinamide biosynthesis to drive the recovery phenotype. Our findings implicate that quantifying AZIN1 A-to-I editing could potentially identify individuals who have transitioned to an endogenous recovery phase. This phase would reflect their past inflammation and indicate their potential for future recovery.

The Impact of Childhood Traumatization on Diabetes Mellitus Type 2 Risk in World War II Refugees and Their Offspring.

OBJECTIVE: Type 2 diabetes mellitus (T2D) is a chronic disease that is influenced by different factors. The extent to which degree adverse childhood events (ACEs) can modify the potential to development of T2D is still not explored and therefore represents one of the central questions of the childhood escape-late life outcome (DRKS00012419) study. In addition, transgenerational effects were considered in the analyses. METHODS: The study analyzed the association of self-reported traumatic experiences and T2D disease of refugees from East Prussia, who were displaced from their former homeland at the end of the World War II. In addition, an independent sample consisting of participants of first-generation offspring of refugees was analyzed. RESULTS: Of the 242 refugees, all aged between 73 and 93 years, 17.36% reported T2D disease, whereas among the offspring ( n = 272), aged between 47 and 73 years, it was 5.5%, meaning reduced T2D prevalence for both generations compared with the German population of comparable age. In the refugee generation, emotional neglect showed a negative association with development of T2D in later life. In women, separation from close caregivers in childhood showed a negative association with later T2D. In contrast, experiencing emotional abuse in childhood showed a positive association with later T2D. The offspring generation showed no associations of adverse childhood events and reported T2D diagnoses in later life. CONCLUSIONS: Our results demonstrate that individual trauma in childhood is responded to with different mechanisms that can lead to both increased and decreased reported T2D diagnoses in adulthood and thus should by no means be considered in a generalized manner.

Translation Rescue by Targeting Ppp1r15a through Its Upstream Open Reading Frame in Sepsis-Induced Acute Kidney Injury in a Murine Model.

BACKGROUND: Translation shutdown is a hallmark of late-phase, sepsis-induced kidney injury. Methods for controlling protein synthesis in the kidney are limited. Reversing translation shutdown requires dephosphorylation of the eukaryotic initiation factor 2 (eIF2) subunit eIF2 α ; this is mediated by a key regulatory molecule, protein phosphatase 1 regulatory subunit 15A (Ppp1r15a), also known as GADD34. METHODS: To study protein synthesis in the kidney in a murine endotoxemia model and investigate the feasibility of translation control in vivo by boosting the protein expression of Ppp1r15a, we combined multiple tools, including ribosome profiling (Ribo-seq), proteomics, polyribosome profiling, and antisense oligonucleotides, and a newly generated Ppp1r15a knock-in mouse model and multiple mutant cell lines. RESULTS: We report that translation shutdown in established sepsis-induced kidney injury is brought about by excessive eIF2 α phosphorylation and sustained by blunted expression of the counter-regulatory phosphatase Ppp1r15a. We determined the blunted Ppp1r15a expression persists because of the presence of an upstream open reading frame (uORF). Overcoming this barrier with genetic and antisense oligonucleotide approaches enabled the overexpression of Ppp1r15a, which salvaged translation and improved kidney function in an endotoxemia model. Loss of this uORF also had broad effects on the composition and phosphorylation status of the immunopeptidome-peptides associated with the MHC-that extended beyond the eIF2 α axis. CONCLUSIONS: We found Ppp1r15a is translationally repressed during late-phase sepsis because of the existence of an uORF, which is a prime therapeutic candidate for this strategic rescue of translation in late-phase sepsis. The ability to accurately control translation dynamics during sepsis may offer new paths for the development of therapies at codon-level precision. PODCAST: This article contains a podcast at.

The Hidden Pandemic: Impact of the COVID-19 Pandemic on Trauma Cases Due to Domestic Violence Admitted to the Biggest Level-One Trauma Center in Austria.

BACKGROUND: An alarming increase in domestic violence was reported during the COVID-19 pandemic worldwide. The aim of this study is to investigate changes in the frequency and the nature of domestic violence at the largest level-one trauma center in Austria. METHODS: All patients admitted to our institution with domestic violence injuries 15 months before and after the beginning of the COVID-19 pandemic were included. For our analysis, we investigated the frequency of trauma patients after domestic violence in relation to all other trauma patients. Furthermore, age, sex, citizenship, injury pattern, injured body regions, injury mechanism, offender-victim relationship, and hospitalization rate were also analyzed. RESULTS: Among all trauma patients admitted, the ratio of patients who reported domestic violence injuries increased from 0.465% to 0.548% since the start of the pandemic. In addition, out of the total count of domestic violence victims, the percentage of Austrian citizens increased significantly from 51.2% to 60.6% (p = 0.016). All other parameters showed no significant changes pre and post-pandemic. CONCLUSION: The COVID-19 pandemic contributed to a relative increase in patients with domestic violence injuries at the largest trauma unit in Austria, along with a significant increase among Austrian citizens. The remaining study parameters did not differ significantly, indicating that the frequency changed during the pandemic but not the underlying pattern of domestic violence.

Alterations in Protein Translation and Carboxylic Acid Catabolic Processes in Diabetic Kidney Disease.

Diabetic kidney disease (DKD) remains the leading cause of end-stage kidney disease despite decades of study. Alterations in the glomerulus and kidney tubules both contribute to the pathogenesis of DKD although the majority of investigative efforts have focused on the glomerulus. We sought to examine the differential expression signature of human DKD in the glomerulus and proximal tubule and corroborate our findings in the db/db mouse model of diabetes. A transcriptogram network analysis of RNAseq data from laser microdissected (LMD) human glomerulus and proximal tubule of DKD and reference nephrectomy samples revealed enriched pathways including rhodopsin-like receptors, olfactory signaling, and ribosome (protein translation) in the proximal tubule of human DKD biopsy samples. The translation pathway was also enriched in the glomerulus. Increased translation in diabetic kidneys was validated using polyribosomal profiling in the db/db mouse model of diabetes. Using single nuclear RNA sequencing (snRNAseq) of kidneys from db/db mice, we prioritized additional pathways identified in human DKD. The top overlapping pathway identified in the murine snRNAseq proximal tubule clusters and the human LMD proximal tubule compartment was carboxylic acid catabolism. Using ultra-performance liquid chromatography-mass spectrometry, the fatty acid catabolism pathway was also found to be dysregulated in the db/db mouse model. The Acetyl-CoA metabolite was down-regulated in db/db mice, aligning with the human differential expression of the genes ACOX1 and ACACB. In summary, our findings demonstrate that proximal tubular alterations in protein translation and carboxylic acid catabolism are key features in both human and murine DKD.

Adverse childhood experiences and late-life diurnal HPA axis activity: Associations of different childhood adversity types and interaction with timing in a sample of older East Prussian World War II refugees.

Adverse childhood experiences (ACEs) have been associated with unfavorable health outcomes throughout the life up to old age. Mechanisms through which ACEs impact later life health are still not entirely clear. There is growing evidence for the idea that alterations in the hypothalamic pituitary adrenal (HPA) axis might cause the effects of ACEs on later health consequences. Only few studies have investigated associations between ACEs and diurnal HPA axis functioning in older adults. Therefore, we investigated the impact of type and timing of ACEs linked to flight of war on diurnal HPA axis activity in a sample of East Prussian World War II refugees aged 74-91 years. We calculated a dichotomous variable according to the (minimum) age at trauma: early ACE (eACE; 0-5 years) and late ACE (lACE; 6-17 years). Multiple linear regression analysis using different ACEs linked to flight of war (war-related trauma, individual experience of violence, neglect) as well as age at trauma and the interactions of ACEs and age at trauma as predictors and three cortisol outcomes (AUCG (area under the curve with respect to the ground), decline (morning to night) and CAR (cortisol awakening response)) was performed. For AUCG, we found a negative association of individual experience of violence only in lACE participants. For decline, a positive association with neglect was observed for the whole study sample. The overall model for CAR was not statistically significant. Our findings support the hypothesis that type as well as timing of ACEs might influence diurnal HPA axis functioning into old age. These findings may contribute to a better understanding of the lifelong influence of ACEs.

Deoxyhypusine synthase promotes a pro-inflammatory macrophage phenotype.

The metabolic inflammation (meta-inflammation) of obesity is characterized by proinflammatory macrophage infiltration into adipose tissue. Catalysis by deoxyhypusine synthase (DHPS) modifies the translation factor eIF5A to generate a hypusine (Hyp) residue. Hypusinated eIF5A (eIF5AHyp) controls the translation of mRNAs involved in inflammation, but its role in meta-inflammation has not been elucidated. Levels of eIF5AHyp were found to be increased in adipose tissue macrophages from obese mice and in murine macrophages activated to a proinflammatory M1-like state. Global proteomics and transcriptomics revealed that DHPS deficiency in macrophages altered the abundance of proteins involved in NF-κB signaling, likely through translational control of their respective mRNAs. DHPS deficiency in myeloid cells of obese mice suppressed M1 macrophage accumulation in adipose tissue and improved glucose tolerance. These findings indicate that DHPS promotes the post-transcriptional regulation of a subset of mRNAs governing inflammation and chemotaxis in macrophages and contributes to a proinflammatory M1-like phenotype.

The orchestrated cellular and molecular responses of the kidney to endotoxin define a precise sepsis timeline.

Sepsis is a dynamic state that progresses at variable rates and has life-threatening consequences. Staging patients along the sepsis timeline requires a thorough knowledge of the evolution of cellular and molecular events at the tissue level. Here, we investigated the kidney, an organ central to the pathophysiology of sepsis. Single-cell RNA-sequencing in a murine endotoxemia model revealed the involvement of various cell populations to be temporally organized and highly orchestrated. Endothelial and stromal cells were the first responders. At later time points, epithelial cells upregulated immune-related pathways while concomitantly downregulating physiological functions such as solute homeostasis. Sixteen hours after endotoxin, there was global cell-cell communication failure and organ shutdown. Despite this apparent organ paralysis, upstream regulatory analysis showed significant activity in pathways involved in healing and recovery. This rigorous spatial and temporal definition of murine endotoxemia will uncover precise biomarkers and targets that can help stage and treat human sepsis.

Hypusine biosynthesis in ß cells links polyamine metabolism to facultative cellular proliferation to maintain glucose homeostasis.

Deoxyhypusine synthase (DHPS) uses the polyamine spermidine to catalyze the hypusine modification of the mRNA translation factor eIF5A and promotes oncogenesis through poorly defined mechanisms. Because germline deletion of Dhps is embryonically lethal, its role in normal postnatal cellular function in vivo remains unknown. We generated a mouse model that enabled the inducible, postnatal deletion of Dhps specifically in postnatal islet ß cells, which function to maintain glucose homeostasis. Removal of Dhps did not have an effect under normal physiologic conditions. However, upon development of insulin resistance, which induces ß cell proliferation, Dhps deletion caused alterations in proteins required for mRNA translation and protein secretion, reduced production of the cell cycle molecule cyclin D2, impaired ß cell proliferation, and induced overt diabetes. We found that hypusine biosynthesis was downstream of protein kinase C-ζ and was required for c-Myc-induced proliferation. Our studies reveal a requirement for DHPS in ß cells to link polyamines to mRNA translation to effect facultative cellular proliferation and glucose homeostasis.

The archaeal Dps nanocage targets kidney proximal tubules via glomerular filtration.

Nature exploits cage-like proteins for a variety of biological purposes, from molecular packaging and cargo delivery to catalysis. These cage-like proteins are of immense importance in nanomedicine due to their propensity to self-assemble from simple identical building blocks to highly ordered architecture and the design flexibility afforded by protein engineering. However, delivery of protein nanocages to the renal tubules remains a major challenge because of the glomerular filtration barrier, which effectively excludes conventional size nanocages. Here, we show that DNA-binding protein from starved cells (Dps) - the extremely small archaeal antioxidant nanocage - is able to cross the glomerular filtration barrier and is endocytosed by the renal proximal tubules. Using a model of endotoxemia, we present an example of the way in which proximal tubule-selective Dps nanocages can limit the degree of endotoxin-induced kidney injury. This was accomplished by amplifying the endogenous antioxidant property of Dps with addition of a dinuclear manganese cluster. Dps is the first-in-class protein cage nanoparticle that can be targeted to renal proximal tubules through glomerular filtration. In addition to its therapeutic potential, chemical and genetic engineering of Dps will offer a nanoplatform to advance our understanding of the physiology and pathophysiology of glomerular filtration and tubular endocytosis.

HIV-Nef Protein Transfer to Endothelial Cells Requires Rac1 Activation and Leads to Endothelial Dysfunction Implications for Statin Treatment in HIV Patients.

RATIONALE: Even in antiretroviral therapy-treated patients, HIV continues to play a pathogenic role in cardiovascular diseases. A possible cofactor may be persistence of the early HIV response gene Nef, which we have demonstrated recently to persist in the lungs of HIV+ patients on antiretroviral therapy. Previously, we have reported that HIV strains with Nef, but not Nef-deleted HIV strains, cause endothelial proinflammatory activation and apoptosis. OBJECTIVE: To characterize mechanisms through which HIV-Nef leads to the development of cardiovascular diseases using ex vivo tissue culture approaches as well as interventional experiments in transgenic murine models. METHODS AND RESULTS: Extracellular vesicles derived from both peripheral blood mononuclear cells and plasma from HIV+ patient blood samples induced human coronary artery endothelial cells dysfunction. Plasma-derived extracellular vesicles from antiretroviral therapy+ patients who were HIV-Nef+ induced significantly greater endothelial apoptosis compared with HIV-Nef-plasma extracellular vesicles. Both HIV-Nef expressing T cells and HIV-Nef-induced extracellular vesicles increased transfer of cytosol and Nef protein to endothelial monolayers in a Rac1-dependent manner, consequently leading to endothelial adhesion protein upregulation and apoptosis. HIV-Nef induced Rac1 activation also led to dsDNA breaks in endothelial colony forming cells, thereby resulting in endothelial colony forming cell premature senescence and endothelial nitric oxide synthase downregulation. These Rac1-dependent activities were characterized by NOX2-mediated reactive oxygen species production. Statin treatment equally inhibited Rac1 inhibition in preventing or reversing all HIV-Nef-induction abnormalities assessed. This was likely because of the ability of statins to block Rac1 prenylation as geranylgeranyl transferase inhibitors were effective in inhibiting HIV-Nef-induced reactive oxygen species formation. Finally, transgenic expression of HIV-Nef in endothelial cells in a murine model impaired endothelium-mediated aortic ring dilation, which was then reversed by 3-week treatment with 5 mg/kg atorvastatin. CONCLUSIONS: These studies establish a mechanism by which HIV-Nef persistence despite antiretroviral therapy could contribute to ongoing HIV-related vascular dysfunction, which may then be ameliorated by statin treatment.

Bacterial sepsis triggers an antiviral response that causes translation shutdown.

In response to viral pathogens, the host upregulates antiviral genes that suppress translation of viral mRNAs. However, induction of such antiviral responses may not be exclusive to viruses, as the pathways lie at the intersection of broad inflammatory networks that can also be induced by bacterial pathogens. Using a model of Gram-negative sepsis, we show that propagation of kidney damage initiated by a bacterial origin ultimately involves antiviral responses that result in host translation shutdown. We determined that activation of the eukaryotic translation initiation factor 2-α kinase 2/eukaryotic translation initiation factor 2α (Eif2ak2/Eif2α) axis is the key mediator of translation initiation block in late-phase sepsis. Reversal of this axis mitigated kidney injury. Furthermore, temporal profiling of the kidney translatome revealed that multiple genes involved in formation of the initiation complex were translationally altered during bacterial sepsis. Collectively, our findings imply that translation shutdown is indifferent to the specific initiating pathogen and is an important determinant of tissue injury in sepsis.

HIV-Nef Protein Persists in the Lungs of Aviremic Patients with HIV and Induces Endothelial Cell Death.

It remains a mystery why HIV-associated end-organ pathologies persist in the era of combined antiretroviral therapy (ART). One possible mechanism is the continued production of HIV-encoded proteins in latently HIV-infected T cells and macrophages. The proapoptotic protein HIV-Nef persists in the blood of ART-treated patients within extracellular vesicles (EVs) and peripheral blood mononuclear cells. Here we demonstrate that HIV-Nef is present in cells and EVs isolated from BAL of patients on ART. We hypothesize that HIV-Nef persistence in the lung induces endothelial apoptosis leading to endothelial dysfunction and further pulmonary vascular pathologies. The presence of HIV-Nef in patients with HIV correlates with the surface expression of the proapoptotic endothelial-monocyte-activating polypeptide II (EMAPII), which was implicated in progression of pulmonary emphysema via mechanisms involving endothelial cell death. HIV-Nef protein induces EMAPII surface expression in human embryonic kidney 293T cells, T cells, and human and mouse lung endothelial cells. HIV-Nef packages itself into EVs and increases the amount of EVs secreted from Nef-expressing T cells and Nef-transfected human embryonic kidney 293T cells. EVs from BAL of HIV+ patients and Nef-transfected cells induce apoptosis in lung microvascular endothelial cells by upregulating EMAPII surface expression in a PAK2-dependent fashion. Transgenic expression of HIV-Nef in vascular endothelial-cadherin+ endothelial cells leads to lung rarefaction, characterized by reduced alveoli and overall increase in lung inspiratory capacity. These changes occur concomitantly with lung endothelial cell apoptosis. Together, these data suggest that HIV-Nef induces endothelial cell apoptosis via an EMAPII-dependent mechanism that is sufficient to cause pulmonary vascular pathologies even in the absence of inflammation.

[Current challenges in the treatment of paediatric burn patients: a retrospective experience at a Viennese burn unit]. / Aktuelle Herausforderungen des thermischen Traumas im Kindesund Jugendalter ­ ein retrospektiver Erfahrungsbericht an einem Wiener Verbrennungszentrum.

BACKGROUND: Burn trauma in paediatric patients continues to be highly relevant socio-economically since the number of inpatients treated per year has not declined over the past few decades. The treatment of paediatric burn victims places high demands on medical staff and the use of wound dressings and surgical techniques. This study aimed to give a current overview of the inpatient management and treatment methods for paediatric burn patients at a specialised burn centre in Vienna. PATIENTS/MATERIAL AND METHODS: All children and adolescents who were treated at the children's ward of the Division of Plastic and Reconstructive Surgery at the Medical University of Vienna between 2012 and 2016 due to a recent burn trauma were retrospectively analysed. RESULTS: 115patients were treated due to a recent burn trauma. Median age was 2 years (0-18). Scalds accounted for 74 % of traumas. Median affected body surface area was 5 % (1-40 %). Conservative treatment of superficial partial-thickness wounds (62 %) was performed with MepilexAg in 98 % of cases and required a median healing time of 11 days (4-34). 38 % (n = 44) of patients had deep partial-thickness or full-thickness burns . The use of Suprathel after tangential excision of the burn eschar in more superficial deep partial-thickness burns led to satisfying healing times. CONCLUSION: The use of modern dressings in the conservative treatment of superficial partial-thickness burns allows for atraumatic dressing changes and fast recoveries. The use of Suprathel in more superficial deep partial-thickness burns is a reliable and safe alternative to autologous skin grafting. Scar prophylaxis and regular follow-up examinations are crucial to prevent secondary morbidity due to scar contractures. It is important to raise awareness among parents in order to decrease the number of paediatric burn patients in the future.

Ultralong TE In Vivo 1 H MR Spectroscopy of Omega-3 Fatty Acids in Subcutaneous Adipose Tissue at 7 T.

BACKGROUND: Omega-3 (n-3) fatty acids (FA) play and important role in neural development and other metabolic diseases such as obesity and diabetes. The knowledge about the in vivo content and distribution of n-3 FA in human body tissues is not well established and the standard quantification of FA is invasive and costly. PURPOSE: To detect omega-3 (n-3 CH3 ) and non-omega-3 (CH3 ) methyl group resonance lines with echo times up to 1200 msec, in oils, for the assessment of n-3 FA content, and the n-3 FA fraction in adipose tissue in vivo. STUDY TYPE: Prospective technical development. POPULATION: Three oils with different n-3 FA content and 24 healthy subjects. FIELD STRENGTH/SEQUENCE: Single-voxel MR spectroscopy (SVS) with a point-resolved spectroscopy (PRESS) sequence with an echo time (TE) of 1000 msec at 7 T. ASSESSMENT: Knowledge about the J-coupling evolution of both CH3 resonances was used for the optimal detection of the n-3 CH3 resonance line at a TE of 1000 msec. The accuracy of the method in oils and in vivo was validated from a biopsy sample with gas chromatography analysis. STATISTICAL TESTS: SVS data were compared to gas chromatography with the Pearson correlation coefficient. RESULTS: T2 relaxation times in oils were assessed as follows: CH2 , 65 ± 22 msec; CH3 , 325 ± 7 msec; and n-3 CH3 , 628 ± 34 msec. The n-3 FA fractions from oil phantom experiments (n = 3) were in agreement with chromatography analysis and the comparison of in vivo obtained data with the results of chromatography analysis (n = 5) yielded a significant correlation (P = 0.029). DATA CONCLUSION: PRESS with ultralong-TE can detect and quantify the n-3 CH3 signal in vivo at 7 T. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:71-82.

Beta cell extracellular vesicle miR-21-5p cargo is increased in response to inflammatory cytokines and serves as a biomarker of type 1 diabetes.

AIMS/HYPOTHESIS: Improved biomarkers are acutely needed for the detection of developing type 1 diabetes, prior to critical loss of beta cell mass. We previously demonstrated that elevated beta cell microRNA 21-5p (miR-21-5p) in rodent and human models of type 1 diabetes increased beta cell apoptosis. We hypothesised that the inflammatory milieu of developing diabetes may also increase miR-21-5p in beta cell extracellular vesicle (EV) cargo and that circulating EV miR-21-5p would be increased during type 1 diabetes development. METHODS: MIN6 and EndoC-ßH1 beta cell lines and human islets were treated with IL-1ß, IFN-γ and TNF-α to mimic the inflammatory milieu of early type 1 diabetes. Serum was collected weekly from 8-week-old female NOD mice until diabetes onset. Sera from a cross-section of 19 children at the time of type 1 diabetes diagnosis and 16 healthy children were also analysed. EVs were isolated from cell culture media or serum using sequential ultracentrifugation or ExoQuick precipitation and EV miRNAs were assayed. RESULTS: Cytokine treatment in beta cell lines and human islets resulted in a 1.5- to threefold increase in miR-21-5p. However, corresponding EVs were further enriched for this miRNA, with a three- to sixfold EV miR-21-5p increase in response to cytokine treatment. This difference was only partially reduced by pre-treatment of beta cells with Z-VAD-FMK to inhibit cytokine-induced caspase activity. Nanoparticle tracking analysis showed cytokines to have no effect on the number of EVs, implicating specific changes within EV cargo as being responsible for the increase in beta cell EV miR-21-5p. Sequential ultracentrifugation to separate EVs by size suggested that this effect was mostly due to cytokine-induced increases in exosome miR-21-5p. Longitudinal serum collections from NOD mice showed that EVs displayed progressive increases in miR-21-5p beginning 3 weeks prior to diabetes onset. To validate the relevance to human diabetes, we assayed serum from children with new-onset type 1 diabetes compared with healthy children. While total serum miR-21-5p and total serum EVs were reduced in diabetic participants, serum EV miR-21-5p was increased threefold compared with non-diabetic individuals. By contrast, both serum and EV miR-375-5p were increased in parallel among diabetic participants. CONCLUSIONS/INTERPRETATION: We propose that circulating EV miR-21-5p may be a promising marker of developing type 1 diabetes. Additionally, our findings highlight that, for certain miRNAs, total circulating miRNA levels are distinct from circulating EV miRNA content.

Endotoxin Preconditioning Reprograms S1 Tubules and Macrophages to Protect the Kidney.

Preconditioning with a low dose of endotoxin confers unparalleled protection against otherwise lethal models of sepsis. The mechanisms of preconditioning have been investigated extensively in isolated immune cells such as macrophages. However, the role of tissue in mediating the protective response generated by preconditioning remains unknown. Here, using the kidney as a model organ, we investigated cell type-specific responses to preconditioning. Compared with preadministration of vehicle, endotoxin preconditioning in the cecal ligation and puncture mouse model of sepsis led to significantly enhanced survival and reduced bacterial load in several organs. Furthermore, endotoxin preconditioning reduced serum levels of proinflammatory cytokines, upregulated molecular pathways involved in phagocytosis, and prevented the renal function decline and injury induced in mice by a toxic dose of endotoxin. The protective phenotype involved the clustering of macrophages around S1 segments of proximal tubules, and full renal protection required both macrophages and renal tubular cells. Using unbiased S1 transcriptomic and tissue metabolomic approaches, we identified multiple protective molecules that were operative in preconditioned animals, including molecules involved in antibacterial defense, redox balance, and tissue healing. We conclude that preconditioning reprograms macrophages and tubules to generate a protective environment, in which tissue health is preserved and immunity is controlled yet effective. Endotoxin preconditioning can thus be used as a discovery platform, and understanding the role and participation of both tissue and macrophages will help refine targeted therapies for sepsis.

Chronic high fat feeding restricts islet mRNA translation initiation independently of ER stress via DNA damage and p53 activation.

Under conditions of high fat diet (HFD) consumption, glucose dyshomeostasis develops when ß-cells are unable to adapt to peripheral insulin demands. Few studies have interrogated the molecular mechanisms of ß-cell dysfunction at the level of mRNA translation under such conditions. We sought to address this issue through polyribosome profile analysis of islets from mice fed 16-weeks of 42% HFD. HFD-islet analysis revealed clear trends toward global reductions in mRNA translation with a significant reduction in the polyribosome/monoribosome ratio for Pdx1 mRNA. Transcriptional and translational analyses revealed endoplasmic reticulum stress was not the etiology of our findings. HFD-islets demonstrated evidence of oxidative stress and DNA damage, as well as activation of p53. Experiments in MIN-6 ß-cells revealed that treatment with doxorubicin to directly induce DNA damage mimicked our observed effects in islets. Islets from animals treated with pioglitazone concurrently with HFD demonstrated a reversal of effects observed from HFD alone. Finally, HFD-islets demonstrated reduced expression of multiple ribosome biogenesis genes and the key translation initiation factor eIF4E. We propose a heretofore unappreciated effect of chronic HFD on ß-cells, wherein continued DNA damage owing to persistent oxidative stress results in p53 activation and a resultant inhibition of mRNA translation.

Management of the Nipple-Areola Complex in Selected Patients Undergoing Primary Breast Reconstruction: A Comparison of Immediate Replantation and Delayed Reconstruction.

BACKGROUND: Management of the nipple-areola complex is an important issue in primary breast reconstruction. When nipple-sparing mastectomy is not suitable, alternatives are immediate nipple-areola complex replantation and delayed reconstruction. The aim of this study was to examine whether patients benefit more from nipple-areola complex preservation by immediate replantation or delayed nipple-areola complex reconstruction. METHODS: Postoperative results and patient satisfaction after 54 primary breast reconstructions with immediate nipple-areola complex replantation or delayed nipple-areola complex reconstruction were retrospectively evaluated. RESULTS: The nipple-areola complex was replanted immediately in 37 cases and reconstructed later with nipple sharing and full-thickness skin grafting in 17 cases. Compared with immediate replantation, delayed reconstruction resulted in significantly better postoperative nipple projection (P = 0.01*, Mann-Whitney U test), greater similarity of color and projection with the contralateral side and greater patient satisfaction (Breast-Q). Complete loss of projection occurred in 4 of the 37 replanted nipple-areola complexes. No complete nipple-areola complex necrosis or tumor recurrence was observed in any patient. CONCLUSIONS: Immediate nipple-areola complex replantation is a safe and reliable procedure for selected patients with contraindications for nipple-sparing mastectomy who have a strong desire to maintain their own nipple-areola complexes, or in bilateral cases. However, drawbacks of this procedure include loss of projection and depigmentation. Delayed reconstruction with nipple sharing and full-thickness skin grafting is a good alternative, especially in unilateral cases; it leads to better postoperative results and greater patient satisfaction, but it involves a nipple-areola complex-free period.