Systemic liberation of interleukin-1β and interleukin-1 receptor antagonist in the perioperative phase of liver transplantation

We measured systemic serum levels of interleukin-1 receptor antagonist (IL-1ra), interleukin-1 (IL-1), tumor necrosis factor (TNF-), and interleukin-6 (IL-6) during the preoperative, anhepatic, and postreperfusional phases up to the 7th postoperative day in 60 patients undergoing orthotopic liver transplantation (LTx). In contrast to IL-1, IL-1ra, TNF-, and IL-6 showed a significant elevation in relation to the early phase after reperfusion, while TNF- displayed a high grade of scatter. In addition, IL-1ra levels were significantly elevated during the anhepatic phase. Maximum serum levels were found at 15 min after reperfusion, 120 min after reperfusion, and on the 1st postoperative day, respectively. Serum levels decreased considerably at 24 h and 7 days after reperfusion. The comparative monitoring of systemic cytokine and cytokine antagonist levels, in particular the liberation of IL-1ra and IL-6 may provide useful parameters for the development of new liver preservation theories for LTx.     

Mouse models and the genetics of diabetes: is there evidence for genetic overlap between type 1 and type 2 diabetes?

In humans, both type 1 and type 2 diabetes exemplify genetically heterogeneous complex diseases in which epigenetic factors contribute to underlying genetic susceptibility. Extended human pedigrees often show inheritance of both diabetes types. A common pathophysiological denominator in both disease forms is pancreatic beta-cell exposure to proinflammatory cytokines. Hence, it is intuitive that systemically expressed genes regulating beta-cell ability to withstand chronic diabetogenic stress may represent a component of shared susceptibility to both major disease forms. In this review, the authors assemble evidence from genetic experiments using animal models developing clearly distinct diabetes syndromes to inquire whether some degree of overlap in genes contributing susceptibility can be demonstrated. The conclusion is that although overlap exists in the pathophysiological insults leading to beta-cell destruction in the currently studied rodent models, the genetic bases seem quite distinct.     

Is latent autoimmune diabetes in adults distinct from type 1 diabetes or just type 1 diabetes at an older age?

Diabetes is classified clinically into two types: type 1 and type 2 diabetes. Type 1 diabetes is an autoimmune diabetes, whereas, in contrast, type 2 diabetes is nonautoimmune. However, there is a group of phenotypic adult type 2 diabetic patients ( approximately 10%) who have islet autoantibodies similar to type 1 diabetes. These patients are said to have latent autoimmune diabetes in adults (LADA) or type 1.5 diabetes. T-cells reacting with islet proteins have been demonstrated in type 1 and type 1.5 diabetic patients. In contrast, classic autoantibody-negative type 2 diabetic patients are also negative for T-cell responses to islet proteins. Therefore, we questioned whether type 1 and type 1.5 diabetes are similar or different autoimmune diseases. We have investigated the immunological and metabolic differences between type 1, type 1.5, and classic type 2 diabetic patients. We have identified autoantibody differences, differences in islet proteins recognized by T-cells, and differences in insulin resistance. We have also identified a small group of patients who have T-cells responsive to islet proteins but who are autoantibody negative. These patients appear to be similar to type 1.5 patients in having decreased stimulated C-peptide values. These immunological differences between type 1 and type 1.5 diabetes suggest at least partially distinct disease processes.     

Analysis of polymorphisms in the promoter region of interleukin-1β by restriction fragment length polymorphism-PCR

Objective: To investigate the frequencies of -1470, -511 and -31 single nucleotide polymorphisms (SNPs) in the promoter of IL-1β and its haplotype constitution in Chongqing population. Methods: One hundred and twelve healthy Chongqing people were enrolled in this study. Polymorphisms at -1470 (G to C), -511 (T to C) and -31(C to T) of IL-1β were genotyped with the method of restriction fragment length polymorphism ( RFLP ). Haplotype frequencies were analyzed by Adequine software. Results: Frequencies of IL-1β -1470, -511 and -31 SNPs were 41.67%, 50% and 45.33%, respectively. Genotype frequencies of -1470 locus were 39.81%, 37.04% and 23.15% for G/G, G/C and C/C respectively. As for T-511C SNP, genotype frequencies of T/T, T/C and C/C were 29.91%, 40.18% and 29.91%, respectively. Genotyping results of C/C, C/T, and T/T of -31 locus were 35.51%, 38.32 % and 26.71% respectively. Haplotype analysis found that there were mainly three haplotypes constituted by three SNPs, ie., G-T-C, C-T-Cand G-C-T. Conclusions: Polymorphisms exist in the promoter of IL-1β in Chongqing population. Three SNPs locate in the same haplotype block. Key words : lnterleukin-1 ; Polymorphism, restriction fragment length ; Polymorphisms, single nucleotide; Genotype; Haplotypes.     

Effect of the PTPN22 and INS risk genotypes on the progression to clinical type 1 diabetes after the initiation of β-cell autoimmunity

We set out to analyze the role of two major non-HLA gene polymorphisms associated with type 1 diabetes (T1D), PTPN22 1858C/T and insulin gene INS-23 A/T in progression to clinical T1D after the appearance of β-cell autoimmunity. The study population comprised 249 children with HLA-associated T1D susceptibility. All subjects were persistently positive for at least one of the T1D-associated biochemically defined autoantibodies (insulin autoantibody, GAD antibody, or IA-2 antibody), and 136 subjects presented with T1D over a median follow-up of 4.3 years (range 0.0-12.5) after the appearance of the first autoantibody. The PTPN22 1858T allele was strongly associated with progression to T1D after the appearance of the first biochemically defined β-cell autoantibody (hazard ratio 1.68 [95% CI 1.09-2.60], P = 0.02 Cox regression analysis, multivariate test), and the effect remained similar when analyzed after the appearance of the second autoantibody (P = 0.013), whereas INS-23 HphI AA genotype was not associated with progression to clinical diabetes after the appearance of the first or second autoantibody (P = 0.38 and P = 0.88, respectively). The effect of the INS risk genotype seems to be limited to the induction and early phases of β-cell autoimmunity, but the PTPN22 1858T allele instead affects the initiation and late progression phase of diabetes-associated autoimmunity.     

Multimodality imaging of β-cells in mouse models of type 1 and 2 diabetes

OBJECTIVE

β-Cells that express an imaging reporter have provided powerful tools for studying β-cell development, islet transplantation, and β-cell autoimmunity. To further expedite diabetes research, we generated transgenic C57BL/6 “MIP-TF” mice that have a mouse insulin promoter (MIP) driving the expression of a trifusion (TF) protein of three imaging reporters (luciferase/enhanced green fluorescent protein/HSV1-sr39 thymidine kinase) in their β-cells. This should enable the noninvasive imaging of β-cells by charge-coupled device (CCD) and micro-positron emission tomography (PET), as well as the identification of β-cells at the cellular level by fluorescent microscopy.

RESEARCH DESIGN AND METHODS

MIP-TF mouse β-cells were multimodality imaged in models of type 1 and type 2 diabetes.

RESULTS

MIP-TF mouse β-cells were readily identified in pancreatic tissue sections using fluorescent microscopy. We show that MIP-TF β-cells can be noninvasively imaged using microPET. There was a correlation between CCD and microPET signals from the pancreas region of individual mice. After low-dose streptozotocin administration to induce type 1 diabetes, we observed a progressive reduction in bioluminescence from the pancreas region before the appearance of hyperglycemia. Although there have been reports of hyperglycemia inducing proinsulin expression in extrapancreatic tissues, we did not observe bioluminescent signals from extrapancreatic tissues of diabetic MIP-TF mice. Because MIP-TF mouse β-cells express a viral thymidine kinase, ganciclovir treatment induced hyperglycemia, providing a new experimental model of type 1 diabetes. Mice fed a high-fat diet to model early type 2 diabetes displayed a progressive increase in their pancreatic bioluminescent signals, which were positively correlated with area under the curve–intraperitoneal glucose tolerance test (AUC-IPGTT).

CONCLUSIONS

MIP-TF mice provide a new tool for monitoring β-cells from the single cell level to noninvasive assessments of β-cells in models of type 1 diabetes and type 2 diabetes.The expression of imaging reporter genes in β-cells has provided powerful tools for studying β-cell development, embryonic and adult stem cell differentiation into β-cells, transdifferentiation, and islet transplantation (1–13). Bioluminescent reporters, such as firefly luciferase, emit photons that can be detected with high sensitivity using a cooled charge-coupled device (CCD). We and others have demonstrated human and rodent islets can be genetically engineered ex vivo to express luciferase so that the islets can be monitored following their transplantation by CCD and that CCD signal corresponded with the implanted β-cell mass (1,2). Several laboratories have generated transgenic mice that express luciferase in their β-cells and shown that the CCD signal from the pancreas is correlated with β-cell mass (3–5). Moreover, the transgenic islets can be monitored after transplantation (3,4,6). Fluorescence imaging and bioluminescence imaging (BLI) are highly useful for research purposes in small animals, but they are not yet applicable to imaging internal organs in large animals because of the limited transparency of tissues to photons.Positron emission tomography (PET) imaging is used clinically to assess various disorders of the heart and brain and for detecting various cancers (7,8). Islets that were engineered ex vivo to express a PET can be noninvasively monitored by microPET after implantation into the liver (9,10). The microPET signal reflects β-cell mass, and islets can be monitored long-term after implantation (11). Radiolabeled ligands of vesicular monoamine transporter (VMAT2) can image β-cells in BB rats, although VMAT2 may not be a sensitive biomarker of β-cell mass in humans (12–14). Mouse pancreatic β-cells are inherently difficult to detect by microPET because of the small size of mice, the long thin shape of the pancreas and its proximity to the probe excretion pathway—which eliminates the vast majority of the tracer and obscures the weaker signals from the pancreas, and the resolution of microPET (1–2 mm³). Recent advances in PET reporter genes and PET probes with better clearance kinetics and biodistribution, however, have allowed progress towards microPET imaging of mouse β-cells in situ (14).Previous imaging studies of β-cells have used animal models in which the β-cells express a single reporter gene. We have developed a series of trifusion imaging reporters consisting of a bioluminescent reporter (e.g., luciferase), linked by a few alanine residues to a fluorescent reporter gene (e.g., enhanced green fluorescent protein [EGFP]), which in turn is linked to a PET reporter (e.g., herpes simplex virus [HSV] thymidine kinase) (15). All three reporters are expressed as a single fusion protein, allowing noninvasive CCD and PET imaging, as well as fluorescent microscopic analysis of tissue sections or fluorescence-activated cell sorter (FACS) isolation of single cells expressing EGFP (15,16). Using an insulin promoter to drive the expression of a trifusion reporter in transgenic mouse β-cells should enable the longitudinal monitoring of β-cells in the same mice by both CCD and microPET. After killing, fluorescent microscopy can identify β-cells at the cellular level and facilitate correlation of β-cell number and mass with the CCD and microPET signals. Because all three reporters are linked together in a fusion protein, the magnitude of signals from one imaging reporter should predict the magnitude of the signals from the other imaging reporters. Here, we provide proof-of principle of the utility of mice expressing a trifusion imaging reporter specifically in their β-cells in mouse models of type 1 diabetes and type 2 diabetes.     

Is there a role for locally produced interleukin-1 in the deleterious effects of high glucose or the type 2 diabetes milieu to human pancreatic islets?

Different degrees of beta-cell failure and apoptosis are present in type 1 and type 2 diabetes. It has been recently suggested that high glucose-induced beta-cell apoptosis in type 2 diabetes shares a final common pathway with type 1 diabetes, involving interleukin-1beta (IL-1beta) production by beta-cells, nuclear factor-kappaB (NF-kappaB) activation, and death via Fas-FasL. The aim of this study was to test whether human islet exposure to high glucose in vitro, or to the type 2 diabetes environment in vivo, induces IL-1beta expression and consequent activation of NF-kappaB-dependent genes. Human islets were isolated from five normoglycemic organ donors. The islets were cultured for 48 h to 7 days at 5.6, 11, or 28 mmol/l glucose. For comparative purposes, islets were also exposed to IL-1beta. Gene mRNA expression levels were assessed by real-time RT-PCR in a blinded fashion. Culture of the human islets at 11 and 28 mmol/l glucose induced a four- to fivefold increase in medium insulin as compared with 5.6 mmol/l glucose, but neither IL-1beta nor IL-1 receptor antagonist (IL-1ra) expression changed. IL-1beta and IL-1ra protein release to the medium was also unchanged. Stimulated human monocytes, studied in parallel, released >50-fold more IL-1beta than the islets. There was also no glucose-induced islet Fas expression. Expression of the NF-kappaB-dependent genes IkappaB-alpha and monocyte chemoattractant protein (MCP)-1 was induced in human islets by IL-1beta but not by high glucose. In a second set of experiments, human islets were isolated from seven type 2 diabetic patients and eight control subjects. The findings on mRNA levels were essentially the same as in the in vitro experiments, namely the in vivo diabetic state did not induce IL-1beta, Fas, or MCP-1 expression in human islets, and also did not modify IL-1ra expression. The present findings suggest that high glucose in vitro, or the diabetic milieu in vivo, does not induce IL-1beta production or NF-kappaB activation in human islets. This makes it unlikely that locally produced IL-1beta is an important mediator of glucotoxicity to human islets and argues against the IL-1beta-NF-kappaB-Fas pathway as a common mediator for beta-cell death in type 1 and type 2 diabetes.     

Intracapsular pressure and interleukin-1β cytokine in hips with acetabular dysplasia

Background and purpose Several studies have demonstrated an increased intracapsular pressure in several hip disorders such as septic arthritis, synovitis, and trauma. We therefore measured the intracapsular pressure in different positions in early dysplasic hips and its relation to the concentration of interleukin-1β (IL-1β), the volume of joint fluid, and the clinical and radiographic findings before a periacetabular osteotomy.

Methods 12 female patients (12 hips, mean age 35 (18–52)) with hip dysplasia were investigated. The intracapsular pressure was recorded and we investigated possible correlations with the Harris hip score, the Tönnis scale, radiographic findings, the volume of joint fluid, and the concentration of IL-1β.

Results An increased intracapsular pressure was noted, especially in flexion or extension with internal rotation. We found positive correlations between the intracapsular pressure and both the volume of joint fluid and the concentration of IL-1β.

Interpretation Increased intracapsular pressure varied with different positions, indicating the presence of synovitis resulting from early osteoarthritis in dysplastic hips. Positive correlations between the pressure and both the concentration of IL-1β and the volume of joint fluid suggest that the inflammatory cytokines produced by the synovial membrane as a consequence of mechanical instability of the hip joint may be of importance for the initiation and/or development of osteoarthritis in dysplastic hips.     

Changes of interleukin-1 β, tumor necrosis factor α and interleukin-6 in brain and plasma after brain injury in rats

Objective: To study the changes of interleukin-1 β(IL-1β), tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) levels in brain and plasma after brain injury and to assess the relationship between the cytokine levels and injury severity in rats. Methods. A total of 51 male Wistar rats, weighing 280-340g, were anesthetized with chloral hydrate(400 mg/kg body weight) through intraperitoneal injection and fixed on a stereotaxic instrument. Severe brain injury was created in 16 rats (severe injury group) and moderate brain injury in 18 rats (moderate injury group) by a fluid percussion model, and cytokine levels of IL-1β, TNFα and IL-6 were measured with biological assay. And sham operation was made on the other 17 rats (control group). Results: In the control group, the levels of IL-1β,TNFα and IL-6 were hardly detected in the cortex of the rats, but in the ipsilateral cortex of the rats in both injury groups, they increased obviously at 8 hours after injury.The increasing degree of these cytokines had no significant difference between the two injury groups. The levels of IL-6 in the plasma of all the rats increased slightly, whereas the levels of IL-1β and TNFα were undetectable. Conc|usions: The increase of IL-1β, TNFα and IL-6 levels is closely related to brain injury. The increased cytokine levels in the central nervous system are not parallel to those in the peripheral blood. It suggests that inflammatory cytokines play important roles in the secondary neural damage after brain injury.     

How to preoxygenate in operative room: Healthy subjects and situations “at risk”

Intubation is one of the most common procedures performed in operative rooms. It can be associated with life-threatening complications when difficult airway access occurs, in patients who cannot tolerate even a slight hypoxemia or when performed in patients at risk of oxygen desaturation during intubation, as obese, critically-ill and pregnant patients. To improve intubation safety, preoxygenation is a major technique, extending the duration of safe apnoea, defined as the time until a patient reaches an arterial saturation level of 88% to 90%, to allow for placement of a definitive airway. Preoxygenation consists in increasing the lung stores of oxygen, located in the functional residual capacity, and helps preventing hypoxia that may occur during intubation attempts. Obese, critically-ill and pregnant patients are especially at risk of reduced effectiveness of preoxygenation because of pathophysiological modifications (reduced functional residual capacity (FRC), increased risk of atelectasis, shunt). Three minutes tidal volume breathing or 3–8 vital capacities are recommended in general population, mostly allowing achieving a 90% end-tidal oxygen level. Recent studies have indicated that in order to maximize the value of preoxygenation (i.e, oxygenation stores) obese and critically-ill patients can benefit from the combination of breathing 100% oxygen and non-invasive positive pressure ventilation (NIV) with end-expiratory positive pressure (PEEP) in the proclive position (Trendelenburg reverse). Recruitment manoeuvres may be of interest immediately after intubation to limit the risk of lung derecruitment. Further studies are needed in the field of preoxygenation in pregnant women.     

Gene and cell-replacement therapy in the treatment of type 1 diabetes: how high must the standards be set?

Recent advances in molecular and cell biology may allow for the development of novel strategies for the treatment and cure of type 1 diabetes. In particular, it is now possible to envisage restoration of insulin secretion by gene or cell-replacement therapy. The beta-cell is, however, remarkably sophisticated, and many of the features of this highly differentiated secretory cell will have to be faithfully mimicked in surrogate cells. In particular, insulin is normally secreted in a well-regulated fashion in rapid response to the metabolic needs of the individual and most specifically (but not exclusively) to changes in circulating levels of glucose. Such regulated secretion will be indispensable in order to avoid both hyper- and hypoglycemic episodes and depends on the ability of cells to store insulin in secretory granules before exocytosis in response to physiological stimuli. Furthermore, any newly created insulin-secreting cell will have to be able to adapt to alterations in insulin requirements that accompany changes with exercise, body weight, and aging. Fine tuning of insulin secretion over the longer term will also be important to avoid "clinical shifting" that could be caused by over-insulinization, including increased adiposity and cardiovascular disease. Finally, it will be necessary to ensure that newly created or implanted (surrogate) beta-cells are protected in some way from recognition by the immune system and in particular from autoimmune destruction.     

Enterovirus and type 1 diabetes: What is the matter?

A complex interaction of genetic and environmental factors can trigger the immune-mediated mechanism responsible for type 1 diabetes mellitus(T1DM) establishment. Environmental factors may initiate and possibly sustain, accelerate, or retard damage to β-cells. The role of environmental factors in this process has been exhaustive studied and viruses are among the most probable ones, especially enteroviruses. Improvements in enterovirus detection methods and randomized studies with patient follow-up have confirmed the importance of human enterovirus in the pathogenesis of T1 DM. The genetic risk of T1 DM and particular innate and acquired immune responses to enterovirus infection contribute to a tolerance to T1DM-related autoantigens. However, the frequency, mechanisms, and pathways of virally induced autoimmunity and β-cell destruction in T1 DM remain to be determined. It is difficult to investigate the role of enterovirus infection in T1 DM because of several concomitant mechanisms by which the virus damages pancreatic β-cells, which, consequently, may lead to T1 DM establishment. Advances in molecular and genomic studies may facilitate the identification of pathways at earlier stages of autoimmunity when preventive and therapeutic approaches may be more effective.     

Cigarette smoking and risk of albuminuria in patients with type 2 diabetes: a systematic review and meta-analysis of observational studies

Background

The aim of this study was to assess the effects of smoking on albuminuria risk in adults with type 2 diabetes mellitus (T2DM).

Methods

A literature search was conducted using MEDLINE, EMBASE, and China National Knowledge Infrastructure from the established date to October 2017. Summary relative risks (SRR) and 95% confidence intervals (CI) were computed utilizing a random effect inverse variance method.

Results

This meta-analysis included a total of 19 relevant observational studies (four prospective cohort, seven case–control, and eight cross-sectional studies), reporting 105,031 participants and 23,366 albuminuria events. Compared with never-smokers with T2DM, the SRRs of albuminuria were 1.43 (95% CIs 1.27–1.61) for ever-smokers, 2.61 (95% CIs 1.86–3.64) for current smokers, and 1.86 (95% CIs 1.37–2.52) for former smokers. Considerable heterogeneity was observed among these studies, and study design was a significant modifier for this association. There were significantly elevated risk associations for microalbuminuria (SRRs = 1.24, 95% CIs 1.05–1.46) and for macroalbuminuria (SRRs = 1.65, 95% CIs 1.03–2.66), respectively.

Conclusions

Our systematic review and meta-analysis indicates that cigarette smoking might be a potential factor for the development of albuminuria in adults with T2DM. Future studies are required to investigate the association between smoking cessation and intensity and incident albuminuria in adults with T2DM.

     

Progressive erosion of β-cell function precedes the onset of hyperglycemia in the NOD mouse model of type 1 diabetes

OBJECTIVE

A progressive decline in insulin responses to glucose was noted in individuals before the onset of type 1 diabetes. We determined whether such abnormalities occurred in prediabetic NOD mice—the prototypic model for human type 1 diabetes.

RESEARCH DESIGN AND METHODS

Morning blood glucose was measured every other day in a cohort of NOD females. Glucose tolerance and insulin secretion were measured longitudinally by intraperitoneal glucose tolerance tests in NOD/ShiLtJ and BALB/cJ mice 6 to 14 weeks of age. Arginine-stimulated insulin secretion and insulin sensitivity were assessed during intraperitoneal arginine or intraperitoneal insulin tolerance tests.

RESULTS

During prediabetes, NOD females displayed a progressive increase in glucose levels followed by an acute onset of hyperglycemia. First-phase insulin responses (FPIRs) during the intraperitoneal glucose tolerance test (IPGTT) declined before loss of glucose tolerance in NOD. The failure of FPIR could be detected, with a decline in peak insulin secretion during IPGTT. Arginine-stimulated insulin secretion remained unchanged during the study period. The decline in insulin secretion in NOD mice could not be explained by changes in insulin sensitivity.

CONCLUSIONS

There was an impressive decline in FPIR before changes in glucose tolerance, suggesting that impairment of FPIR is an early in vivo marker of progressive β-cell failure in NOD mice and human type 1 diabetes. We portend that these phenotypes in NOD mice follow a similar pattern to those seen in humans with type 1 diabetes and validate, in a novel way, the importance of this animal model for studies of this disease.Type 1 diabetes is an autoimmune disease resulting from the destruction of pancreatic insulin-producing β-cells. The NOD mouse is the most commonly used rodent model of the disease. Studies in this mouse strain have led to interventions that have been translated to clinical investigations with human type 1 diabetic patients (1–5). However, intervening at the right therapeutic window is critical to the efficacy of certain therapies. For example, anti-mouse thymocyte globulin can delay or reverse diabetes in NOD only when used in the late prediabetes stage or at onset of the disease (6).Islet autoimmunity can be identified in the prediabetic stage. Specifically, in NOD mice, insulin autoantibodies can be detected as early as at 3 weeks of age (7). However, as in humans, autoantibody positivity can be transient as well as observed in nonprogressors (8,9). Therefore, markers of β-cell mass and function are needed to identify progression from the onset of islet autoimmunity to and through the stages of prediabetes.Previous cross-sectional studies have demonstrated decreased first-phase insulin secretion in NOD females at different ages. Using pancreatic perfusion, Kano et al. (10) documented that NOD mice maintain normal fasting glucose even though a significant decrease was measured in first-phase insulin response (FPIR) to glucose. In these studies, increased fasting glucose and loss of FPIR was associated with the degree of insulitis. In cross-sectional studies using intravenous glucose tolerance test, Reddy et al. (11) showed an age-related progressive decline in FPIR to glucose. In another cross-sectional study using in situ pancreas perfusion, Sreenan et al. (12) reported progressive decreases in glucose- and arginine-stimulated insulin secretion in NOD females at 8, 13, and 18 weeks of age. Although single-point analyses were performed, there have not been reports involving sequential analysis of single mice over time to confirm this progression. In this study, we sought to determine whether similar metabolic signatures exist in both humans and in prediabetic NOD mice.