Nondeletional α-thalassemia: First description of αHphα and αNcoα mutations in a Spanish population

Several different deletions underlie the molecular basis of α-thalassemia. The most common α-thalassemia determinant in Spain is the rightward deletion (−α^3.7). To our knowledge, however, no cases of α-thalassemia due to nondeletional mutations have so far been described in this particular Mediterranean area. Here, we report the existence of nondeletional forms of α-thalassemia in ten Spanish families. The α₂-globin gene was characterized in ten unrelated patients and their relatives only when the presence of deletional α-thalassemia was ruled out. The α₂-globin gene analysis was performed using the polymerase chain reaction (PCR) followed by restriction enzyme analysis or by allele-specific priming. This allowed the identification of a 5-base pair (bp) deletion at the donor site of IVS I (α^Hphα) in 9 cases and the α₂ initiation codon mutation (α^Ncoα) in one case. Although these α₂-globin gene mutations are found in other Mediterranean areas, our results demonstrate their presence in the Spanish population and suggest that the α^Hphα/αα genotype is probably the most common nondeletional form of α-thalassemia in Spain. © 1996 Wiley-Liss, Inc.     

Angiogenesis promoted by vascular endothelial growth factor: Regulation through α1β1 and α2β1 integrins

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is a cytokine of central importance for the angiogenesis associated with cancers and other pathologies. Because angiogenesis often involves endothelial cell (EC) migration and proliferation within a collagen-rich extracellular matrix, we investigated the possibility that VEGF promotes neovascularization through regulation of collagen receptor expression. VEGF induced a 5- to 7-fold increase in dermal microvascular EC surface protein expression of two collagen receptors—the α₁β₁ and α₂β₁ integrins—through induction of mRNAs encoding the α₁ and α₂ subunits. In contrast, VEGF did not induce increased expression of the α₃β₁ integrin, which also has been implicated in collagen binding. Integrin α₁-blocking and α₂-blocking antibodies (Ab) each partially inhibited attachment of microvascular EC to collagen I, and α₁-blocking Ab also inhibited attachment to collagen IV and laminin-1. Induction of α₁β₁ and α₂β₁ expression by VEGF promoted cell spreading on collagen I gels which was abolished by a combination of α₁-blocking and α₂-blocking Abs. In vivo, a combination of α₁-blocking and α₂-blocking Abs markedly inhibited VEGF-driven angiogenesis; average cross-sectional area of individual new blood vessels was reduced 90% and average total new vascular area was reduced 82% without detectable effects on the pre-existing vasculature. These data indicate that induction of α₁β₁ and α₂β₁ expression by EC is an important mechanism by which VEGF promotes angiogenesis and that α₁β₁ and α₂β₁ antagonists may prove effective in inhibiting VEGF-driven angiogenesis in cancers and other important pathologies.     

Interferon α2–Thymosin α1 Fusion Protein (IFNα2–Tα1): A Genetically Engineered Fusion Protein with Enhanced Anticancer and Antiviral Effect

Human interferon α2 (IFNα2) and thymosin α1 (Tα1) are therapeutic proteins used for the treatment of viral infections and different types of cancer. Both IFNα2 and Tα1 show a synergic effect in their activities when used in combination. Furthermore, the therapeutic fusion proteins produced through the genetic fusion of two genes can exhibit several therapeutic functions in one molecule. In this study, we determined the anticancer and antiviral effect of human interferon α2–thymosin α1 fusion protein (IFNα2–Tα1) produced in our laboratory for the first time. The cytotoxic and genotoxic effect of IFNα2–Tα1 was evaluated in HepG2 and MDA-MB-231 cells. The in vitro assays confirmed that IFNα2–Tα1 inhibited the growth of cells more effectively than IFNα2 alone and showed an elevated genotoxic effect. The expression of proapoptotic genes was also significantly enhanced in IFNα2–Tα1-treated cells compared to IFNα2-treated cells. Furthermore, the HCV RNA level was significantly reduced in IFNα2–Tα1-treated HCV-infected Huh7 cells compared to IFNα2-treated cells. The quantitative PCR analysis showed that the expression of various genes, the products of which inhibit HCV replication, was significantly enhanced in IFNα2–Tα1-treated cells compared to IFNα2-treated cells. Our findings demonstrate that IFNα2–Tα1 is more effective than single IFNα2 as an anticancer and antiviral agent.     

Fulminant type 1 diabetes mellitus with anti‐programmed cell death‐1 therapy

Anti‐programmed cell death‐1 (PD‐1) antibodies are regarded as a risk factor for insulin‐dependent diabetes mellitus as a side‐effect. While a small number of cases have been reported, evidence remains limited. This is the first report of an Asian patient developing insulin‐dependent diabetes during anti‐PD‐1 therapy. A 55‐year‐old euglycemic woman receiving nivolumab for malignant melanoma showed abrupt onset of ketonuria, and elevated levels of plasma glucose (580 mg/dL) and hemoglobin A1c (7.0%). Over the next 2 weeks, serum C‐peptide levels fell below the limit of detection. Islet autoantibodies were negative, and the patient showed a human leukocyte antigen haplotype associated with type 1 diabetes. Anti‐PD‐1 therapy can cause rapid onset of insulin‐dependent diabetes, possibly because of inappropriate activation of T cells. Human leukocyte antigen haplotypes might be related to the onset of this disease. Physicians should be aware of this serious adverse event and carry out routine blood glucose testing during anti‐PD‐1 therapy.     

Melatonin prevents Drp1‐mediated mitochondrial fission in diabetic hearts through SIRT1‐PGC1α pathway

Myocardial contractile dysfunction is associated with an increase in mitochondrial fission in patients with diabetes. However, whether mitochondrial fission directly promotes diabetes‐induced cardiac dysfunction is still unknown. Melatonin exerts a substantial influence on the regulation of mitochondrial fission/fusion. This study investigated whether melatonin protects against diabetes‐induced cardiac dysfunction via regulation of mitochondrial fission/fusion and explored its underlying mechanisms. Here, we show that melatonin prevented diabetes‐induced cardiac dysfunction by inhibiting dynamin‐related protein 1 (Drp1)‐mediated mitochondrial fission. Melatonin treatment decreased Drp1 expression, inhibited mitochondrial fragmentation, suppressed oxidative stress, reduced cardiomyocyte apoptosis, improved mitochondrial function and cardiac function in streptozotocin (STZ )‐induced diabetic mice, but not in SIRT 1^?/? diabetic mice. In high glucose‐exposed H9c2 cells, melatonin treatment increased the expression of SIRT 1 and PGC ‐1α and inhibited Drp1‐mediated mitochondrial fission and mitochondria‐derived superoxide production. In contrast, SIRT 1 or PGC ‐1α siRNA knockdown blunted the inhibitory effects of melatonin on Drp1 expression and mitochondrial fission. These data indicated that melatonin exerted its cardioprotective effects by reducing Drp1‐mediated mitochondrial fission in a SIRT 1/PGC ‐1α‐dependent manner. Moreover, chromatin immunoprecipitation analysis revealed that PGC ‐1α directly regulated the expression of Drp1 by binding to its promoter. Inhibition of mitochondrial fission with Drp1 inhibitor mdivi‐1 suppressed oxidative stress, alleviated mitochondrial dysfunction and cardiac dysfunction in diabetic mice. These findings show that melatonin attenuates the development of diabetes‐induced cardiac dysfunction by preventing mitochondrial fission through SIRT 1‐PGC 1α pathway, which negatively regulates the expression of Drp1 directly. Inhibition of mitochondrial fission may be a potential target for delaying cardiac complications in patients with diabetes.     

Familial α1-Antichymotrypsin Deficiency

ABSTRACT We studied patients and their relatives with partial deficiency, approximately 50% of normal plasma levels, of α₁-antichymotrypsin (ACT), an acute phase reactant with anti-cathepsin G activity. Six of eight ACT deficient individuals, over 25 years of age, had liver and three of eight lung manifestations, varying from severe disease to subtle laboratory abnormalities. The ACT of deficient individuals (who are heterozygotes for a rare gene, q=0.003) had normal crossed immunoelectrophoretic properties. The abnormal gene is inherited in an autosomal, dominant way. The results suggest that deficiency of this antiprotease, which also has immune response modulating properties, may predispose to liver and lung disease.     

The anti‐interleukin‐1 in type 1 diabetes action trial—background and rationale

Type 1 diabetes (T1D) is caused by an inflammatory destruction of pancreatic beta‐cells. Pro‐inflammatory cytokines, in particular interleukin‐1 (IL‐1), have been suggested to be effector molecules based on the observations that pro‐inflammatory cytokines cause beta‐cell apoptosis in vitro and aggravate diabetes in vivo, and that inhibition of the action of these cytokines reduce diabetes incidence in animal models of type 1 diabetes and islet graft destruction. This review presents the rationale for and design of a recently launched double‐blind, multicenter, randomized clinical trial that investigates the effect of interleukin‐1 antagonism on beta‐cell function in subjects with T1D of recent‐onset. Copyright © 2009 John Wiley & Sons, Ltd.     

An association between Type 2 diabetes and α1‐antitrypsin deficiency

Aims α₁‐Antitrypsin (AAT) is a serine protease inhibitor which recently has been shown to prevent Type 1 diabetes development, to prolong islet allograft survival and to inhibit pancreatic B‐cell apoptosis in vivo. It has also been reported that Type 1 diabetic patients have significantly lower plasma concentrations of AAT, suggesting the potential role of AAT in the pathogenesis of Type 1 diabetes. We have investigated whether plasma AAT levels are altered in Type 2 diabetes. Methods The study included patients with Type 2 diabetes (n = 163) and non‐diabetic control subjects matched for age, sex and smoking habits (n = 158) derived from the population‐based Malmö Diet and Cancer study. Plasma samples were analysed for AAT concentration and phenotype and serum glucose, insulin, C‐reactive protein and lipid levels were measured. Glycated haemoglobin was also measured. Results In the diabetic group, the women had higher mean plasma AAT levels than men (P < 0.05). The mean plasma AAT levels did not differ between diabetic and control subjects. However, the number of individuals with low AAT levels (< 1.0 mg/ml) was 50% higher in the diabetic group (P < 0.05) and the frequency of AAT deficiency genotypes was 50% higher (NS) in diabetic compared with control subjects. In the group of diabetic patients with AAT < 1 mg/ml, AAT directly correlated with systolic blood pressure (P = 0.048) and inversely correlated with waist–hip ratio (P = 0.031). Conclusions Our results provide evidence that deficiency of AAT may be associated with an increased risk of developing Type 2 diabetes.     

Proteolytic inactivation of α1-antitrypsin and α1-antichymotrypsin by neutrophils in arthritic joints

Objective. In vitro, activated neutrophils create a microenvironment in which proteinase inhibitors are inactivated through the coordinate action of reactive oxygen species and released elastase. We investigated whether such a mechanism may contribute to the destruction of the joint tissues in arthritis. Methods. We analyzed the state of α₁-antitrypsin (α₁AT) and α₁-antichymotrypsin (α₁ACT), the two major inhibitors of the neutrophilic serine proteinases, in synovial fluid (SF) from patients with inflammatory arthropathies (n = 71) and osteoarthritis (OA) (n = 11), and related the results to neutrophil activation in SF. Results. The ratio of functional to antigenic levels of α₁AT in SF of patients with inflammatory joint diseases was similar to that of α₁AT in normal plasma, whereas that of α₁ACT was significantly decreased. Patients with inflammatory arthropathies had significantly higher levels of inactivated α₁AT (iα₁AT) and inactivated α₁ACT (iα₁ACT) in SF (as determined with monoclonal antibodies specific for the inactivated [i.e., proteolytically inactivated and/or complexed] forms of these inhibitors) than patients with OA (P < 0.005). Inactivated α₁AT and iα₁ACT levels corresponded to 0.3–11% and 3–99%, respectively, of the total amount of these inhibitors in SF. Most of the iα₁AT in SF had a lower M_r than that of native α₁AT. Inactivated α₁ACT in SF had an M_r identical to that of nonfunctional α₁ACT in plasma treated with chymotrypsin. Levels of both iα₁AT and iα₁ACT correlated significantly with lactoferrin and elastase levels. Conclusion. These results suggest that α₁AT and α₁ACT in arthritic joints are inactivated in part by activated neutrophils, suggesting a role for these cells in impairment of the local balance between proteinases and their inhibitors in arthritis.     

Myeloid neoplasms with t(16;21)(q24;q22)/<Emphasis Type="Italic">RUNX1-RUNX1T3</Emphasis> mimics acute myeloid leukemia with <Emphasis Type="Italic">RUNX1-RUNX1T1</Emphasis>

Chromosome translocation t(16;21)(q24;q22)/RUNX1-RUNX1T3 is an infrequent but recurrent chromosomal abnormality identified in myeloid neoplasms, with only 25 cases have been reported to date. Here, we report eight cases (six women and two men) of myeloid neoplasms associated with t(16;21)(q24;q22): five with therapy-related myeloid neoplasms, two with relapsed acute myeloid leukemia (AML), and one with blast phase of chronic myeloid leukemia. Morphologic and immunophenotypic features include granulocytic dysplasia, blasts with prominent perinuclear hof, large orange-pink granules, long and slim Auer rods, and aberrant expression of CD19. Six patients received AML-based regimens, and five achieved complete remission after initial induction therapy. Our study suggests that myeloid neoplasm with t(16;21)/RUNX1-RUNX1T1 resembles AML with t(8;21)(q22;q22)/RUNX1-RUNX1T1, in regard to morphology, immunophenotype, and response to therapy. Therefore, the clinical management of AML with t(8;21) may provide the best model for patients with myeloid neoplasms with t(16;21).     

Case of fulminant type 1 diabetes induced by the anti‐programmed death‐ligand 1 antibody,avelumab

With the expansive use of immune checkpoint inhibitors, the frequency of immune‐related adverse events, including autoimmune type 1 diabetes, has been exponentially increased. The anti‐programmed death‐ligand 1 antibody, avelumab, has recently been approved for metastatic Merkel cell carcinoma therapy. Here, we report a patient that developed fulminant type 1 diabetes during avelumab treatment. An 81‐year‐old woman with no history of diabetes received avelumab for metastatic Merkel cell carcinoma. Elevated plasma glucose level (483 mg/dL), hemoglobin A1c level (7.5%) and ketosis were observed after 10 courses of avelumab without any symptoms related to hyperglycemia. As the laboratory tests showed insulin depletion, we diagnosed her with fulminant type 1 diabetes induced by avelumab. This is the first reported case of avelumab‐induced type 1 diabetes, illustrating the necessity for close monitoring of glycemic control during avelumab therapy, as well as other immune checkpoint inhibitors.     

Downregulation of CX<Subscript>3</Subscript>CR1 ameliorates experimental colitis: evidence for CX<Subscript>3</Subscript>CL1-CX<Subscript>3</Subscript>CR1-mediated immune cell recruitment

Purpose

Inflammatory conditions like inflammatory bowel diseases (IBD) are characterized by increased immune cell infiltration. The chemokine ligand CX₃CL1 and its receptor CX₃CR1 have been shown to be involved in leukocyte adhesion, transendothelial recruitment, and chemotaxis. Therefore, the objective of this study was to describe CX3CL1-CX3CR1-mediated signaling in the induction of immune cell recruitment during experimental murine colitis.

Methods

Acute colitis was induced by dextran sodium sulfate (DSS), and sepsis was induced by injection of lipopolysaccharide (LPS). Serum concentrations of CX₃CR1 and CX₃CL1 were measured by ELISA. Wild-type and CX₃CR1^-/- mice were challenged with DSS, and on day 6, intravital microscopy was performed to monitor colonic leukocyte and platelet recruitment. Intestinal inflammation was assessed by disease activity, histopathology, and neutrophil infiltration.

Results

CX₃CR1 was upregulated in DSS colitis and LPS-induced sepsis. CX₃CR1^-/- mice were protected from disease severity and intestinal injury in DSS colitis, and CX₃CR1 deficiency resulted in reduced rolling of leukocytes and platelets.

Conclusions

In the present study, we provide evidence for a crucial role of CX₃CL1-CX₃CR1 in experimental colitis, in particular for intestinal leukocyte recruitment during murine colitis. Our findings suggest that CX₃CR1 blockade represents a potential therapeutic strategy for treatment of IBD.