Role of L-selectin in the development of autoimmune diabetes in non-obese diabetic mice

Autoimmune diabetes is characterized by an early mononuclear infiltration of pancreatic islets and later selective autoimmune destruction of insulin-producing beta cells. Lymphocyte homing receptors have been considered candidate targets to prevent autoimmune diabetes. L-selectin (CD62L) is an adhesion molecule highly expressed in naive T and B cells. It has been reported that blocking L-selectin in vivo with a specific antibody (Mel-14) partially impairs insulitis and diabetes in autoimmune diabetes-prone non-obese diabetic (NOD) mice. In the present study we aimed to elucidate whether genetic blockade of leukocyte homing into peripheral lymph nodes would prevent the development of diabetes. We backcrossed L-selectin-deficient mice onto the NOD genetic background. Surprisingly NOD/L-selectin-deficient mice exhibited unaltered islet mononuclear infiltration, timing of diabetes onset and cumulative incidence of spontaneous diabetes when compared to L-selectin-sufficient animals. CD4, CD8 T cells and B cells were present in islet infiltrates from 9-week-old L-selectin-sufficient and -deficient littermates. Moreover, total splenocytes from wild-type, heterozygous or NOD/L-selectin-deficient donor mice showed similar capability to adoptively transfer diabetes into NOD/SCID recipients. On the other hand, homing of activated, cloned insulin-specific autoaggressive CD8 T cells (TGNFC8 clone) is not affected in NOD/L-selectin-deficient recipients. We conclude that L-selectin plays a small role in the homing of autoreactive lymphocytes to regional (pancreatic) lymph nodes in NOD mice.     

Eosinophilic pancreatitis in the newborn infant of a diabetic mother

Summary The authors have studied the pancreas of a premature female infant born to a diabetic mother. The findings included a peri-insular eosinophilic leucocyte infiltration, macropolinesia and a marked increase in B cells. In the exocrime parenchyma small B cells aggregates were also observed. B cells contained voluminous hypercromatic muclei and degranulated cytoplasm. Morphometric data demonstrated an increase in islet tissue. These morphological findings are indicative of excessive insulin secretion. The presence of eosinophilic leucocytes in pancreatic tissue and the pathogenic mechanism involved are discussed.     

长期实验性应激对老龄、青龄糖尿病倾向鼠血糖影响的比较及其机制

目的:比较长期实验性应激源对老龄、青龄糖尿病倾向鼠血糖和胰岛素分泌的不同影响并探讨其机制。方法:取1-5 月龄( 青龄) 和15 月龄( 老龄) 昆明小鼠各40 只,用链脲佐菌素诱导糖尿病倾向后(STZ 鼠) ,各分为应激组与对照组。两组应激STZ 鼠均给予6 周实验性应激源刺激( 限制、旋转、拥挤) ,检测其空腹血糖(FBG) 、空腹血浆胰岛素(FINS) 、胰腺组织脂质过氧化物(LPO) 和一氧化氮代谢产物(NO-2 ,NO-3 ) 水平,观察胰腺组织超氧化物歧化酶(SOD) 活性的变化,并对STZ 鼠胰岛炎的严重程度进行评分。结果:经长期实验性应激的老龄STZ 鼠FBG 水平增高较青龄者显著,且FINS 水平明显下降;胰岛炎恶化较青龄STZ鼠严重;胰腺组织LPO 和NO-2 ,NO-3 含量增高及SOD 活性降低均较青龄STZ鼠明显;上述各指标间存在相关性。结论:长期实验性应激促使老龄STZ 鼠血糖增高、胰岛炎加重和胰岛素分泌机能耗竭的效应较青龄STZ 鼠明显;胰腺NO 过量及过氧化损伤可能参与这一差异的产生机制     

From immunohistological to anatomical alterations of human pancreas in type 1 diabetes: New concepts on the stage

The histological analysis of human pancreatic samples in type 1 diabetes (T1D) has been proven essential to move forward in the evaluation of in situ events characterizing T1D. Increasing availability of pancreatic tissues collected from diabetic multiorgan donors by centralized biorepositories, which have shared tissues among researchers in the field, has allowed a deeper understanding of T1D pathophysiology, using novel immunohistological and high‐throughput methods. In this review, we provide a comprehensive update of the main recent advancements in the characterization of cellular and molecular events involving endocrine and exocrine pancreas as well as the immune system in the onset and progression of T1D. Additionally, we underline novel elements, which provide evidence that T1D pathological changes affect not only islet β‐cells but also the entire pancreas.     

Role of Fas-FasL in insulitis in nonobese diabetic mouse

Type 1 diabetes results from autoimmune damage to β cells and insulitis typically characterizes its pathological presentation. Apoptosis could be a main mechanism.There are several pathways of apoptosis including Fas-FasL.^1 Fas is a type 1 transmembrane glycoprotein in the super familv of TNF/NGF receptors and FasL (the     

Interleukin-4-expressing plasmid DNA inhibits reovirus type-2-triggered autoimmune insulitis in DBA/1 J suckling mice

In this study we have examined the effect of systemic administration of T helper (Th) 2 cytokines on reovirus type-2 (Reo-2)-triggered Th1-mediated autoimmune insulitis with impaired glucose tolerance (IGT) in DBA/1J suckling mice. We have demonstrated clearly that the systemic administration of both interleukin (IL)-4-expressing plasmid DNA (pIL-4) and recombinant IL-4 (rIL-4) inhibited the development of insulitis with IGT in a dose dependent manner as compared to untreated groups in Reo-2-infected DBA/1J suckling mice. The inhibitory effects of IL-4 on the development of insulitis with IGT and the advantages of pIL-4 as compared to rIL-4 in this model are discussed.     

Spontaneous glucose intolerance in the progeny of low dose streptozotocin-induced diabetic mice

Summary Multiple low doses of streptozotocin (LDS) induce low-incidence diabetes mellitus in Balb/cHan and high-incidence diabetes in CD-1 mice. We studied offspring of diabetic parents in both strains. Group 1 consisted of litters from control mice with no streptozotocin treatment. Group 2 litters had an LDS diabetic mother and a control father, group 3 litters had control mother with LDS diabetic father, and group 4 litters had both, LDS diabetic mother and father. Diabetes was induced by 5×40 mg streptozotocin per kg on five consecutive days. Progeny of diabetic mothers showed a state of reduced glucose tolerance associated with reduced glucose disappearance during intravenous glucose tolerance test and increased insulin secretion of isolated islets of Langerhans. These metabolic abnormalities predominated in the male litters of both strains of mice. Amniotic insulin was increased in diabetic mothers during pregnancy. No histologic abnormalities were observed in group 2 progeny. Pancreases in male offspring of LDS diabetic CD-1 fathers (group 3) were studied for insulitis. Insulitis was found in 40% of mice with normal glucose tolerance. A single subdiabetogenic dose of streptozotocin (40 mg/kg) induced insulitis in 90% of pancreases accompanied by reduced insulin release of isolated islets. By contrast, male Balb/cHan progeny of diabetic fathers failed to develop insulitis. In conclusion, we found (1) parental LDS diabetes was transmitted more often to male offspring, (2) maternal LDS diabetes was associated with hyperinsulin secretion and glucose intolerance in the offspring and (3) paternal LDS diabetes was accompanied by insulitis and insulin secretion deficiency in CD-1 progeny.     

Absence of H-2 genetic influence on streptozotocin-induced diabetes in mice

Summary Five daily injections of streptozotocin (40 mg/kg) produced a delayed but progressively increasing level of hyperglycaemia in long term studies with male Naval Medical Research Institute mice and C3D2F1 (DBA 2 J male × C3H/ Tif female) F1 hybrid mice. The development of hyperglycaemia was paralleled by decreased amounts of pancreatic immunoreactive insulin as well as degranulation and necrosis of pancreatic B cells. Insulitis was found from days 9–25 after the first injection of streptozotocin. Compared with the F1 hybrid strain the parental inbred strains DBA 2 J and C3H/Tif demonstrated a certain resistance to streptozotocin. Development of hyperglycaemia did not differ in four congenic resistant lines of mice on the C57 BL/10 genetic background, indicating that major histocompatibility complex genes are not likely to determine susceptibility to streptozotocin-induced islet B cell damage.