Report of Two Contrasting Cases of Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis: Comparison to Infectious Mononucleosis and Flow Cytometric Analysis of Bone Marrow.

Purpose: This study aims to investigate the characteristics of Epstein-Barr virus associated-hemophagocytic lymphohistiocytosis (EBV-HLH) and HLH caused by a severe form of infectious mononucleosis (IM-HLH) compared to IM by EBV, and thus also to assist in early diagnosis and providing appropriate treatment. Methods: Data for this analysis were collected from patients at the Department of General Medicine, Nara Medical University, between April 1, 2012, and August 1, 2020. EBV infection was diagnosed using clinical presentation and laboratory tests. HLH diagnosis followed the HLH-2004 protocol, supplemented by plasma EBV DNA detection. A range of clinical and laboratory parameters were collected, including age, sex, clinical outcomes, blood cell counts, hemoglobin, platelets, and various serum values. Plasma EBV DNA levels and flow cytometric analysis (FCM) of bone marrow were performed for HLH cases. Results: Among 1850 hospitalized patients, 14 cases were identified, including 2 HLH cases and 12 IM cases. Comparative analysis revealed distinctive features of HLH, including lower lymphocyte and platelet counts and higher levels of ferritin, soluble interleukin 2 receptor (sIL-2R), and D dimer compared to IM. Notably, one HLH case responded well to corticosteroid monotherapy, while the other case did not, resulting in a fatal outcome. Detection of a cluster of CD5-CD7 lymphocytes in bone marrow is a hallmark of EBV-HLH and useful to distinguish from IM-HLH. Conclusion: This study underscores the importance of early differentiation among EBV-HLH, IM-HLH, and IM in adults to guide appropriate treatment strategies. While specific laboratory markers help distinguish HLH from IM, a more detailed analysis of FCM is crucial for precise diagnosis of HLH cases and tailored therapeutic interventions.

Neuro-Behçet's disease with atypical subcortical nodular lesions: A case report and treatment approach.

Neuro-Behçet's disease (NB) is a rare complication of Behçet's disease (BD) characterised by central nervous system involvement. While NB typically presents with brainstem lesions, we report an unusual case of NB in a 27-year-old male with multiple subcortical nodular brain lesions but without brainstem, thalamic, or basal ganglia involvement, making this presentation exceptionally rare. The patient had a prior diagnosis of BD and was HLA-B51 positive. He presented with a sudden loss of consciousness, which was attributed to a seizure. Imaging studies showed low-density areas in the white matter of the bilateral temporal lobes and the right frontoparietal lobe on brain CT. Cerebrospinal fluid examination indicated elevated initial pressure and protein concentration, along with increased interleukin-6. Despite presenting with nodular brain lesions, distinguishing between NB and infectious diseases such as tuberculosis (TB) was challenging, and required brain biopsy revealing vasculitis. However, even with this biopsy result, TB could not be ruled out, so TB was treated at the same time. Treatment with anti-TB drugs and standard steroid therapy initially failed to improve the patient's condition. However, increasing the steroid dosage considering the increased steroid degradation by rifampicin, including pulse therapy with 2 g of methylprednisolone, followed by 18 mg of betamethasone, led to remission of the nodular brain lesions and resolution of the nasopharyngeal ulcer. This case highlights the diagnostic challenge of differentiating between NB and TB based on imaging alone and the potential efficacy of high-dose steroid therapy in cases of steroid-resistant NB with subcortical nodular brain lesions.

Giant Cell Arteritis after COVID-19 Vaccination with Long-Term Follow-Up: A Case Report and Review of the Literature.

Giant cell arteritis (GCA) is a chronic vasculitis that primarily affects the elderly, and can cause visual impairment, requiring prompt diagnosis and treatment. The global impact of the coronavirus disease 2019 (COVID-19) pandemic has been substantial. Although vaccination programs have been a key defense strategy, concerns have arisen regarding post-vaccination immune-mediated disorders and related risks. We present a case of GCA after COVID-19 vaccination with 2 years of follow-up. A 69-year-old woman experienced fever, headaches, and local muscle pain two days after receiving the COVID-19 vaccine. Elevated inflammatory markers were observed, and positron emission tomography (PET) revealed abnormal uptake in the major arteries, including the aorta and subclavian and iliac arteries. Temporal artery biopsy confirmed the diagnosis of GCA. Treatment consisted of pulse therapy with methylprednisolone, followed by prednisolone (PSL) and tocilizumab. Immediately after the initiation of treatment, the fever and headaches disappeared, and the inflammation markers normalized. The PSL dosage was gradually reduced, and one year later, a PET scan showed that the inflammation had resolved. After two years, the PSL dosage was reduced to 3 mg. Fourteen reported cases of GCA after COVID-19 vaccination was reviewed to reveal a diverse clinical picture and treatment response. The time from onset of symptoms to GCA diagnosis varied from two weeks to four months, highlighting the challenge of early detection. The effectiveness of treatment varied, but was generally effective similarly to that of conventional GCA. This report emphasizes the need for clinical vigilance and encourages further data collection in post-vaccination GCA cases.

The Combination of the Lactate Dehydrogenase/Hemoglobin Ratio with the PLASMIC Score Facilitates Differentiation of TTP from Septic DIC Without Identification of Schistocytes.

In some cases, differentiating thrombotic thrombocytopenic purpura (TTP) from septic disseminated intravascular coagulation (DIC) without measuring ADAMTS13 activity is critical for urgent lifesaving plasma exchange. To investigate whether PLASMIC score without identifying the presence of schistocytes, D-dimer, fibrin/fibrinogen degradation products (FDP), FDP/D-dimer ratio, prothrombin time-international normalized ratio (PT-INR), lactate dehydrogenase (LD), hemoglobin (Hb), and LD/Hb ratio are useful in differentiating patients with TTP from those with septic DIC. Retrospective analysis was conducted on the medical records of the patients with septic DIC (32 patients) or TTP (16 patients). The PLASMIC score and other laboratory measurements all were helpful in differentiating TTP from septic DIC. When dichotomized between high risk (scores 6-7) and intermediate-low risk (scores 0-5), the PLASMIC score predicted TTP with a sensitivity of 75.0% and a specificity of 100%. However, 4 of 16 patients with TTP and 19 of 32 patients with septic DIC showed comparable PLASMIC scores of 4 or 5, making it difficult to distinguish between the two by PLASMIC score alone. Among the measurements examined, the LDH/Hb ratio was the most useful for differentiation. Receiver operating characteristic analysis of the LD/Hb ratio for predicting TTP revealed a cutoff of 53.7 (IU/10 g) (sensitivity 0.94, specificity 0.91). If the LD/Hb ratio was less than 53.7, it was unlikely that the patient had TTP. A combination of the LD/Hb ratio and the PLASMIC score may be useful for distinguishing between TTP and DIC and identifying patients who need rapid plasma exchange or caplacizumab administration.

A Case of Mycoplasma Infection with an Atypical Presentation of Abducens Nerve Palsy, Erythema Multiforme and Polyarthritis without Respiratory Manifestations.

Mycoplasma pneumoniae is a self-propagating microorganism that commonly causes respiratory tract infections. It can also cause a variety of extrapulmonary symptoms with or independently of respiratory symptoms, such as skin lesions, arthralgia, myalgia, hemolysis, cardiac lesions, gastrointestinal symptoms, and central nervous system lesions, which are rare manifestations reported in approximately 0.1% of cases. In this study, we present a unique case of Mycoplasma-related abducens nerve palsy, polyarthritis, and erythema multiforme without respiratory disease. The patient was a 69-year-old woman who presented to our hospital with a skin rash, fever, arthralgia, and diplopia without respiratory symptoms. Brain magnetic resonance imaging showed optic neuritis on the right side, suggesting the diplopia was caused by right abducens nerve palsy. However, the etiologies of abducens nerve palsy were not revealed by the physical examination, blood biochemistry tests, or bacteriological examinations, including the cerebrospinal fluid examination obtained at admission. Mycoplasma infection was suspected from erythema multiforme revealed by a skin biopsy and polyarthralgia, and it was finally diagnosed according to elevated Mycoplasma particle agglutination (PA) antibodies in paired serum. Though minocycline did not improve her diplopia, the daily administration of 30 mg of prednisolone gradually improved her symptoms, and the Mycoplasma PA antibody titer, which was regularly measured in the clinical course, also decreased, suggesting a relationship between Mycoplasma infection and abducens nerve palsy. This is the first case of isolated abducens nerve palsy, which was reported as the only central neurological symptom in an adult patient with Mycoplasma infection. The mechanism or pathogenesis of CNS manifestations caused by Mycoplasma pneumoniae remains to be elucidated, and further investigation is needed. Hence, Mycoplasma infection is a common disease. Clinicians should be aware of the diverse manifestations, including abducens nerve palsy, of Mycoplasma infection and should consider Mycoplasma infection even in the absence of typical respiratory symptoms.

The balance of comprehensive coagulation and fibrinolytic potential is disrupted in patients with moderate to severe COVID-19.

Coagulation and fibrinolytic mechanisms are enhanced in patients with coronavirus (COVID-19), but disturbances in the balance of both functions in COVID-19 patients remain unclear. We assessed global coagulation and fibrinolysis in plasma from 167 COVID-19 patients (mild/moderate/severe: 62/88/17, respectively) on admission using clot-fibrinolysis waveform analysis (CFWA). Maximum coagulation velocity (|min1|) and maximum fibrinolysis velocity (|FL-min1|) were expressed as ratios relative to normal plasma. Ten patients (6.0%) developed thrombosis, 5 (3.0%) had bleeding tendency, and 13 (7.8%) died during admission. FDP levels increased with severity of COVID-19 symptoms (mild/moderate/severe; median 2.7/4.9/9.9 µg/mL, respectively). The |min1| ratios were elevated in all categories (1.27/1.61/1.58) in keeping with enhanced coagulation potential, with significant differences between mild cases and moderate to severe cases. The |FL-min1| ratios were also elevated in all groups (1.19/1.39/1.40), reflecting enhanced fibrinolytic potential. These data identified coagulation dominance in moderate to severe cases, but balanced coagulation and fibrinolysis in mild cases. There were significant differences in FDP and TAT, but no significant differences in |min1| or |FL-min1| ratios, between patients with and without thrombosis. CFWA monitoring of coagulation and fibrinolysis dynamics could provide valuable data for understanding hemostatic changes and disease status in COVID-19 patients.

Hot-water bathing before bedtime and shorter sleep onset latency are accompanied by a higher distal-proximal skin temperature gradient in older adults.

STUDY OBJECTIVES: Passive body heating in controlled settings could shorten sleep onset latency (SOL). The hypothesized mechanism is vasodilation-induced heat loss before bedtime. However, this evidence is based on small sample-sized studies in specific populations. Thus, we analyzed the association of hot-water bathing and its before-bedtime timing with SOL and heat loss in a large study population of older adults. METHODS: We conducted a longitudinal analysis using repeated measurements of hot-water bathing and sleep among 1,094 older adults (mean age, 72.0 years). SOL was recorded using actigraphy and self-reported sleep estimates and was categorized into conditions (intervals of 1-60, 61-120, 121-180, and > 181 minutes between hot bath and bedtime) and compared with the control condition of no bathing. The heat-loss indicator, distal-proximal skin temperature gradient, was examined in the same categorization. RESULTS: Mixed-effects linear regression models suggested that the bathing conditions of 61-120 minutes and 121-180 minutes showed significantly shorter log-transformed actigraphic SOL by 0.23 log-minutes (95% confidence interval (CI), 0.03-0.42) and 0.32 log-minutes (95% CI, 0.09-0.56), shorter self-reported SOL by 0.16 log-minutes (95% CI, 0.02-0.30) and 0.18 log-minutes (95% CI, 0.01-0.35), and higher distal-proximal skin temperature gradient for 30 minutes before bedtime by 0.49°C (95% CI, 0.22-0.75) and 0.51°C (95% CI, 0.20-0.83), respectively, independent of potential confounders. CONCLUSIONS: Hot-water bathing before bedtime is significantly associated with shorter SOL and higher distal-proximal skin temperature gradient among the large-scale older population. This finding could enhance the generalizability of hot-water bathing habits for ameliorating sleep initiation difficulty.

Complete Resolution of a Case of TAFRO Syndrome Accompanied by Mediastinal Panniculitis, Adrenal Lesion, and Liver Damage with Hyperbilirubinemia.

TAFRO syndrome is a systemic inflammatory, lymphoproliferative disorder, but the pathophysiology of the disease is unknown. It is typically characterized by thrombocytopenia, anasarca, a fever, reticulin fibrosis, renal dysfunction, and organomegaly. However, other manifestations have been also reported. We encountered a 43-year-old man with TAFRO syndrome who showed mediastinal panniculitis, liver damage, and adrenal lesions in addition to the core signs. He achieved complete remission with combination therapy of corticosteroids, tocilizumab, and cyclosporin, and remission was maintained even after drug discontinuation at 15 months. Atypical manifestations and complete remission of TAFRO syndrome were remarkable features of our case.

Plasma Level of von Willebrand Factor Propeptide at Diagnosis: A Marker of Subsequent Renal Dysfunction in Autoimmune Rheumatic Diseases.

INTRODUCTION: Patients with systemic autoimmune rheumatic diseases (SARDs) such as rheumatoid arthritis, systemic lupus erythematosus (SLE), Sjögren syndrome, and systemic sclerosis, which are chronic inflammatory diseases, are prone to develop renal dysfunction, which is related to vascular endothelial cell damage. MATERIAL AND METHODS: We evaluated plasma levels of von Willebrand factor (VWF), VWF propeptide (VWF-pp), disintegrin-like and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), and VWF multimer pattern in patients with SARDs at diagnosis and investigated whether they may serve as markers to identify patients destined to develop renal dysfunction within 1 year. Renal dysfunction was defined as subsequent reduced estimated glomerular filtration rate (eGFR) by >25% or the new appearance of abnormal urine findings such as proteinuria (protein > 30 mg/dL) or hematuria (red blood cells >20/HPF in urine sediments). Overall, 63 patients with SARDs were studied. RESULTS AND CONCLUSIONS: We observed a significant increase of VWF-pp and a significant decrease of ADAMTS13 in patients with SARDs compared with normal healthy controls. The highest level of VWF-pp was observed in patients with SLE among the groups. The levels of VWF and multimer pattern of VWF were not different compared with normal healthy controls. Von Willebrand factor propeptide predicted a subsequent decrease in eGFR at a cutoff point of 210% (sensitivity, 78.6%; specificity, 73.5%) and new urinary abnormal findings at a cutoff point of 232% (sensitivity, 77.8%; specificity, 77.8%) Using these cutoff points, multivariable analysis revealed that VWF-pp was a significant risk factor for renal dysfunction at an odds ratio of 8.78 and 22.8, respectively, and may lead to a new therapeutic approach to prevent vasculitis and renal dysfunction.

Association between timing of hot water bathing before bedtime and night-/sleep-time blood pressure and dipping in the elderly: a longitudinal analysis for repeated measurements in home settings.

Hot water bathing - a Japanese traditional practice - has not been evaluated for its association with night- and sleep-time blood pressure (BP) in large population. In this longitudinal analysis, bathing parameters and ambulatory BP were repeatedly measured for 2 nights in 758 Japanese elderly individuals. Participants were divided into three groups according to tertile values of time soaked in the bathtub (Duration: tertile value, 11 and 15 min), time from bathing-end to bedtime (Time before bedtime: tertile value, 42 and 106 min), and temperature of hot water in the bathtub (Water temp: tertile value, 40.3 and 41.2 °C). Participants' mean age was 70.9 years, and mean night- and sleep-time systolic BP (SBP) and dipping were 115.1 ± 16.1, 114.2 ± 16.2 mmHg, and 14.2 ± 8.8%, respectively. Multivariable mixed-effect linear regression models adjusted for potential confounding factors suggested that nighttime SBP was significantly lower in the intermediate Time before bedtime group by 1.7 mmHg (95% CI, 0.2-3.1) and in the short group by 1.9 mmHg (95% CI, 0.1-3.7) than that in the long group. Dipping was significantly greater in the intermediate Time before bedtime group by 1.8% (95% CI, 0.7-2.9) and in the short group by 1.8% (95% CI, 0.6-3.1) than that in the long group. These associations were consistent regarding sleep-time SBP. Conversely, Water temp and Duration did not significantly associate with any ambulatory BP parameter. Remarkably, Time before bedtime significantly prolonged with increases in tertiles of Water temp (P for trend = 0.006). In conclusion, the findings of this study revealed that Japanese hot water bathing, especially the short time from bathing-end to bedtime, was associated with lower night- and sleep-time BP and greater dipping in an elderly population.

Functional regulation of von Willebrand factor ameliorates acute ischemia-reperfusion kidney injury in mice.

Acute kidney injury (AKI), an abrupt loss of renal function, is often seen in clinical settings and may become fatal. In addition to its hemostatic functions, von Willebrand factor (VWF) is known to play a role in cross-talk between inflammation and thrombosis. We hypothesized that VWF may be involved in the pathophysiology of AKI, major causes of which include insufficient renal circulation or inflammatory cell infiltration in the kidney. To test this hypothesis, we studied the role of VWF in AKI using a mouse model of acute ischemia-reperfusion (I/R) kidney injury. We analyzed renal function and blood flow in VWF-gene deleted (knock-out; KO) mice. The functional regulation of VWF by ADAMTS13 or a function-blocking anti-VWF antibody was also evaluated in this pathological condition. Greater renal blood flow and lower serum creatinine were observed after reperfusion in VWF-KO mice compared with wild-type (WT) mice. Histological analysis also revealed a significantly lower degree of tubular damage and neutrophil infiltration in kidney tissues of VWF-KO mice. Both human recombinant ADAMTS13 and a function-blocking anti-VWF antibody significantly improved renal blood flow, renal function and histological findings in WT mice. Our results indicate that VWF plays a role in the pathogenesis of AKI. Proper functional regulation of VWF may improve the microcirculation and vessel function in the kidney, suggesting a novel therapeutic option against AKI.

Importance Of Laboratory Detection Of Macro-Aspartate Aminotransferase.

The macroenzyme form of aspartate aminotransferase (macro-AST) is formed by the binding of AST with immunoglobulins. Macro-AST excretion from serum is prolonged because of its high molecular weight, leading to increased AST activities. Because of the difficulty in detecting macro-AST through routine laboratory tests, affected patients often undergo repeated examinations, with associated anxiety. We report a case in which macro-AST was detected by assaying the patient's serum after refrigeration at 4ºC for 3 days. The sample showed progressive loss of AST activity compared with that frozen in the refrigerator, indicating the presence of macro-AST, which was confirmed as a complex with IgG-κ. The cold storage method was validated using many samples obtained from several patients. Use of this simple method to detect macro-AST may avoid unnecessary examinations and patient anxiety even at primary care facilities.

Von Willebrand Factor Aggravates Hepatic Ischemia-Reperfusion Injury by Promoting Neutrophil Recruitment in Mice.

Hepatic ischaemia-reperfusion (I/R) injury is a serious liver damage that critically influences the clinical outcome of liver surgery or transplantation. Since recent studies indicated the critical involvement of von Willebrand factor (VWF) in reperfusion injuries of brain and myocardium, we hypothesized that VWF-dependent thrombotic or inflammatory responses also play a role in hepatic I/R injury. Using a mouse model of hepatic I/R injury, we explored the functional relevance of the VWF-ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) axis in this pathologic condition. Time-course studies during hepatic I/R revealed significantly lower alanine aminotransferase (ALT) values, as well as greater hepatic blood flow, in VWF gene-deleted (KO) mice in comparison with wild-type (WT) mice. Histological analysis revealed a significantly lesser extent of neutrophil infiltration and hepatocellular necrosis in liver tissues of VWF-KO mice. Human recombinant ADAMTS13 significantly improved the impairment in ALT values and hepatic blood flow and decreased neutrophil infiltration within the liver tissue of WT mice. Real-time intravital imaging successfully visualized significantly reduced leukocyte-vessel wall interactions in I/R liver of VWF-KO mice. Taken together, our results indicate that VWF promotes neutrophil recruitment in ischaemic mouse liver, critically aggravating reperfusion injury, and suggest that functional regulation of VWF by ADAMTS13 represents a promising therapeutic option for hepatic I/R injury.

Significance of Interleukin-6/STAT Pathway for the Gene Expression of REG Iα, a New Autoantigen in Sjögren's Syndrome Patients, in Salivary Duct Epithelial Cells.

The regenerating gene, Reg, was originally isolated from a rat regenerating islet complementary DNA (cDNA) library, and its human homologue was named REG Iα. Recently, we reported that REG Iα messenger RNA (mRNA), as well as its product, was overexpressed in ductal epithelial cells in the salivary glands of Sjögren's syndrome patients. Furthermore, autoantibodies against REG Iα were found in the sera of Sjögren's syndrome patients, and the patients who were positive for the anti-REG Iα antibody showed significantly lower saliva secretion than antibody-negative patients. We found the mechanism of REG Iα induction in salivary ductal epithelial cells. Reporter plasmid containing REG Iα promoter (-1190/+26) upstream of a luciferase gene was introduced into human NS-SV-DC and rat A5 salivary ductal cells. The cells were treated with several cytokines (interleukin (IL)-6, IL-8, etc.), upregulated in Sjögren's syndrome salivary ducts, and the transcriptional activity was measured. IL-6 stimulation significantly enhanced the REG Iα promoter activity in both cells. Deletion analysis revealed that the -141∼-117 region of the REG Iα gene was responsible for the promoter activation by IL-6, which contains a consensus sequence for signal transducer and activator of transcription (STAT) binding. The introduction of small interfering RNA for human STAT3 abolished IL-6-induced REG Iα transcription. These results indicated that IL-6 stimulation induced REG Iα transcription through STAT3 activation and binding to the REG Iα promoter in salivary ductal cells. This dependence of REG Iα induction upon IL-6/STAT in salivary duct epithelial cells may play an important role in the pathogenesis/progression of Sjögren's syndrome.

Synergistic activations of REG I α and REG I ß promoters by IL-6 and Glucocorticoids through JAK/STAT pathway in human pancreatic ß cells.

Reg (Regenerating gene) gene was originally isolated from rat regenerating islets and its encoding protein was revealed as an autocrine/paracrine growth factor for ß cells. Rat Reg gene is activated in inflammatory conditions for ß cell regeneration. In human, although five functional REG family genes (REG Iα, REG Iß, REG III, HIP/PAP, and REG IV) were isolated, their expressions in ß cells under inflammatory conditions remained unclear. In this study, we found that combined addition of IL-6 and dexamethasone (Dx) induced REG Iα and REG Iß expression in human 1.1B4 ß cells. Promoter assay revealed that a signal transducer and activator of transcription- (STAT-) binding site in each promoter of REG Iα (TGCCGGGAA) and REG Iß (TGCCAGGAA) was essential for the IL-6+Dx-induced promoter activation. A Janus kinase 2 (JAK2) inhibitor significantly inhibited the IL-6+Dx-induced REG Iα and REG Iß transcription. Electrophoretic mobility shift assay and chromatin immunoprecipitation revealed that IL-6+Dx stimulation increased STAT3 binding to the REG Iα promoter. Furthermore, small interfering RNA-mediated targeting of STAT3 blocked the IL-6+Dx-induced expression of REG Iα and REG Iß. These results indicate that the expression of REG Iα and REG Iß should be upregulated in human ß cells under inflammatory conditions through the JAK/STAT pathway.

Interleukin-6/STAT pathway is responsible for the induction of gene expression of REG Iα, a new auto-antigen in Sjögren׳s syndrome patients, in salivary duct epithelial cells.

The regenerating gene, Reg, was originally isolated from a rat regenerating islet cDNA library, and its human homolog was named REG Iα. Recently, we reported that REG Iα mRNA as well as its product were overexpressed in ductal epithelial cells in the minor salivary glands of Sjögren׳s syndrome (SS) patients. This study was undertaken to elucidate the role of cytokines and the subsequent intracellular mechanism for induction of REG Iα in the salivary glands of SS patients. We prepared a reporter plasmid containing REG Iα promoter (-1190/+26) upstream of a luciferase reporter gene. The promoter plasmid was introduced by lipofection into human NS-SV-DC and rat A5 salivary ductal cells. The cells were treated with interleukin (IL)-6, IL-8, and a combination of the two. Thereafter transcriptional activity of REG Iα was measured by luciferase assay. We found that IL-6 stimulation, but not IL-8, significantly enhanced the REG Iα promoter activity in salivary ductal cells. Deletion analysis revealed that the region of -141 to -117 of the REG Iα gene was responsible for the promoter activation by IL-6, which contains a consensus sequence for signal transduction and activation of transcription (STAT). The introduction of siRNA for human STAT3 abolished IL-6-induced REG Iα transcription. These results showed that IL-6 stimulation induced REG Iα transcription through STAT3 activation and binding to the consensus sequence of REG Iα promoter in salivary ductal cells. This IL-6/STAT dependent REG Iα induction might play a role in the pathogenesis of SS.

Pancreatic ß cell proliferation by intermittent hypoxia via up-regulation of Reg family genes and HGF gene.

AIMS: Although accumulating evidence suggests the associations between sleep apnea syndrome (SAS) and type 2 diabetes, the direct effect of intermittent hypoxia (IH) on pancreatic ß cell proliferation remains a missing piece of the puzzle. MAIN METHODS: Rat RINm5F ß cells, hamster HIT-T15 ß cells, and human 1.1B4 ß cells were exposed to normoxia (21% O2, 5% CO2, and balance N2), to sustained hypoxia (SH: 1% O2, 5% CO2, and balance N2), or to intermittent hypoxia (IH: 64 cycles of 5 min SH and 10 min normoxia) for 24 h. After the treatment, cellular proliferation and apoptosis were measured by WST-8 assay and TUNEL method, respectively. The expression of regenerating gene (Reg) family, interleukin (IL)-6, and hepatocyte growth factor (HGF) was determined by real-time RT-PCR. KEY FINDINGS: The cellular proliferation of HIT-T15, RINm5F and 1.1B4 cells by IH was significantly increased, whereas apoptosis of these cells was unchanged. Real-time RT-PCR revealed that the mRNA levels of Reg family genes, IL-6, a typical Reg family gene inducer, and HGF, an inhibitor of high-concentration of Reg protein-induced apoptosis, were increased in IH-treated cells. In addition, siRNAs against rat Reg family genes except for PAP I/Reg 2 attenuated IH-induced ß cell proliferation. SIGNIFICANCE: IH stress stimulates pancreatic ß cell to induce IL-6 gene expression. By the IL-6 stimulation, ß cells over-express Reg family genes as well as HGF gene. Reg family proteins stimulate ß cell proliferation and HGF inhibits apoptosis of ß cells. As a result, ß cell numbers are increased by IH.