Megumi Inoue

A Novel Anti-Inflammatory Role for Spleen-Derived Interleukin-10 in Obesity-Induced Inflammation in White Adipose Tissue and Liver

Obesity is associated with systemic low-grade inflammation and obesity-related metabolic disorders. Considering that obesity decreases the expression of proinflammatory cytokines in the spleen, we assessed the role of interleukin (IL)-10, an anti-inflammatory cytokine produced by the spleen, in the pathogenesis of obesity. Changes in obesity-related pathogenesis, including inflammatory responses in multiple organs, were assessed after systemic administration of exogenous IL-10 to splenectomy (SPX)-treated obese wild-type and IL-10 knockout (IL-10KO) mice. Obesity resulted in the inability of the spleen to synthesize cytokines, including IL-10, and proinflammatory cytokines in obesity are then likely to emerge from tissues other than the spleen because serum levels of IL-10, but not proinflammatory cytokines, decreased despite the expression of these cytokines in the spleen being reduced in high fat–induced obese mice. SPX aggravated the inflammatory response in white adipose tissue (WAT) and the liver and suppressed adiposity in WAT. However, it accentuated adiposity in the liver. These SPX-induced changes were inhibited by systemic administration of IL-10. Moreover, SPX had little effect on the inflammatory responses in WAT and the liver of IL-10KO mice. These data show the role of spleen-derived IL-10 in diet-induced changes as a result of inflammatory responses in WAT and the liver.

Obesity-related chronic kidney disease is associated with spleen-derived IL-10

BACKGROUNDnObesity is associated with systemic low-grade inflammation and is a risk factor for chronic kidney disease (CKD), but the molecular mechanism remains uncertain. We noticed spleen-derived interleukin (IL)-10 because it is observed that obesity reduces several cytokines in the spleen.nnnMETHODSnWe examined whether spleen-derived IL-10 regulates CKD caused by a high-fat diet (HF)-induced obesity as follows: (i) male mice were fed with HF (60% fat) during 8 weeks and IL-10 induction from the spleen was examined, (ii) glomerular hypertrophy, fibrosis, inflammatory responses in the kidney and systolic blood pressure (SBP) were evaluated in splenectomy (SPX)-treated mice fed HF, (iii) exogenous IL-10 was systemically administered to HF-induced obese mice and the alteration of obesity-induced pathogenesis caused by IL-10 treatment was assessed. (iv) IL-10 knockout (IL-10KO) mice were treated with SPX and glomerular hypertrophy, fibrosis and the inflammatory condition in the kidney and SBP were also investigated.nnnRESULTSnObesity decreased serum levels of only IL-10, an anti-inflammatory cytokine even though pro- and anti-inflammatory cytokine expression in the spleen was significantly lower in the obese group. SPX aggravated HF-induced inflammatory responses in the kidney and hypertension. These HF-induced alterations were inhibited by systemically administered IL-10. Moreover, SPX had little effect on inflammatory responses and SBP in the kidney of IL-10KO mice.nnnCONCLUSIONSnWe suggest that obesity reduces IL-10 induction from the spleen, and spleen-derived IL-10 may protect against the development of CKD induced by obesity.

A novel anti‐inflammatory role for spleen‐derived interleukin‐10 in obesity‐induced hypothalamic inflammation

J. Neurochem. (2012) 120, 752–764.

Spleen-Derived Interleukin-10 Downregulates the Severity of High-Fat Diet-Induced Non-Alcoholic Fatty Pancreas Disease

Obesity is associated with systemic low-grade inflammation and is a risk factor for non-alcoholic fatty pancreas disease (NAFPD), but the molecular mechanisms of these associations are not clear. Interleukin (IL)-10, a potent anti-inflammatory cytokine, is released during acute pancreatitis and is known to limit inflammatory responses by downregulating the release of proinflammatory mediators. The origin of IL-10 that suppresses pancreatitis has not been investigated. Since obesity is known to reduce expression of proinflammatory cytokines in the spleen, we examined whether spleen-derived IL-10 regulates NAFPD caused by high-fat (HF) diet-induced obesity. The following investigations were performed: 1) IL-10 induction from spleen was examined in male mice fed a HF diet; 2) triglyceride content, expression of pro- and anti-inflammatory cytokines and infiltration of M1 and M2 macrophages were determined to evaluate ectopic fat accumulation and inflammatory responses in the pancreas of splenectomy (SPX)-treated mice fed HF diet; 3) exogenous IL-10 was systemically administered to SPX-treated obese mice and the resulting pathogenesis caused by SPX was assessed; and 4) IL-10 knockout (IL-10KO) mice were treated with SPX and ectopic fat deposition and inflammatory conditions in the pancreas were investigated. Obesity impaired the ability of the spleen to synthesize cytokines, including IL-10. SPX aggravated fat accumulation and inflammatory responses in the pancreas of HF diet-induced obese mice and these effects were inhibited by systemic administration of IL-10. Moreover, SPX had little effect on fat deposition and inflammatory responses in the pancreas of IL-10KO mice. Our findings indicate that obesity reduces IL-10 production by the spleen and that spleen-derived IL-10 may protect against the development of NAFPD.

Behçet’s disease complicated by multiple aseptic abscesses of the liver and spleen

Aseptic abscesses are an emergent entity and have been described in inflammatory bowel disease, especially in Crohns disease, and in other diseases. However, aseptic abscesses associated with Behçets disease are extremely rare. We report a Japanese male diagnosed with an incomplete type of Behçets disease who developed multiple aseptic abscesses of the spleen and liver. In 2002, the spleen abscesses were accompanied by paroxysmal oral aphthous ulcers and erythema nodosum. As the patients response to antibiotic treatment was inadequate, a splenectomy was performed. Severe inflammatory cell infiltration, largely of polymorphonuclear neutrophils, was observed without evidence of bacterial or fungal growth. Although the patient had no history of ocular symptoms or genital ulcers, a diagnosis of incomplete Behçets disease was made according to the Japanese diagnostic criteria because of the presence of paroxysmal arthritis and epididymitis since 2002. In 2005, multiple liver abscesses developed with right hypochondrial pain and seemed to be attributed to Behçets disease because the abscesses yielded negative results during a microbiologic investigation and failed to go into remission under antibiotic therapy. Oral prednisone (15 mg/d) was started in May 2006, and the abscesses dramatically disappeared 4 wk after treatment. Although the patient had a relapse of the liver abscesses in association with the tapering of prednisone, the augmentation of prednisone dosage yielded a response. The abscesses of the liver and spleen were strongly suggested to be attributed to Behçets disease. Clinician should be aware of the existence of aseptic abscesses as uncommon manifestations of Behçets disease.

Involvement of remnant spleen volume on the progression of steatohepatitis in diet‐induced obese rats after a splenectomy

Aim:u2002 This study investigated the correlation between remnant spleen volume after splenectomy (SPX) and the degree of hepatic steatosis and/or inflammation.

Role of the spleen in the development of steatohepatitis in high-fat-diet-induced obese rats

Obesity is considered a systemic low-grade inflammatory state. Although the spleen is the main immune organ with a close anatomical relationship with the liver, its role in the progression of fatty liver disease remains uncertain. Therefore, we sought to clarify the functional role of the spleen in the development of steatohepatitis in high-fat (HF)-diet-induced obese rats. Male Sprague-Dawley rats were fed HF food and divided into two groups, a splenectomy (SPX) group and a sham-operation (Sham) group. The liver and abdominal white adipose tissue (WAT) were removed one and six months after surgery, and we evaluated the effects of SPX on WAT and HF-induced fatty liver. SPX rats exhibited worse dyslipidemia and inflammatory changes in WAT one month after surgery. Hepatic steatosis and inflammation were accelerated by SPX, based on the time after surgery. At one month after surgery, the tissue triglyceride content increased in SPX rats, compared with Sham controls (P < 0.05). The liver histology also showed a worsening of steatosis in those rats. At six months after SPX, dramatic inflammatory and fibrotic changes were observed in liver tissue sections. Hepatic carnitine palmitoyltransferase-1 was suppressed at one and six months after SPX (P < 0.05 for each). WAT and liver tissue levels of inflammatory markers such as tumor necrosis factor-α, and the expression of Kupffer cells were all increased at six months in SPX rats, compared with Sham controls (P < 0.05 for each). Our results indicate that the preservation of the spleen contributes to the prevention of the progression of hepatic steatosis to steatohepatitis in obese rats.

High alanine aminotransferase level as a predictor for the incidence of macrovascular disease in type 2 diabetic patients with fatty liver disease

PurposeWe investigated whether fatty liver (FL) disease in type 2 diabetic mellitus (T2DM) patients affects their incidence of macrovascular disease. In addition, we detected a useful marker for predicting the incidence of macrovascular disease events.Methods A total of 458 patients who underwent abdominal ultrasonography (US) between April 2003 and March 2004 in a diabetic clinic were divided into FL (nxa0=xa0211) and non-FL (NFL; nxa0=xa0247) groups, and followed by a diabetologist and/or hepatologist for 5xa0years.ResultsNo significant difference in the incidence of macrovascular disease, neither cerebrovascular disease nor coronary heart disease, was observed between FL and NFL patients. Interestingly, in FL diabetic patients, only an alanine aminotransferase (ALT) level ≥30xa0IU/l was significantly associated with the incidence of macrovascular events in univariate (odds ratio [OR], 10.632; 95xa0% confidence interval [CI], 1.302–86.841; pxa0=xa00.0274) and multivariate (OR, 10.134; CI 1.223–83.995; pxa0=xa00.0318) analyses. Patients with higher ALT levels had a higher cumulative incidence of macrovascular disease events than did those with lower ALT levels (pxa0=xa00.0068). In conclusion, an ALT level ≥30xa0IU/l is an independent risk indicator of macrovascular disease in diabetic patients with FLD, whereas the presence of FL itself in T2DM patients is not associated with an increased incidence of macrovascular events.ConclusionsOur findings indicate that therapeutic interventions may be necessary for FL patients with high ALT levels to prevent macrovascular disease.