Auraptene Enhances AMP-Activated Protein Kinase Phosphorylation and Thereby Inhibits the Proliferation, Migration and Expression of Androgen Receptors and Prostate-Specific Antigens in Prostate Cancer Cells.

Citrus hassaku extract reportedly activates AMPK. Because this extract contains an abundance of auraptene, we investigated whether pure auraptene activates AMPK and inhibits proliferation using prostate cancer cell lines. Indeed, auraptene inhibited the proliferation and migration of LNCaP cells and induced phosphorylation of AMPK or its downstream ACC in LNCaP, PC3, and HEK-293 cells, but not in DU145 cells not expressing LKB1. In addition, the mTOR-S6K pathway, located downstream from activated AMPK, was also markedly suppressed by auraptene treatment. Importantly, it was shown that auraptene reduced androgen receptor (AR) and prostate-specific antigen (PSA) expressions at both the protein and the mRNA level. This auraptene-induced downregulation of PSA was partially but significantly reversed by treatment with AMPK siRNA or the AMPK inhibitor compound C, suggesting AMPK activation to, at least partially, be causative. Finally, in DU145 cells lacking the LKB1 gene, exogenously induced LKB1 expression restored AMPK phosphorylation by auraptene, indicating the essential role of LKB1. In summary, auraptene is a potent AMPK activator that acts by elevating the AMP/ATP ratio, thereby potentially suppressing prostate cancer progression, via at least three molecular mechanisms, including suppression of the mTOR-S6K pathway, reduced lipid synthesis, and AR downregulation caused by AMPK activation.

Hepatic Pin1 Expression, Particularly in Nuclei, Is Increased in NASH Patients in Accordance with Evidence of the Role of Pin1 in Lipid Accumulation Shown in Hepatoma Cell Lines.

Our previous studies using rodent models have suggested an essential role for Pin1 in the pathogenesis of non-alcoholic steatohepatitis (NASH). In addition, interestingly, serum Pin1 elevation has been reported in NASH patients. However, no studies have as yet examined the Pin1 expression level in human NASH livers. To clarify this issue, we investigated the expression level and subcellular distribution of Pin1 in liver specimens obtained using needle-biopsy samples from patients with NASH and healthy liver donors. Immunostaining using anti-Pin1 antibody revealed the Pin1 expression level to be significantly higher, particularly in nuclei, in the livers of NASH patients than those of healthy donors. In the samples from patients with NASH, the amount of nuclear Pin1 was revealed to be negatively related to serum alanine aminotransferase (ALT), while tendencies to be associated with other serum parameters such as aspartate aminotransferase (AST) and platelet number were noted but did not reach statistical significance. Such unclear results and the lack of a significant relationship might well be attributable to our small number of NASH liver samples (n = 8). Moreover, in vitro, it was shown that addition of free fatty acids to medium induced lipid accumulation in human hepatoma HepG2 and Huh7 cells, accompanied with marked increases in nuclear Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1), in accordance with the aforementioned observations in human NASH livers. In contrast, suppression of Pin1 gene expression using siRNAs attenuated the free fatty acid-induced lipid accumulation in Huh7 cells. Taken together, these observations strongly suggest that increased expression of Pin1, particularly in hepatic nuclei, contributes to the pathogenesis of NASH with lipid accumulation.

Involvement of neuronal and muscular Trk-fused gene (TFG) defects in the development of neurodegenerative diseases.

Trk-fused gene (TFG) mutations have been identified in patients with several neurodegenerative diseases. In this study, we attempted to clarify the effects of TFG deletions in motor neurons and in muscle fibers, using tissue-specific TFG knockout (vMNTFG KO and MUSTFG KO) mice. vMNTFG KO, generated by crossing TFG floxed with VAChT-Cre, showed deterioration of motor function and muscle atrophy especially in slow-twitch soleus muscle, in line with the predominant Cre expression in slow-twitch fatigue-resistant (S) and fast-twitch fatigue-resistant (FR) motor neurons. Consistently, denervation of the neuromuscular junction (NMJ) was apparent in the soleus, but not in the extensor digitorum longus, muscle. Muscle TFG expressions were significantly downregulated in vMNTFG KO, presumably due to decreased muscle IGF-1 concentrations. However, interestingly, MUSTFG KO mice showed no apparent impairment of muscle movements, though a denervation marker, AChRγ, was elevated and Agrin-induced AChR clustering in C2C12 myotubes was inhibited. Our results clarify that loss of motor neuron TFG is sufficient for the occurrence of NMJ degeneration and muscle atrophy, though lack of muscle TFG may exert an additional effect. Reduced muscle TFG, also observed in aged mice, might be involved in age-related NMJ degeneration, and this issue merits further study.

Pathological Role of Pin1 in the Development of DSS-Induced Colitis.

Inflammatory bowel diseases (IBDs) are serious disorders of which the etiologies are not, as yet, fully understood. In this study, Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) protein was shown to be dramatically upregulated in the colons of dextran sodium sulfate (DSS)-induced ulcerative colitis model mice. Interestingly, Pin1 knockout (KO) mice exhibited significant attenuation of DSS-induced colitis compared to wild-type (WT) mice, based on various parameters, including body weight, colon length, microscopic observation of the intestinal mucosa, inflammatory cytokine expression, and cleaved caspase-3. In addition, a role of Pin1 in inflammation was suggested because the percentage of M1-type macrophages in the colon was decreased in the Pin1 KO mice while that of M2-type macrophages was increased. Moreover, Pin1 KO mice showed downregulation of both Il17 and Il23a expression in the colon, both of which have been implicated in the development of colitis. Finally, oral administration of Pin1 inhibitor partially but significantly prevented DSS-induced colitis in mice, raising the possibility of Pin1 inhibitors serving as therapeutic agents for IBD.

Tuberculosis Relapse in the Epididymis After the Completion of Nine Months of Anti-Tuberculosis Chemotherapy in a Patient with Poorly Controlled Diabetes Mellitus.

The standard six-month tuberculosis (TB) treatment comprises an intensive phase lasting two months, followed by a continuation phase lasting four months. Meanwhile, the nine-month regimen, which has a prolonged continuation phase, is indicated for patients with complicated diabetes mellitus (DM) because of their poor response to treatment. A 61-year-old Japanese man with poorly controlled DM for five years presented with bilateral scrotal swelling noticed two weeks ago. He had a history of pleuritis, pericarditis, and peritonitis two years ago. These symptoms led to the diagnosis of culture-negative extrapulmonary TB. He received the nine-month chemotherapy regimen (isoniazid, rifampin, pyrazinamide, and ethambutol for two months, followed by isoniazid and rifampin for seven months), and his symptoms significantly improved. The swollen scrotum was accompanied by mild tenderness and pus discharge from a fistula. Imaging study revealed bilaterally diffusely enlarged epididymis. However, the acid-fast bacilli smear and culture and polymerase chain reaction using urine and pus discharge tested negative. Bilateral epididymectomy was performed. Although the acid-fast bacilli smear was negative, the pathology demonstrated granuloma formation and acid-fast bacilli tissue culture confirmed multi-drug resistant Mycobacterium tuberculosis. The optimal treatment regimen and duration for extrapulmonary TB with unknown drug susceptibility are debatable. The nine-month regimen can be insufficient in some cases. Thus, detailed follow-up is essential, and TB relapse should be thoroughly monitored.

Carnosic Acid and Carnosol Activate AMPK, Suppress Expressions of Gluconeogenic and Lipogenic Genes, and Inhibit Proliferation of HepG2 Cells.

Carnosic acid (CA), carnosol (CL) and rosmarinic acid (RA), components of the herb rosemary, reportedly exert favorable metabolic actions. This study showed that both CA and CL, but not RA, induce significant phosphorylation of AMP-dependent kinase (AMPK) and its downstream acetyl-CoA carboxylase 1 (ACC1) in HepG2 hepatoma cells. Glucose-6-phosphatase (G6PC) and phosphoenolpyruvate carboxykinase 1 (PCK1), rate-limiting enzymes of hepatic gluconeogenesis, are upregulated by forskolin stimulation, and this upregulation was suppressed when incubated with CA or CL. Similarly, a forskolin-induced increase in CRE transcriptional activity involved in G6PC and PCK1 regulations was also stymied when incubated with CA or CL. In addition, mRNA levels of ACC1, fatty acid synthase (FAS) and sterol regulatory element-binding protein 1c (SREBP-1c) were significantly reduced when incubated with CA or CL. Finally, it was shown that CA and CL suppressed cell proliferation and reduced cell viability, possibly as a result of AMPK activation. These findings raise the possibility that CA and CL exert a protective effect against diabetes and fatty liver disease, as well as subsequent cases of hepatoma.

A Single Episode of Hypoglycemia as a Possible Early Warning Sign of Adrenal Insufficiency.

A 65-year-old woman without a history of diabetes mellitus was admitted for elective total knee arthroplasty for osteoarthrosis. There were no specific complaints except for knee flexion contractures, and the results of preoperative tests were unremarkable. On the day of surgery, the patient suffered from a hypoglycemic attack (52 mg/dL) after preoperative overnight fasting. A dextrose infusion immediately corrected the hypoglycemia, and a total knee arthroplasty was then performed. Although a hypoglycemic attack did not recur, further evaluation was required because of nausea that persisted after surgery. The morning serum cortisol level was 0.15 µg/dL with undetectable adrenocorticotropic hormone (ACTH), and the insulin-like growth factor-1 level was 9 ng/mL. An empty sella and bilateral adrenal atrophy were evident in imaging studies. ACTH and growth hormone (GH) did not respond to testing with corticotropin-releasing hormone and GH-releasing peptide-2, respectively. While serum cortisol did not increase on a rapid ACTH stimulation test, urinary free cortisol excretion responded to a prolonged ACTH stimulation test. Finally, the patient was diagnosed as having empty sella syndrome with ACTH and GH deficiencies. After the administration of hydrocortisone as maintenance replacement therapy, the patient's prolonged postoperative nausea disappeared. Adrenal insufficiency is latent in patients with hypoglycemia episodes. Because patients with adrenal insufficiency require appropriate perioperative corticosteroid supplementation, clinicians should give priority to identifying the underlying etiology of hypoglycemia over non-urgent elective surgery when these co-occur.

Isolated ACTH deficiency during single-agent pembrolizumab for squamous cell lung carcinoma: a case report.

BACKGROUND: The programmed cell death 1 (PD-1) inhibitor pembrolizumab is a promising agent for treatment of several different malignancies, but as with all immunotherapy there is a potential risk of immune-related adverse events. Adrenocorticotropic hormone (ACTH) deficiency and hypophysitis have been reported in patients treated with a different PD-1 inhibitor, nivolumab. However, clinical characteristics of these side effects associated with pembrolizumab have yet to be described in detail. CASE PRESENTATION: An 85-year-old Japanese woman was diagnosed with advanced squamous cell lung cancer. The patient was treated with 200 mg pembrolizumab every three weeks as first-line therapy. Routine examination including thyroid function, complete blood count, serum cortisol and sodium levels before each pembrolizumab infusion had shown no significant changes up to the eighth cycle. However, 8 days after the eighth cycle of single-agent pembrolizumab, she presented with rapidly worsening general fatigue and appetite loss over two days. Laboratory data revealed a low serum cortisol level (0.92 µg/dL) with inappropriately low ACTH (8.3 pg/mL), hyponatremia (122 mmol/L) and hypoglycemia (68 mg/dL). Standard-dose short ACTH testing showed an unsatisfactory cortisol response, indicating adrenal insufficiency. Pituitary magnetic resonance imaging showed diffuse substantial gadolinium enhancement, T2 hyperintensity, loss of pituitary bright spot, but no pituitary enlargement. Serum cortisol and ACTH levels were low throughout the day, and urinary free cortisol excretion fell below the lower normal limit. There was no ACTH and cortisol response in the corticotropin-releasing hormone test, despite significant responses of other anterior pituitary hormones to their corresponding challenge tests. Thus, isolated ACTH deficiency was diagnosed, and hypophysitis was suspected as the etiology. After administration of 15 mg/day hydrocortisone, the patient's debilitation, hyponatremia, and hypoglycemia swiftly disappeared. CONCLUSION: This is a case of isolated ACTH deficiency possibly due to hypophysitis in a patient with advanced lung cancer, in whom recent routine examinations had shown unremarkable results. We therefore conclude that isolated ACTH deficiency can suddenly arise during pembrolizumab monotherapy, albeit probably only rarely. Caution should be exercised to make sure that adrenal insufficiency is recognized immediately in order to achieve swift recovery by steroid replacement.

Prolyl isomerase Pin1 in metabolic reprogramming of cancer cells.

Pin1 is one member of a group consisting of three prolyl isomerases. Pin1 interacts with the motif containing phospho-Ser/Thr-Pro of substrates and enhances cis-trans isomerization of peptide bonds, thereby controlling the functions of these substrates. Importantly, the Pin1 expression level is highly upregulated in most cancer cells and correlates with malignant properties, and thereby with poor outcomes. In addition, Pin1 was revealed to promote the functions of multiple oncogenes and to abrogate tumor suppressors. Accordingly, Pin1 is well recognized as a master regulator of malignant processes. Recent studies have shown that Pin1 also binds to a variety of metabolic regulators, such as AMP-activated protein kinase, acetyl CoA carboxylase and pyruvate kinase2, indicating Pin1 to have major impacts on lipid and glucose metabolism in cancer cells. In this review, we focus on the roles of Pin1 in metabolic reprogramming, such as "Warburg effects", of cancer cells. Our aim is to introduce these important roles of Pin1, as well as to present evidence supporting the possibility of Pin1 inhibition as a novel anti-cancer strategy.

Development of Pin1 Inhibitors and their Potential as Therapeutic Agents.

The prolyl isomerase Pin1 is a unique enzyme, which isomerizes the cis-trans conformation between pSer/pThr and proline and thereby regulates the function, stability and/or subcellular distribution of its target proteins. Such regulations by Pin1 are involved in numerous physiological functions as well as the pathogenic mechanisms underlying various diseases. Notably, Pin1 deficiency or inactivation is a potential cause of Alzheimer's disease, since Pin1 induces the degradation of Tau. In contrast, Pin1 overexpression is highly correlated with the degree of malignancy of cancers, as Pin1 controls a number of oncogenes and tumor suppressors. Accordingly, Pin1 inhibitors as anti-cancer drugs have been developed. Interestingly, recent intensive studies have demonstrated Pin1 to be responsible for the onset or development of nonalcoholic steatosis, obesity, atherosclerosis, lung fibrosis, heart failure and so on, all of which have been experimentally induced in Pin1 deficient mice. In this review, we discuss the possible applications of Pin1 inhibitors to a variety of diseases including malignant tumors and also introduce the recent advances in Pin1 inhibitor research, which have been reported.

Xanthine Oxidase Inhibitor Febuxostat Exerts an Anti-Inflammatory Action and Protects against Diabetic Nephropathy Development in KK-Ay Obese Diabetic Mice.

Hyperuricemia has been recognized as a risk factor for insulin resistance as well as one of the factors leading to diabetic kidney disease (DKD). Since DKD is the most common cause of end-stage renal disease, we investigated whether febuxostat, a xanthine oxidase (XO) inhibitor, exerts a protective effect against the development of DKD. We used KK-Ay mice, an established obese diabetic rodent model. Eight-week-old KK-Ay mice were provided drinking water with or without febuxostat (15 µg/mL) for 12 weeks and then subjected to experimentation. Urine albumin secretion and degrees of glomerular injury judged by microscopic observations were markedly higher in KK-Ay than in control lean mice. These elevations were significantly normalized by febuxostat treatment. On the other hand, body weights and high serum glucose concentrations and glycated albumin levels of KK-Ay mice were not affected by febuxostat treatment, despite glucose tolerance and insulin tolerance tests having revealed febuxostat significantly improved insulin sensitivity and glucose tolerance. Interestingly, the IL-1ß, IL-6, MCP-1, and ICAM-1 mRNA levels, which were increased in KK-Ay mouse kidneys as compared with normal controls, were suppressed by febuxostat administration. These data indicate a protective effect of XO inhibitors against the development of DKD, and the underlying mechanism likely involves inflammation suppression which is independent of hyperglycemia amelioration.

Possible involvement of normalized Pin1 expression level and AMPK activation in the molecular mechanisms underlying renal protective effects of SGLT2 inhibitors in mice.

BACKGROUND: Recently, clinical studies have shown the protective effects of sodium glucose co-transporter2 (SGLT2) inhibitors against progression of diabetic nephropathy, but the underlying molecular mechanisms remain unclear. METHODS: Diabetic mice were prepared by injecting nicotinamide and streptozotocin, followed by high-sucrose diet feeding (NA/STZ/Suc mice). The SGLT2 inhibitor canagliflozin was administered as a 0.03% (w/w) mixture in the diet for 4 weeks. Then, various parameters and effects of canagliflozin on diabetic nephropathy were investigated. RESULTS: Canagliflozin administration to NA/STZ/Suc mice normalized hyperglycemia as well as elevated renal mRNA of collagen 1a1, 1a2, CTGF, TNFα and MCP-1. Microscopic observation revealed reduced fibrotic deposition in the kidneys of canagliflozin-treated NA/STZ/Suc mice. Interestingly, the protein level of Pin1, reportedly involved in the inflammation and fibrosis affecting several tissues, was markedly increased in the NA/STZ/Suc mouse kidney, but this was normalized with canagliflozin treatment. The cells showing increased Pin1 expression in the kidney were mainly mesangial cells, along with podocytes, based on immunohistochemical analysis. Furthermore, it was revealed that canagliflozin induced AMP-activated kinase (AMPK) activation concentration-dependently in CRL1927 mesangial as well as THP-1 macrophage cell lines. AMPK activation was speculated to suppress mesangial cell proliferation and exert anti-inflammatory effects in hematopoietic cells. CONCLUSION: Therefore, we can reasonably suggest that normalized Pin1 expression and AMPK activation contribute to the molecular mechanisms underlying SGLT2 inhibitor-induced suppression of diabetic nephropathy, possibly at least in part by reducing inflammation and fibrotic change.

Prolyl isomerase Pin1 binds to and stabilizes acetyl CoA carboxylase 1 protein, thereby supporting cancer cell proliferation.

The prolyl isomerase Pin1 expression level is reportedly increased in most malignant tissues and correlates with poor outcomes. On the other hand, acetyl CoA carboxylase 1 (ACC1), the rate limiting enzyme of lipogenesis is also abundantly expressed in cancer cells, to satisfy the demand for the fatty acids (FAs) needed for rapid cell proliferation. We found Pin1 expression levels to correlate positively with ACC1 levels in human prostate cancers, and we focused on the relationship between Pin1 and ACC1. Notably, it was demonstrated that Pin1 associates with ACC1 but not with acetyl CoA carboxylase 2 (ACC2) in the overexpression system as well as endogenously in the prostate cancer cell line DU145. This association is mediated by the WW domain in the Pin1 and C-terminal domains of ACC1. Interestingly, Pin1 deficiency or treatment with Pin1 siRNA or the inhibitor juglone markedly reduced ACC1 protein expression without affecting its mRNA level, while Pin1 overexpression increased the ACC1 protein level. In addition, chloroquine treatment restored the levels of ACC1 protein reduced by Pin1 siRNA treatment, indicating that Pin1 suppressed ACC1 degradation through the lysosomal pathway. In brief, we have concluded that Pin1 leads to the stabilization of and increases in ACC1. Therefore, it is likely that the growth-enhancing effect of Pin1 in cancer cells is mediated at least partially by the stabilization of ACC1 protein, corresponding to the well-known potential of Pin1 inhibitors as anti-cancer drugs.

Roles of Gut-Derived Secretory Factors in the Pathogenesis of Non-Alcoholic Fatty Liver Disease and Their Possible Clinical Applications.

The rising prevalence of non-alcoholic fatty liver disease (NAFLD) parallels the global increase in the number of people diagnosed with obesity and metabolic syndrome. The gut-liver axis (GLA) plays an important role in the pathogenesis of NAFLD/non-alcoholic steatohepatitis (NASH). In this review, we discuss the clinical significance and underlying mechanisms of action of gut-derived secretory factors in NAFLD/NASH, focusing on recent human studies. Several studies have identified potential causal associations between gut-derived secretory factors and NAFLD/NASH, as well as the underlying mechanisms. The effects of gut-derived hormone-associated drugs, such as glucagon-like peptide-1 analog and recombinant variant of fibroblast growth factor 19, and other new treatment strategies for NAFLD/NASH have also been reported. A growing body of evidence highlights the role of GLA in the pathogenesis of NAFLD/NASH. Larger and longitudinal studies as well as translational research are expected to provide additional insights into the role of gut-derived secretory factors in the pathogenesis of NAFLD/NASH, possibly providing novel markers and therapeutic targets in patients with NAFLD/NASH.

Elsberg syndrome related to varicella zoster virus infection with painless skin lesions in an elderly woman with poorly controlled type 2 diabetes mellitus.

Patients with diabetes mellitus (DM) are at increased risk of infections, with the urinary tract being the most frequent infection site. Incomplete bladder emptying, frequent urination and abdominal distension are typical symptoms of urinary tract infections (UTIs). A 68-year-old female with a long history of poorly controlled type 2 DM (T2DM) visited our hospital complaining of urinary retention, which was initially diagnosed as cystitis by another doctor. The urologist at our hospital identified a skin rash extending from the left hip to her genital area. A dermatologist was consulted. She was clinically diagnosed with herpes zoster (HZ) involving the left sacral dermatome area. As Elsberg syndrome (ES) was suspected, a lumbar puncture was performed, revealing aseptic meningitis associated with varicella zoster virus (VZV) infection. Intravenous acyclovir with urinary catheterization in combination with methylprednisolone pulse therapy resulted in a good clinical course. HZ very uncommonly involves sacral dermatomes, but it can develop in patients with prolonged poorly controlled DM. Furthermore, early diagnosis can be difficult when patients have diabetic peripheral neuropathy, which may mask symptoms related to skin lesions. Because this disease is potentially severe, detailed examination is important for clinicians managing patients with DM who have complaints indicative of urinary tract disorders.

Protective Effect of Sex Hormone-Binding Globulin against Metabolic Syndrome: In Vitro Evidence Showing Anti-Inflammatory and Lipolytic Effects on Adipocytes and Macrophages.

Sex hormone-binding globulin (SHBG) is a serum protein released mainly by the liver, and a low serum level correlates with a risk for metabolic syndrome including diabetes, obesity, and cardiovascular events. However, the underlying molecular mechanism(s) linking SHBG and metabolic syndrome remains unknown. In this study, using adipocytes and macrophages, we focused on the in vitro effects of SHBG on inflammation as well as lipid metabolism. Incubation with 20 nM SHBG markedly suppressed lipopolysaccharide- (LPS-) induced inflammatory cytokines, such as MCP-1, TNFα, and IL-6 in adipocytes and macrophages, along with phosphorylations of JNK and ERK. Anti-inflammatory effects were also observed in 3T3-L1 adipocytes cocultured with LPS-stimulated macrophages. In addition, SHBG treatment for 18 hrs or longer significantly induced the lipid degradation of differentiated 3T3-L1 cells, with alterations in its corresponding gene and protein levels. Notably, these effects of SHBG were not altered by coaddition of large amounts of testosterone or estradiol. In conclusion, SHBG suppresses inflammation and lipid accumulation in macrophages and adipocytes, which might be among the mechanisms underlying the protective effect of SHBG, that is, its actions which reduce the incidence of metabolic syndrome.

The SGLT2 Inhibitor Luseogliflozin Rapidly Normalizes Aortic mRNA Levels of Inflammation-Related but Not Lipid-Metabolism-Related Genes and Suppresses Atherosclerosis in Diabetic ApoE KO Mice.

Recent clinical studies have revealed the treatment of diabetic patients with sodium glucose co-transporter2 (SGLT2) inhibitors to reduce the incidence of cardiovascular events. Using nicotinamide and streptozotocin (NA/STZ) -treated ApoE KO mice, we investigated the effects of short-term (seven days) treatment with the SGLT2 inhibitor luseogliflozin on mRNA levels related to atherosclerosis in the aorta, as well as examining the long-term (six months) effects on atherosclerosis development. Eight-week-old ApoE KO mice were treated with NA/STZ to induce diabetes mellitus, and then divided into two groups, either untreated, or treated with luseogliflozin. Seven days after the initiation of luseogliflozin administration, atherosclerosis-related mRNA levels in the aorta were compared among four groups; i.e., wild type C57/BL6J, native ApoE KO, and NA/STZ-treated ApoE KO mice, with or without luseogliflozin. Short-term luseogliflozin treatment normalized the expression of inflammation-related genes such as F4/80, TNFα, IL-1ß, IL-6, ICAM-1, PECAM-1, MMP2 and MMP9 in the NA/STZ-treated ApoE KO mice, which showed marked elevations as compared with untreated ApoE KO mice. In contrast, lipid metabolism-related genes were generally unaffected by luseogliflozin treatment. Furthermore, after six-month treatment with luseogliflozin, in contrast to the severe and widely distributed atherosclerotic changes in the aortas of NA/STZ-treated ApoE KO mice, luseogliflozin treatment markedly attenuated the progression of atherosclerosis, without affecting serum lipid parameters such as high density lipoprotein, low density lipoprotein and triglyceride levels. Given that luseogliflozin normalized the aortic mRNA levels of inflammation-related, but not lipid-related, genes soon after the initiation of treatment, it is not unreasonable to speculate that the anti-atherosclerotic effect of this SGLT2 inhibitor emerges rapidly, possibly via the prevention of inflammation rather than of hyperlipidemia.

Reduced SHARPIN and LUBAC Formation May Contribute to CCl4- or Acetaminophen-Induced Liver Cirrhosis in Mice.

Linear ubiquitin chain assembly complex (LUBAC), composed of SHARPIN (SHANK-associated RH domain-interacting protein), HOIL-1L (longer isoform of heme-oxidized iron-regulatory protein 2 ubiquitin ligase-1), and HOIP (HOIL-1L interacting protein), forms linear ubiquitin on nuclear factor-κB (NF-κB) essential modulator (NEMO) and induces NF-κB pathway activation. SHARPIN expression and LUBAC formation were significantly reduced in the livers of mice 24 h after the injection of either carbon tetrachloride (CCl4) or acetaminophen (APAP), both of which produced the fulminant hepatitis phenotype. To elucidate its pathological significance, hepatic SHARPIN expression was suppressed in mice by injecting shRNA adenovirus via the tail vein. Seven days after this transduction, without additional inflammatory stimuli, substantial inflammation and fibrosis with enhanced hepatocyte apoptosis occurred in the livers. A similar but more severe phenotype was observed with suppression of HOIP, which is responsible for the E3 ligase activity of LUBAC. Furthermore, in good agreement with these in vivo results, transduction of Hepa1-6 hepatoma cells with SHARPIN, HOIL-1L, or HOIP shRNA adenovirus induced apoptosis of these cells in response to tumor necrosis factor-α (TNFα) stimulation. Thus, LUBAC is essential for the survival of hepatocytes, and it is likely that reduction of LUBAC is a factor promoting hepatocyte death in addition to the direct effect of drug toxicity.

Physiological and Pathogenic Roles of Prolyl Isomerase Pin1 in Metabolic Regulations via Multiple Signal Transduction Pathway Modulations.

Prolyl isomerases are divided into three groups, the FKBP family, Cyclophilin and the Parvulin family (Pin1 and Par14). Among these isomerases, Pin1 is a unique prolyl isomerase binding to the motif including pSer/pThr-Pro that is phosphorylated by kinases. Once bound, Pin1 modulates the enzymatic activity, protein stability or subcellular localization of target proteins by changing the cis- and trans-formations of proline. Several studies have examined the roles of Pin1 in the pathogenesis of cancers and Alzheimer's disease. On the other hand, recent studies have newly demonstrated Pin1 to be involved in regulating glucose and lipid metabolism. Interestingly, while Pin1 expression is markedly increased by high-fat diet feeding, Pin1 KO mice are resistant to diet-induced obesity, non-alcoholic steatohepatitis and diabetic vascular dysfunction. These phenomena result from the binding of Pin1 to several key factors regulating metabolic functions, which include insulin receptor substrate-1, AMPK, Crtc2 and NF-κB p65. In this review, we focus on recent advances in elucidating the physiological roles of Pin1 as well as the pathogenesis of disorders involving this isomerase, from the viewpoint of the relationships between signal transductions and metabolic functions.

Involvement of resistin-like molecule ß in the development of methionine-choline deficient diet-induced non-alcoholic steatohepatitis in mice.

Resistin-like molecule ß (RELMß) reportedly has multiple functions including local immune responses in the gut. In this study, we investigated the possible contribution of RELMß to non-alcoholic steatohepatitis (NASH) development. First, RELMß knock-out (KO) mice were shown to be resistant to methionine-choline deficient (MCD) diet-induced NASH development. Since it was newly revealed that Kupffer cells in the liver express RELMß and that RELMß expression levels in the colon and the numbers of RELMß-positive Kupffer cells were both increased in this model, we carried out further experiments using radiation chimeras between wild-type and RELMß-KO mice to distinguish between the contributions of RELMß in these two organs. These experiments revealed the requirement of RELMß in both organs for full manifestation of NASH, while deletion of each one alone attenuated the development of NASH with reduced serum lipopolysaccharide (LPS) levels. The higher proportion of lactic acid bacteria in the gut microbiota of RELMß-KO than in that of wild-type mice may be one of the mechanisms underlying the lower serum LPS level the former. These data suggest the contribution of increases in RELMß in the gut and Kupffer cells to NASH development, raising the possibility of RELMß being a novel therapeutic target for NASH.