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1.
Biochem Biophys Res Commun ; 715: 150001, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38676996

ABSTRACT

The skeletal muscle is a pivotal organ involved in the regulation of both energy metabolism and exercise capacity. There is no doubt that exercise contributes to a healthy life through the consumption of excessive energy or the release of myokines. Skeletal muscles exhibit insulin sensitivity and can rapidly uptake blood glucose. In addition, they can undergo non-shivering thermogenesis through actions of both the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) and small peptide, sarcolipin, resulting in systemic energy metabolism. Accordingly, the maintenance of skeletal muscles is important for both metabolism and exercise. Prolyl isomerase Pin1 is an enzyme that converts the cis-trans form of proline residues and controls substrate function. We have previously reported that Pin1 plays important roles in insulin release, thermogenesis, and lipolysis. However, the roles of Pin1 in skeletal muscles remains unknown. To clarify this issue, we generated skeletal muscle-specific Pin1 knockout mice. Pin1 deficiency had no effects on muscle weights, morphology and ratio of fiber types. However, they showed exacerbated obesity or insulin resistance when fed with a high-fat diet. They also showed a lower ability to exercise than wild type mice did. We also found that Pin1 interacted with SERCA and elevated its activity, resulting in the upregulation of oxygen consumption. Overall, our study reveals that Pin1 in skeletal muscles contributes to both systemic energy metabolism and exercise capacity.


Subject(s)
Energy Metabolism , Mice, Knockout , Muscle, Skeletal , NIMA-Interacting Peptidylprolyl Isomerase , Physical Conditioning, Animal , Sarcoplasmic Reticulum Calcium-Transporting ATPases , Animals , Muscle, Skeletal/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics , NIMA-Interacting Peptidylprolyl Isomerase/metabolism , NIMA-Interacting Peptidylprolyl Isomerase/genetics , Mice , Mice, Inbred C57BL , Male , Insulin Resistance , Diet, High-Fat
3.
Yakugaku Zasshi ; 143(6): 541-544, 2023.
Article in English | MEDLINE | ID: mdl-37258187

ABSTRACT

A 72-year-old man with a malignant retroperitoneal soft tissue tumor was treated with ifosfamide (IFO) for 5 consecutive days (1.8 g/m2/d×5 d, expected dose 9 g/m2). The patient developed neurological symptoms such as mild somnolence, seizures, and inability to write from Day 1, and became delirious on Day 3, so IFO was discontinued on Day 4 (dose: 7.2 g/m2). Since there are reports of drug interactions that increase the frequency of encephalopathy when combined with aprepitant (Apr), Dexamethasone was increased and IFO was administered without the use of Apr after the second course, and there was no recurrence of encephalopathy in the second and third courses. IFO-induced encephalopathy is considered to occur due to an increase in blood concentration of IFOs caused by high dosage, decreased renal function, or other factors. In this case, encephalopathy was observed even though the dose of IFO was reduced due to the patient's advanced age and impaired renal function. The combination use of Apr with IFO should be considered with caution for the occurrence of adverse events, including encephalopathy, and if possible, control of gastrointestinal toxicity with other antiemetic agents should be considered.


Subject(s)
Antiemetics , Brain Diseases , Male , Humans , Aged , Ifosfamide/adverse effects , Aprepitant , Brain Diseases/chemically induced , Brain Diseases/drug therapy , Antiemetics/adverse effects , Drug Interactions
4.
Arch Biochem Biophys ; 734: 109501, 2023 01 15.
Article in English | MEDLINE | ID: mdl-36592647

ABSTRACT

A well-tuned inflammatory response is crucial for an effective immune process. Nuclear factor-kappa B (NF-κB) is a key mediator of inflammatory and innate immunity responses, and its dysregulation is closely associated with immune-related diseases. MicroRNAs (miRNAs) are important inflammation modulators. However, miRNA-regulated mechanisms that implicate NF-κB activity are not fully understood. This study aimed to identify a potential miRNA that could modulate the dysregulated NF-κB signaling during inflammation. We identified miR-582-5p that was significantly downregulated in inflamed murine adipose tissues and RAW264.7 cells. S-phase kinase-associated protein 1 (SKP1), a core component of an E3 ubiquitin ligase that regulates the NF-κB pathway, was proposed as a biological target of miR-582-5p by using TargetScan. The binding of miR-582-5p to a 3'-untranslated region site on Skp1 was confirmed using a dual-luciferase reporter assay; in addition, transfection with a miR-582-5p mimic suppressed SKP1 expression in RAW264.7 cells. Importantly, exogenous miR-582-5p attenuated the production of pro-inflammatory cytokines such as tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 through suppressing the degradation of the NF-κB inhibitor alpha, followed by the nuclear translocation of NF-κB. Therefore, exogenously applied miR-582-5p can attenuate the NF-κB signaling pathway via targeting Skp1; this provides a prospective therapeutic strategy for treating inflammatory and immune diseases.


Subject(s)
MicroRNAs , NF-kappa B , Animals , Mice , Inflammation/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , NF-kappa B/metabolism , S-Phase Kinase-Associated Proteins/genetics , S-Phase Kinase-Associated Proteins/metabolism , Signal Transduction
5.
Front Cell Dev Biol ; 10: 1061216, 2022.
Article in English | MEDLINE | ID: mdl-36531939

ABSTRACT

The expression profiles of exosomal microRNAs (miRNAs) are regulated by the microenvironment, and appropriate priming with mesenchymal stem cells (MSCs) is one of the strategies to enhance the paracrine potency of MSCs. Our previous work demonstrated that exosomes from tumor necrosis factor (TNF)-α-primed human gingiva-derived MSCs (GMSCs) could be a therapeutic tool against periodontitis, and that TNFα-inducible exosomal miR-1260b is essential for the inhibition of alveolar bone loss. However, the precise molecular mechanism underlying miR-1260b-mediated inhibition of osteoclastogenesis is not yet fully understood. Here, we found that the activating transcription factor (ATF)-6ß, a novel miR-1260b-targeting gene, is critical for the regulation of osteoclastogenesis under endoplasmic reticulum (ER) stress. An experimental periodontal mouse model demonstrated that induction of ER stress was accompanied by enhanced ATF6ß expression, and local administration of miR-1260b and ATF6ß siRNA using polyethylenimine nanoparticles (PEI-NPs) significantly suppressed the periodontal bone resorption. In periodontal ligament (PDL) cells, the ER stress inducer, tunicamycin, enhanced the expression of the receptor activator of NF-κB ligand (RANKL), while miR-1260b-mediated downregulation of ATF6ß caused RANKL inhibition. Furthermore, the secretome from miR-1260b/ATF6ß-axis-activated PDL cells inhibited osteoclastogenesis in human CD14+ peripheral blood-derived monocytes. These results indicate that the miR-1260b/ATF6ß axis mediates the regulation of ER stress, which may be used as a novel therapeutic strategy to treat periodontal disease.

6.
Acta Diabetol ; 59(10): 1275-1286, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35829914

ABSTRACT

AIMS: Pancreatic ß-cell apoptosis may be involved in the onset and progression of type 2 diabetes mellitus, although its mechanism remains unclear. We previously demonstrated that macrophage-derived interferon (IFN) ß induced X-linked inhibitor of apoptosis-associated factor 1 (XAF1) expression in ß-cells and accelerated ß-cell apoptosis in vitro. Here, we explored the effects of XAF1 on ß-cell function and progression of diabetes in vivo. METHODS: Pancreatic ß-cell-selective XAF1 overexpressing (Xaf1 Tg) mice were generated. Xaf1 Tg mice and their wild-type (WT) littermates were fed either a normal diet or a 40% or 60% high-fat diet (HFD). The effects of ß-cell XAF1 on ß-cell apoptosis and exacerbation of diabetes were investigated. RESULTS: Palmitic acid induced IFNß expression in macrophages, and HFD intake promoted macrophage infiltration in pancreatic islets, both of which cooperatively upregulated XAF1 expression in mouse islets. Furthermore, HFD-fed Xaf1 Tg mice demonstrated increased ß-cell apoptosis, lowered insulin expression, and impaired glucose tolerance compared with WT mice fed the same diet. These effects were more pronounced in the 60%HFD group than in the 40%HFD group. CONCLUSIONS: Pancreatic ß-cell XAF1 expression was enhanced via HFD-induced, macrophage-derived IFNß, which promoted ß-cell apoptosis and led to a reduction in insulin secretion and progression of diabetes. To our knowledge, this is the first report to demonstrate an association between pancreatic ß-cell XAF1 overexpression and exacerbation of diabetes, thus providing insight into the mechanism of ß-cell mass reduction in diabetes.


Subject(s)
Adaptor Proteins, Signal Transducing , Apoptosis Regulatory Proteins , Diabetes Mellitus, Type 2 , Insulin-Secreting Cells , Islets of Langerhans , Adaptor Proteins, Signal Transducing/genetics , Animals , Apoptosis/genetics , Apoptosis Regulatory Proteins/genetics , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Diet, High-Fat/adverse effects , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/metabolism , Islets of Langerhans/metabolism , Mice , Mice, Inbred C57BL
7.
J Endocrinol ; 254(1): 27-36, 2022 05 31.
Article in English | MEDLINE | ID: mdl-35638559

ABSTRACT

Menopausal women are susceptible to visceral obesity, which increases the risk of metabolic disorders. However, the mechanisms of menopause-induced visceral fat accumulation are not fully understood. Circulating levels of receptor activator of nuclear factor-kappa B (NF-κB) ligand (RANKL) are elevated in an animal model of menopause. RANKL, a multifunctional cytokine, activates the NF-κB pathway, which serves as a pivotal mediator of inflammatory responses. Here, we investigated whether RANKL-induced non-canonical NF-κB pathway activation induces inflammation and lipid accumulation in adipose tissues. RANKL induced Tnfa expression via the non-canonical NF-κB pathway in bone marrow cells. We therefore analyzed aly/aly mice, in which the non-canonical NF-κB pathway is not activated, owing to an inactive form of NF-κB-inducing kinase. A postmenopausal obesity model was generated by ovariectomy and subsequent high-fat and high-sucrose diet feeding. In aly/aly mice with postmenopausal obesity, serum RANKL levels were elevated, and hepatic lipid accumulation and adipocyte hypertrophy were suppressed, resulting in reduced macrophage infiltration and inflammatory cytokine mRNA expression in visceral adipose tissue. Furthermore, aly/aly mice showed protection from glucose intolerance and insulin resistance, which were observed in ovariectomized WT obese mice. These findings indicate that non-canonical NF-κB pathway activation via serum RANKL elevation contributes to postmenopausal obesity.


Subject(s)
Insulin Resistance , NF-kappa B , Animals , Female , Humans , Lipids , Mice , Mice, Obese , NF-kappa B/metabolism , Obesity/etiology
8.
Case Rep Dermatol Med ; 2021: 5548760, 2021.
Article in English | MEDLINE | ID: mdl-34712500

ABSTRACT

Palmoplantar pustulosis (PPP) is a recurrent pustular dermatosis located on the palms and soles. Focal infection may exacerbate the symptoms of PPP, but the etiology is not fully clear. A 56-year-old woman with PPP was diagnosed with severe chronic periodontitis. Initial treatment for periodontitis combined with topical application of antibiotics and surgical treatment was performed. In this case, attention was paid to the relevance of systemic inflammation caused by periodontitis with the clinical symptoms of PPP. With periodontal treatment, the symptoms of PPP and periodontitis, high-sensitivity C-reactive protein (hs-CRP) level, and periodontal inflamed surface area (PISA) improved. This case highlights the importance of comprehensive dental examinations, including those for oral infections, such as periodontitis and other unrecognized sources of infection, and dental treatment in the overall management of PPP.

9.
Article in English | MEDLINE | ID: mdl-34031140

ABSTRACT

INTRODUCTION: Enlarged adipose tissue is characterized by infiltration of activated immune cells and increased expression of chemokines recruiting these cells including C-C motif ligand 19 (CCL19), although the role of adipose CCL19 is still inconclusive. RESEARCH DESIGN AND METHODS: Adipocyte-specific Ccl19 knock-in (KI) mice were generated, and the mice were fed either a normal diet or 40% or 60% fat diet (FD) to investigate the effects of CCL19 on the induction of inflammation and lipid metabolism. RESULTS: Ccl19KI mice exhibited increased inflammatory signs in adipose tissue and enlarged subcutaneous white and brown adipose tissue than those of wild-type (WT) mice. The adipose tissue of Ccl19KI mice was characterized by increased extracellular signal-regulated kinase 1/2 and decreased AMP-activated protein kinase α phosphorylation. The protein expression of peroxisome proliferator-activated receptor γ coactivator 1α and uncoupling protein 1 was significantly reduced in brown adipose tissue of Ccl19KI mice compared with that in WT mice. The most remarkable changes between genotypes were observed in mice fed a 40% FD. CONCLUSION: A 40% FD enhanced the effects of CCL19 overexpression, and these mice could be a suitable model to study metabolic disorders in overweight Asians.


Subject(s)
Insulin Resistance , Adipose Tissue, White , Animals , Insulin Resistance/genetics , Ligands , Mice , Obesity , Weight Gain
10.
Opt Express ; 29(6): 9157-9164, 2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33820348

ABSTRACT

We present a novel single-MCF connector without any additional or high-precision parts not found on a standard single-SMF connector. The proposed connector realizes rotational fiber alignment and ferrule floating simultaneously by employing a standard MU ferrule with a straight flange edge and a modified LC housing with a tapered hole that can make contact with the ferrule flange. Fabricated connectors achieved an average loss of 0.07 dB in a random connection test and passed the Telcordia GR-326-CORE mechanical and environmental reliability test. Furthermore, we conducted numerical simulations and confirmed these positive results were due to suppression of ferrule rotation from external forces.

11.
Biochem Biophys Res Commun ; 552: 106-113, 2021 05 07.
Article in English | MEDLINE | ID: mdl-33743346

ABSTRACT

Cancer is characterized by uncontrolled proliferation resulting from aberrant cell cycle progression. The activation of phosphatidylinositol 3-kinase (PI3K)/AKT signaling, a regulatory pathway for the cell cycle, stabilizes cyclin D1 in the G1 phase by inhibiting the activity of glycogen synthase kinase 3ß (GSK3ß) via phosphorylation. We previously reported that phospholipase C-related catalytically inactive protein (PRIP), a phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] binding protein, regulates PI3K/AKT signaling by competitively inhibiting substrate recognition by PI3K. Therefore, in this study, we investigated whether PRIP is involved in cell cycle progression. PRIP silencing in MCF-7 cells, a human breast cancer cell line, demonstrated PI(3,4,5)P3 signals accumulated at the cell periphery compared to that of the control. This suggests that PRIP reduction enhances PI(3,4,5)P3-mediated signaling. Consistently, PRIP silencing in MCF-7 cells exhibited increased phosphorylation of AKT and GSK3ß which resulted in cyclin D1 accumulation. In contrast, the exogenous expression of PRIP in MCF-7 cells evidenced stronger downregulation of AKT and GSK3ß phosphorylation, reduced accumulation of cyclin D1, and diminished cell proliferation in comparison to control cells. Flow cytometry analysis indicated that MCF-7 cells stably expressing PRIP attenuate cell cycle progression. Importantly, tumor growth of MCF-7 cells stably expressing PRIP was considerably prevented in an in vivo xenograft mouse model. In conclusion, PRIP expression downregulates PI3K/AKT/GSK3ß-mediated cell cycle progression and suppresses tumor growth. Therefore, we propose that PRIP is a new therapeutic target for anticancer therapy.


Subject(s)
Carrier Proteins/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Neoplasms/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Phosphatidylinositol 4,5-Diphosphate/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Animals , Carrier Proteins/genetics , Cells, Cultured , Cyclin D1/genetics , Cyclin D1/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Humans , Intracellular Signaling Peptides and Proteins/genetics , MCF-7 Cells , Male , Mice, Inbred BALB C , Mice, Knockout , Mice, Nude , Neoplasms/genetics , Neoplasms/pathology , Phosphatidylinositols/blood , Phosphatidylinositols/metabolism , Signal Transduction , Transplantation, Heterologous , Tumor Burden/genetics
12.
J Biol Chem ; 296: 100274, 2021.
Article in English | MEDLINE | ID: mdl-33428938

ABSTRACT

The G protein-coupled receptor GPRC6A regulates various physiological processes in response to its interaction with multiple ligands, such as extracellular basic amino acids, divalent cations, testosterone, and the uncarboxylated form of osteocalcin (GluOC). Global ablation of GPRC6A increases the susceptibility of mice to diet-induced obesity and related metabolic disorders. However, given that GPRC6A is expressed in many tissues and responds to a variety of hormonal and nutritional signals, the cellular and molecular mechanisms underlying the development of metabolic disorders in conventional knockout mice have remained unclear. On the basis of our previous observation that long-term oral administration of GluOC markedly reduced adipocyte size and improved glucose tolerance in WT mice, we examined whether GPRC6A signaling in adipose tissue might be responsible for prevention of metabolic disorders. We thus generated adipocyte-specific GPRC6A knockout mice, and we found that these animals manifested increased adipose tissue weight, adipocyte hypertrophy, and adipose tissue inflammation when fed a high-fat and high-sucrose diet compared with control mice. These effects were associated with reduced lipolytic activity because of downregulation of lipolytic enzymes such as adipose triglyceride lipase and hormone-sensitive lipase in adipose tissue of the conditional knockout mice. Given that, among GPR6CA ligands tested, GluOC and ornithine increased the expression of adipose triglyceride lipase in cultured 3T3-L1 adipocytes in a manner dependent on GPRC6A, our results suggest that the constitutive activation of GPRC6A signaling in adipocytes by GluOC or ornithine plays a key role in adipose lipid handling and the prevention of obesity and related metabolic disorders.


Subject(s)
Inflammation/genetics , Obesity/genetics , Osteocalcin/genetics , Receptors, G-Protein-Coupled/genetics , 3T3-L1 Cells , Adipocytes/metabolism , Adipose Tissue/metabolism , Animals , Glucose Tolerance Test , Humans , Inflammation/pathology , Insulin/genetics , Insulin Resistance/genetics , Lipase/genetics , Lipolysis/genetics , Mice , Mice, Knockout , Obesity/metabolism , Obesity/pathology
13.
Biochem Biophys Res Commun ; 533(4): 1076-1082, 2020 12 17.
Article in English | MEDLINE | ID: mdl-33012508

ABSTRACT

SPOCK1 is a calcium-binding matricellular proteoglycan that has been extensively studied in several cancer cells. Previously, we generated a mouse line overexpressing SPOCK1 (Spock1-Tg mouse) and showed that SPOCK1 might play an important role in drug-induced gingival overgrowth, indicating that it possesses physiological functions in non-cancer diseases as well. Although SPOCK1 was reported to be secreted from human adipocytes, its role in adipocyte physiology has not been addressed yet. In this study, SPOCK1 protein expression was confirmed in pancreas, adipose tissues, spleen, and liver of normal diet (ND)-fed mice. Interestingly, SPOCK1 was up-regulated in the pancreas and adipose tissues of the high-fat diet (HFD)-fed mice. Spock1-Tg mice fed with ND showed increased maturation in epididymal and inguinal adipose tissues. In addition, Spock1 overexpression strongly decreased expression of UCP-1 in adipose tissues, suggesting that SPOCK1 might regulate thermogenic function through suppression of UCP-1 expression. Finally, exogenous SPOCK1 treatment directly accelerated the differentiation of 3T3-L1 adipocytes, accompanied by the up-regulation of adipocyte differentiation-related gene expression. In conclusion, we demonstrated for the first time that SPOCK1 induced adipocyte differentiation via the up-regulation of adipogenesis-related genes.


Subject(s)
Adipocytes/metabolism , Adipogenesis/genetics , Adipose Tissue/cytology , Gene Expression Regulation/genetics , Proteoglycans/metabolism , 3T3-L1 Cells , Adipose Tissue/metabolism , Animals , Diet, High-Fat , Immunohistochemistry , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Pancreas/metabolism , Proteoglycans/genetics , Recombinant Proteins , Uncoupling Protein 1/genetics , Uncoupling Protein 1/metabolism , Up-Regulation
14.
Sci Rep ; 10(1): 9785, 2020 06 17.
Article in English | MEDLINE | ID: mdl-32555336

ABSTRACT

Few studies have investigated the role of extracellular-matrix proteoglycans in the pathogenesis of drug-induced gingival overgrowth (DIGO). SPOCK1 is an extracellular proteoglycan that induces epithelial to mesenchymal transition (EMT) in several cancer cell lines and exhibits protease-inhibitory activity. However, the role of SPOCK1 in non-cancerous diseases such as DIGO has not been well-addressed. We demonstrated that the expression of SPOCK1, TGF-ß1, and MMP-9 in calcium channel blocker-induced gingival overgrowth is higher than that in non-overgrowth tissues. Transgenic mice overexpressing Spock1 developed obvious gingival-overgrowth and fibrosis phenotypes, and positively correlated with EMT-like changes. Furthermore, in vitro data indicated a tri-directional interaction between SPOCK1, TGF-ß1, and MMP-9 that led to gingival overgrowth. Our study shows that SPOCK1 up-regulation in a noncancerous disease and SPOCK1-induced EMT in gingival overgrowth occurs via cooperation and crosstalk between several potential signaling pathways. Therefore, SPOCK1 is a novel therapeutic target for gingival overgrowth and its expression is a potential risk of EMT induction in cancerous lesions.


Subject(s)
Epithelial-Mesenchymal Transition , Gingival Diseases/chemically induced , Proteoglycans/physiology , Animals , Calcium Channel Blockers/pharmacology , Cell Line, Tumor , Humans , Male , Matrix Metalloproteinase 9/metabolism , Mice, Inbred C57BL , Mice, Transgenic , Nifedipine/pharmacology , Proteoglycans/genetics , Transforming Growth Factor beta1/metabolism , Up-Regulation
15.
Biochem Biophys Rep ; 22: 100757, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32346618

ABSTRACT

MicroRNA (miRNA) plays an important role in diverse cellular biological processes such as inflammatory response, differentiation and proliferation, and carcinogenesis. miR-146a has been suggested as a negative regulator of the inflammatory reaction. Although, it has been reported as expressed in inflamed adipose and periodontal tissues, however, miR-146a's inhibitory effects against inflammatory response in both the tissues, are not well understood. Therefore, in this study, the inhibitory effects of miR-146a on both adipose and periodontal inflammation, was investigated. In vitro study has revealed that miR-146a transfection into either adipocytes or gingival fibroblasts, has resulted in a reduced cytokine gene expression, observed on co-culturing the cells with macrophages in the presence of lipopolysaccharides (LPS), in comparison to the control miRNA transfected. Similarly, miR-146a transfection into macrophages resulted in a reduced expression of TNF-α gene and protein in response to LPS stimulation. In vivo study revealed that a continuous intravenous miR-146a administration into mice via tail vein, protected the mice from developing high-fat diet-induced obesity and the inflammatory cytokine gene expression was down-regulated in both adipose and periodontal tissues. miR-146a appeared to be induced by macrophage-derived inflammatory signals such as TNF-α by negative feed-back mechanism, and it suppressed inflammatory reaction in both adipose and periodontal tissues. Therefore, miR-146a could be suggested as a potential therapeutic molecule and as a common inflammatory regulator for both obesity-induced diabetes and related periodontal diseases.

16.
Diabetol Metab Syndr ; 11: 57, 2019.
Article in English | MEDLINE | ID: mdl-31367234

ABSTRACT

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.

17.
Nutr Metab (Lond) ; 16: 43, 2019.
Article in English | MEDLINE | ID: mdl-31312229

ABSTRACT

BACKGROUND: The chemokine receptor CCR7, expressed on various immune cells, is associated with cell migration and lympho-node homing. Mice lacking Ccr7 are protected from diet-induced obesity and subsequent insulin resistance. We evaluated the mechanism underlying these protective effects from the standpoint of energy expenditure. METHODS: Wild-type and Ccr7 null mice were fed a high-fat diet, and the regulation of energy metabolism and energy metabolism-related molecules, e.g., Ucp1, Cidea, and Pgc1α, were evaluated. RESULTS: Food intake did not differ between groups. O2 consumption and CO2 production were higher in Ccr7 null mice than in wild-type mice, despite a similar respiratory quotient and glucose and lipid utilization, suggesting that energy expenditure increased in Ccr7 null mice via enhanced metabolism. In white adipose tissues of Ccr7 null mice, Prdm16, Cd137, Tmem26, Th, and Tbx1 expression increased. Similarly, in brown adipose tissues of Ccr7 null mice, Dio2, Pgc1α, Cidea, Sirt1, and Adiponectin expression increased. In both white and brown adipose tissues, Ucp1 gene and protein expression levels were higher in null mice than in wild-type mice. CONCLUSIONS: In Ccr7 null mice, browning of white adipocytes as well as the activation of brown adipocytes cause enhanced energy metabolism, resulting in protection against diet-induced obesity.

18.
Cell Rep ; 26(12): 3221-3230.e3, 2019 03 19.
Article in English | MEDLINE | ID: mdl-30893596

ABSTRACT

Non-shivering thermogenesis in adipocytes provides defense against low temperatures and obesity development, but the underlying regulatory mechanism remains to be fully clarified. Based on both markedly increased Pin1 expression in states of excess nutrition and resistance to obesity development in Pin1 null mice, we speculated that adipocyte Pin1 may play a role in thermogenic programs. Adipose-specific Pin1 knockout (adPin1 KO) mice showed enhanced transcription of thermogenic genes and tolerance to hypothermia when exposed to cold. In addition, adPin1 KO mice were resistant to high-fat diet-induced obesity and glucose intolerance. A series of experiments revealed that Pin1 binds to PRDM16 and thereby promotes its degradation through the ubiquitin-proteasome system. Consistent with these results, Pin1 deletion in differentiated adipocytes showed enhancement of thermogenic programs in response to the ß3 agonist CL316243 through the upregulation of PRDM16 proteins. These observations indicate that Pin1 is a negative regulator of non-shivering thermogenesis.


Subject(s)
Adipocytes/metabolism , DNA-Binding Proteins/metabolism , NIMA-Interacting Peptidylprolyl Isomerase/metabolism , Proteolysis , Thermogenesis/physiology , Transcription Factors/metabolism , Adipocytes/cytology , Animals , DNA-Binding Proteins/genetics , Mice , Mice, Knockout , NIMA-Interacting Peptidylprolyl Isomerase/genetics , Protein Binding , Transcription Factors/genetics , Transcription, Genetic/physiology , Ubiquitination/physiology
19.
Sci Rep ; 9(1): 3825, 2019 03 07.
Article in English | MEDLINE | ID: mdl-30846715

ABSTRACT

It is well known that dental pulp tissue can evoke some of the most severe acute inflammation observed in the human body. We found that dental pulp cells secrete a factor that induces tumor necrosis factor-α production from macrophages, and designated this factor, dental pulp cell-derived powerful inducer of TNF-α (DPIT). DPIT was induced in dental pulp cells and transported to recipient cells via microvesicles. Treatment of dental pulp cells with a PKR inhibitor markedly suppressed DPIT activity, and weak interferon signals were constitutively activated inside the cells. In recipient macrophages, stimulation with DPIT-containing supernatants from pulp cells resulted in activation of both nuclear factor-κB and MAP kinases like JNK and p38. Proteomics analyses revealed that many stress granule-related proteins were present in supernatants from dental pulp cells as well as microvesicle marker proteins like GAPDH, ß-actin, HSPA8, HSPB1, HSPE1, and HSPD1. Furthermore, giant molecule AHNAK and PKR were detected in microvesicles derived from dental pulp cells, and gene silencing of AHNAK in dental pulp cells led to reduced DPIT activity. Thus, it appeared that the core protein of DPIT was PKR, and that PKR was maintained in an active state in stress granule aggregates with AHNAK and transported via microvesicles. The activity of DPIT for TNF-α induction was far superior to that of gram-negative bacterial endotoxin. Therefore, we, report for the first time, that active PKR is transported via microvesicles as stress granule aggregates and induces powerful inflammatory signals in macrophages.


Subject(s)
Cell-Derived Microparticles/metabolism , Dental Pulp/metabolism , Tumor Necrosis Factor-alpha/metabolism , Cell Line , Cells, Cultured , Humans , Inflammation/metabolism , JNK Mitogen-Activated Protein Kinases/metabolism , Macrophages/metabolism , Monocytes/metabolism , Signal Transduction
20.
ACS Biomater Sci Eng ; 3(8): 1809-1814, 2017 Aug 14.
Article in English | MEDLINE | ID: mdl-33429661

ABSTRACT

Highly water-soluble cationic palladium porphyrin as a sensitizer and 9,10-bis(4-trimethylammoniumphenyl)anthracene as an emitter were newly synthesized. They were shown to be bound and immobilized in DNA double helix assembly from absorption, fluorescence, phosphorescence, and circular dichroism spectra. Upon excitation at 532 nm in deaerated aqueous solutions, they showed weak blue upconversion fluorescence, the efficiency of which increased dramatically in the presence of DNA. The threshold power density between the second-order and first-order power dependence of upconversion fluorescence decreased to less than a half upon addition of DNA. The emitter triplet lifetime estimated from time dependences of upconversion fluorescence at low power ns pulsed laser was found to considerably increase in the presence of DNA. From these results, DNA was concluded to work effectively in concentrating both sensitizer and emitter and in migrating excited triplet states, resulting in efficient upconversion.

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