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Neutrophils are primed for neutrophil extracellular trap (NET) formation during diabetes, and excessive NET formation from primed neutrophils compromises wound healing in patients with diabetes. Here, we demonstrate that trained immunity mediates diabetes-induced NET priming in neutrophils. Under diabetic conditions, neutrophils exhibit robust metabolic reprogramming comprising enhanced glycolysis via the pentose phosphate pathway and fatty acid oxidation, which result in the accumulation of acetyl-coenzyme A. Adenosine 5'-triphosphate-citrate lyase-mediated accumulation of acetyl-coenzyme A and histone acetyltransferases further induce the acetylation of lysine residues on histone 3 (AcH3K9, AcH3K14, and AcH3K27) and histone 4 (AcH4K8). The pharmacological inhibition of adenosine 5'-triphosphate-citrate lyase and histone acetyltransferases completely inhibited high-glucose-induced NET priming. The trained immunity of neutrophils was further confirmed in neutrophils isolated from patients with diabetes. Our findings suggest that trained immunity mediates functional changes in neutrophils in diabetic environments, and targeting neutrophil-trained immunity may be a potential therapeutic target for controlling inflammatory complications of diabetes.
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BACKGRUOUND: CycloZ, a combination of cyclo-His-Pro and zinc, has anti-diabetic activity. However, its exact mode of action remains to be elucidated. METHODS: KK-Ay mice, a type 2 diabetes mellitus (T2DM) model, were administered CycloZ either as a preventive intervention, or as a therapy. Glycemic control was evaluated using the oral glucose tolerance test (OGTT), and glycosylated hemoglobin (HbA1c) levels. Liver and visceral adipose tissues (VATs) were used for histological evaluation, gene expression analysis, and protein expression analysis. RESULTS: CycloZ administration improved glycemic control in KK-Ay mice in both prophylactic and therapeutic studies. Lysine acetylation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha, liver kinase B1, and nuclear factor-κB p65 was decreased in the liver and VATs in CycloZ-treated mice. In addition, CycloZ treatment improved mitochondrial function, lipid oxidation, and inflammation in the liver and VATs of mice. CycloZ treatment also increased the level of ß-nicotinamide adenine dinucleotide (NAD+), which affected the activity of deacetylases, such as sirtuin 1 (Sirt1). CONCLUSION: Our findings suggest that the beneficial effects of CycloZ on diabetes and obesity occur through increased NAD+ synthesis, which modulates Sirt1 deacetylase activity in the liver and VATs. Given that the mode of action of an NAD+ booster or Sirt1 deacetylase activator is different from that of traditional T2DM drugs, CycloZ would be considered a novel therapeutic option for the treatment of T2DM.
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Diabetes Mellitus Tipo 2 , Hiperglucemia , Ratones , Animales , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Lisina/metabolismo , Lisina/uso terapéutico , Metabolismo de los Lípidos , Sirtuina 1/genética , Sirtuina 1/metabolismo , Sirtuina 1/uso terapéutico , NAD/metabolismo , NAD/uso terapéutico , Acetilación , Hiperglucemia/tratamiento farmacológicoRESUMEN
Ca2+ overload-induced mitochondrial dysfunction is considered as a major contributing factor in the pathogenesis of alcohol-associated liver disease (ALD). However, the initiating factors that drive mitochondrial Ca2+ accumulation in ALD remain elusive. Here, we demonstrate that an aberrant increase in hepatic GRP75-mediated mitochondria-associated ER membrane (MAM) Ca2+-channeling (MCC) complex formation promotes mitochondrial dysfunction in vitro and in male mouse model of ALD. Unbiased transcriptomic analysis reveals PDK4 as a prominently inducible MAM kinase in ALD. Analysis of human ALD cohorts further corroborate these findings. Additional mass spectrometry analysis unveils GRP75 as a downstream phosphorylation target of PDK4. Conversely, non-phosphorylatable GRP75 mutation or genetic ablation of PDK4 prevents alcohol-induced MCC complex formation and subsequent mitochondrial Ca2+ accumulation and dysfunction. Finally, ectopic induction of MAM formation reverses the protective effect of PDK4 deficiency in alcohol-induced liver injury. Together, our study defines a mediatory role of PDK4 in promoting mitochondrial dysfunction in ALD.
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Retículo Endoplásmico , Hepatopatías , Ratones , Animales , Masculino , Humanos , Retículo Endoplásmico/metabolismo , Mitocondrias , Hepatopatías/metabolismoRESUMEN
BACKGROUND: Acellular dermal matrix (ADM) is composed of extracellular matrix (ECM) and is widely used in implant-based breast reconstructions. However, long-term changes in the ADM around implants have not been established. This study aimed to investigate long-term changes in the ADM covering breast implants using serial ultrasound and histologic evaluations. METHODS: The authors evaluated the ultrasound results of 145 patients who underwent implant-based breast reconstructions with ADM coverings. The ultrasound results obtained within 18 months of surgery and those obtained 5 years postoperatively were analyzed to determine the change in ADM thickness. For histologic analysis, the ADM was harvested from 30 patients who underwent secondary breast surgery. Histologic features of the ECM and cellular components within the ADM were compared at specific intervals from ADM implantation and the second operation (early ADM group, <18 months; late ADM group, >5 years postoperatively). RESULTS: The ADM thickness on ultrasound examination was significantly decreased in the late ADM group compared with that in the early ADM group ( P < 0.001). Histologic analyses revealed that the late ADM group had less thickness with lower ECM levels versus the early ADM group. Increased infiltration of host cells, such as vascular endothelial cells, myofibroblasts, and immune cells, occurred in the late ADM group. CONCLUSIONS: Implanted ADMs underwent gradual thinning over time, in addition to ECM reduction and infiltration of host cells. These findings are useful in understanding the natural course of ADMs currently used in implant-based breast reconstructions. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.
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Dermis Acelular , Implantación de Mama , Implantes de Mama , Mamoplastia , Humanos , Células Endoteliales , Mamoplastia/métodos , Implantación de Mama/métodosRESUMEN
BACKGROUND: Adipose-derived stem cells (ASCs) have been reported to reduce fibrosis in various tissues. In this study, we investigated the inhibitory role of ASCs on capsule formation by analyzing the histologic, cellular, and molecular changes in a mouse model of peri-implant fibrosis. We also investigated the fate and distribution of ASCs in the peri-implant capsule. METHODS: To establish a peri-implant fibrosis model, customized silicone implants were inserted into the dorsal site of C57BL/6 wild-type mice. ASCs were harvested from the fat tissues of transgenic mice that express a green fluorescent protein (GFP-ASCs) and then injected into the peri-implant space of recipient mice. The peri-implant tissues were harvested from postoperative week 2 to 8. We measured the capsule thickness, distribution, and differentiation of GFP-ASCs, as well as the cellular and molecular changes in capsular tissue following ASC treatment. RESULTS: Injected GFP-ASCs were distributed within the peri-implant capsule and proliferated. Administration of ASCs reduced the capsule thickness, decreased the number of myofibroblasts and macrophages in the capsule, and decreased the mRNA level of fibrogenic genes within the peri-implant tissue. Angiogenesis was enhanced due to trans-differentiation of ASCs into vascular endothelial cells, and tissue hypoxia was relieved upon ASC treatment. CONCLUSIONS: We uncovered that implanted ASCs inhibit capsule formation around the implant by characterizing a series of biological alterations upon ASC treatment and the fate of injected ASCs. These findings highlight the value of ASCs for future clinical applications in the prevention of capsular contracture after implant-based reconstruction surgery.
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Tejido Adiposo , Células Endoteliales , Ratones , Animales , Proteínas Fluorescentes Verdes , Ratones Endogámicos C57BL , Fibrosis , Ratones Transgénicos , Células MadreRESUMEN
BACKGROUND: Although implant-based breast reconstruction is a common surgical modality, a periprosthetic capsule inevitably forms and worsens in cases of postmastectomy radiation therapy. Previous animal studies have reported that antiadhesive agents (AAAs) inhibit periprosthetic capsule formation. The authors prospectively examined the clinical effects of an AAA (Mediclore) on capsule formation in implant-based breast reconstruction. METHODS: The authors analyzed patients who underwent immediate two-stage implant-based breast reconstruction following total mastectomy for breast malignancy between November of 2018 and March of 2019. Each patient was randomly allocated to the control or AAA group. After inserting the breast expander and acellular dermal matrix, AAA was applied around the expander before skin closure. The capsule specimen was obtained during the expander-implant change; capsule thickness and immunohistochemistry were investigated. RESULTS: A total of 48 patients were enrolled and allocated to the control ( n = 22) and AAA ( n = 26) groups. There were no significant differences in patient- and operation-related characteristics. Submuscular capsule thickness was significantly reduced in the AAA group compared with the control group. The levels of pro-capsular-forming cells (myofibroblasts, fibroblasts, and M1 macrophages) in the capsule were significantly lower in the AAA group than in the control group. CONCLUSIONS: AAA reduced the thickness of periprosthetic capsules and changed the profiles of cells involved in capsule formation during the tissue expansion. These findings demonstrate the clinical value of AAA for mitigating capsule formation in implant-based breast reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.
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Dermis Acelular , Implantación de Mama , Implantes de Mama , Mamoplastia , Implantación de Mama/efectos adversos , Mastectomía/efectos adversos , Dispositivos de Expansión Tisular , Expansión de Tejido , Implantes de Mama/efectos adversos , Estudios RetrospectivosRESUMEN
Autologous fat grafting is among the safest and most effective treatments for soft-tissue restoration and augmentation, and many efforts have been made to improve its efficiency, including adipose-derived stem cell (ASC) supplementation. Here, we investigated the role of Notch ligand Delta-like ligand 4 (Dll4) in angiogenesis within grafted fat and its effect on graft retention, as well as the effect of Dll4 inhibition on ASC supplementation. Using a murine fat graft model, we investigated the expression of Dll4 in fat grafts and assessed the graft volume, vascularity, and perfusion within the graft, and ASC differentiation patterns depending on the blockade of Dll4. The underlying mechanism of Dll4 inhibition on ASC supplemented fat grafts was investigated using transcriptome analysis. Dll4 was highly expressed in vascular endothelial cells (ECs) within grafted fat, where Dll4-blocking antibody treatment-induced angiogenesis, promoting fat graft retention. In addition, its effect on fat graft retention was synergistically improved when ASCs were concomitantly supplemented. The expression of junctional proteins was increased in ECs, and inflammatory processes were downregulated in grafted fat upon ASC supplementation and Dll4 inhibition. Dll4 inhibition induced vascularization within the grafted fat, thereby promoting graft retention and exhibiting synergistic effects with concomitant ASC supplementation. This study serves as a basis for developing new potential therapeutic approaches targeting Dll4 to improve graft retention after cell-assisted transfer.
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Proteínas Adaptadoras Transductoras de Señales , Tejido Adiposo , Proteínas de Unión al Calcio , Células Endoteliales , Supervivencia de Injerto , Proteínas Adaptadoras Transductoras de Señales/fisiología , Tejido Adiposo/trasplante , Animales , Proteínas de Unión al Calcio/fisiología , Supervivencia de Injerto/fisiología , Ratones , Células MadreRESUMEN
BACKGROUND: Acellular dermal matrix (ADM) in implant-based breast reconstruction can show various ultrasound (US) findings. However, there are limited reports on the US features of the ADM. The aims of this study were to evaluate US findings of the ADM in implant-based breast reconstruction and correlate them with histopathological findings. METHODS: Between January 2015 and August 2020, 250 women who underwent implant-based breast reconstruction with ADM and a breast US examination at 6 months to 1 year after reconstruction were retrospectively analyzed. Abnormal US findings were classified as type 1 (focal thickening with decreased echogenicity), 2 (diffusely hyperechoic), or 3 (bright echogenic spots). ADM biopsy was performed in 33 patients who underwent second stage or revisional surgeries. RESULTS: In total, 176 consecutive women with 207 US findings were analyzed. The US findings were normal in 52.2% of the women. The percentages of type 1, 2, and 3 patients were 13.5%, 11.1%, and 23. 2%, respectively. These patients had microscopic findings that showed patchy areas with chronic inflammatory infiltrates, dense collagen bundles without degenerative or inflammatory changes, and empty spaces or degenerated foci unaccompanied by inflammation. CONCLUSION: Knowing the various ADM presentations on US can help avoid unnecessary invasive procedures.
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Dyslipidemia-induced atherosclerosis, which has a risk of high morbidity and mortality, can be alleviated by metabolic activation associated with mitochondrial function. The effect of dichloroacetate (DCA), a general pyruvate dehydrogenase kinase (PDK) inhibitor, on in vivo energy expenditure in ApoE-/- mice fed a western diet (WD) has not yet been investigated. WD-fed ApoE-/- mice developed atherosclerotic plaques and hyperlipidemia along with obesity, which were significantly ameliorated by DCA administration. Increased oxygen consumption was associated with heat production in the DCA-treated group, with no change in food intake or physical activity compared with those of the control. These processes were correlated with the increased gene expression of Dio2 and Ucp-1, which represents brown adipose tissue (BAT) activation, in both WD-induced atherosclerosis and high-fat-induced obesity models. In addition, we found that DCA stimulated hepatic fibroblast growth factor 21 (Fgf21) mRNA expression, which might be important for lowering lipid levels and insulin sensitization via BAT activation, in a dose- and time-dependent manner associated with serum FGF21 levels. Interestingly, Fgf21 mRNA expression was mediated in an AMP-activated protein kinase (AMPK)-dependent manner within several minutes after DCA treatment independent of peroxisome proliferator-activated receptor alpha (PPARα). Taken together, the results suggest that enhanced glucose oxidation by DCA protects against atherosclerosis by inducing hepatic FGF21 expression and BAT activation, resulting in augmented energy expenditure for heat generation.
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Proteínas Quinasas Activadas por AMP/genética , Aterosclerosis/tratamiento farmacológico , Fármacos Cardiovasculares/farmacología , Ácido Dicloroacético/farmacología , Inhibidores Enzimáticos/farmacología , Factores de Crecimiento de Fibroblastos/genética , Placa Aterosclerótica/tratamiento farmacológico , Proteínas Quinasas Activadas por AMP/metabolismo , Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Pardo/patología , Animales , Apolipoproteínas E/deficiencia , Apolipoproteínas E/genética , Aterosclerosis/etiología , Aterosclerosis/genética , Aterosclerosis/patología , Dieta Occidental/efectos adversos , Dislipidemias/tratamiento farmacológico , Dislipidemias/etiología , Dislipidemias/genética , Dislipidemias/patología , Metabolismo Energético/efectos de los fármacos , Factores de Crecimiento de Fibroblastos/agonistas , Factores de Crecimiento de Fibroblastos/metabolismo , Regulación de la Expresión Génica , Yoduro Peroxidasa/genética , Yoduro Peroxidasa/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Obesidad/tratamiento farmacológico , Obesidad/etiología , Obesidad/genética , Obesidad/patología , Consumo de Oxígeno/efectos de los fármacos , PPAR alfa/genética , PPAR alfa/metabolismo , Placa Aterosclerótica/etiología , Placa Aterosclerótica/genética , Placa Aterosclerótica/patología , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora/antagonistas & inhibidores , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora/genética , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo , Yodotironina Deyodinasa Tipo IIRESUMEN
Mitochondrial dysfunction is a hallmark of metabolic diseases such as obesity, type 2 diabetes mellitus, neurodegenerative diseases, and cancers. Dysfunction occurs in part because of altered regulation of the mitochondrial pyruvate dehydrogenase complex (PDC), which acts as a central metabolic node that mediates pyruvate oxidation after glycolysis and fuels the Krebs cycle to meet energy demands. Fine-tuning of PDC activity has been mainly attributed to post-translational modifications of its subunits, including the extensively studied phosphorylation and de-phosphorylation of the E1α subunit of pyruvate dehydrogenase (PDH), modulated by kinases (pyruvate dehydrogenase kinase [PDK] 1-4) and phosphatases (pyruvate dehydrogenase phosphatase [PDP] 1-2), respectively. In addition to phosphorylation, other covalent modifications, including acetylation and succinylation, and changes in metabolite levels via metabolic pathways linked to utilization of glucose, fatty acids, and amino acids, have been identified. In this review, we will summarize the roles of PDC in diverse tissues and how regulation of its activity is affected in various metabolic disorders.
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In fasting or diabetes, gluconeogenic genes are transcriptionally activated by glucagon stimulation of the cAMP-protein kinase A (PKA)-CREB signaling pathway. Previous work showed pyruvate dehydrogenase kinase (PDK) inhibition in skeletal muscle increases pyruvate oxidation, which limits the availability of gluconeogenic substrates in the liver. However, this study found upregulation of hepatic PDK4 promoted glucagon-mediated expression of gluconeogenic genes, whereas knockdown or inhibition of hepatic PDK4 caused the opposite effect on gluconeogenic gene expression and decreased hepatic glucose production. Mechanistically, PDK4 deficiency decreased ATP levels, thus increasing phosphorylated AMPK (p-AMPK), which increased p-AMPK-sensitive phosphorylation of cyclic nucleotide phosphodiesterase 4B (p-PDE4B). This reduced cAMP levels and consequently p-CREB. Metabolic flux analysis showed that the reduction in ATP was a consequence of a diminished rate of fatty acid oxidation (FAO). However, overexpression of PDK4 increased FAO and increased ATP levels, which decreased p-AMPK and p-PDE4B and allowed greater accumulation of cAMP and p-CREB. The latter were abrogated by the FAO inhibitor etomoxir, suggesting a critical role for PDK4 in FAO stimulation and the regulation of cAMP levels. This finding strengthens the possibility of PDK4 as a target against diabetes.
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AMP Cíclico/metabolismo , Glucagón/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Western Blotting , Células Cultivadas , Gluconeogénesis/efectos de los fármacos , Prueba de Tolerancia a la Glucosa , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Isoquinolinas/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Serina-Treonina Quinasas/deficiencia , Proteínas Serina-Treonina Quinasas/genética , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora , Reacción en Cadena en Tiempo Real de la Polimerasa , Sulfonamidas/farmacología , Triglicéridos/metabolismoRESUMEN
Hepatic steatosis is associated with increased insulin resistance and tricarboxylic acid (TCA) cycle flux, but decreased ketogenesis and pyruvate dehydrogenase complex (PDC) flux. This study examined whether hepatic PDC activation by inhibition of pyruvate dehydrogenase kinase 2 (PDK2) ameliorates these metabolic abnormalities. Wild-type mice fed a high-fat diet exhibited hepatic steatosis, insulin resistance, and increased levels of pyruvate, TCA cycle intermediates, and malonyl-CoA but reduced ketogenesis and PDC activity due to PDK2 induction. Hepatic PDC activation by PDK2 inhibition attenuated hepatic steatosis, improved hepatic insulin sensitivity, reduced hepatic glucose production, increased capacity for ß-oxidation and ketogenesis, and decreased the capacity for lipogenesis. These results were attributed to altered enzymatic capacities and a reduction in TCA anaplerosis that limited the availability of oxaloacetate for the TCA cycle, which promoted ketogenesis. The current study reports that increasing hepatic PDC activity by inhibition of PDK2 ameliorates hepatic steatosis and insulin sensitivity by regulating TCA cycle anaplerosis and ketogenesis. The findings suggest PDK2 is a potential therapeutic target for nonalcoholic fatty liver disease.
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Hígado Graso/enzimología , Hígado Graso/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Ciclo del Ácido Cítrico/genética , Ciclo del Ácido Cítrico/fisiología , Dieta Alta en Grasa/efectos adversos , Hígado Graso/etiología , Glucosa/metabolismo , Resistencia a la Insulina , Lipogénesis/fisiología , Hígado/metabolismo , Hígado/patología , Masculino , Malonil Coenzima A/metabolismo , Ratones , Ratones Noqueados , Ácido Oxaloacético/metabolismo , Proteínas Serina-Treonina Quinasas/deficiencia , Proteínas Serina-Treonina Quinasas/genética , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora , Complejo Piruvato Deshidrogenasa/metabolismo , Ácido Pirúvico/metabolismoRESUMEN
Central serotonin (5-HT) is an anorexigenic neurotransmitter in the brain. However, accumulating evidence suggests peripheral 5-HT may affect organismal energy homeostasis. Here we show 5-HT regulates white and brown adipose tissue function. Pharmacological inhibition of 5-HT synthesis leads to inhibition of lipogenesis in epididymal white adipose tissue (WAT), induction of browning in inguinal WAT and activation of adaptive thermogenesis in brown adipose tissue (BAT). Mice with inducible Tph1 KO in adipose tissues exhibit a similar phenotype as mice in which 5-HT synthesis is inhibited pharmacologically, suggesting 5-HT has localized effects on adipose tissues. In addition, Htr3a KO mice exhibit increased energy expenditure and reduced weight gain when fed a high-fat diet. Treatment with an Htr2a antagonist reduces lipid accumulation in 3T3-L1 adipocytes. These data suggest important roles for adipocyte-derived 5-HT in controlling energy homeostasis.
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Adipogénesis/genética , Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Homeostasis/genética , Obesidad/metabolismo , Serotonina/metabolismo , Células 3T3-L1 , Adipocitos Marrones/metabolismo , Adipocitos Marrones/patología , Adipocitos Blancos/metabolismo , Adipocitos Blancos/patología , Tejido Adiposo Pardo/patología , Tejido Adiposo Blanco/patología , Animales , Dieta Alta en Grasa , Metabolismo Energético/genética , Epidídimo/metabolismo , Epidídimo/patología , Expresión Génica , Masculino , Ratones , Ratones Noqueados , Obesidad/etiología , Obesidad/patología , Receptor de Serotonina 5-HT2A/genética , Receptor de Serotonina 5-HT2A/metabolismo , Receptores de Serotonina 5-HT3/deficiencia , Receptores de Serotonina 5-HT3/genética , Termogénesis/genética , Triptófano Hidroxilasa/deficiencia , Triptófano Hidroxilasa/genéticaRESUMEN
OBJECTIVE: We analyzed information surveyed from a community-based sample of Korean women older than 40 years of age to understand the relationships between health status and screening behavior. METHODS: In a cross-sectional population-based study, a two-stage, geographically stratified household-based sampling design was used for assembly of a probability sample of women aged 40-69 years living in Gunpo in Korea, resulting in a total sample size of 503 women. The primary outcome variable for this analysis was the respondent's intention to obtain a mammogram. Predictor variables included health status and other factors known to influence the use of cancer screening, such as age, education, income, marital status and the presence of co-morbid illnesses. Health status was assessed by using the EuroQol (EQ-5D). RESULTS: The median EQ visual analogue scale score was 75.0, ranging from 20 to 100. In bivariate analyses, the percentage of women reporting to have intention toward mammography use decreased with worsening health status. Women who had problems with mobility or anxiety/depression showed lower intention to undergo future screening mammography. Multivariate logistic regression confirmed that health status was significantly associated with intention toward mammography use. Anxiety or depression was an independent predictor of future screening mammography use. CONCLUSIONS: Health status is significantly associated with intention regarding screening mammography use. Physicians or other health professionals should be aware that health status is an important component for health promotion, and should pay more attention to clients' possible vulnerability in screening mammography use due to their poor health status.