Adrenomedullin2 stimulates progression of thyroid cancer in mice and humans under nutrient excess conditions.

Thyroid cancer is associated with genetic alterations, e.g. BRAFV600E , which may cause carcinomatous changes in hormone-secreting epithelial cells. Epidemiological studies have shown that overnutrition is related to the development and progression of cancer. In this study, we attempted to identify the cell nonautonomous factor responsible for the progression of BRAFV600E thyroid cancer under overnutrition conditions. We developed a mouse model for inducible thyrocyte-specific activation of BRAFV600E , which showed features similar to those of human papillary thyroid cancer. LSL-BrafV600E ;TgCreERT2 showed thyroid tumour development in the entire thyroid, and the tumour showed more abnormal cellular features with mitochondrial abnormalities in mice fed a high-fat diet (HFD). Transcriptomics revealed that adrenomedullin2 (Adm2) was increased in LSL-BrafV600E ;TgCreERT2 mice fed HFD. ADM2 was upregulated on the addition of a mitochondrial complex I inhibitor or palmitic acid with integrated stress response (ISR) in cancer cells. ADM2 stimulated protein kinase A and extracellular signal-regulated kinase in vitro. The knockdown of ADM2 suppressed the proliferation and migration of thyroid cancer cells. We searched The Cancer Genome Atlas and Genotype-Tissue Expression databases and found that increased ADM2 expression was associated with ISR and poor overall survival. Consistently, upregulated ADM2 expression in tumour cells and circulating ADM2 molecules were associated with aggressive clinicopathological parameters, including body mass index, in thyroid cancer patients. Collectively, we identified that ADM2 is released from cancer cells under mitochondrial stress resulting from overnutrition and acts as a secretory factor determining the progressive properties of thyroid cancer. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Dsg2-mediated c-Met activation in anaplastic thyroid cancer motility and invasion.

Anaplastic thyroid cancer (ATC) is a rapidly growing, highly metastatic cancer with limited therapeutic alternatives, thus targeted therapies need to be developed. This study aimed to examine desmoglein 2 (Dsg2) expression in ATC and its biological role and potential as a therapeutic target in ATC. Consequently, Dsg2 was downregulated or aberrantly expressed in ATC tissues. ATC patients with low Dsg2 expression levels also presented with distant metastasis. Dsg2 depletion significantly increased cell migration and invasion, with a relatively limited effect on ATC cell proliferation in vitro and increased distant metastasis in vivo. Dsg2 knockdown induced cell motility through the hepatocyte growth factor receptor (HGFR, c-Met)/Src/Rac1 signaling axis, with no alterations in the expression of EMT-related molecules. Further, specific targeting of c-Met significantly inhibited the motility of shDsg2-depleted ATC cells. Decreased membrane Dsg2 expression increased the metastatic potential of ATC cells. These results indicate that Dsg2 plays an important role in ATC cell migration and invasiveness. Therapies targeting c-Met might be effective among ATC patients with low membrane Dsg2 expression levels, indicating that the analysis of Dsg2 expression potentially provides novel insights into treatment strategies for ATC.

A Phase II Multi-Center, Non-Randomized, Parallel Group, Non-Inferiority Study to Compare the Efficacy of No Radioactive Iodine Remnant Ablation to Remnant Ablation Treatment in Low- to Intermediate-Risk of Papillary Thyroid Cancer: The MOREthyroid Trial Protocol.

BACKGROUND: Radioactive iodine (RAI) remnant ablation is recommended in patients with papillary thyroid cancer (PTC) and extrathyroidal extension or central lymph node metastasis. However, there exists little evidence about the necessity of remnant ablation in PTC patients with low- to intermediate-risk, those have been increasing in recent decades. METHODS: This multicenter, prospective, non-randomized, parallel group clinical trial will enroll 310 eligible patients with low- to intermediate-risk of thyroid cancer. Inclusion criteria are patients who recently underwent total thyroidectomy for PTC with 3 or less tumors of size 1≤ to ≤2 cm with no microscopic extension and N0/x, or size ≤2 cm with microscopic extension and/or N1a (number of lymph node ≤3, size of tumor foci ≤0.2 cm, and lymph node ratio <0.4). Patients choose to undergo RAI ablation (131I, dose 1.1 GBq) or diagnostic whole-body scan (DxWBS) (131I or 123I, dose 0.074 to 0.222 GBq), followed by subsequent measurement of stimulated thyroglobulin (sTg) within 1 year. Survey for quality of life (QOL) will be performed at baseline and at 1 year after follow-up. The total enrollment period is 5 years, and patients will be followed up for 1 year. The primary endpoint is the non-inferiority of surgery alone to surgery with ablation in terms of biochemical remission (BCR) rate (sTg ≤2 ng/mL) without evidence of structural recurrence. The secondary endpoint was the difference of QOL. CONCLUSION: This study will evaluate whether surgery alone achieves similar BCR and improved QOL compared to RAI ablation in patients with low- to intermediate-risk PTC within 1 year.

Genetic Analysis of CLCN7 in an Old Female Patient with Type II Autosomal Dominant Osteopetrosis.

BACKGROUND: Type II autosomal dominant osteopetrosis (ADO II) is a rare genetically heterogeneous disorder characterized by osteosclerosis and increased bone mass, predominantly involving spine, pelvis, and skull. It is closely related to functional defect of osteoclasts caused by chloride voltage-gated channel 7 (CLCN7) gene mutations. In this study, we aimed to identify the pathogenic mutation in a Korean patient with ADO II using whole exome sequencing. METHODS: We evaluated the clinical, biochemical, and radiographic analysis of a 68-year-old woman with ADO II. We also performed whole exome sequencing to identify pathogenic mutation of a rare genetic disorder of the skeleton. Moreover, a polymorphism phenotyping program, Polymorphism Phenotyping v2 (PolyPhen-2), was used to assess the effect of the identified mutation on protein function. RESULTS: Whole exome sequencing using peripheral leukocytes revealed a heterozygous c.296A>G missense mutation in the CLCN7 gene. The mutation was also confirmed using Sanger sequencing. The mutation c.296A>G was regarded to have a pathogenic effect by PolyPhen-2 software. CONCLUSION: We detect a heterozygous mutation in CLCN7 gene of a patient with ADO II, which is the first report in Korea. Our present findings suggest that symptoms and signs of ADO II patient having a c.296A>G mutation in CLCN7 may appear at a very late age. The present study would also enrich the database of CLCN7 mutations and improve our understanding of ADO II.

Loss-of-function of IFT88 determines metabolic phenotypes in thyroid cancer.

Primary cilia are microtubule-based, dynamic organelles characterized by continuous assembly and disassembly. The intraflagellar transport (IFT) machinery, including IFT88 in cilia, is involved in the maintenance of bidirectional motility along the axonemes, which is required for ciliogenesis and functional competence. Cancer cells are frequently associated with loss of primary cilia and IFT functions. However, there is little information on the role of IFT88 or primary cilia in the metabolic remodeling of cancer cells. Therefore, we investigated the cellular and metabolic effects of the loss-of-function (LOF) mutations of IFT88/primary cilia in thyroid cancer cells. IFT88-deficient 8505C thyroid cancer cells were generated using the CRISPR/Cas9 system, and RNA-sequencing analysis was performed. LOF of the IFT88 gene resulted in a marked defect in ciliogenesis and mitochondrial oxidative function. Gene expression patterns in IFT88-deficient thyroid cancer cells favored glycolysis and lipid biosynthesis. However, LOF of IFT88/primary cilia did not promote thyroid cancer cell proliferation, migration, and invasion. The results suggest that IFT88/primary cilia play a role in metabolic reprogramming in thyroid cancer cells.

Clinical Implications of UCP1 mRNA Expression in Human Cervical Adipose Tissue Under Physiological Conditions.

OBJECTIVE: The clinical implications of human brown adipose tissue (BAT) were investigated based on the analysis of cervical adipose tissue gene expression under normal physiological conditions. METHODS: Matched-pair specimens of adipose tissue (AT) were collected from beneath the incision plane (subcutaneous AT) and from the area surrounding the carotid sheath (carotid AT) from 60 patients undergoing thyroidectomy. The mRNA expression of BAT-associated genes in these tissues was examined, and this expression was correlated with the clinical characteristics of the subjects. RESULTS: The UCP1 mRNA level was significantly higher in the carotid AT than in the subcutaneous AT. There was an inverse correlation between subject age and the ratio of UCP1 mRNA expression in the carotid AT relative to the subcutaneous AT, which is a measure of BAT activity (r = -0.459; P = 0.004), and there was a negative correlation between BMI and the ratio of UCP1 mRNA expression in subjects with higher BAT activity (r = -0.532; P = 0.016). CONCLUSIONS: UCP1 was identified as the only marker of cervical BAT in humans. There was a negative correlation between obesity and BAT activity in subjects with higher BAT activity, although BAT activity decreased with age.

Reduced oxidative capacity in macrophages results in systemic insulin resistance.

Oxidative functions of adipose tissue macrophages control the polarization of M1-like and M2-like phenotypes, but whether reduced macrophage oxidative function causes systemic insulin resistance in vivo is not clear. Here, we show that mice with reduced mitochondrial oxidative phosphorylation (OxPhos) due to myeloid-specific deletion of CR6-interacting factor 1 (Crif1), an essential mitoribosomal factor involved in biogenesis of OxPhos subunits, have M1-like polarization of macrophages and systemic insulin resistance with adipose inflammation. Macrophage GDF15 expression is reduced in mice with impaired oxidative function, but induced upon stimulation with rosiglitazone and IL-4. GDF15 upregulates the oxidative function of macrophages, leading to M2-like polarization, and reverses insulin resistance in ob/ob mice and HFD-fed mice with myeloid-specific deletion of Crif1. Thus, reduced macrophage oxidative function controls systemic insulin resistance and adipose inflammation, which can be reversed with GDF15 and leads to improved oxidative function of macrophages.

Proteomic Analysis of Urothelium of Rats with Detrusor Overactivity Induced by Bladder Outlet Obstruction.

Overactive bladder (OAB) syndrome is a condition that has four symptoms: urgency, urinary frequency, nocturia, and urge incontinence and negatively affects a patient's life. Recently, it is considered that the urinary bladder urothelium is closely linked to pathogenesis of OAB. However, the mechanisms of pathogenesis of OAB at the molecular level remain poorly understood, mainly because of lack of modern molecular analysis. The goal of this study is to identify a potential target protein that could act as a predictive factor for effective diagnosis and aid in the development of therapeutic strategies for the treatment of OAB syndrome. We produced OAB in a rat model and performed the first proteomic analysis on the mucosal layer (urothelium) of the bladders of sham control and OAB rats. The resulting data revealed the differential expression of 355 proteins in the bladder urothelium of OAB rats compared with sham subjects. Signaling pathway analysis revealed that the differentially expressed proteins were mainly involved in the inflammatory response and apoptosis. Our findings suggest a new target for accurate diagnosis of OAB that can provide essential information for the development of drug treatment strategies as well as establish criteria for screening patients in the clinical environment.

GDF15 deficiency exacerbates chronic alcohol- and carbon tetrachloride-induced liver injury.

Growth differentiation factor 15 (GDF15) has recently been shown to have an important role in the regulation of mitochondrial function and in the pathogenesis of complex human diseases. Nevertheless, the role of GDF15 in alcohol-induced or fibrotic liver diseases has yet to be determined. In this study, we demonstrate that alcohol- or carbon tetrachloride (CCl4)-mediated hepatic GDF15 production ameliorates liver inflammation and fibrosis. Alcohol directly enhanced GDF15 expression in primary hepatocytes, which led to increased oxygen consumption. Moreover, GDF15 reduced the expression of pro-inflammatory cytokines in liver-resident macrophages, leading to an improvement in inflammation and fibrosis in the liver. GDF15 knockout (KO) mice had more TNF-α-producing T cells and more activated CD4+ and CD8+ T cells in the liver than wild-type mice. Liver-infiltrating monocytes and neutrophils were also increased in the GDF15 KO mice during liver fibrogenesis. These changes in hepatic immune cells were associated with increased tissue inflammation and fibrosis. Finally, recombinant GDF15 decreased the expression of pro-inflammatory cytokines and fibrotic mediators and prevented the activation of T cells in the livers of mice with CCl4-induced liver fibrosis. These results suggest that GDF15 could be a potential therapeutic target for the treatment of alcohol-induced and fibrotic liver diseases.

Growth Differentiation Factor 15 Mediates Systemic Glucose Regulatory Action of T-Helper Type 2 Cytokines.

T-helper type 2 (Th2) cytokines, including interleukin (IL)-13 and IL-4, produced in adipose tissue, are critical regulators of intra-adipose and systemic lipid and glucose metabolism. Furthermore, IL-13 is a potential therapy for insulin resistance in obese mouse models. Here, we examined mediators produced by adipocytes that are responsible for regulating systemic glucose homeostasis in response to Th2 cytokines. We used RNA sequencing data analysis of cultured adipocytes to screen factors secreted in response to recombinant IL-13. Recombinant IL-13 induced expression of growth differentiation factor 15 (GDF15) via the Janus kinase-activated STAT6 pathway. In vivo administration of α-galactosylceramide or IL-33 increased IL-4 and IL-13 production, thereby increasing GDF15 levels in adipose tissue and in plasma of mice; however, these responses were abrogated in STAT6 knockout mice. Moreover, administration of recombinant IL-13 to wild-type mice fed a high-fat diet (HFD) improved glucose intolerance; this was not the case for GDF15 knockout mice fed the HFD. Taken together, these data suggest that GDF15 is required for IL-13-induced improvement of glucose intolerance in mice fed an HFD. Thus, beneficial effects of Th2 cytokines on systemic glucose metabolism and insulin sensitivity are mediated by GDF15. These findings open up a potential pharmacological route for reversing insulin resistance associated with obesity.

The Eosinophil Count Tends to Be Negatively Associated with Levels of Serum Glucose in Patients with Adrenal Cushing Syndrome.

BACKGROUND: Cushing syndrome is characterized by glucose intolerance, cardiovascular disease, and an enhanced systemic inflammatory response caused by chronic exposure to excess cortisol. Eosinopenia is frequently observed in patients with adrenal Cushing syndrome, but the relationship between the eosinophil count in peripheral blood and indicators of glucose level in patients with adrenal Cushing syndrome has not been determined. METHODS: A retrospective study was undertaken of the clinical and laboratory findings of 40 patients diagnosed with adrenal Cushing syndrome at Chungnam National University Hospital from January 2006 to December 2016. Clinical characteristics, complete blood cell counts with white blood cell differential, measures of their endocrine function, description of imaging studies, and pathologic findings were obtained from their medical records. RESULTS: Eosinophil composition and count were restored by surgical treatment of all of the patients with adrenal Cushing disease. The eosinophil count was inversely correlated with serum and urine cortisol, glycated hemoglobin, and inflammatory markers in the patients with adrenal Cushing syndrome. CONCLUSION: Smaller eosinophil populations in patients with adrenal Cushing syndrome tend to be correlated with higher levels of blood sugar and glycated hemoglobin. This study suggests that peripheral blood eosinophil composition or count may be associated with serum glucose levels in patients with adrenal Cushing syndrome.

PDE 5 inhibitor improves insulin sensitivity by enhancing mitochondrial function in adipocytes.

Adipocytes are involved in many metabolic disorders. It was recently reported that phosphodiesterase type 5 (PDE5) is expressed in human adipose tissue. In addition, PDE5 inhibitors have been shown to improve insulin sensitivity in humans. However, the mechanism underlying the role of PDE5 inhibitors as an insulin sensitizer remains largely unknown. The present study was undertaken to investigate the role of the PDE5 inhibitor udenafil in insulin signaling in adipocytes and whether this is mediated through the regulation of mitochondrial function. To study the mechanism underlying the insulin sensitizing action of PDE5 inhibitors, we evaluated quantitative changes in protein or mRNA levels of mitochondrial oxidative phosphorylation (OxPhos) complex, oxygen consumption rate (OCR), and fatty acid oxidation with varying udenafil concentrations in 3T3-L1 cells. Our cell study suggested that udenafil enhanced the insulin signaling pathway in 3T3-L1 cells. Following udenafil treatment, basal mitochondrial OCR, maximal OxPhos capacity, and OxPhos gene expression significantly increased. Finally, we examined whether udenafil can affect the fatty acid oxidation process. Treatment of 3T3-L1 cells with udenafil (10 and 20 µM) significantly increased fatty acid oxidation rate in a dose-dependent manner. In addition, the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) significantly increased. We demonstrated that the PDE5 inhibitor udenafil enhances insulin sensitivity by improving mitochondrial function in 3T3-L1 cells. This might be the mechanism underlying the PDE5 inhibitor-enhanced insulin signaling in adipocytes. This also suggests that udenafil may provide benefit in the treatment of type 2 diabetes and other related cardiovascular diseases.

Oncogenes, mitochondrial metabolism, and quality control in differentiated thyroid cancer.

Thyroid cancer is one of the most common malignancies of endocrine organs, and its incidence rate has increased steadily over the past several decades. Most differentiated thyroid tumors derived from thyroid epithelial cells exhibit slow-growing cancers, and patients with these tumors can achieve a good prognosis with surgical removal and radioiodine treatment. However, a small proportion of patients present with advanced thyroid cancer and are unusually resistant to current drug treatment modalities. Thyroid tumorigenesis is a complex process that is regulated by the activation of oncogenes, inactivation of tumor suppressors, and alterations in programmed cell death. Mitochondria play an essential role during tumor formation, progression, and metastasis of thyroid cancer. Recent studies have successfully observed the mitochondrial etiology of thyroid carcinogenesis. This review focuses on the recent progress in understanding the molecular mechanisms of thyroid cancer relating to altered mitochondrial metabolism.

High Expression of Angiopoietin-1 is Associated with Lymph Node Metastasis and Invasiveness of Papillary Thyroid Carcinoma.

BACKGROUND: We investigated the expression of angiopoietins in patients with papillary thyroid carcinoma (PTC) and the role of angiopoietins as biomarkers predicting the aggressiveness of PTC. METHODS: Expression of angiopoietins was evaluated by immunohistochemistry of tumor specimens from patients with PTC. We demonstrated potential correlations between expression of angiopoietins and clinicopathologic features. RESULTS: High expression of Ang-1 was positively correlated with a tumor size >1 cm, capsular invasion, extrathyroid extension, lymphovascular invasion, lymph node metastasis, and recurrence (P < 0.05). Moreover, multivariate analysis revealed that high expression of Ang-1 was an independent risk factor for lymph node metastasis (P < 0.001, odds ratio [OR] = 62.113) and lymphovascular invasion (P = 0.027, OR 4.405). However, there was no significant correlation between Ang-2 and clinicopathologic features. CONCLUSIONS: Our results suggest that Ang-1 can serve as a valuable prognostic biomarker for lymph node metastasis and invasiveness in patients with PTC.

ANGPTL6 expression is coupled with mitochondrial OXPHOS function to regulate adipose FGF21.

Recent studies revealed that the inhibition of mitochondrial oxidative phosphorylation (OXPHOS) is coupled with the mitochondrial unfolded protein response, thereby stimulating the secretion of non-cell autonomous factors, which may control systemic energy metabolism and longevity. However, the nature and roles of non-cell autonomous factors induced in adipose tissue in response to reduced OXPHOS function remain to be clarified in mammals. CR6-interacting factor 1 (CRIF1) is an essential mitoribosomal protein for the intramitochondrial production of mtDNA-encoded OXPHOS subunits. Deficiency of CRIF1 impairs the proper formation of the OXPHOS complex, resulting in reduced function. To determine which secretory factors are induced in response to reduced mitochondrial OXPHOS function, we analyzed gene expression datasets in Crif1-depleted mouse embryonic fibroblasts. Crif1 deficiency preferentially increased the expression of angiopoietin-like 6 (Angptl6) and did not affect other members of the ANGPTL family. Moreover, treatment with mitochondrial OXPHOS inhibitors increased the expression of Angptl6 in cultured adipocytes. To confirm Angptl6 induction in vivo, we generated a murine model of reduced mitochondrial OXPHOS function using adipose tissue-specific Crif1-deficient mice and verified the upregulation of Angptl6 and fibroblast growth factor 21 (Fgf21) in white adipose tissue. Treatment with recombinant ANGPTL6 protein increased oxygen consumption and Pparα expression through the extracellular signal-regulated kinase/mitogen-activated protein kinase pathway in cultured adipocytes. Furthermore, the ANGPTL6-mediated increase in Pparα expression resulted in increased FGF21 expression, thereby promoting ß-oxidation. In conclusion, mitochondrial OXPHOS function governs the expression of ANGPTL6, which is an essential factor for FGF21 production in adipose tissue and cultured adipocytes.

Upregulation of RSPO2-GPR48/LGR4 signaling in papillary thyroid carcinoma contributes to tumor progression.

The signaling pathway involving the R-spondins and its cognate receptor, GPR48/LGR4, is crucial in development and carcinogenesis. However, the functional implications of the R-spondin-GPR48/LGR4 pathway in thyroid remain to be identified. The aim of this study was to investigate the role of R-spondin-GPR48/LGR4 signaling in papillary thyroid carcinomas. We retrospectively reviewed a total of 214 patients who underwent total thyroidectomy and cervical lymph node dissection for papillary thyroid carcinoma. The role of GPR48/LGR4 in proliferation and migration was examined in thyroid cancer cell lines. R-spondin 2, and GPR48/LGR4 were expressed at significantly higher levels in thyroid cancer than in normal controls. Elevated GPR48/LGR4 expression was significantly associated with tumor size (P=0.049), lymph node metastasis (P=0.004), recurrence (P=0.037), and the BRAFV600E mutation (P=0.003). Moreover, high GPR48/LGR4 expression was an independent risk factor for lymph node metastasis (P=0.027) and the BRAFV600E mutation (P=0.009). in vitro assays demonstrated that elevated expression of GPR48/LGR4 promoted proliferation and migration of thyroid cancer cells, whereas downregulation of GPR48/LGR4 decreased proliferation and migration by inhibition of the ß-catenin pathway. Moreover, treatment of thyroid cancer cells with exogenous R-spondin 2 induced activation of the ß-catenin pathway through GPR48/LGR4. The R-spondin 2-GPR48/LGR4 signaling axis also induced the phosphorylation of ERK, as well as phosphorylation of LRP6 and serine 9 of GSK3ß. Our findings demonstrate that upregulation of the R-spondin 2-GPR48/LGR4 pathway contributes to tumor aggressiveness in papillary thyroid carcinoma by promoting ERK phosphorylation, suggesting that this pathway represents a novel therapeutic target for treatment of differentiated thyroid cancer.

Growth differentiation factor 15 is a myomitokine governing systemic energy homeostasis.

Reduced mitochondrial electron transport chain activity promotes longevity and improves energy homeostasis via cell-autonomous and -non-autonomous factors in multiple model systems. This mitohormetic effect is thought to involve the mitochondrial unfolded protein response (UPRmt), an adaptive stress-response pathway activated by mitochondrial proteotoxic stress. Using mice with skeletal muscle-specific deficiency of Crif1 (muscle-specific knockout [MKO]), an integral protein of the large mitoribosomal subunit (39S), we identified growth differentiation factor 15 (GDF15) as a UPRmt-associated cell-non-autonomous myomitokine that regulates systemic energy homeostasis. MKO mice were protected against obesity and sensitized to insulin, an effect associated with elevated GDF15 secretion after UPRmt activation. In ob/ob mice, administration of recombinant GDF15 decreased body weight and improved insulin sensitivity, which was attributed to elevated oxidative metabolism and lipid mobilization in the liver, muscle, and adipose tissue. Thus, GDF15 is a potent mitohormetic signal that safeguards against the onset of obesity and insulin resistance.

Inhibiting poly ADP-ribosylation increases fatty acid oxidation and protects against fatty liver disease.

BACKGROUND & AIMS: To date, no pharmacological therapy has been approved for non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to evaluate the therapeutic potential of poly ADP-ribose polymerase (PARP) inhibitors in mouse models of NAFLD. METHODS: As poly ADP-ribosylation (PARylation) of proteins by PARPs consumes nicotinamide adenine dinucleotide (NAD+), we hypothesized that overactivation of PARPs drives NAD+ depletion in NAFLD. Therefore, we assessed the effectiveness of PARP inhibition to replenish NAD+ and activate NAD+-dependent sirtuins, hence improving hepatic fatty acid oxidation. To do this, we examined the preventive and therapeutic benefits of the PARP inhibitor (PARPi), olaparib, in different models of NAFLD. RESULTS: The induction of NAFLD in C57BL/6J mice using a high-fat high-sucrose (HFHS)-diet increased PARylation of proteins by PARPs. As such, increased PARylation was associated with reduced NAD+ levels and mitochondrial function and content, which was concurrent with elevated hepatic lipid content. HFHS diet supplemented with PARPi reversed NAFLD through repletion of NAD+, increasing mitochondrial biogenesis and ß-oxidation in liver. Furthermore, PARPi reduced reactive oxygen species, endoplasmic reticulum stress and fibrosis. The benefits of PARPi treatment were confirmed in mice fed with a methionine- and choline-deficient diet and in mice with lipopolysaccharide-induced hepatitis; PARP activation was attenuated and the development of hepatic injury was delayed in both models. Using Sirt1hep-/- mice, the beneficial effects of a PARPi-supplemented HFHS diet were found to be Sirt1-dependent. CONCLUSIONS: Our study provides a novel and practical pharmacological approach for treating NAFLD, fueling optimism for potential clinical studies. LAY SUMMARY: Non-alcoholic fatty liver disease (NAFLD) is now considered to be the most common liver disease in the Western world and has no approved pharmacological therapy. PARP inhibitors given as a treatment in two different mouse models of NAFLD confer a protection against its development. PARP inhibitors may therefore represent a novel and practical pharmacological approach for treating NAFLD.

An engineered FGF21 variant, LY2405319, can prevent non-alcoholic steatohepatitis by enhancing hepatic mitochondrial function.

Non-alcoholic fatty liver disease (NAFLD) is a prevalent obesity-related disease that affects large populations throughout the world due to excessive calorie intake and an increasingly sedentary lifestyle. Fibroblast growth factor 21 (FGF21) has recently emerged as a promising therapeutic candidate for the treatment of obesity and diabetes. FGF21 is a starvation-induced pleiotropic hormone with various beneficial metabolic effects, and pharmacological treatment in rodents has been shown to improve insulin sensitivity and decrease simple fatty liver disease. However, its effects on reversing the symptoms of advanced liver disease have yet to be validated. Here, we investigated the protective effects of the LY2405319 compound, an engineered FGF21 variant, in a non-alcoholic steatohepatitis (NASH) model using leptin-deficient ob/ob mice and a methionine- and choline-deficient (MCD) diet to induce steatohepatitis. LY2405319 treatment in ob/ob mice corroborated previous results showing that improvements in the metabolic parameters were due to increased mitochondrial oxygen consumption rate and fatty acid oxidation. LY2405319 treatment in ob/ob mice on an MCD diet significantly reduced the symptoms of steatohepatitis, as confirmed by Masson's trichrome staining intensity. Serum levels of AST and ALT were also reduced, suggesting an attenuation of liver injury, while detection of inflammatory markers showed decreased mRNA expression of TGF-ß1 and type-I collagen, and decreased phosphorylation of NF-kB p65, JNK1/2, and p38. Collectively, these data show that LY2405319 treatment attenuated MCD diet-induced NASH progression. We propose that the LY2405319 compound is a potential therapeutic candidate for the treatment of advanced liver disease.

Defective ciliogenesis in thyroid hürthle cell tumors is associated with increased autophagy.

Primary cilia are found in the apical membrane of thyrocytes, where they may play a role in the maintenance of follicular homeostasis. In this study, we examined the distribution of primary cilia in the human thyroid cancer to address the involvement of abnormal ciliogenesis in different thyroid cancers. We examined 92 human thyroid tissues, including nodular hyperplasia, Hashimoto's thyroiditis, follicular tumor, Hürthle cell tumor, and papillary carcinoma to observe the distribution of primary cilia. The distribution and length of primary cilia facing the follicular lumen were uniform across variable-sized follicles in the normal thyroid gland. However, most Hürthle cells found in benign and malignant thyroid diseases were devoid of primary cilia. Conventional variant of papillary carcinoma (PTC) displayed longer primary cilia than those of healthy tissue, whereas both the frequency and length of primary cilia were decreased in oncocytic variant of PTC. In addition, ciliogenesis was markedly defective in primary Hürthle cell tumors, including Hürthle cell adenomas and carcinomas, which showed higher level of autophagosome biogenesis. Remarkably, inhibition of autophagosome formation by Atg5 silencing or treatment with pharmacological inhibitors of autophagosome formation restored ciliogenesis in the Hürthle cell carcinoma cell line XTC.UC1 which exhibits a high basal autophagic flux. Moreover, the inhibition of autophagy promoted the accumulation of two factors critical for ciliogenesis, IFT88 and ARL13B. These results suggest that abnormal ciliogenesis, a common feature of Hürthle cells in diseased thyroid glands, is associated with increased basal autophagy.