Incidental thyroid carcinoma in an endemic goiter area in Italy: histopathological features and predictors of a common finding.

PURPOSE: The occurrence and histopathological features of incidental thyroid carcinoma (ITC) vary considerably among populations from different geographical regions. The aim of this study is to assess the prevalence and histopathological characteristics of ITC in patients who underwent thyroid surgery for apparently benign thyroid diseases in an endemic goiter area in Italy. METHODS: A total of 649 consecutive patients (531 females and 118 males; mean age, 52.9 ± 11.0 years), who underwent thyroid surgery at the Endocrine Surgery Unit of the tertiary care "Renato Dulbecco" University Hospital (Catanzaro, Italy) in the period between years 2017 and 2022, were included in this retrospective study. A comprehensive histopathological examination was performed on surgically excised thyroid tissue. Logistic regression analysis was employed to identify potential predictors of ITC. RESULTS: The histopathological examination revealed the presence of ITC in 81 patients, accounting for 12.5% of the total study population. The female to male ratio was found to be 6.4 to 1. Among the patients with ITC, 72 had papillary carcinoma (PTC), with 53 of these tumors being microcarcinomas (microPTC). Additionally, 5 patients had follicular thyroid carcinoma, 2 patients had low-risk follicular cell-derived thyroid neoplasms, 1 patient had an oncocytic carcinoma, and 1 patient had a medullary thyroid carcinoma. Logistic regression analysis demonstrated a significant association between female sex and incidental microPTC. CONCLUSIONS: These findings provide further evidence of the common occurrence of ITC, typically in the form of microPTC, among individuals who undergo thyroid surgery for apparently benign thyroid diseases.

Coexistence of Hashimoto's Thyroiditis in Differentiated Thyroid Cancer: Post-Operative Monitoring of Anti-Thyroglobulin Antibodies and Assessment of Treatment Response.

INTRODUCTION: Differentiated thyroid carcinoma (DTC) is frequently found in conjunction with autoimmune thyroid disorders, particularly Hashimoto's thyroiditis (HT). This study investigates the impact of coexisting HT on the persistence of an indeterminate response to therapy due to positive anti-thyroglobulin antibodies (AbTg), measured via competitive immunoassay, in a consecutive patient series from Calabria, Southern Italy. METHODS: This retrospective longitudinal study analyzed 259 consecutive DTC patients managed at the Endocrinology Unit of Renato Dulbecco Hospital (Catanzaro, Italy) up to 2023. Patients with medullary and undifferentiated thyroid carcinoma, partial thyroidectomy, less than six months of post-operative monitoring, or missing clinical data were excluded. Demographic information, histological findings, initial tumor stage, and ATA risk category were collected. The response to therapy was assessed based on ATA guidelines. RESULTS: Among the 259 patients, 29% had coexisting HT. Patients with HT exhibited distinct characteristics: a higher proportion of females (87.0% vs. 74.7%), a shorter post-operative monitoring duration (median 3 vs. 5 years), and a higher prevalence of papillary thyroid carcinoma (PTC) (97.4% vs. 86.3%). The tumor size, lymph node involvement, and distant metastasis were similar between the groups, with patients without HT having a higher incidence of extrathyroidal tumor extension. However, the initial TNM stage and ATA risk category did not differ significantly. At the six-month follow-up, HT patients showed a higher rate of indeterminate responses, primarily due to positive AbTg. After 12 months, the response categories aligned, with decreasing AbTg levels in the HT group. After 24 months, most patients with long-term follow-up demonstrated an excellent response to DTC therapy, irrespective of HT coexistence. CONCLUSIONS: While HT does not worsen DTC prognosis, it may result in indeterminate responses. AbTg measurements in the peri-operative period should be encouraged to facilitate post-operative monitoring, emphasizing the importance of using standardized assays. Further research in larger populations with extended follow-up is needed to comprehensively understand the HT-DTC relationship.

The anticancer effects of Metformin in the male germ tumor SEM-1 cell line are mediated by HMGA1.

Introduction: Germ cell tumors (GCTs) are the most common type of cancer in young men. These tumors usually originate from the testis, but they can occasionally develop from extragonadal sites probably due to primordial germ cells (PGCs) migration errors. Cisplatin-based chemotherapy is usually effective for male GCTs, but the risk of toxicity is high and new therapeutic strategies are needed. Although Metformin (Met) has been widely studied as a potential cancer treatment over the past decades, there is limited evidence to support its use in treating male GCTs. Additionally, the mechanism by which it acts on tumor cells is still not entirely understood. Methods: SEM-1 cells, a newly established human cell line of extragonadal origin, were treated with Met. Cell viability was studied by MTT assay, while cell migration and invasion were studied by the wound healing assay and the transwell assay, respectively. The effect of Met on 3D spheroid formation was determined by seeding SEM-1 cells in appropriate cell suspension culture conditions, and cell cycle was characterized by flow cytometry. Factors involved in PGCs migration and GCT invasion, such as IGFBP1, IGF1R, MMP-11 and c-Kit, together with cyclin D1 (a key regulator of cell cycle progression), and the upstream factor, HMGA1, were determined by immunoblots. Results: Treatment of SEM-1 cells with Met resulted in a potent and dose-dependent reduction of cell proliferation, as evidenced by decreased nuclear abundance of cyclin D1 and cell cycle arrest in G1 phase. Also, Met prevented the formation of 3D spheroids, and blocked cell migration and invasion by reducing the expression of IGFBP1, IGF1R and MMP-11. Both, IGFBP1 and MMP-11 are under control of HMGA1, a chromatin-associated protein that is involved in the regulation of important oncogenic, metabolic and embryological processes. Intriguingly, an early reduction in the nuclear abundance of HMGA1 occurred in SEM-1 cells treated with Met. Conclusions: Our results document the antiproliferative and antimigratory effects of Met in SEM-1 cells, providing new insights into the potential treatments for male GCTs. The anticancer properties of Met in SEM-1 cells are likely related to its ability to interfere with HMGA1 and downstream targets, including cyclin D1, the IGFs system, and MMP-11.

Insulin Resistance and Cancer: In Search for a Causal Link.

Insulin resistance (IR) is a condition which refers to individuals whose cells and tissues become insensitive to the peptide hormone, insulin. Over the recent years, a wealth of data has made it clear that a synergistic relationship exists between IR, type 2 diabetes mellitus, and cancer. Although the underlying mechanism(s) for this association remain unclear, it is well established that hyperinsulinemia, a hallmark of IR, may play a role in tumorigenesis. On the other hand, IR is strongly associated with visceral adiposity dysfunction and systemic inflammation, two conditions which favor the establishment of a pro-tumorigenic environment. Similarly, epigenetic modifications, such as DNA methylation, histone modifications, and non-coding RNA, in IR states, have been often associated with tumorigenesis in numerous types of human cancer. In addition to these observations, it is also broadly accepted that gut microbiota may play an intriguing role in the development of IR-related diseases, including type 2 diabetes and cancer, whereas potential chemopreventive properties have been attributed to some of the most commonly used antidiabetic medications. Herein we provide a concise overview of the most recent literature in this field and discuss how different but interrelated molecular pathways may impact on tumor development.

Overexpression of p75NTR in Human Seminoma: A New Biomarker?

Several studies have demonstrated that the p75NTR low-affinity receptor of Nerve Growth Factor (NGF), is produced in abnormally large amounts in several human cancer types. However, the role of p75NTR varies substantially depending on cell context, so that a dual role of this receptor protein in tumor cell survival and invasion, as well as cell death, has been supported in recent studies. Herein we explored for the first time the expression of p75NTR in human specimens (nr = 40) from testicular germ cell tumors (TGCTs), mostly seminomas. Nuclear overexpression of p75NTR was detected by immunohistochemistry in seminoma tissue as compared to normal tissue, whereas neither NGF nor its high-affinity TrkA receptor was detected. An increased nuclear staining of phospho-JNK, belonging to the p75NTR signaling pathway and its pro-apoptotic target gene, p53, was concomitantly observed. Interestingly, our analysis revealed that decreased expression frequency of p75NTR, p-JNK and p53 was related to staging progression, thus suggesting that p75NTR may represent a specific marker for seminoma and staging in TGCTs.

Methods to Study Protein-Binding to Pseudogene Transcripts.

One of the most commonly described biological feature of processed pseudogenes is the ability to influence the expression of their parental coding genes. As evidenced in several studies, the high sequence similarity between these RNA pairs sets up a certain level of competition for posttranscriptional regulators, including, among others, RNA-binding proteins (RBPs). RBPs may affect, positively or negatively, the stability of bound mRNAs, so that, if an overexpressed pseudogene competes with its homologous coding gene, the downstream protein synthesis would change, with potential pathological consequences. Given these premises, a rigorous and comprehensive understanding of interactions between pseudogene-parental gene RNA pairs and RBPs could provide further insights into the biological bases of complex diseases, such as cancer, cardiovascular disease, and type 2 diabetes, identifying novel predictive and/or prognostic biomarkers.Herein, we detail easily adaptable protocols of plasmid-based molecular cloning and RNA-electrophoretic mobility shift assay (EMSA) used in our laboratory for determining the interaction between a cytoplasmatic stabilizing protein (αCP1) and the pseudogene-parental gene RNA pair HMGA1-p /HMGA1. We also offer a general overview of RNA immunoprecipitation procedures and present novel bioinformatic tools for predicting RBPs binding sites on pseudogene transcripts.

The penile duplex ultrasound: How and when to perform it?

BACKGROUND: Because it is a superficial structure, the penis is ideally suited to ultrasound imaging. A number of disease processes, including Peyronie's disease, penile fractures and tumors, are clearly visualized with ultrasound. Baseline and dynamic assessment of cavernosal arterial changes after pharmaco-stimulation with alprostadil allows standardized diagnosis of arterial and venogenic causes of erectile dysfunction (ED). OBJECTIVE: To illustrate how to correctly perform flaccid and dynamic penile duplex ultrasound (D-PDU) and in which patients to recommend it. MATERIALS/METHODS: An extensive search of the literature was carried out on Pubmed with the insertion of the following Medical Subjects Headings (MeSH) terms and keywords "penile color Doppler ultrasound" "peak systolic velocity" "end-diastolic velocity", "acceleration time", "resistance index". EVIDENCE: In our experience, arterial erectile dysfunction is identified after standardized intracavernous injection (ICI) of alprostadil (10 mcg) when values of peak systolic velocity (PSV) are <35 cm/s and, in the most severe forms, for values <25 cm/s. Arterial insufficiency can also be identified by increased acceleration time (AT) values (>110 ms) and/or by a lack of visualization of helicine arteries at power Doppler mode along with incomplete achievement of penile rigidity. The veno-occlusive incompetence is determined when end-diastolic velocity (EDV) values are >4.5-5 cm/s or in the case of resistance index (RI) values <0.75. The assessment of additional surrogate markers of endothelial dysfunction, that is, intima-media thickness, mean platelet volume (MPV), endothelial progenitor cells (EPC), endothelial cell specific molecule-1(endocan) are also useful in assessing the patient's cardiovascular risk but are still considered investigational in the interpretation of D-PDU results. CONCLUSION: D-PDU scan after ICI with vasoactive drugs is a safe procedure and represents the gold standard for the diagnostics of penile pathologies and should be performed in men with ED not responding to oral conventional therapies and/or in those requiring accurate stratification of cardiovascular risk.

MicroRNA-1281 as a Novel Circulating Biomarker in Patients With Diabetic Retinopathy.

Objective: Recently, the role of circulating miRNAs as non-invasive biomarkers for the identification and monitoring of diabetes microvascular complications has emerged. Herein, we aimed to: identify circulating miRNAs differentially expressed in patients with and without diabetic retinopathy (DR); examine their predictive value; and understand their pathogenic impact. Methods: Pooled serum samples from randomly selected matched patients with type 2 diabetes, either with or without DR, were used for initial serum miRNA profiling. Validation of the most relevant miRNAs was thereafter conducted by RT-qPCR in an extended sample of patients with DR and matched controls. Results: Following miRNA profiling, 43 miRNAs were significantly up- or down-regulated in patients with DR compared with controls. After individual validation, 5 miRNAs were found significantly overexpressed in patients with DR. One of them, miR-1281, was the most up-regulated and appeared to be specifically related to DR. Furthermore, secreted levels of miR-1281 were increased in high glucose-cultured retinal cells, and there was evidence of a potential link between glucose-induced miR-1281 up-regulation and DR. Conclusion: Our findings suggest miR-1281 as a circulating biomarker of DR. Also, they highlight the pathogenic significance of miR-1281, providing insights for a new potential target in treating DR.

Mediterranean Diet Nutrients to Turn the Tide against Insulin Resistance and Related Diseases.

Insulin resistance (IR), defined as an attenuated biological response to circulating insulin, is a fundamental defect in obesity and type 2 diabetes (T2D), and is also linked to a wide spectrum of pathological conditions, such as non-alcoholic fatty liver disease (NAFLD), cognitive impairment, endothelial dysfunction, chronic kidney disease (CKD), polycystic ovary syndrome (PCOS), and some endocrine tumors, including breast cancer. In obesity, the unbalanced production of pro- and anti-inflammatory adipocytokines can lead to the development of IR and its related metabolic complications, which are potentially reversible through weight-loss programs. The Mediterranean diet (MedDiet), characterized by high consumption of extra-virgin olive oil (EVOO), nuts, red wine, vegetables and other polyphenol-rich elements, has proved to be associated with greater improvement of IR in obese individuals, when compared to other nutritional interventions. Also, recent studies in either experimental animal models or in humans, have shown encouraging results for insulin-sensitizing nutritional supplements derived from MedDiet food sources in the modulation of pathognomonic traits of certain IR-related conditions, including polyunsaturated fatty acids from olive oil and seeds, anthocyanins from purple vegetables and fruits, resveratrol from grapes, and the EVOO-derived, oleacein. Although the pharmacological properties and clinical uses of these functional nutrients are still under investigation, the molecular mechanism(s) underlying the metabolic benefits appear to be compound-specific and, in some cases, point to a role in gene expression through an involvement of the nuclear high-mobility group A1 (HMGA1) protein.

First Trimester Combined Test (FTCT) as a Predictor of Gestational Diabetes Mellitus.

Background-The first trimester combined test (FTCT) is an effective screening tool to estimate the risk of fetal aneuploidy. It is obtained by the combination of maternal age, ultrasound fetal nuchal translucency (NT) measurement, and the maternal serum markers free ß-human chorionic gonadotropin (ß-hCG) and pregnancy-associated plasma protein A (PAPP-A). However, conflicting data have been reported about the association of FTCT, ß-hCG, or PAPP-A with the subsequent diagnosis of gestational diabetes mellitus (GDM). Research design and methods-2410 consecutive singleton pregnant women were retrospectively enrolled in Calabria, Southern Italy. All participants underwent examinations for FTCT at 11-13 weeks (plus 6 days) of gestation, and screening for GDM at 16-18 and/or 24-28 weeks of gestation, in accordance with current Italian guidelines and the International Association Diabetes Pregnancy Study Groups (IADPSG) glycemic cut-offs. Data were examined by univariate and logistic regression analyses. Results-1814 (75.3%) pregnant women were normal glucose tolerant, while 596 (24.7%) were diagnosed with GDM. Spearman univariate analysis demonstrated a correlation between FTCT values and subsequent GDM diagnosis (ρ = 0.048, p = 0.018). The logistic regression analysis showed that women with a FTCT <1:10000 had a major GDM risk (p = 0.016), similar to women with a PAPP-A <1 multiple of the expected normal median (MoM, p = 0.014). Conversely, women with ß-hCG ≥2.0 MoM had a reduced risk of GDM (p = 0.014). Conclusions-Our findings indicate that GDM susceptibility increases with fetal aneuploidy risk, and that FTCT and its related maternal serum parameters can be used as early predictors of GDM.

Does a polarization state exist for mast cells in cancer?

The data of literature are discordant about the role of mast cells in different types of neoplasms. In this paper the authors propose the hypothesis that tumor-associated mast cells may switch to different polarization states, conditioning the immunogenic capacities of the different neoplasms. Anti-inflammatory polarized mast cells should express cytokines such as interleukin-10 (IL-10) and then mast cells number should be inversely related to the intensity of inflammatory infiltrate. On the contrary, when mast cells do not express anti-inflammatory cytokines their number should be directly related to the intensity of the inflammatory infiltrate. In this paper we briefly argue around feasible approaches, based on the retrospective studies of tumor tissue samples from neoplasms considered "immunologically hot" and neoplasms considered "immunologically cold", through immunohistochemistry and immunofluorescence techniques (confocal microscopy). The establishment of the actual existence of a polarization interchange of mast cells, could lead to a new vision in prognostic terms, useful to contrive new approaches in immunotherapy of tumors.

Barriers to Postpartum Glucose Intolerance Screening in an Italian Population.

Background: Gestational diabetes mellitus (GDM) is a strong risk factor for type 2 diabetes mellitus (T2D) and the postpartum period is crucial for early treatment in at-risk women. However, despite recommendations, only a fraction of women undergo a postpartum screening for glucose intolerance (ppOGTT). The present study aims to verify the reason(s) for poor adherence in our population. Research design and methods: This retrospective study includes 451 women in which GDM was diagnosed between 2015⁻2016. During 2017, we verified by phone interview how many women underwent ppOGTT at 6⁻12 weeks postpartum, as recommended by the Italian guidelines. The non-compliant women were asked about the reason(s) for failing to screen. The non-parametric Mann-Whitney test and the 2-tailed Fisher exact test were used to compare continuous and categorical features, respectively, among women performing or non-performing ppOGTT. Results: Out of 451 women with GDM diagnosis, we recorded information from 327. Only 97 (29.7%) performed ppOGTT. The remaining 230 women (70.3%) provided the following explanation for non-compliance: (1) newborn care (30.4%); (2) misunderstood importance (28.3%); (3) oversight (13.0%); (4) unavailability of test reservation in the nearest centers (10.4%); (5) normal glycemic values at delivery (8.3%); (6) discouragement by primary care physician (5.6%). Conclusions: In our population, most women with recent GDM failed to perform ppOGTT. Our results indicated that the prominent barriers could potentially be overcome.

Cross-talk among HMGA1 and FoxO1 in control of nuclear insulin signaling.

As a mediator of insulin-regulated gene expression, the FoxO1 transcription factor represents a master regulator of liver glucose metabolism. We previously reported that the high-mobility group AT-hook 1 (HMGA1) protein, a molecular switch for the insulin receptor gene, functions also as a downstream target of the insulin receptor signaling pathway, representing a critical nuclear mediator of insulin function. Here, we investigated whether a functional relationship existed between FoxO1 and HMGA1, which might help explain insulin-mediated gene transcription in the liver. To this end, as a model study, we investigated the canonical FoxO1-HMGA1-responsive IGFBP1 gene, whose hepatic expression is regulated by insulin. By using a conventional GST-pull down assay combined with co-immunoprecipitation and Fluorescence Resonance Energy Transfer (FRET) analyses, we provide evidence of a physical interaction between FoxO1 and HMGA1. Further investigation with chromatin immunoprecipitation, confocal microscopy, and Fluorescence Recovery After Photobleaching (FRAP) technology indicated a functional significance of this interaction, in both basal and insulin-stimulated states, providing evidence that, by modulating FoxO1 transactivation, HMGA1 is essential for FoxO1-induced IGFBP1 gene expression, and thereby a critical modulator of insulin-mediated FoxO1 regulation in the liver. Collectively, our findings highlight a novel FoxO1/HMGA1-mediated mechanism by which insulin may regulate gene expression and metabolism.

High Mobility Group A (HMGA) proteins: Molecular instigators of breast cancer onset and progression.

Cancer heterogeneity is one of the factors that constitute an obstacle towards an efficient targeting of this multifaceted disease. Molecular information can help in classifying cancer subtypes and in providing clinicians with novel targeted therapeutic opportunities. In this regard, classification of breast cancer into intrinsic subtypes based on molecular profiling represents a valuable prototype. The High Mobility Group A (HMGA) chromatin architectural factors (HMGA1a, HMGA1b, and HMGA2) have a relevant and causal role in breast cancer onset and development, by influencing virtually all cancer hallmarks. The regulation of HMGA expression is under the control of major pathways involved in cell proliferation and survival, as well as in other cancer-related processes, thereby suggesting, for the HMGA members, a high degree of homology and overlapping activities. Despite of this evidence, HMGA proteins display also specific functions. In this review, we provide an overview of (i) the pathways involved in HMGA transcriptional and post-transcriptional regulation, (ii) the utilization of HMGA as molecular markers, and (iii) the biological role of HMGA in the context of breast cancer. We focus on the potential significance of HMGA in governing the onset and development of this tumour, as well as on the potential of these factors as novel specific targets for preventing and treating strategies. The emerging picture is a highly interconnected triad of proteins that could mutually influence each other, either in a competitive or cooperative manner, and that, in our opinion, should be considered as a unified and integrated protein system.

HMGA1 and MMP-11 Are Overexpressed in Human Non-melanoma Skin Cancer.

BACKGROUND/AIM: The High-Mobility Group A1 (HMGA1) protein has been implicated in human malignancies, playing an important role in cancer proliferation, angiogenesis and metastasis. Increased HMGA1 expression has been found in skin mouse tumors, whereas Hmga1-null mice were protected against skin carcinogenesis. Here, we examined the expression of HMGA1 in human skin tumors, squamous cell carcinoma and basal cell carcinoma. MATERIALS AND METHODS: Tumor and normal skin tissues from 15 affected patients were surgically excised, and mRNA and protein extraction was performed. mRNA and protein content for both HMGA1 and MMP-11, a proteinase enzyme that plays a role in tumor development and progression, was measured by real-time PCR and western blotting, respectively. Data were analyzed by the SPSS software. RESULTS: HMGA1 mRNA and protein expression patterns were higher in neoplastic skin lesions, compared to normal skin (p<0.001). Similar results were observed for MMP-11. CONCLUSION: Our data confirm previous observations in mice studies, and suggest that HMGA1 and MMP-11 may play a key role in the proliferation and progression of skin tumors in humans.

Postpartum glucose intolerance: an updated overview.

The prevalence of type 2 diabetes mellitus has increased worldwide over the past three decades, as a consequence of the more westernized lifestyle, which is responsible for the increasing obesity rate in the modern adult's life. Concomitant with this increase there has been a gradual rise in the overall prevalence of gestational diabetes mellitus, a condition that strongly predisposes to overt diabetes later in life. Many women with previous gestational diabetes mellitus show glucose intolerance in the early postpartum period. Although the best screening strategy for postpartum glucose intolerance is still debated, numerous evidences indicate that identification of these women at this time is of critical importance, as efforts to initiate early intensive lifestyle modification, including hypocaloric diet and physical activity, and to ameliorate the metabolic profile of these high-risk subjects can prevent or delay the onset of type 2 diabetes mellitus. Nevertheless, less than one fifth of women attend the scheduled postpartum screening following gestational diabetes mellitus and they are at increased risk to develop type 2 diabetes mellitus later in their lives. Unsatisfying results have also come from early intervention strategies and tools that have been developed during the last few years to help improving the rate of adherence to postpartum glycemic testing, thereby indicating that more effective strategies are needed to improve women's participation in postpartum screening.

Innate immunity in cardiac myxomas and its pathological and clinical correlations.

Cardiac myxomas are the most common benign cardiac tumor. We investigated the immunohistochemical properties of 11 surgically excised cardiac myxomas, in order to analyze the correlation between macrophages and mast cell populations and clinical parameters. CD68+/CD163-/iNOS- (M0) cells represent the most abundant macrophage phenotype; however, CD68+/CD163+ cells (M2) were also frequent. CD68+/iNOS+ (M1) elements were rare. Mast cells, defined as a population of c-kit (CD117)+ and/or tryptase+ cells were also detected. Statistical analysis showed significant correlations between c-kit (CD117)+ and tryptase, CD68 and erythrocyte sedimentation rate (ESR), ESR and red blood cell count (RBC), and prothrombin time and platelet count. The inverse correlation between RBCs in peripheral blood and ESR suggested that anemia associated with chronic inflammatory disease is a noncasual event in patients suffering from cardiac myxoma. Mechanical hemolysis may be only a minor component of anemia, according to the lack of correlation between echographic surface and RBCs. Moreover, tumor size did not correlate with ESR, showing that inflammatory state may depend from both tumor cells population and inflammatory infiltrate. In the future, modulation of macrophage polarization in cardiac myxomas might represent important therapeutic target.

HMGA1 is a novel transcriptional regulator of the FoxO1 gene.

PURPOSE: The forkhead transcription factor (FoxO1) is a master transcriptional regulator of fundamental cellular processes ranging from cell proliferation and differentiation to inflammation and metabolism. However, despite its relevance, the mechanism(s) underlying FoxO1 gene regulation are largely unknown. We have previously shown that the chromatin factor high-mobility group A1 (HMGA1) plays a key role in the transcriptional regulation of glucose-responsive genes, including some that are involved in FoxO1-mediated glucose metabolism. Here we investigated the impact of HMGA1 on FoxO1 gene expression. METHODS: FoxO1 protein and gene expression studies were performed by Western blot analysis combined with qRT-PCR of material from human cultured cells and EBV-transformed lymphoblasts, and from primary cultured hepatocytes from wild-type and Hmga1 -/- mice. Reporter gene assays and chromatin immunoprecipitation for binding of HMGA1 to the endogenous FoxoO1 locus were performed in cells overexpressing HMGA1 and in cells pretreated with siRNA targeting HMGA1. RESULTS: HMGA1 increased FoxO1 mRNA and protein expression in vitro, in cultured HepG2 and HEK-293 cells by binding FoxO1 gene promoter, thereby activating FoxO1 gene transcription. Forced expression of HMGA1 in primary cultured hepatocytes from Hmga1 -/- mice and in EBV-transformed lymphoblasts from subjects with reduced expression of endogenous HMGA1 increased FoxO1 mRNA and protein levels. CONCLUSION: These findings may contribute to the understanding of FoxO1 gene regulation and its role in metabolism.

Expression of matrix metalloproteinase-11 is increased under conditions of insulin resistance.

AIM: To investigate matrix metalloproteinase-11 (MMP-11) expression in adipose tissue dysfunction, using in vitro and in vivo models of insulin resistance. METHODS: Culture of mouse 3T3-L1 preadipocytes were induced to differentiation into mature 3T3-L1 adipocytes. Cellular insulin resistance was induced by treating differentiated cultured adipocytes with hypoxia and/or tumor necrosis factor (TNF)-α, and transcriptional changes were analyzed in each condition thereafter. For the in vivo studies, MMP-11 expression levels were measured in white adipose tissue (WAT) from C57BL/6J mice that underwent low fat diet or high-fat feeding in order to induce obesity and obesity-related insulin resistance. Statistical analysis was carried out with GraphPad Prism Software. RESULTS: MMP-11 mRNA expression levels were significantly higher in insulin resistant 3T3-L1 adipocytes compared to control cells (1.46 ± 0.49 vs 0.83 ± 0.21, respectively; P < 0.00036). The increase in MMP-11 expression was observed even in the presence of TNF-α alone (3.79 ± 1.11 vs 1 ± 0.17, P < 0.01) or hypoxia alone (1.79 ± 0.7 vs 0.88 ± 0.1, P < 0.00023). The results obtained in in vitro experiments were confirmed in the in vivo model of insulin resistance. In particular, MMP-11 mRNA was upregulated in WAT from obese mice compared to lean mice (5.5 ± 2.8 vs 1.1 ± 0.7, respectively; P < 3.72E-08). The increase in MMP-11 levels in obese mice was accompanied by the increase in typical markers of fibrosis, such as collagen type VI alpha 3 (Col6α3), and fibroblast-specific protein 1. CONCLUSION: Our results indicate that dysregulation of MMP-11 expression is an early process in the adipose tissue dysfunction, which leads to obesity and obesity-related insulin resistance.