Altered pathways of keratinization, extracellular matrix generation, angiogenesis, and stromal stem cells proliferation in patients with systemic sclerosis.

Objective: Systemic sclerosis is characterized by endothelial dysfunction, autoimmunity abnormalities, and fibrosis of the skin and internal organs. The pathogenetic mechanisms underlying systemic sclerosis vasculopathy are still not clarified. A complex cellular and extracellular network of interactions has been studied, but it is currently unclear what drives the activation of fibroblasts/myofibroblasts and the extracellular matrix deposition. Methods: Using RNA sequencing, the aim of the work was to identify potential functional pathways implied in systemic sclerosis pathogenesis and markers of endothelial dysfunction and fibrosis in systemic sclerosis patients. RNA-sequencing analysis was performed on RNA obtained from biopsies from three systemic sclerosis patients and three healthy controls enrolled in our University Hospital. RNA was used to generate sequencing libraries that were sequenced according to proper transcriptomic analyses. Subsequently, we performed gene set enrichment analysis of differentially expressed genes on the entire list of genes that compose the RNA-sequencing expression matrix. Results: Gene set enrichment analysis revealed that healthy controls were characterized by gene signatures related to stromal stem cells proliferation, cytokine-cytokine receptor interaction, macrophage-enriched metabolic network, whereas systemic sclerosis tissues were enriched in signatures associated with keratinization, cornification, retinoblastoma 1 and tumor suppressor 53 signaling. Conclusion: According to our data, RNA-sequencing and pathway analysis revealed that systemic sclerosis subjects display a discrete pattern of gene expression associated with keratinization, extracellular matrix generation, and negative regulation of angiogenesis and stromal stem cells proliferation. Further analysis on larger numbers of patients is needed; however, our findings provide an interesting framework for the development of biomarkers useful to explore potential future therapeutic approaches.

Secondary Autologous Fat Grafting for the Treatment of Chin Necrosis as a Consequence of Prone Position in COVID-19 Patients.

Due to the spread of the coronavirus disease 2019 pandemic, an increasing number of ill patients have been admitted to intensive care unit requiring mechanical ventilation. Although prone positioning is considered beneficial, long periods in this position may induce important complications, including pressure ulcers in high-risk and uncommon body areas. We report five cases of pressure ulcer necrosis of the chin in coronavirus disease 2019 patients as a consequence of mechanical ventilation in prone positioning using autologous fat grafting (AFG) as a secondary technique. A series of five patients with secondarily-healed chin necrosis treated by AFG between February and June 2020 were reviewed. All patients had been treated initially with surgical debridement followed by conservative treatment. Secondary AFG was performed to reduce patient's pain, improve chin contour-projection, and minimize cosmetic sequelae and scarring. Patient satisfaction was assessed using a five-point Likert scale (0-4). Vancouver scale was used to evaluate the chin scars clinically. The average amount of fat injected into the chin area was 8.1 ± 2.0 ml. At 6-month follow-up, all patients were mostly satisfied (average Likert-scale 3.2 ± 0.4). Based on the Vancouver scale, improvement of the chin scar from 9.5 ± 0.8 to 4.7 ± 0.8 was found. We report a positive experience with secondary AFG for correction of painful and unaesthetic scarring and contour abnormality following surgical debridement and secondary-intention healing of chin pressure ulcers.

Autologous Marrow Mesenchymal Stem Cell Driving Bone Regeneration in a Rabbit Model of Femoral Head Osteonecrosis.

Osteonecrosis of the femoral head (ONFH) is a progressive degenerative disease that ultimately requires a total hip replacement. Mesenchymal stromal/stem cells (MSCs), particularly the ones isolated from bone marrow (BM), could be promising tools to restore bone tissue in ONFH. Here, we established a rabbit model to mimic the pathogenic features of human ONFH and to challenge an autologous MSC-based treatment. ON has been originally induced by the synergic combination of surgery and steroid administration. Autologous BM-MSCs were then implanted in the FH, aiming to restore the damaged tissue. Histological analyses confirmed bone formation in the BM-MSC treated rabbit femurs but not in the controls. In addition, the model also allowed investigations on BM-MSCs isolated before (ON-BM-MSCs) and after (ON+BM-MSCs) ON induction to dissect the impact of ON damage on MSC behavior in an affected microenvironment, accounting for those clinical approaches foreseeing MSCs generally isolated from affected patients. BM-MSCs, isolated before and after ON induction, revealed similar growth rates, immunophenotypic profiles, and differentiation abilities regardless of the ON. Our data support the use of ON+BM-MSCs as a promising autologous therapeutic tool to treat ON, paving the way for a more consolidated use into the clinical settings.

Human Adipose Mesenchymal Stromal/Stem Cells Improve Fat Transplantation Performance.

The resorption rate of autologous fat transfer (AFT) is 40-60% of the implanted tissue, requiring new surgical strategies for tissue reconstruction. We previously demonstrated in a rabbit model that AFT may be empowered by adipose-derived mesenchymal stromal/stem cells (AD-MSCs), which improve graft persistence by exerting proangiogenic/anti-inflammatory effects. However, their fate after implantation requires more investigation. We report a xenograft model of adipose tissue engineering in which NOD/SCID mice underwent AFT with/without human autologous AD-MSCs and were monitored for 180 days (d). The effect of AD-MSCs on AFT grafting was also monitored by evaluating the expression of CD31 and F4/80 markers. Green fluorescent protein-positive AD-MSCs (AD-MSC-GFP) were detected in fibroblastoid cells 7 days after transplantation and in mature adipocytes at 60 days, indicating both persistence and differentiation of the implanted cells. This evidence also correlated with the persistence of a higher graft weight in AFT-AD-MSC compared to AFT alone treated mice. An observation up to 180 d revealed a lower resorption rate and reduced lipidic cyst formation in the AFT-AD-MSC group, suggesting a long-term action of AD-MSCs in support of AFT performance and an anti-inflammatory/proangiogenic activity. Together, these data indicate the protective role of adipose progenitors in autologous AFT tissue resorption.

Factors related to delayed treatment: A case report of a huge cutaneous horn and review of the literature.

We present a case of a man with a giant cutaneous horn over his frontal region. This case has been presented for the size of the lesion, due to delayed treatment, and to illustrate the reasons why the growth of this lesion has been possible in a western country, in the 21st century. It was a solitary, not painful lesion which caused significant aesthetic problems. The diagnosis was based on an ultrasonographic study and the treatment of choice was a surgical excision. This case is an opportunity to review the literature about the cutaneous horns, to talk about the main causes of delayed diagnosis and treatment of cutaneous lesions and, to define the role of the specialist in the assessment of emotions and patient support.

Atomistic Simulations of Geopolymer Models: The Impact of Disorder on Structure and Mechanics.

Geopolymers are hydrated aluminosilicates with excellent binding properties. Geopolymers appeal to the construction sector as a more sustainable alternative to traditional cements, but their exploitation is limited by a poor understanding of the linkage between chemical composition and macroscopic properties. Molecular simulations can help clarify this linkage, but existing models based on amorphous or crystalline aluminosilicate structures provide only a partial explanation of experimental data on the nanoscale. This paper presents a new model for the molecular structure of geopolymers, in particular for nanoscale interfacial zones between crystalline and amorphous nanodomains, which are crucial for the overall mechanical properties of the material. For a range of Si-Al molar ratios and water contents, the proposed structures are analyzed in terms of skeletal density, ring structure, pore structure, bond-angle distribution, bond length distribution, X-ray diffraction, X-ray pair distribution function, elastic moduli, and large-strain mechanics. Results are compared with experimental data and with other simulation results for amorphous and crystalline molecular models, showing that the newly proposed structures better capture important structural features with an impact on mechanical properties. This offers a new starting point for the multiscale modeling of geopolymers.

Androgenetic alopecia: a review.

PURPOSE: Androgenetic alopecia, commonly known as male pattern baldness, is the most common type of progressive hair loss disorder in men. The aim of this paper is to review recent advances in understanding the pathophysiology and molecular mechanism of androgenetic alopecia. METHODS: Using the PubMed database, we conducted a systematic review of the literature, selecting studies published from 1916 to 2016. RESULTS: The occurrence and development of androgenetic alopecia depends on the interaction of endocrine factors and genetic predisposition. Androgenetic alopecia is characterized by progressive hair follicular miniaturization, caused by the actions of androgens on the epithelial cells of genetically susceptible hair follicles in androgen-dependent areas. Although the exact pathogenesis of androgenetic alopecia remains to be clarified, research has shown that it is a polygenetic condition. Numerous studies have unequivocally identified two major genetic risk loci for androgenetic alopecia, on the X-chromosome AR/EDA2R locus and the chromosome 20p11 locus. CONCLUSIONS: Candidate gene and genome-wide association studies have reported that single-nucleotide polymorphisms at different genomic loci are associated with androgenetic alopecia development. A number of genes determine the predisposition for androgenetic alopecia in a polygenic fashion. However, further studies are needed before the specific genetic factors of this polygenic condition can be fully explained.

The CB1 receptor mediates the peripheral effects of ghrelin on AMPK activity but not on growth hormone release.

This study aimed to investigate whether the growth hormone release and metabolic effects of ghrelin on AMPK activity of peripheral tissues are mediated by cannabinoid receptor type 1 (CB1) and the central nervous system. CB1-knockout (KO) and/or wild-type mice were injected peripherally or intracerebroventricularly with ghrelin and CB1 antagonist rimonabant to study tissue AMPK activity and gene expression (transcription factors SREBP1c, transmembrane protein FAS, enzyme PEPCK, and protein HSL). Growth hormone levels were studied both in vivo and in vitro. Peripherally administered ghrelin in liver, heart, and adipose tissue AMPK activity cannot be observed in CB1-KO or CB1 antagonist-treated mice. Intracerebroventricular ghrelin treatment can influence peripheral AMPK activity. This effect is abolished in CB1-KO mice and by intracerebroventricular rimonabant treatment, suggesting that central CB1 receptors also participate in the signaling pathway that mediates the effects of ghrelin on peripheral tissues. Interestingly, in vivo or in vitro growth hormone release is intact in response to ghrelin in CB1-KO animals. Our data suggest that the metabolic effects of ghrelin on AMPK in peripheral tissues are abolished by the lack of functional CB1 receptor via direct peripheral effect and partially through the central nervous system, thus supporting the existence of a possible ghrelin-cannabinoid-CB1-AMPK pathway.

Measurement of AMP-activated protein kinase activity and expression in response to ghrelin.

Ghrelin is a circulating brain-gut peptide that is known to exert several metabolic effects such as stimulating appetite, inducing adiposity, increasing bone formation, and influencing the cardiovascular functions. AMP-activated protein kinase (AMPK), a highly conserved heterotrimeric protein that plays a key role in energy homeostasis, has been shown to mediate many of these metabolic effects of ghrelin. Ghrelin is shown to stimulate hypothalamic AMPK activity and inhibit liver and adipose tissue AMPK activity. The effects of ghrelin on AMPK activity can be studied using an elegant kinase assay, which involves immunoprecipitating AMPK protein from the tissue of interest followed by quantifying its enzymatic activity using radiolabeled adenosine triphosphate (ATP) in the presence of a suitable substrate. As a surrogate marker of AMPK activity, AMPK Thr(172) phosphorylation can be measured by Western blotting. Information about the AMPK pathway can also be gained by studying the mRNA expression of various AMPK subunits and by Western blotting for phosphorylated acetyl-CoA carboxylase, a key AMPK target. These methods have been widely used and published for investigating the effects of ghrelin on AMPK activity. In this chapter, we look into these experiments' methodology in detail.

Androgen modulation of pro-inflammatory and anti-inflammatory cytokines during preadipocyte differentiation.

BACKGROUND: Macrophages and adipocytes contribute to release of cytokines resulting in the chronic inflammatory profile of the metabolic syndrome. The local increase of proinflammatory cytokines impairs adipogenesis, resulting in formation of dysfunctional adipocytes that are unable to store and handle lipids. The altered lipid fluxes in/from adipocytes affect whole-body metabolism. We investigated the role of androgens on adipocyte-derived proinflammatory and anti-inflammatory cytokines during preadipocyte differentiation. MATERIALS AND METHODS: Various differentiation methods were used to obtain full conversion of 3T3-L1 into mature adipocytes. The degree of adipocyte conversion in the presence/absence of dihydrotestosterone (DHT) was analyzed by measuring intracellular triglycerides (Oil Red O staining). The effects of DHT administration on interleukin 1ß (IL-1ß), IL-2, IL-6, IL-10, IL-12, interferon γ (IFNγ) and tumor necrosis factor α (TNFα) secretion was measured at days 0, 4, 6 and 8 of differentiation using the SearchLight multiplex protein array. RESULTS: DHT regulates a number of cytokines in committed and mature 3T3-L1 adipocytes. IL-1ß and TNFα were readily suppressed at the very early stages of differentiation. IFNγ release was inhibited at day 4, but the effect was no longer detectable on day 8. IL-6 and IL-12 were significantly reduced at day 8 of differentiation. Conversely, the differentiation-dependent increase of IL-2 and IL-10 was further stimulated by DHT since day 0. CONCLUSIONS: We provide evidence that androgens promote an anti-inflammatory profile that parallels the acquisition of a functional adipocyte phenotype. The crosstalk between androgens, adipocyte-derived mediators of inflammation and intracellular lipid fluxes could have profound implications on metabolism of men with obesity and metabolic syndrome.

Changes in adenosine 5'-monophosphate-activated protein kinase as a mechanism of visceral obesity in Cushing's syndrome.

OBJECTIVE: Features of the metabolic syndrome such as central obesity with insulin resistance and dyslipidemia are typical signs of Cushing's syndrome and common side effects of prolonged glucocorticoid treatment. AMP-activated protein kinase (AMPK), a key regulatory enzyme of lipid and carbohydrate metabolism as well as appetite, is involved in the development of the deleterious metabolic effects of excess glucocorticoids, but no data are available in humans. In the current study, we demonstrate the effect of high glucocorticoid levels on AMPK activity of human adipose tissue samples from patients with Cushing's syndrome. METHODS: AMPK activity and mRNA expression of genes involved in lipid metabolism were assessed in visceral adipose tissue removed at abdominal surgery of 11 patients with Cushing's syndrome, nine sex-, age-, and weight-matched patients with adrenal incidentalomas, and in visceral adipose tissue from four patients with non-endocrine-related abdominal surgery. RESULTS: The patients with Cushing's syndrome exhibited a 70% lower AMPK activity in visceral adipose tissue as compared with both incidentalomas and control patients (P = 0.007 and P < 0.001, respectively). Downstream targets of AMPK fatty acid synthase and phosphoenol-pyruvate carboxykinase were up-regulated in patients with Cushing's syndrome. AMPK activity was inversely correlated with 0900 h serum cortisol and with urinary free cortisol. CONCLUSIONS: Our data suggest that glucocorticoids inhibit AMPK activity in adipose tissue, suggesting a novel mechanism to explain the deposition of visceral adipose tissue and the consequent central obesity observed in patients with iatrogenic or endogenous Cushing's syndrome.

The role of the aryl hydrocarbon receptor-interacting protein gene in familial and sporadic pituitary adenomas.

CONTEXT: Mutations have been identified in the aryl hydrocarbon receptor-interacting protein (AIP) gene in familial isolated pituitary adenomas (FIPA). It is not clear, however, how this molecular chaperone is involved in tumorigenesis. OBJECTIVE: AIP sequence changes and expression were studied in FIPA and sporadic adenomas. The function of normal and mutated AIP molecules was studied on cell proliferation and protein-protein interaction. Cellular and ultrastructural AIP localization was determined in pituitary cells. PATIENTS: Twenty-six FIPA kindreds and 85 sporadic pituitary adenoma patients were included in the study. RESULTS: Nine families harbored AIP mutations. Overexpression of wild-type AIP in TIG3 and HEK293 human fibroblast and GH3 pituitary cell lines dramatically reduced cell proliferation, whereas mutant AIP lost this ability. All the mutations led to a disruption of the protein-protein interaction between AIP and phosphodiesterase-4A5. In normal pituitary, AIP colocalizes exclusively with GH and prolactin, and it is found in association with the secretory vesicle, as shown by double-immunofluorescence and electron microscopy staining. In sporadic pituitary adenomas, however, AIP is expressed in all tumor types. In addition, whereas AIP is expressed in the secretory vesicle in GH-secreting tumors, similar to normal GH-secreting cells, in lactotroph, corticotroph, and nonfunctioning adenomas, it is localized to the cytoplasm and not in the secretory vesicles. CONCLUSIONS: Our functional evaluation of AIP mutations is consistent with a tumor-suppressor role for AIP and its involvement in familial acromegaly. The abnormal expression and subcellular localization of AIP in sporadic pituitary adenomas indicate deranged regulation of this protein during tumorigenesis.

The orexigenic effect of ghrelin is mediated through central activation of the endogenous cannabinoid system.

INTRODUCTION: Ghrelin and cannabinoids stimulate appetite, this effect possibly being mediated by the activation of hypothalamic AMP-activated protein kinase (AMPK), a key enzyme in appetite and metabolism regulation. The cannabinoid receptor type 1 (CB1) antagonist rimonabant can block the orexigenic effect of ghrelin. In this study, we have elucidated the mechanism of the putative ghrelin-cannabinoid interaction. METHODS: The effects of ghrelin and CB1 antagonist rimonabant in wild-type mice, and the effect of ghrelin in CB1-knockout animals, were studied on food intake, hypothalamic AMPK activity and endogenous cannabinoid content. In patch-clamp electrophysiology experiments the effect of ghrelin was assessed on the synaptic inputs in parvocellular neurons of the hypothalamic paraventricular nucleus, with or without the pre-administration of a CB1 antagonist or of cannabinoid synthesis inhibitors. RESULTS AND CONCLUSIONS: Ghrelin did not induce an orexigenic effect in CB1-knockout mice. Correspondingly, both the genetic lack of CB1 and the pharmacological blockade of CB1 inhibited the effect of ghrelin on AMPK activity. Ghrelin increased the endocannabinoid content of the hypothalamus in wild-type mice and this effect was abolished by rimonabant pre-treatment, while no effect was observed in CB1-KO animals. Electrophysiology studies showed that ghrelin can inhibit the excitatory inputs on the parvocellular neurons of the paraventricular nucleus, and that this effect is abolished by administration of a CB1 antagonist or an inhibitor of the DAG lipase, the enzyme responsible for 2-AG synthesis. The effect is also lost in the presence of BAPTA, an intracellular calcium chelator, which inhibits endocannabinoid synthesis in the recorded parvocellular neuron and therefore blocks the retrograde signaling exerted by endocannabinoids. In summary, an intact cannabinoid signaling pathway is necessary for the stimulatory effects of ghrelin on AMPK activity and food intake, and for the inhibitory effect of ghrelin on paraventricular neurons.

AMP-activated protein kinase mediates glucocorticoid-induced metabolic changes: a novel mechanism in Cushing's syndrome.

Chronic exposure to glucocorticoid hormones, resulting from either drug treatment or Cushing's syndrome, results in insulin resistance, central obesity, and symptoms similar to the metabolic syndrome. We hypothesized that the major metabolic effects of corticosteroids are mediated by changes in the key metabolic enzyme adenosine monophosphate-activated protein kinase (AMPK) activity. Activation of AMPK is known to stimulate appetite in the hypothalamus and stimulate catabolic processes in the periphery. We assessed AMPK activity and the expression of several metabolic enzymes in the hypothalamus, liver, adipose tissue, and heart of a rat glucocorticoid-excess model as well as in in vitro studies using primary human adipose and primary rat hypothalamic cell cultures, and a human hepatoma cell line treated with dexamethasone and metformin. Glucocorticoid treatment inhibited AMPK activity in rat adipose tissue and heart, while stimulating it in the liver and hypothalamus. Similar data were observed in vitro in the primary adipose and hypothalamic cells and in the liver cell line. Metformin, a known AMPK regulator, prevented the corticosteroid-induced effects on AMPK in human adipocytes and rat hypothalamic neurons. Our data suggest that glucocorticoid-induced changes in AMPK constitute a novel mechanism that could explain the increase in appetite, the deposition of lipids in visceral adipose and hepatic tissue, as well as the cardiac changes that are all characteristic of glucocorticoid excess. Our data suggest that metformin treatment could be effective in preventing the metabolic complications of chronic glucocorticoid excess.