Publications by authors named "Pascal De Santa Barbara"

Bariatric surgery induces a decrease in areal bone mineral density (aBMD), but the long-term effect on trabecular and cortical volumetric bone mineral density (vBMD) has not been well assessed. The main aim of this 5-year longitudinal study was to investigate the changes following sleeve gastrectomy (SG) in aBMD, bone turnover markers and trabecular and cortical vBMD. Forty-five patients with obesity were assessed before and 1, 2 and 5 years after SG.

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Intestinal smooth muscle differentiation is a complex physico-biological process involving several different pathways. Here, we investigate the properties of Ca waves in the developing intestinal mesenchyme using GCamp6f expressing mouse embryos and investigate their relationship with smooth muscle differentiation. We find that Ca waves are absent in the pre-differentiation mesenchyme and start propagating immediately following α-SMA expression.

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The enteric nervous system (ENS) is principally derived from vagal neural crest cells that migrate caudally along the entire length of the gastrointestinal tract, giving rise to neurons and glial cells in two ganglionated plexuses. Incomplete migration of enteric neural crest-derived cells (ENCDC) leads to Hirschsprung disease, a congenital disorder characterized by the absence of enteric ganglia along variable lengths of the colorectum. Our previous work strongly supported the essential role of the avian ceca, present at the junction of the midgut and hindgut, in hindgut ENS development, since ablation of the cecal buds led to incomplete ENCDC colonization of the hindgut.

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Article Synopsis
  • Bariatric surgery, specifically sleeve gastrectomy (SG), causes bone loss, but the exact mechanisms remain unclear.
  • A study on 83 obesity patients tracked changes in bone mineral density (aBMD) and bone turnover markers at 1, 12, and 24 months post-surgery.
  • Findings indicated that bone turnover increased over time, with a significant decrease in aBMD primarily observed in the hip region, attributed mainly to weight loss rather than changes in specific biological markers like periostin, sclerostin, and semaphorin 4D.
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Visceral myopathy is a rare, life-threatening disease linked to identified genetic mutations in 60% of cases. Mostly due to the dearth of knowledge regarding its pathogenesis, effective treatments are lacking. The disease is most commonly diagnosed in children with recurrent or persistent disabling episodes of functional intestinal obstruction, which can be life threatening, often requiring long-term parenteral or specialized enteral nutritional support.

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Spinal cord injury (SCI) induces severe losses of trabecular and cortical volumetric bone mineral density (vBMD), which cannot be discriminated with conventional dual-energy X-ray absorptiometry (DXA) analysis. The objectives were to: (i) determine the effects of SCI on areal BMD (aBMD) and vBMD determined by advanced 3D-DXA-based methods at various femoral regions and (ii) model the profiles of 3D-DXA-derived parameters with the time since injury. Eighty adult males with SCI and 25 age-matched able-bodied (AB) controls were enrolled in this study.

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Gastrointestinal stromal tumor (GIST), the most common sarcoma, is mainly caused by an oncogenic mutation in the KIT receptor tyrosine kinase. Targeting KIT using tyrosine kinase inhibitors, such as imatinib and sunitinib, provides substantial benefit; however, in most patients, the disease will eventually progress due to KIT secondary mutations leading to treatment failure. Understanding how GIST cells initially adapt to KIT inhibition should guide the selection of appropriate therapies to overcome the emergence of resistance.

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Sleeve gastrectomy (SG) induces weight loss but its effects on body composition (BC) are less well known. The aims of this longitudinal study were to analyse the BC changes from the acute phase up to weight stabilization following SG. Variations in the biological parameters related to glucose, lipids, inflammation, and resting energy expenditure (REE) were concomitantly analysed.

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YAP1 and TAZ are transcriptional co-activator proteins that play fundamental roles in many biological processes, from cell proliferation and cell lineage fate determination to tumorigenesis. We previously demonstrated that Limb Expression 1 (LIX1) regulates YAP1 and TAZ activity and controls digestive mesenchymal progenitor proliferation. However, LIX1 mode of action remains elusive.

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Gastrointestinal motor activity has been extensively studied in adults; however, only few studies have investigated fetal motor skills. It is unknown when the gastrointestinal tract starts to contract during the embryonic period and how this function evolves during development. Here, we adapted a non-invasive high-resolution echography technique combined with speckle tracking analysis to examine the gastrointestinal tract motor activity dynamics during chick embryo development.

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Background: Most obese women with low-trauma fractures present normal areal bone mineral density (aBMD), suggesting that other bone parameters are more determinant for fracture risk in these patients.

Objectives: (i) Determine the effects of obesity in young women on areal bone mineral density (aBMD), bone geometry, strength, and volumetric BMD determined by advanced DXA-based methods; (ii) model the profiles of bone parameters for each population with age; and (iii) determine the factors related to body composition (i.e.

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  • Smooth Muscle Cells (SMCs) can change their behavior and functionality, switching between a relaxed state and a more active, proliferative state, which can be linked to dysfunction.
  • In a study of infants with chronic intestinal pseudo-obstruction (CIPO), it was found that SMCs had reduced contractile markers and increased levels of a receptor called PDGFRA, indicating a shift towards a less differentiated state.
  • Understanding this phenotypic change in CIPO-SMCs could lead to new therapeutic strategies aimed at encouraging these cells to differentiate properly and improve gut motility.
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  • The developing chicken gut starts with movements caused only by smooth muscle, but later changes to movements controlled by special cells called interstitial cells of Cajal (ICCs).
  • ICCs, which help make gut movements more regular and faster, start working in the gut around embryonic day 14.
  • Researchers used special techniques to see these changes and believe humans experience this shift from smooth muscle to ICC control between 12 and 14 weeks of development.
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Gastrointestinal stromal tumours (GISTs), the most common mesenchymal neoplasm of the gastrointestinal tract, result from deregulated proliferation of transformed KIT-positive interstitial cells of Cajal that share mesenchymal progenitors with smooth muscle cells. Despite the identification of selective KIT inhibitors, primary resistance and relapse remain a major concern. Moreover, most patients develop resistance partly through reactivation of KIT and its downstream signalling pathways.

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The enteric nervous system (ENS) is a complex network constituted of neurons and glial cells that ensures the intrinsic innervation of the gastrointestinal tract. ENS cells originate from vagal and sacral neural crest cells that are initially located at the border of the neural tube. In birds, sacral neural crest cells (sNCCs) first give rise to an extramural ganglionated structure (the so-called Nerve of Remak [NoR]) and to the pelvic plexus.

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Background: Inflammation is deeply involved in the pathophysiology of ischemia-reperfusion (I/R) lesions and ventricular remodeling due to an acute myocardial infarction (AMI). Colchicine as a pleiotropic anti-inflammatory molecule may exert cardioprotective effects under acute ischemia. Here, we aimed to evaluate the impact of colchicine on reperfusion injury in a mouse model.

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During development, the gastrointestinal (GI) tract arises from a primary tube composed of mesoderm and endoderm. The mesoderm gives rise to the digestive mesenchyme, which in turn differentiates into multiple tissues, namely the submucosa, the interstitial cells of Cajal and the smooth muscle cells (SMCs). Concomitant with these early patterning events, the primitive GI tract is colonized by vagal enteric neural crest-derived cells (vENCDCs), a population of cells that gives rise to the enteric nervous system, the intrinsic innervation of the GI tract.

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During spinal cord development, astrocyte precursors arise from neuroepithelial progenitors, delaminate from the ventricular zone, and migrate toward their final locations where they differentiate. Although the mechanisms underlying their early specification and late differentiation are being deciphered, less is known about the temporal control of their migration. Here, we show that the epithelial-mesenchymal transition regulator Zeb1 is expressed in glial precursors and report that loss of Zeb1 function specifically delays the onset of astrocyte precursor delamination from the ventricular zone, correlating with transient deregulation of the adhesion protein Cadherin-1.

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Background: Smooth muscle cell (SMC) plasticity maintains the balance between differentiated SMCs and proliferative mesenchymal progenitors, crucial for muscular tissue homeostasis. Studies on the development of mesenchymal progenitors into SMCs have proven useful in identifying molecular mechanisms involved in digestive musculature plasticity in physiological and pathological conditions.

Results: Here, we show that Limb Expression 1 (LIX1) molecularly defines the population of mesenchymal progenitors in the developing stomach.

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In vertebrates, stomach smooth muscle development is a complex process that involves the tight transcriptional or post-transcriptional regulation of different signalling pathways. Here, we identified the RNA-binding protein Epithelial Splicing Regulatory Protein 1 (ESRP1) as an early marker of developing and undifferentiated stomach mesenchyme. Using a gain-of-function approach, we found that in chicken embryos, sustained expression of ESRP1 impairs stomach smooth muscle cell (SMC) differentiation and FGFR2 splicing profile.

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The gastrointestinal tract develops from a simple and uniform tube into a complex organ with specific differentiation patterns along the anterior-posterior and dorso-ventral axes of asymmetry. It is derived from all three germ layers and their cross-talk is important for the regulated development of fetal and adult gastrointestinal structures and organs. Signals from the adjacent mesoderm are essential for the morphogenesis of the overlying epithelium.

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Article Synopsis
  • In vertebrates, the digestive tract starts as a simple structure and gets shaped into complex parts by interactions between different cell types.
  • Special cells called vagal enteric neural crest cells (vENCCs) are important for the early growth and function of the stomach.
  • Reducing the number of vENCCs causes problems in stomach development and leads to it not working correctly, showing that these cells are crucial for keeping the stomach's identity and helping it develop properly.
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  • Scientists discovered a new syndrome called CAID syndrome that affects the heart and gut rhythm in 17 people from France and Sweden.
  • They found that a specific change in a gene called SGOL1 causes this syndrome, which leads to problems with cell growth and function.
  • The researchers also studied zebrafish and found that when they altered the same gene, the fish showed similar issues to those in humans with CAID syndrome, helping them understand how it works.
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  • Smooth muscle cells in vertebrates can switch between two functions: contracting to help with movement and growing to heal or repair tissues.
  • A protein called RBPMS2 helps control this switching by interacting with specific molecules in the cell.
  • RBPMS2 has a special structure that allows it to connect with itself and other proteins, which is important for its role in helping smooth muscle cells change and function properly.
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Nonylphenol (NP) is an endocrine disruptor with harmful effects including feminization and carcinogenesis on various organisms. This substance is a degradation product of nonylphenol ethoxylates (NPEO) that is used in several industrial and agricultural processes. In this paper, we examined the assessment of NP exposure on chick embryo development, using a concentration consistent with the environmental concentrations of NP.

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Synopsis of recent research by authors named "Pascal De Santa Barbara"

  • - Recent research by Pascal De Santa Barbara focuses on the complex biological processes involved in gut development and smooth muscle differentiation, emphasizing the role of calcium wave dynamics and signaling pathways in these processes.
  • - Investigations into the enteric nervous system development and the effects of bariatric surgery on bone density and biological markers highlight the multifaceted impact of gastrointestinal health on overall wellness and disease mechanisms.
  • - The studies also explore advanced methodologies for assessing tissue properties and responses, particularly in contexts such as visceral myopathy, spinal cord injuries, and metabolic changes post-surgery, indicating a strong emphasis on integrating multi-disciplinary approaches in his research.