Cytochalasin B Influences Cytoskeletal Organization and Osteogenic Potential of Human Wharton's Jelly Mesenchymal Stem Cells

Among perinatal stem cells of the umbilical cord, human Wharton's jelly mesenchymal stem cells (hWJ-MSCs) are of great interest for cell-based therapy approaches in regenerative medicine, showing some advantages over other MSCs. In fact, hWJ-MSCs, placed between embryonic and adult MSCs, are not tumorigenic and are harvested with few ethical concerns. Furthermore, these cells can be easily cultured in vitro, maintaining both stem properties and a high proliferative rate for several passages, as well as trilineage capacity of differentiation. Recently, it has been demonstrated that cytoskeletal organization influences stem cell biology. Among molecules able to modulate its dynamics, Cytochalasin B (CB), a cyto-permeable mycotoxin, influences actin microfilament polymerization, thus affecting several cell properties, such as the ability of MSCs to differentiate towards a specific commitment. Here, we investigated for the first time the effects of a 24 h-treatment with CB at different concentrations (0.1-3 μM) on hWJ-MSCs. CB influenced the cytoskeletal organization in a dose-dependent manner, inducing changes in cell number, proliferation, shape, and nanomechanical properties, thus promoting the osteogenic commitment of hWJ-MSCs, as confirmed by the expression analysis of osteogenic/autophagy markers.

Mechanobiology: A landscape for reinterpreting stem cell heterogeneity and regenerative potential in diseased tissues

Mechanical forces play a fundamental role in cellular dynamics from the molecular level to the establishment of complex heterogeneity in somatic and stem cells. Here, we highlight the role of cytoskeletal mechanics and extracellular matrix in generating mechanical forces merging into oscillatory synchronized patterns. We discuss how cellular mechanosensing/-transduction can be modulated by mechanical forces to control tissue metabolism and set the basis for nonpharmacologic tissue rescue. Control of bone anabolic activity and repair, as well as obesity prevention, through a fine-tuning of the stem cell morphodynamics are highlighted. We also discuss the use of mechanical forces in the treatment of cardiovascular diseases and heart failure through the fine modulation of stem cell metabolic activity and regenerative potential. We finally focus on the new landscape of delivering specific mechanical stimuli to reprogram tissue-resident stem cells and enhance our self-healing potential, without the need for stem cell or tissue transplantation.

P34 ASYMPTOMATIC VENTRICULAR PRE–EXCITATION WITH DISAPPEARANCE DURING EXERTION: ALWAYS AN INDEX OF BENIGNITY?

Introduction

The disappearance of pre–excitation at high heart rates points to a low arrhythmic risk: why resort to electrophysiological studies anyway?

Clinical Case

L.S., a 12–year–old patient, performed an ECG for sports examination with evidence of ventricular pre–excitation from an asymptomatic left lateral accessory route (Fig. A). A 24 h ECG–Holter during training showed the disappearance of the pre–excitation at high frequencies (Fig. B) which is considered a low risk index. The patient underwent a transesophageal electrophysiological study (SETE) during which an effective refractory antegrade period of 228 ms of the pathway was objectified through atrial extrastimuli (*) (Fig. C: drive of atrial stimuli (*) followed by extrastimulus with conduction on an accessory route (E)). In addition, a 1: 1 conduction was observed on the atrial pathway up to at least 270 bpm (222 ms). The antegrade refractory period of the resting path was <250 ms and therefore identified a high–risk condition to be treated with ablation.

Discussion

The disappearance of pre–excitation at high heart rates is usually considered indicative of an accessory pathway with a long refractory period and therefore at low risk, however it must be sudden. According to European guidelines, the execution of invasive studies in asymptomatic patients who are employed in high–risk jobs or competitive sports has a class I B indication, but in the remaining asymptomatic cases the indication is IIa B. The Holter ECG alone or the stress test, with a careless evaluation of the disappearance of the pre–excitation (sudden vs progressive with minimal residual pre–excitation) would have erroneously led to labeling this accessory pathway at low risk. In the left lateral accessory pathways, with the increase of the HR, there can be a disappearance or pseudo–disappearance of the pre–excitation for anatomical reasons (being further away from the SA node) and for an increase in the AV conduction speed, not therefore for a long refractory period of the pathway. SETE is closer to the atrial side of the left accessory pathway and allows to correctly classify the risk.

Conclusion

SETE is a low–cost and minimally invasive method that should be considered as an integral part of the study of patients with asymptomatic ventricular pre–excitation even if non–invasive stratification indicates low risk.

Cytochalasin B Modulates Nanomechanical Patterning and Fate in Human Adipose-Derived Stem Cells

Cytoskeletal proteins provide architectural and signaling cues within cells. They are able to reorganize themselves in response to mechanical forces, converting the stimuli received into specific cellular responses. Thus, the cytoskeleton influences cell shape, proliferation, and even differentiation. In particular, the cytoskeleton affects the fate of mesenchymal stem cells (MSCs), which are highly attractive candidates for cell therapy approaches due to their capacity for self-renewal and multi-lineage differentiation. Cytochalasin B (CB), a cyto-permeable mycotoxin, is able to inhibit the formation of actin microfilaments, resulting in direct effects on cell biological properties. Here, we investigated for the first time the effects of different concentrations of CB (0.1–10 μM) on human adipose-derived stem cells (hASCs) both after 24 h (h) of CB treatment and 24 h after CB wash-out. CB influenced the metabolism, proliferation, and morphology of hASCs in a dose-dependent manner, in association with progressive disorganization of actin microfilaments. Furthermore, the removal of CB highlighted the ability of cells to restore their cytoskeletal organization. Finally, atomic force microscopy (AFM) revealed that cytoskeletal changes induced by CB modulated the viscoelastic properties of hASCs, influencing their stiffness and viscosity, thereby affecting adipogenic fate.

Cell Responsiveness to Physical Energies: Paving the Way to Decipher a Morphogenetic Code

We discuss emerging views on the complexity of signals controlling the onset of biological shapes and functions, from the nanoarchitectonics arising from supramolecular interactions, to the cellular/multicellular tissue level, and up to the unfolding of complex anatomy. We highlight the fundamental role of physical forces in cellular decisions, stressing the intriguing similarities in early morphogenesis, tissue regeneration, and oncogenic drift. Compelling evidence is presented, showing that biological patterns are strongly embedded in the vibrational nature of the physical energies that permeate the entire universe. We describe biological dynamics as informational processes at which physics and chemistry converge, with nanomechanical motions, and electromagnetic waves, including light, forming an ensemble of vibrations, acting as a sort of control software for molecular patterning. Biomolecular recognition is approached within the establishment of coherent synchronizations among signaling players, whose physical nature can be equated to oscillators tending to the coherent synchronization of their vibrational modes. Cytoskeletal elements are now emerging as senders and receivers of physical signals, "shaping" biological identity from the cellular to the tissue/organ levels. We finally discuss the perspective of exploiting the diffusive features of physical energies to afford in situ stem/somatic cell reprogramming, and tissue regeneration, without stem cell transplantation.

Protective effects of exosomes derived from lyophilized porcine liver against acetaminophen damage on HepG2 cells

Background

Recently, extracellular vesicles have come to the fore following their emerging role in cell communication, thanks to their ability to reach cells into the human body without dissipating their cargo, transferring biological active molecules, such as proteins, nucleic acids, lipids, etc. They appear as a promising tool in medicine, because of their capability to modulate cellular response in recipient cells. Moreover, a considerable number of publications suggests that exosome uptake is selective but not specific, and it can cross species and cell-type boundaries. This study aims to explore the potential role of porcine liver derived extracellular vesicles, exosomes in particular, to protect human cells from acute damage induced by acetaminophen.

Methods

Extracellular vesicles were isolated from porcine lyophilized liver using polymer-based precipitation and a further enrichment was performed using affinity beads. The effects of obtained fractions, total extracellular vesicles and enriched extracellular vesicles, were assessed on human liver derived HepG2 cells. Cell growth and survival were tested, with MTT and area coverage analysis designed by us, as well as protein expression, with immunofluorescence and Western blot. Oxidative stress in live cells was also measured with fluorogenic probes.

Results

After proving that porcine extracellular vesicles did not have a toxic effect on HepG2, quite the contrary total extracellular vesicle fraction improved cell growth, we investigated their protective capability with a preconditioning strategy in APAP-induced damage. EVs displayed not only the ability to strongly modulate cell survival responses, but they also were able to boost cell cycle progression.

Conclusions

Extracellular vesicles derived from farm animal food derivatives are able to modulate human hepatic cell metabolism, also improving cell survival in a damaged context.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03476-y.

Unveiling the morphogenetic code: A new path at the intersection of physical energies and chemical signaling

In this editorial, we discuss the remarkable role of physical energies in the control of cell signaling networks and in the specification of the architectural plan of both somatic and stem cells. In particular, we focus on the biological relevance of bioelectricity in the pattern control that orchestrates both developmental and regenerative pathways. To this end, the narrative starts from the dawn of the first studies on animal electricity, reconsidering the pioneer work of Harold Saxton Burr in the light of the current achievements. We finally discuss the most recent evidence showing that bioelectric signaling is an essential component of the informational processes that control pattern specification during embryogenesis, regeneration, or even malignant transformation. We conclude that there is now mounting evidence for the existence of a Morphogenetic Code, and that deciphering this code may lead to unprecedented opportunities for the development of novel paradigms of cure in regenerative and precision medicine.

Unprotected left main coronary artery stenting: true vs. non true bifurcation lesions; a single-centre experience

Aims

We investigated the impact of bifurcation lesions involving a side branch lesion combined with a main branch stenosis on clinical outcomes after percutaneous coronary intervention (PCI) on unprotected left main coronary artery (ULM).

Methods and results

We defined “true” bifurcation lesions as significant (>50%) side branch stenosis associated with a significant main branch lesion, either proximal or distal, according to the Medina classification (1.1.1, 1.0.1 or 0.1.1 lesions). “Non true” lesions were defined by absence of significant side lesions, or significant side lesions without concomitant main branch stenosis. We compared patients with “non-true” bifurcation lesions (N=132; 56%) with those with “true” bifurcation lesions (N=105; 44%) in their 12-month incidence of target vessel failure (TVF) (composite of (i) cardiac death related to target vessel; (ii) myocardial infarction related to target vessel, or (iii) ischemia-driven target vessel revascularization), death from any cause, target lesion revascularization (TLR) and stent thrombosis (ST). TVF occurred in 56 patients (24%) (figure 1). Patients with “true” bifurcation lesions had a significantly higher risk of TVF than those with “non-true” bifurcation lesions (HR 2.39; 95% CI 1.39–4.11, P=0.002). “True” bifurcation lesions were also associated with a higher risk of all cause of death (HR, 2.54; 95% CI, 1.09–5.94; P=0.031) and TLR (HR, 2.33; 95% CI, 1.1–4.94, P=0.027). 'True' bifurcation lesions, diabetes mellitus, as well as cardiogenic shock, were independently associated with an increased risk of TVF (figure 2). Of note, the SYNTAX score I was not identified as an independent predictor of TVF. The stenting strategy (1 vs 2 stents) did not show any significant association with the outcome.

Conclusions

Patients with ULM and “true” bifurcation lesions who undergo PCI have a worse clinical outcome than those with “non-true” bifurcation lesions.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Kaplan-Meier curves for TVFFigure 2. Independent predictors of TVF

Cardiac procedural myocardial injury, infarction and mortality in patients undergoing elective PCI: a pooled analysis of patient-level data

Background

The prognostic implications of cardiac procedural myocardial injury and infarction (MI) in chronic coronary syndrome patients undergoing elective percutaneous coronary intervention (PCI) is still debated.

Objective

To determine the optimal cardiac troponin threshold for identifying prognostically important events.

Methods

Using a pooled dataset of nine registries and one randomized trial, we analysed individual data of 14,433 patients undergoing elective PCI with a normal or moderately elevated baseline pre-PCI cardiac troponin (cTn). A multivariate model was performed to evaluate the associations between post-PCI cTn elevation and 1-year mortality after PCI, including thresholds used by existing procedural myocardial injury definitions (Fourth Universal Definition of MI [UDMI] and Academic Research Consortium 2 [ARC-2] / Society for Cardiovascular Angiography and Interventions (SCAI)). The association between type 4a MI and 1-year mortality was also evaluated.

Results

Procedural myocardial injury defined by the Fourth UDMI occurred in 52.5% of patients and was not associated with 1-year mortality (adjOR 1.27, 95% CI [0.90–1.81] p=0.18). The association between post-PCI cTn elevation and 1-year mortality was significant above a 3-fold increase above the upper reference limit, and was optimal for a 5.2-fold increase which corresponded to an 18.3% rate of event, and an adjOR of 2.03 (95% CI [1.31–3.14], p=0.002) (figure). Procedural myocardial injury defined by the ARC-2/SCAI definition occurred in 1.3% of the patients, had a strong association with 1-year mortality (adjOR 4.15, 95% CI [1.62–10.64], p<0.01) but lacked sensitivity (5.2% sensitivity). Type 4a MI occurred in 12.7% of patients, was strongly associated with 1-year mortality (adjOR 3.18, 95% CI [1.47–6.90], p=0.002), but could only be evaluated in a subset of patients (n=3 084) with available data on new myocardial ischaemia post-PCI.

Conclusions

We have demonstrated that a post-PCI cTn elevation ≥5x the 99th percentile URL in CCS patients with normal baseline cTn, represents the optimal threshold for defining prognostically important or “Major” procedural myocardial injury in the absence of evidence for new myocardial ischaemia. Major procedure related myocardial injury and type 4a MI should be considered as a quality metric and endpoints in clinical trials.

Adjusted OR of mortality at 1 year

Funding Acknowledgement

Type of funding source: None

Atrial fibrillation recurrence after transcatheter ablation worsens left atrial strain

Introduction

Left atrial strain (LAs) shows correlation with atrial fibrosis and is a predictor of atrial fibrillation (AF) recurrence after transcatheter ablation. Little is known about LAs evolution after ablation.

Purpose

We sought to evaluate the atrial function with echocardiographic strain before and 6 months after AF ablation.

Methods

65 consecutive patients undergoing radiofrequency or cryoballoon ablation for atrial fibrillation at our centre were enrolled. They underwent a transthoracic echocardiography before the procedure and at 6 months follow-up. 5 patients were excluded because of low quality images. Global left atrial strain during the reservoir phase (LASr) was calculated as a mean of the values obtained in 4 and 2 chamber apical view; the ventricular end-diastole was set as reference to allow the calculation both in patients in AF and sinus rhythm during the echocardiography. Recurrence was defined as any atrial arrhythmia episode lasting more than 30 seconds recorded on an EKG strip after the 3 months blanking period; all patients underwent a 24 hours EKG Holter after the blanking period to detect asymptomatic recurrence. Quality of life was assessed before the procedure and at follow-up with the EQ-5D-3L model.

Results

At 6 months 14 patients (13%) had AF recurrence. Patients with recurrence (AF-R) had similar baseline characteristics compared to those without recurrence (AF-NR) but the former had a longer history of AF (39±53 vs 85±94 months, p=0,018). LASr, LA volume and left ventricle ejection fraction (EF) were similar at baseline between groups. At follow-up LASr was significantly impaired in the AF-R group compared to AF-NR (14±6% vs 26±10% respectively, p<0,0001) whereas LA volume, LV end systolic volume and EF remained similar. Compared to baseline LASr worsened in patients experiencing AF recurrence (22±11% vs 14±6%, p=0.016) and this finding was consistent also in patients in sinus rhythm during both examinations (29±8 vs 17±7, p=0,005). Compared to baseline LASr (22±10% vs 26±10%, p=0.024), LV end-systolic volume (29±15 ml vs 22±6 ml, p=0,006) and EF (51±9% vs 58±18%, p=0,038) improved in the AF-NR group but the effect was driven mainly by patients restoring sinus rhythm. Both groups showed a significant improvement of the quality of life (55±23 vs 85±13, p<0,0001 AF-NR; 63±17 vs 80±12, p=0,012 AF-R).

Conclusions

Atrial fibrillation recurrence after transcatheter ablation is associated with significant left atrial strain worsening which indicates disease progression and may predispose to further long-term recurrences whereas a successful ablation has a protective effect on atrial function.

Funding Acknowledgement

Type of funding source: None

P1187Pocket-Hematoma after cardiac implantable electronic devices surgery: a single centre study

Intro

Pocket hematoma is a common complication after pacemaker (PMK) or implantable cardioverter defibrillator (ICD) surgery. In this clinical setting anticoagulant and antiplatelet therapy are associated with an increased risk of hemorrhagic complications, but data are sparse.

Purpose

We examined  the impact of antiplatelet therapy and anticoagulation with vitamin K antagonists (VKA) or heparin on the risk of pocket hematoma. Materials and method: between august 2017 and june 2019, a total of 639 devices were implanted or replaced at our centre. Predictors of hematoma occurrence were determined by multivariate regression analysis. We used a specific definition of pocket hematoma: a) any palpable swelling in the pocket area requiring an unscheduled visit or prolonged hospitalization > 24 h or re-hospitalization for hematoma, b) interruption of antithrombotics, c) reoperation, d) hemoglobin drop > 2 g/dl or blood transfusion. The above criteria were assessed during hospitalization and up to 10 days after discharge. Results: the incidence of pocket hematoma was 7.5%. Among 639 patients (pts) including in the study 33.5% (214 pts) didn’ t take any antithrombotic therapy, 40.2 % (257 pts) were on single antiplatelet therapy (SAPT), 8.8 % (56 pts) were on dual antiplatelet therapy, 11.1 % (71 pts) were on uninterrupted VKA (mean INR 2). Heparin bridging was administered in 6.4% (41 pts). Ejection fraction (43 ±13 %) and  hemoglobin value before implantation (12.3 ±2.6 g/dL) in patients who developed hematoma were significantly lower compared with whose without hematoma. Patients with hematoma had a higher prevalence of congestive heart failure, ischemic cardiomyopathy and intake antithrombotic therapy. After adjusting for confounding factors with multivariate logistic regression only the use of dual antiplatelet therapy (OR 5.9 95% CI 1.5-21 p = 0.008) and the bridging with enoxaparin (OR 5.6 95% CI 1.4-22 p = 0.013) increased the risk of pocket hematoma. Single antiplatelet therapy (OR 2.6 95% CI 0.8-8.4 p = ns) and uninterrupted VKA (OR 0.9 95% CI 0.7-11 p = ns) did not increased the risk of pocket hematoma compared to no antithrombotic therapy. Pulse generator change and new device implant/upgrading (OR 1.8 95% CI 0.6-5.2 p = ns) carried the same haemorrhagic risk.

Conclusion

the use of DAPT or bridging with enoxaparin are highly predictive for the occurrence of perioperative pocket hematoma in patients scheduled for pmk/icd surgery. In contrast, single antiplatelet therapy and uninterrupted VKA  did not increase the risk of hematoma.

Intracrine Endorphinergic Systems in Modulation of Myocardial Differentiation

A wide variety of peptides not only interact with the cell surface, but govern complex signaling from inside the cell. This has been referred to as an "intracrine" action, and the orchestrating molecules as "intracrines". Here, we review the intracrine action of dynorphin B, a bioactive end-product of the prodynorphin gene, on nuclear opioid receptors and nuclear protein kinase C signaling to stimulate the transcription of a gene program of cardiogenesis. The ability of intracrine dynorphin B to prime the transcription of its own coding gene in isolated nuclei is discussed as a feed-forward loop of gene expression amplification and synchronization. We describe the role of hyaluronan mixed esters of butyric and retinoic acids as synthetic intracrines, controlling prodynorphin gene expression, cardiogenesis, and cardiac repair. We also discuss the increase in prodynorphin gene transcription and intracellular dynorphin B afforded by electromagnetic fields in stem cells, as a mechanism of cardiogenic signaling and enhancement in the yield of stem cell-derived cardiomyocytes. We underline the possibility of using the diffusive features of physical energies to modulate intracrinergic systems without the needs of viral vector-mediated gene transfer technologies, and prompt the exploration of this hypothesis in the near future.

Physical energies to the rescue of damaged tissues

Rhythmic oscillatory patterns sustain cellular dynamics, driving the concerted action of regulatory molecules, microtubules, and molecular motors. We describe cellular microtubules as oscillators capable of synchronization and swarming, generating mechanical and electric patterns that impact biomolecular recognition. We consider the biological relevance of seeing the inside of cells populated by a network of molecules that behave as bioelectronic circuits and chromophores. We discuss the novel perspectives disclosed by mechanobiology, bioelectromagnetism, and photobiomodulation, both in term of fundamental basic science and in light of the biomedical implication of using physical energies to govern (stem) cell fate. We focus on the feasibility of exploiting atomic force microscopy and hyperspectral imaging to detect signatures of nanomotions and electromagnetic radiation (light), respectively, generated by the stem cells across the specification of their multilineage repertoire. The chance is reported of using these signatures and the diffusive features of physical waves to direct specifically the differentiation program of stem cells in situ, where they already are resident in all the tissues of the human body. We discuss how this strategy may pave the way to a regenerative and precision medicine without the needs for (stem) cell or tissue transplantation. We describe a novel paradigm based upon boosting our inherent ability for self-healing.

Restoring In Vivo-Like Membrane Lipidomics Promotes Exosome Trophic Behavior from Human Placental Mesenchymal Stromal/Stem Cells

Human mesenchymal stem cells (hMSCs) are an effective tool in regenerative medicine notably for their intrinsic plentiful paracrine activity rather than differentiating properties. The hMSC secretome includes a wide spectrum of regulatory and trophic factors, encompassing several naked molecules as well as different kinds of extracellular vesicles (EVs). Among EVs, exosomes represent an intriguing population, able to shuttle proteins, transcription factors, and genetic materials, with a relevant role in cell-to-cell communication, modulating biological responses in recipient cells. In this context, the extracellular milieu can greatly impact the paracrine activity of stem cells, modifying their metabolism, and the dynamics of vesicle secretion. In the present study, we investigated the effects elicited on exosome patterning by tailored, ad hoc formulated lipid supplementation (Refeed^®) in MSCs derived from human fetal membranes (hFM-MSCs). Wound healing experiments revealed that stem cell exposure to exosomes obtained from Refeed^®-supplemented hFM-MSCs increased their migratory capability, although the amount of exosomes released after Refeed^® supplementation was lower than that yielded from non-supplemented cells. We found that such a decrease was mainly due to a different rate of exosomal exocytosis rather than to an effect of the lipid supplement on the endocytic pathway. Endoplasmic reticulum homeostasis was modified by supplementation, through the upregulation of PKR-like ER kinase (PERK) and inositol-requiring enzyme 1α (IRE1α). Increased expression of these proteins did not lead to stress-induced, unfolded protein response (UPR)-mediated apoptosis, nor did it affect phosphorylation of p38 kinase, suggesting that PERK and IRE1α overexpression was due to augmented metabolic activities mediated by optimization of a cellular feeding network afforded through lipid supplementation. In summary, these results demonstrate how tailored lipid supplementation can successfully modify the paracrine features in hFM-MSCs, impacting both intracellular vesicle trafficking and secreted exosome number and function.

Long-term Intake of Pasta Containing Barley (1-3)Beta-D-Glucan Increases Neovascularization-mediated Cardioprotection through Endothelial Upregulation of Vascular Endothelial Growth Factor and Parkin

Barley (1-3)β-D-Glucan (BBG) enhances angiogenesis. Since pasta is very effective in providing a BBG-enriched diet, we hypothesized that the intake of pasta containing 3% BBG (P-BBG) induces neovascularization-mediated cardioprotection. Healthy adult male C57BL/6 mice fed P-BBG (n = 15) or wheat pasta (Control, n = 15) for five-weeks showed normal glucose tolerance and cardiac function. With a food intake similar to the Control, P-BBG mice showed a 109% survival rate (P < 0.01 vs. Control) after cardiac ischemia (30 min)/reperfusion (60 min) injury. Left ventricular (LV) anion superoxide production and infarct size in P-BBG mice were reduced by 62 and 35% (P < 0.0001 vs. Control), respectively. The capillary and arteriolar density of P-BBG hearts were respectively increased by 12 and 18% (P < 0.05 vs. Control). Compared to the Control group, the VEGF expression in P-BBG hearts was increased by 87.7% (P < 0.05); while, the p53 and Parkin expression was significantly increased by 125% and cleaved caspase-3 levels were reduced by 33% in P-BBG mice. In vitro, BBG was required to induce VEGF, p53 and Parkin expression in human umbelical vascular endothelial cells. Moreover, the BBG-induced Parkin expression was not affected by pifithrin-α (10 uM/7days), a p53 inhibitor. In conclusion, long-term dietary supplementation with P-BBG confers post-ischemic cardioprotection through endothelial upregulation of VEGF and Parkin.

Impacted maxillary canines and root resorption of adjacent teeth: A retrospective observational study

Background

The prevalence of impacted maxillary canine is reported to be between 1% and 3%. The lack of monitoring and the delay in the treatment of the impacted canine can cause different complications such as: displacement of adjacent teeth, loss of vitality of neighbouring teeth, shortening of the dental arch, follicular cysts, canine ankylosis, recurrent infections, recurrent pain, internal resorption of the canine and the adjacent teeth, external resorption of the canine and the adjacent teeth, combination of these factors. An appropriate diagnosis, accurate predictive analysis and early intervention are likely to prevent such undesirable effects. The objective is to evaluate, by means of a retrospective observational study, the possibility of carrying out a predictive analysis of root resorption adjacent to the impacted canines by means of orthopantomographs, so as to limit the prescription of additional 3D radiography.

Material and Methods

120 subjects with unilateral or bilateral maxillary impacted canine were examined and 50 patients with 69 impacted maxillary canine (22 male, 28 female; mean age: 11.7 years) satisfied the inclusion criteria of the study. These patients were subjected to a basic clinical and radiographic investigation (orthopantomographs and computerized tomography). All panoramic films were viewed under standardized conditions for the evaluation of two main variables: maxillary canine angulations (a, b, g angles) and the overlapping between the impacted teeth and the lateral incisor (Analysis of Lindauer). Binary logistic regression was used to estimate the likelihood of resorbed lateral incisors depending on sector location and angle measurements.

Results

Results indicated that b angle has the greatest influence on the prediction of root resorption (predictive value of b angle = 76%). If β angle <18° and Lindauer = I, the probability of resorption is 0.06.

Conclusions

Evaluation of b angle and superimposition lateral incisor/impacted canine analysed on orthopantomographs could be one of the evaluation criteria for prescribing second level examination (CT and CTCB) and for detecting root resorption of impacted maxillary canine adjacent teeth.

Key words:Impacted canine, root resorption, panoramic radiography, angulation, prediction.

Infection of human monocytes by Chlamydia pneumoniae and Chlamydia trachomatis: an in vitro comparative study

Background

An increasing number of studies suggest that chlamydiae can infect immune cells. The altered immune cell function could contribute to the progression of several chronic inflammatory diseases.

The aim of this study was to comparatively evaluate Chlamydia pneumoniae (CP) and Chlamydia trachomatis (CT) interactions with in vitro infected human blood monocytes.

Results

Fresh isolated monocytes were infected with viable CP and CT elementary bodies and infectivity was evaluated by recultivating disrupted monocytes in permissive epithelial cells.

The production of reactive oxygen and nitrogen species was studied in the presence of specific fluorescent probes. Moreover, TNF-α, INF-α, INF-β and INF-γ gene expression was determined.

CT clearance from monocytes was complete at any time points after infection, while CP was able to survive up to 48 hours after infection. When NADPH oxydase or nitric oxide synthase inhibitors were used, CT infectivity in monocytes was restored, even if at low level, and CT recovery’s rate was comparable to CP one.

CT-infected monocytes produced significantly higher levels of reactive species compared with CP-infected monocytes, at very early time points after infection. In the same meanwhile, TNF-α and INF-γ gene expression was significantly increased in CT-infected monocytes.

Conclusions

Our data confirm that CP, but not CT, is able to survive in infected monocytes up to 48 hours post-infection. The delay in reactive species and cytokines production by CP-infected monocytes seems to be crucial for CP survival.

The role of MRI and CT in diagnosis and treatment planning of cherubism: a 13-year follow-up case report

AIM

Cherubism is characterised by mesenchymal alterations during the development of the jaws secondary to perivascular fibrosis. According to the ALARA (As Low As Reasonably Achievable) principle, it is important to avoid conditions where the amount of radiation used is more than that needed for the procedure, because there is no benefit from unnecessary radiation. However, the use of MRI has been poorly studied in cherubism.

MATERIALS AND METHODS

The patient underwent head and neck MRI and 3D CT for imaging assessment.

RESULTS

MRI is necessary to evaluate the extension of dysplastic tissue and the cystic part of the lesions. Bone window CT only allows evaluation of strong densitometric alterations of cherubism lesions. Moreover, on radiographic film it is not always possible to distinguish fibrous tissue from mucous pseudocystic tissue. By contrast, these differences are readily evident on MRI.

CONCLUSION

MRI, in addition to other traditional radiographs and CT, could be useful in helping the clinician in the diagnosis and treatment of cherubism.

Radio electric conveyed fields directly reprogram human dermal skin fibroblasts toward cardiac, neuronal, and skeletal muscle-like lineages

Somatic cells can be directly reprogrammed to alternative differentiated fates without first becoming stem/progenitor cells. Nevertheless, the initial need for viral-mediated gene delivery renders this strategy unsafe in humans. Here, we provide evidence that exposure of human skin fibroblasts to a Radio Electric Asymmetric Conveyer (REAC), an innovative device delivering radio electric conveyed fields at a radiofrequency of 2.4 GHz, afforded remarkable commitment toward cardiac, neuronal, and skeletal muscle lineages. REAC induced the transcription of tissue-restricted genes, including Mef2c, Tbx5, GATA4, Nkx2.5, and prodynorphin for cardiac reprogramming, as well as myoD, and neurogenin 1 for skeletal myogenesis and neurogenesis, respectively. Conversely, REAC treatment elicited a biphasic effect on a number of stemness-related genes, leading to early transcriptional increase of Oct4, Sox2, cMyc, Nanog, and Klf4 within 6-20 h, followed by a downregulation at later times. The REAC action bypassed a persistent reprogramming toward an induced pluripotent stem cell-like state and involved the transcriptional induction of the NADPH oxidase subunit Nox4. Our results show for the first time the feasibility of using a physical stimulus to afford the expression of pluripotentiality in human adult somatic cells up to the attainment of three major target lineages for regenerative medicine.

Concise review: Bone marrow for the treatment of spinal cord injury: mechanisms and clinical applications

Transplantation of bone marrow stem cells into spinal cord lesions enhances axonal regeneration and promotes functional recovery in animal studies. There are two types of adult bone marrow stem cell; hematopoietic stem cells (HSCs), and mesenchymal stem cells (MSCs). The mechanisms by which HSCs and MSCs might promote spinal cord repair following transplantation have been extensively investigated. The objective of this review is to discuss these mechanisms; we briefly consider the controversial topic of HSC and MSC transdifferentiation into central nervous system cells but focus on the neurotrophic, tissue sparing, and reparative action of MSC grafts in the context of the spinal cord injury (SCI) milieu. We then discuss some of the specific issues related to the translation of HSC and MSC therapies for patients with SCI and present a comprehensive critique of the current bone marrow cell clinical trials for the treatment of SCI to date.

Anti-angiogenic effects of two cystine-knot miniproteins from tomato fruit

BACKGROUND AND PURPOSE

Cystine-knot miniproteins are characterized by a similar molecular structure. Some cystine-knot miniproteins display therapeutically useful biological activities, as antithrombotic agents or tumour growth inhibitors. A critical event in the progression of tumours is the formation of new blood vessels. The aim of this work was to test two tomato cystine-knot miniproteins for their effects on endothelial cell proliferation and angiogenesis in vitro.

EXPERIMENTAL APPROACH

Two tomato cystine-knot miniproteins (TCMPs) were expressed and purified either as recombinant or as native proteins from tomato fruits. The Matrigel assay was used to investigate the effects of TCMPs on in vitro angiogenesis. Viability and proliferation of endothelial cells were tested. Extracellular signal-regulated kinase (ERK)1/2 phosphorylation was assayed in either HUVEC or A431 epidermal growth factor receptor (EGFR)-overexpressing cells treated with TCMPs. EGFR phosphorylation was tested in A431 cells.

KEY RESULTS

Both recombinant and native TCMPs inhibited in vitro angiogenesis of HUVEC cells at concentrations of 15-100 nM. The anti-angiogenic effect of TCMPs was associated with the inhibition of ERK phosphorylation. The two miniproteins did not alter the viability and proliferation of the endothelial cells.

CONCLUSIONS AND IMPLICATIONS

The anti-angiogenetic properties of TCMPs are of potential pharmacological interest because they are common and natural components of the human diet, they possess low toxicity, they are active at submicromolar concentrations, they share a common molecular structure that can be used as a molecular platform for the design of molecules with enhanced biological activity.

Hyaluronan esters drive Smad gene expression and signaling enhancing cardiogenesis in mouse embryonic and human mesenchymal stem cells

Background

Development of molecules chemically modifying the expression of crucial orchestrator(s) of stem cell commitment may have significant biomedical impact. We have recently developed hyaluronan mixed esters of butyric and retinoic acids (HBR), turning cardiovascular stem cell fate into a high-yield process. The HBR mechanism(s) remain still largely undefined.

Methodology/Principal Findings

We show that in both mouse embryonic stem (ES) cells and human mesenchymal stem cells from fetal membranes of term placenta (FMhMSCs), HBR differentially affected the patterning of Smad proteins, one of the major conductors of stem cell cardiogenesis. Real-time RT-PCR and Western blot analyses revealed that in both cell types HBR enhanced gene and protein expression of Smad1,3, and 4, while down-regulating Smad7. HBR acted at the transcriptional level, as shown by nuclear run-off experiments in isolated nuclei. Immunofluorescence analysis indicated that HBR increased the fluorescent staining for Smad1,3, and 4, confirming that the transcriptional action of HBR encompassed the upregulation of the encoded Smad proteins. Chromatin immune precipitation and transcriptional analyses showed that HBR increased the transcription of the cardiogenic gene Nkx-2.5 through Smad4 binding to its own consensus Smad site. Treatment of mouse ES cells and FMhMSCs with HBR led to the concomitant overexpression of both Smad4 and α-sarcomeric actinin. Smad4 silencing by the aid of lentiviral-mediated Smad4 shRNA confirmed a dominant role of Smad4 in HBR-induced cardiogenesis.

Conclusions/Significance

The use of HBR may pave the way to novel combinatorial strategies of molecular and stem cell therapy based on fine tuning of targeted Smad transciption and signaling leading to a high-throughput of cardiogenesis without the needs of gene transfer technologies.

Hyaluronan mixed esters of butyric and retinoic acid affording myocardial survival and repair without stem cell transplantation

Possible cardiac repair by adult stem cell transplantation is currently hampered by poor cell viability and delivery efficiency, uncertain differentiating fate in vivo, the needs of ex vivo cell expansion, and consequent delay in transplantation after the onset of heart attack. By the aid of magnetic resonance imaging, positron emission tomography, and immunohistochemistry, we show that injection of a hyaluronan mixed ester of butyric and retinoic acid (HBR) into infarcted rat hearts afforded substantial cardiovascular repair and recovery of myocardial performance. HBR restored cardiac [¹⁸F]fluorodeoxyglucose uptake and increased capillary density and led to the recruitment of endogenous Stro-1-positive stem cells. A terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay demonstrated that HBR-treated hearts exhibited a decrease in the number of apoptotic cardiomyocytes. In isolated rat cardiomyocytes and Stro-1 stem cells, HBR enhanced the transcription of vascular endothelial growth factor, hepatocyte growth factor, kdr, akt, and pim-1. HBR also increased the secretion of vascular endothelial growth factor and hepatocyte growth factor, suggesting that the mixed ester may have recruited both myocardial and Stro-1 cells also. An increase in capillarogenesis was induced in vitro with medium obtained from HBR-exposed cells. In the infarcted myocardium, HBR injection increased histone H4 acetylation significantly. Acetyl-H4 immunoreactivity increased in rat cardiomyocytes and Stro-1 cells exposed to HBR, compared with untreated cells. In conclusion, efficient cardiac regenerative therapy can be afforded by HBR without the need of stem cell transplantation or vector-mediated gene delivery.

Changes in aqueductal CSF stroke volume in shunted patients with idiopathic normal-pressure hydrocephalus

BACKGROUND AND PURPOSE

Aqueductal CSF stroke volume (ACSV) measured by phase-contrast MR imaging is a tool for selection of surgical patients with idiopathic normal-pressure hydrocephalus (iNPH). The aim of the present study was to investigate whether there is a relationship between clinical outcome and changes in ACSV in patients with iNPH who have been shunted.

MATERIALS AND METHODS

Sixty-five shunted patients with iNPH underwent clinical evaluation and ACSV measurements 7-30 days before and 1, 3, 6, and 12 months after surgery.

RESULTS

Two patients were excluded from the study for the occurrence of a perioperative complication. In a group of 35 clinically improved patients, the mean preoperative ACSV (157.01 microL) decreased to 18% one month after ventriculoperitoneal shunt (VPS) and < or =49% at 12 months post-VPS. In a group of 15 unimproved patients, the lower mean preoperative ACSV (84.2 microL) decreased to 14.3% one month post-VPS and < or =34% at 12 months post-VPS. In the other 8 improved patients who developed a subdural fluid collection (SDFC), ACSV values decreased by 43%-75% in the 3 months post-VPS. A postoperative ACSV increase was noted in 6 patients with a shunt system malfunction. One patient experienced both SDCF and shunt malfunction.

CONCLUSIONS

ACSV decreases in all patients in whom the VPS system works properly, with the rate of ACSV decrease being higher in the patients who show clinical improvement. Postoperative ACSV increase suggests shunt malfunction. A precipitous drop of ACSV values after VPS may be the consequence of increased drainage and herald the occurrence of SDFC.

[Expression of metanephric differentiation markers in human mesenchymal stem cells]

Stem cells are a potential source for the regeneration of many tissues, including damaged kidneys. The present study describes the adoption of hyaluronic- butyric acid monoesters (HB) to induce expression of nephrogenic genes by mesenchymal cells isolated from human placental membranes. HB at a concentration of 1 mg/mL induces chromatin opening and increases the expression of the observed markers (cadherin 11, CD24, RAR-alpha, stearoyl-CoA desaturase 2, 14-3-3 0, Ewing sarcoma homolog.). These results open new routes toward cell regeneration after kidney injury.

Stem cells and cardiovascular repair: a role for natural and synthetic molecules harboring differentiating and paracrine logics

Stem cells hold considerable promise for cardiovascular rescue in patients with heart failure due to myocardial infarction or hereditary cardiomyopathies. However, cardiogenesis, one of the earliest and most complex morphogenetic events in the embryo, is only partially exploited at molecular level. The yield of myocardial cells spontaneously derived from human embryonic or adult stem cells is extremely low (usually less than 0.1%). Moreover, it is now evident that secretion of specific growth factors from transplanted stem cells may activate angiogenic, antiapoptotic and antifibrotic paracrine patterning within the recipient heart, playing a major role in tissue repair. Within this context, targeting stem cell fate at the level of gene expression represents a potentially powerful therapeutic approach to afford a high-throughput of cardiovascular lineage commitment and paracrine secretion of "trophic factors". Cell-based phenotypic- and pathway-specific screens of natural and synthetic compounds have provided a number of molecules achieving selective control of stem cell growth and differentiation. Novel hyaluronan mixed esters of butyric and retinoic acids have been recently synthesized, emerging as new tools for manipulation of cardio/vasculogenic gene expression through the modulation of targeted signaling pathways and chromatin-remodeling enzymes. These molecules have coaxed both murine embryonic and human mesenchymal stem cells towards cardiovascular decision and paracrine secretion of bioactive factors, remarkably enhancing the rescuing potential of human stem cells in in vivo animal models of myocardial infarction. These molecules may ultimately provide new insights in stem cell biology and pave the way to novel approaches in tissue engineering and cardiovascular repair.

Hyaluronan mixed esters of butyric and retinoic Acid drive cardiac and endothelial fate in term placenta human mesenchymal stem cells and enhance cardiac repair in infarcted rat hearts

We have developed a mixed ester of hyaluronan with butyric and retinoic acid (HBR) that acted as a novel cardiogenic/vasculogenic agent in human mesenchymal stem cells isolated from bone marrow, dental pulp, and fetal membranes of term placenta (FMhMSCs). HBR remarkably enhanced vascular endothelial growth factor (VEGF), KDR, and hepatocyte growth factor (HGF) gene expression and the secretion of the angiogenic, mitogenic, and antiapoptotic factors VEGF and HGF, priming stem cell differentiation into endothelial cells. HBR also increased the transcription of the cardiac lineage-promoting genes GATA-4 and Nkx-2.5 and the yield of cardiac markerexpressing cells. These responses were notably more pronounced in FMhMSCs. FMhMSC transplantation into infarcted rat hearts was associated with increased capillary density, normalization of left ventricular function, and significant decrease in scar tissue. Transplantation of HBR-preconditioned FMhM-SCs further enhanced capillary density and the yield of human vWF-expressing cells, additionally decreasing the infarct size. Some engrafted, HBR-pretreated FMhMSCs were also positive for connexin 43 and cardiac troponin I. Thus, the beneficial effects of HBR-exposed FMhMSCs may be mediated by a large supply of angiogenic and antiapoptotic factors, and FMhMSC differentiation into vascular cells. These findings may contribute to further development in cell therapy of heart failure.