Regenerative potential of human schneiderian membrane: progenitor cells and epithelial-mesenchymal transition

Transcriptome analysis of osteogenic differentiation of human maxillary sinus mesenchymal stem cells using RNA-Seq

Recent studies have demonstrated that human maxillary sinus mesenchymal stem cells (hMSMSCs) have osteogenic potential and can be osteogenically induced. Here, we investigated pivotal molecular functions and candidates that contribute to the osteogenic differentiation of hMSMSCs. Human maxillary sinus membranes were harvested from 3 patients with jaw deformities. hMSMSCs from human maxillary sinus membranes were osteogenically induced for 0 or 21 days. Subsequently, their functional profiles were analysed by RNA sequencing and validated by quantitative PCR. Compared with control hMSMSCs, osteogenically induced hMSMSCs showed (1) osteogenic differentiation phenotype, as evidenced by the cell nodes, alizarin red staining, osteogenesis-related protein, and RNA expression; (2) accelerated osteogenic process of ossification and calcium signalling, as demonstrated by Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway; (3) enriched osteogenesis gene expression of SMOC2, OMD, IGF1, JUNB, BMP5, ADRA1A, and IGF2, which was validated by quantitative PCR. Based on by these results, we demonstrated that accelerated ossification process, calcium signalling, and upregulation of SMOC2, OMD, IGF1, JUNB, BMP5, ADRA1A and IGF2, may contribute to the osteogenic differentiation of hMSMSCs.

A Synopsis of Signaling Crosstalk of Pericytes and Endothelial Cells in Salivary Gland

The salivary gland (SG) microvasculature constitutes a dynamic cellular organization instrumental to preserving tissue stability and homeostasis. The interplay between pericytes (PCs) and endothelial cells (ECs) culminates as a key ingredient that coordinates the development, maturation, and integrity of vessel building blocks. PCs, as a variety of mesenchymal stem cells, enthrall in the field of regenerative medicine, supporting the notion of regeneration and repair. PC-EC interconnections are pivotal in the kinetic and intricate process of angiogenesis during both embryological and post-natal development. The disruption of this complex interlinkage corresponds to SG pathogenesis, including inflammation, autoimmune disorders (Sjögren’s syndrome), and tumorigenesis. Here, we provided a global portrayal of major signaling pathways between PCs and ECs that cooperate to enhance vascular steadiness through the synergistic interchange. Additionally, we delineated how the crosstalk among molecular networks affiliate to contribute to a malignant context. Additionally, within SG microarchitecture, telocytes and myoepithelial cells assemble a labyrinthine companionship, which together with PCs appear to synchronize the regenerative potential of parenchymal constituents. By underscoring the intricacy of signaling cascades within cellular latticework, this review sketched a perceptive basis for target-selective drugs to safeguard SG function.

Radiographic and Histomorphometric Evaluation of Biomaterials Used for Lateral Sinus Augmentation: A Systematic Review on the Effect of Residual Bone Height and Vertical Graft Size on New Bone Formation and Graft Shrinkage

The aim of the present systematic review was to investigate the effect of residual bone height (RBH) and vertical bone gain on new bone formation (NBF) and graft shrinkage after lateral sinus lifts using different biomaterials.

METHODS

An electronic search was conducted on three databases to identify randomized controlled trials (RCTs) published until January 2021 with at least one follow-up at 6 months and at least five patients treated, comparing biomaterials used for maxillary sinus augmentation with a lateral approach. Graft volumetric changes, RBH, vertical bone gain, implant failure, and post-operative complications were evaluated. The risk of bias was assessed using the Cochrane tool.

RESULTS

We used 4010 identified studies, of which 21 were RCTs. Overall, 412 patients and 533 sinuses were evaluated. Only three publications had an overall low risk of bias. After 6 months, xenograft (XG) showed the least volume reduction (7.30 ± 15.49%), while autogenous graft (AU) was the most reabsorbed (41.71 ± 12.63%). NBF appeared to not be directly correlated with RBH; on the contrary, the overall linear regression analysis showed that NBF significantly decreased by 1.6% for each mm of postoperative vertical graft gain. This finding suggests that the greater the augmentation, the lower the NBF. A similar tendency, with a regression coefficient even higher than the overall one, was also observed with alloplast (AP) and XG.

CONCLUSIONS

The present results suggested that NBF was essentially independent of preoperative bone height. On the contrary, the smaller the volume was of the graft placed, the higher the amount of new bone formed, and the smaller the graft shrinkage was. Minimizing the augmentation volume might be beneficial to graft healing and stability especially when using AP and XG.

Nestin Expression Is Associated with Relapses in Head and Neck Lesions

BACKGROUND

The aim was to investigate the clinical significance of nestin immunohistochemical expression in head and neck area lesions and to study its role in patient survival and recurrence.

METHODS

39 (44.3%) nasosinus, 37 (42%) major salivary gland (6 submandibular and 31 parotid) and 12 (13.6%) oral cavity lesions of paraffin-embedded samples were retrospectively included.

RESULTS

The expression was categorized into grades, negative for 55 (62.5%) cases, grade 1 in 10 cases (11.4%), grade 2 in 12 cases (13.6%), and grade 3 in 11 cases (12.5%); 100% of pleomorphic adenomas were positive for nestin with grade 3 intensity, 100% of polyps and inverted papillomas were negative (p < 0.001). The lowest estimate of disease-free-survival (DFS) was for grade 1 expression, with 50 months, confidence interval (CI): 95% 13.3-23.9 months and the highest for grade 3 expression, 167.9 months (CI: 95% 32.1-105 months; Log-Rank = 14.846, p = 0.002). ROC (receiver operating characteristic) curves revealed that the positivity for nestin (+/-) in relation to malignancy, presented a sensitivity of 50.98%, a specificity of 81.08%, with an area under the curve of 0.667 (p = 0.009).

CONCLUSIONS

Nestin could be a useful marker to detect the presence of stem cells in head and neck tumors that have a role in tumor initiation and progression.

Maxillary Sinusitis Associated With Peri-implantitis at Sinus Floor Augmented Sites: Case Series

PURPOSE

The purpose of this case series was to investigate treatment outcomes of maxillary sinusitis associated with peri-implantitis at sinus floor augmented sites for a 3-year follow-up.

MATERIALS AND METHODS

Eighteen implants in 8 patients diagnosed with maxillary sinusitis associated with peri-implantitis were reviewed. Four patients were treated with implant removal and antibiotics, and 4 patients were treated with implant removal, the modified Caldwell-Luc operation (CLOP), and antibiotics. Seven patients, who had 7 survived implants, were followed up to 3 years after treatment. The characteristics between failed and survived implants were compared. Radiographic parameters of survived implants were analyzed using the Friedman test.

RESULTS

Eleven failed implants from 8 patients exhibited approximately 10-mm pocket depths and mobility at diagnosis. Seven survived implants from 7 patients exhibited no significant changes in crestal bone loss at the facial side for 3 years after the treatments. Sinus mucosal thickening was significantly reduced during the 3-year follow-up after the treatments.

CONCLUSION

The progression of peri-implantitis in sinus floor augmented sites may lead to maxillary sinusitis. To confirm the efficacy of the intraoral approaches, such as the modified CLOP, systematic clinical studies with a large sample size and a long-term follow-up should be conducted.

Stromal cells/telocytes and endothelial progenitors in the perivascular niches of the trigeminal ganglion

Stromal cells/telocytes (SCs/TCs) were recently described in the human adult trigeminal ganglion (TG). As some markers are equally expressed in SCs/TCs and endothelial cells, we hypothesized that a subset of the TG SCs/TCs is in fact represented by endothelial progenitor cells of a myelomonocytic origin. This study aimed to evaluate whether the interstitial cells of the human adult TG correlate with the myelomonocytic lineage. We used primary antibodies for c-erbB2/HER-2, CD31, nestin, CD10, CD117/c-kit, von Willebrand factor (vWF), CD34, Stro-1, CD146, α-smooth muscle actin (α-SMA), CD68, VEGFR-2 and cytokeratin 7 (CK7). The TG pial mesothelium and subpial vascular microstroma expressed c-erbB2/HER-2, CK7 and VEGFR-2. SCs/TCs neighbouring the neuronoglial units (NGUs) also expressed HER-2, which suggests a pial origin. These cells were also positive for CD10, CD31, CD34, CD68 and nestin. Endothelial cells expressed CD10, CD31, CD34, CD146, nestin and vWF. We also found vasculogenic networks with spindle-shaped and stellate endothelial progenitors expressing CD10, CD31, CD34, CD68, CD146 and VEGFR-2. Isolated mesenchymal stromal cells expressed Stro-1, CD146, CK7, c-kit and nestin. Pericytes expressed α-SMA and CD146. Using transmission electron microscopy (TEM), we found endothelial-specific Weibel-Palade bodies in spindle-shaped stromal progenitors. Our study supports the hypothesis that an intrinsic vasculogenic niche potentially involved in microvascular maintenance and repair might be present in the human adult trigeminal ganglion and that it might be supplied by either the pial mesothelium or the bone marrow niche.

Influence of Maxillary Sinus Width on New Bone Formation After Transcrestal Sinus Floor Elevation: A Proof-of-Concept Prospective Cohort Study

PURPOSE

Graft maturation in the maxillary sinus requires adequate angiogenesis and osteoprogenitor cells migration from the surrounding bony walls: the aim of this study was to analyze the correlation between sinus cavity dimensions and new bone formation after transcrestal sinus floor elevation (tSFE).

METHODS

Patients needing maxillary sinus augmentation (residual crest height ≤ 4 mm) were treated with tSFE using xenogeneic granules. Six months later, bone-core biopsies were retrieved for histological analysis in the implant insertion sites. Buccopalatal sinus width (SW) was evaluated on cone beam computed tomography, and correlations between histomorphometric and anatomical parameters were quantified by means of linear regression analysis.

RESULTS

Eight consecutive patients underwent tSFE procedures: at 6 months, average percentage of newly formed bone resulted 24.2% ± 7.9%. Statistical analysis showed a strong inverse correlation between SW and new bone formation (R = 0.88), and a strong direct correlation between the number of exposed bone walls and new bone formation (R = 0.82).

CONCLUSION

Within the limitations of this proof-of-concept study, in which a restricted number of patients were analyzed, tSFE showed more predictable results in narrow than in large sinuses, in terms of new bone formation.

Expression of Epithelial and Mesenchymal Differentiation Markers in the Early Human Gonadal Development

Expressions of cytokeratin 8 (CK8), vimentin, nestin, and alpha-smooth-muscle-actin (alpha-SMA) were analyzed in the developing gonads of 12, 5-9 week old (W) human conceptuses by immunohistochemistry and immunofluorescence. During the investigated period, the number of CK8 positive cells increased from 56% to 92% in the gonadal surface epithelium, from 50% to 60% in the stroma, and from 23% to 42% in the medulla. In the early fetal period, the cell expression of CK8 increased in all gonadal parts, whereas primordial germ cells (PGC) remained negative. The expression of vimentin increased in the gonad stroma (gs) from 73% to 88%, and in the surface epithelium from 18% to 97% until ninth W. The medulla had the highest expression of vimentin in the seventh to eighth W (93%). Vimentin and CK8 colocalized in the somatic cells, while some PGCs showed vimentin expression only. Initially, nestin was positive in the gonad surface epithelium (8%) and stroma (52%), however during further development it decreased to 1% and 33%, respectively. In the early fetal period, the nestin positive cells decreased from 44% to 31% in the gonad medulla. Alpha-SMA was positive only in the blood vessels and mesonephros. The described pattern of expression of intermediate filaments (IF) in developing human gonads suggests their role in the control of PGC apoptosis, early differentiation of gs cells and cell migration. Both epithelial and mesenchymal origins of follicular cells and possible epithelial-to-mesenchymal transition of somatic cells is proposed. Lastly, IF intensity expression varies depending on the cell type and developmental period analyzed. Anat Rec, 300:1315-1326, 2017. © 2017 Wiley Periodicals, Inc.