scholarly journals Modulation of fracture healing by the transient accumulation of senescent cells

2021 ◽  
Author(s):  
Sundeep Khosla ◽  
Dominik Saul ◽  
David Monroe ◽  
Jennifer L Rowsey ◽  
Robyn Laura Kosinsky ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Time Course ◽  
Callus Formation ◽  
In Silico Analysis ◽  
Skin Wound ◽  
Luciferase Reporter ◽  
Skin Wound Healing ◽  
Fracture Callus ◽  
Beneficial Effects

Senescent cells have detrimental effects across tissues with aging but may have beneficial effects on tissue repair, specifically on skin wound healing. However, the potential role of senescent cells in fracture healing has not been defined. Here, we performed an in silico analysis of public mRNAseq data and found that senescence and senescence-associated secretory phenotype (SASP) markers increased during fracture healing. We next directly established that the expression of senescence biomarkers increased markedly during murine fracture healing. We also identified a subset of cells in the fracture callus that displayed hallmarks of senescence, including distension of satellite heterochromatin and telomeric DNA damage. Then, using a genetic mouse model (p16LUC) containing a p16Ink4a55-driven luciferase reporter, we demonstrated transient in vivo senescent cell accumulation during callus formation. Finally, we intermittently treated young adult mice following fracture with drugs that selectively eliminate senescent cells ("senolytics", Dasatinib plus Quercetin), and showed that this regimen both decreased senescence and SASP markers in the fracture callus and significantly accelerated the time course of fracture healing. Our findings thus demonstrate that senescent cells accumulate transiently in the murine fracture callus and, in contrast to the skin, their clearance does not impair but rather may improve fracture healing.

scholarly journals Modulation of fracture healing by the transient accumulation of senescent cells

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Dominik Saul ◽  
David G Monroe ◽  
Jennifer L Rowsey ◽  
Robyn Laura Kosinsky ◽  
Stephanie J Vos ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Time Course ◽  
Callus Formation ◽  
Skin Wound ◽  
Luciferase Reporter ◽  
Skin Wound Healing ◽  
Fracture Callus ◽  
Beneficial Effects ◽  
Genetic Mouse Model

Senescent cells have detrimental effects across tissues with aging but may have beneficial effects on tissue repair, specifically on skin wound healing. However, the potential role of senescent cells in fracture healing has not been defined. Here, we performed an in silico analysis of public mRNAseq data and found that senescence and senescence-associated secretory phenotype (SASP) markers increased during fracture healing. We next directly established that the expression of senescence biomarkers increased markedly during murine fracture healing. We also identified cells in the fracture callus that displayed hallmarks of senescence, including distension of satellite heterochromatin and telomeric DNA damage; the specific identity of these cells, however, requires further characterization. Then, using a genetic mouse model (Cdkn2aLUC) containing a Cdkn2aInk4a-driven luciferase reporter, we demonstrated transient in vivo senescent cell accumulation during callus formation. Finally, we intermittently treated young adult mice following fracture with drugs that selectively eliminate senescent cells ('senolytics', Dasatinib plus Quercetin), and showed that this regimen both decreased senescence and SASP markers in the fracture callus and significantly accelerated the time course of fracture healing. Our findings thus demonstrate that senescent cells accumulate transiently in the murine fracture callus and, in contrast to the skin, their clearance does not impair but rather improves fracture healing.

scholarly journals Dissecting the microenvironment around biosynthetic scaffolds in murine skin wound healing

2021 ◽  
Vol 7 (22) ◽  
pp. eabf0787
Author(s):  
Chen Hu ◽  
Chenyu Chu ◽  
Li Liu ◽  
Chenbing Wang ◽  
Shue Jin ◽  
...  
Keyword(s):  
Wound Healing ◽  
Immune Responses ◽  
Time Course ◽  
Skin Wound ◽  
Cellular Heterogeneity ◽  
Cell Behavior ◽  
Skin Wound Healing ◽  
Electrospun Membranes

The structural properties of biomaterials play crucial roles in guiding cell behavior and influencing immune responses against the material. We fabricated electrospun membranes with three types of surface topography (random, aligned, and latticed), introduced them to dorsal skin excisional wounds in mice and rats, and evaluated their effects on wound healing and immunomodulatory properties. An overview of different immune cells in the microenvironment with the help of single-cell RNA sequencing revealed diverse cellular heterogeneity in vivo. The time course of immune response was advanced toward an adaptive immunity–dominant stage by the aligned scaffold. In mice without mature T lymphocytes, lack of wound-induced hair neogenesis indicated a regulatory role of T cells on hair follicle regeneration. The microenvironment around scaffolds involved an intricate interplay of immune and cutaneous cells.

scholarly journals Overexpression of the Oral Mucosa-Specific microRNA-31 Promotes Skin Wound Closure

2019 ◽  
Vol 20 (15) ◽  
pp. 3679 ◽  
Author(s):  
Lin Chen ◽  
Alyne Simões ◽  
Zujian Chen ◽  
Yan Zhao ◽  
Xinming Wu ◽  
...  
Keyword(s):  
Wound Healing ◽  
Oral Mucosa ◽  
Wound Closure ◽  
Expression Patterns ◽  
Skin Wound ◽  
Skin Wound Healing ◽  
Specific Expression ◽  
Keratinocyte Proliferation

Wounds within the oral mucosa are known to heal more rapidly than skin wounds. Recent studies suggest that differences in the microRNAome profiles may underlie the exceptional healing that occurs in oral mucosa. Here, we test whether skin wound-healing can be accelerating by increasing the levels of oral mucosa-specific microRNAs. A panel of 57 differentially expressed high expresser microRNAs were identified based on our previously published miR-seq dataset of paired skin and oral mucosal wound-healing [Sci. Rep. (2019) 9:7160]. These microRNAs were further grouped into 5 clusters based on their expression patterns, and their differential expression was confirmed by TaqMan-based quantification of LCM-captured epithelial cells from the wound edges. Of these 5 clusters, Cluster IV (consisting of 8 microRNAs, including miR-31) is most intriguing due to its tissue-specific expression pattern and temporal changes during wound-healing. The in vitro functional assays show that ectopic transfection of miR-31 consistently enhanced keratinocyte proliferation and migration. In vivo, miR-31 mimic treatment led to a statistically significant acceleration of wound closure. Our results demonstrate that wound-healing can be enhanced in skin through the overexpression of microRNAs that are highly expressed in the privileged healing response of the oral mucosa.

scholarly journals The glycosyltransferase ST3GAL2 is regulated by miR-615-3p in the intestinal tract of Campylobacter jejuni infected mice

Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
De Xi ◽  
Lukas Hofmann ◽  
Thomas Alter ◽  
Ralf Einspanier ◽  
Stefan Bereswill ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Regulatory Networks ◽  
In Silico Analysis ◽  
Luciferase Reporter ◽  
Colonic Tissue ◽  
Tissue Samples ◽  
Vitro Model ◽  
Pathway Analyses

Abstract Background Campylobacter jejuni (C. jejuni) infections are of increasing importance worldwide. As a typical mucosal pathogen, the interaction of C. jejuni with mucins is a prominent step in the colonisation of mucosal surfaces. Despite recent advances in understanding the interaction between bacterial pathogens and host mucins, the mechanisms of mucin glycosylation during intestinal C. jejuni infection remain largely unclear. This prompted us to identify relevant regulatory networks that are concerted by miRNAs and could play a role in the mucin modification and interaction. Results We firstly used a human intestinal in vitro model, in which we observed altered transcription of MUC2 and TFF3 upon C. jejuni NCTC 11168 infection. Using a combined approach consisting of in silico analysis together with in vitro expression analysis, we identified the conserved miRNAs miR-125a-5p and miR-615-3p associated with MUC2 and TFF3. Further pathway analyses showed that both miRNAs appear to regulate glycosyltransferases, which are related to the KEGG pathway ‘Mucin type O-glycan biosynthesis’. To validate the proposed interactions, we applied an in vivo approach utilising a well-established secondary abiotic IL-10−/− mouse model for infection with C. jejuni 81-176. In colonic tissue samples, we confirmed infection-dependent aberrant transcription of MUC2 and TFF3. Moreover, two predicted glycosyltransferases, the sialyltransferases ST3GAL1 and ST3GAL2, exhibited inversely correlated transcriptional levels compared to the expression of the identified miRNAs miR-125a-5p and miR-615-3p, respectively. In this study, we mainly focused on the interaction between miR-615-3p and ST3GAL2 and were able to demonstrate their molecular interaction using luciferase reporter assays and RNAi. Detection of ST3GAL2 in murine colonic tissue by immunofluorescence demonstrated reduced intensity after C. jejuni 81-176 infection and was thus consistent with the observations made above. Conclusions We report here for the first time the regulation of glycosyltransferases by miRNAs during murine infection with C. jejuni 81-176. Our data suggest that mucin type O-glycan biosynthesis is concerted by the interplay of miRNAs and glycosyltransferases, which could determine the shape of intestinal glycosylated proteins during infection.

Abstract 13373: Exercise Improves Angiogenic Function of Circulating Exosomes in Type 2 Diabetes: Role of Extracellular SOD

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Kareem Abdelsaid ◽  
Sudhahar Varadarajan ◽  
Archita Das ◽  
Yutao Liu ◽  
Xuexiu Fang ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Wound Healing ◽  
Endothelial Dysfunction ◽  
Wound Repair ◽  
Cell Communication ◽  
Tube Formation ◽  
Skin Wound ◽  
Skin Wound Healing

Background: Exosomes, key mediators of cell-cell communication, derived from type 2 diabetes mellitus (T2DM) have detrimental effects. Exercise not only improves endothelial dysfunction and angiogenesis in T2DM but also induces secretion of exosomes into circulation. Extracellular superoxide dismutase (ecSOD) is a major secretory Cu containing antioxidant enzyme that catalyzes dismutation of O 2 •- to H 2 O 2 and its full activity requires Cu transporter ATP7A. We reported that ecSOD-derived H 2 O 2 in endothelial cells (ECs) enhances angiogenesis while impaired ATP7A-ecSOD axis in diabetes induces endothelial dysfunction. Here we examined whether exercise-derived exosomes (Exe-Exo) may have pro-angiogenic effects via regulating ATP7A-ecSOD axis in T2DM. Results: Two weeks of voluntary wheel exercise of control C57Bl6 mice increased plasma exosome levels (6.2-fold) characterized by Nanosight, TEM and exosome markers (CD63, CD81, Tsg101). Treatment of HUVECs with equal number of exosomes revealed that angiogenic responses such as EC migration (1.8-fold) and tube formation (1.7-fold) were significantly enhanced by Exe-Exo compared to sedentary-derived exosomes (Sed-Exo). This was associated with increased ATP7A (2.9-fold) and ecSOD (1.4-fold) expression in Exe-Exo. Sed-Exo from high fat-induced T2DM mice significantly decreased EC migration (40%) and tube formation (10%) as well as ATP7A expression (28%) compared to Sed-Exo from control mice, which were restored by T2DM Exe-Exo, but not by T2DM/ecSOD KO Exe-Exo. Furthermore, exosomes overexpressing ecSOD (ecSOD-Exo) which mimic exercise increased angiogenesis and H2O2 levels in ECs, which were inhibited by overexpression of catalase. In vivo, skin wound healing model showed that direct application of T2DM Sed-Exo delayed while T2DM Exe-Exo enhanced wound healing of control mice. Furthermore, defective wound healing in T2DM mice or ecSOD KO mice were rescued by ecSOD-Exo application. Conclusion: Exercise training improves pro-angiogenic function of circulating exosomes in T2DM via increasing ATP7A-ecSOD axis, which may provide an effective therapy for promoting angiogenesis and wound repair in metabolic and cardiovascular diseases.

scholarly journals Rhizogenesis in in vitro shoot cultures of passion fruit (Passiflora edulis f. flavicarpa Deg.) is affected by ethylene precursor and by inhibitors

2001 ◽  
Vol 7 (1) ◽  
Author(s):  
W. M. Marota ◽  
W. C. Otoni ◽  
M. Carnelossi ◽  
E. Silva ◽  
A. A. Azevedo ◽  
...  
Keyword(s):  
Ethylene Production ◽  
Time Course ◽  
Root Formation ◽  
Callus Formation ◽  
Passion Fruit ◽  
Shoot Cultures ◽  
Ethylene Inhibitors ◽  
Beneficial Effects ◽  
Ethylene Precursor

The effects of the ethylene precursor ACC and two inhibitors, AgNO3 and AVG, on root formation were tested in in vitro shoots of passion fruit (Passiflora Midis f.flavicalpa Deg.). The organogenic response was assessed on the basis of percentage of shoot-forming. roots, root number and length. The time course of ethylene production was also monitored. ACC inhibited root formation by delaying root emergence and increasine, callus formation at the basis of the shoots. In addition, ACC caused a marked increase in ethylene production, coupled to leaf chlorosis and senescence with lower rooting frequencies, number and length of roots. IAA supplementation increased ethylene production. Both ethylene inhibitors, AgNO3 and AVG, at appropriate concentrations reduced callus formation at the basis of shoots. AVG increased the number of roots per shoot, but drastically reduced length of differentiated roots. Regarding to leaf pigments, ACC promoted a marked reduction on carotenoids and total chlorophyll, whereas AVG and AgNO3 delayed explant senescence and pigments degradation, not differing from IAA supplemented and non-supplemented control treatments. The results confirm previous reports on the beneficial effects of ethylene inhibitors on in vitro rooting and suggest its reliability to be used as an alternative approach to evaluate sensitivity of Passiflora species to ethylene.  

scholarly journals Systemic and topical administration of spermidine accelerates skin wound healing

2020 ◽  
Author(s):  
Daisuke Ito ◽  
Hiroyasu Ito ◽  
Takayasu Ideta ◽  
Ayumu Kanbe ◽  
Soranobu Ninomiya ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Wound Healing ◽  
Wound Repair ◽  
Healing Process ◽  
Topical Administration ◽  
Skin Wound ◽  
Wound Healing Process ◽  
Skin Wound Healing

Abstract Background The skin wound healing process is regulated by various cytokines, chemokines, and growth factors. Recent reports have demonstrated that spermine/spermidine (SPD) promote wound healing through urokinase-type plasminogen activator (uPA)/uPA receptor (uPAR) signaling in vitro. Here, we investigated whether the systemic and topical administration of SPD would accelerate the skin wound-repair process in vivo.Methods A skin wound repair model was established using C57BL/6 J mice. SPD was mixed with white petrolatum for topical administration. For systemic administration, SPD mixed with drinking water was orally administered. Changes in wound size over time were calculated using digital photography.Results Systemic and topical SPD treatment significantly accelerated skin wound healing. The administration of SPD promoted the uPA/uPAR pathway in wound sites. Moreover, topical treatment with SPD enhanced the expression of IL-6 and TNF-α in wound sites. Scratch and cell proliferation assays revealed that SPD administration accelerated scratch wound closure and cell proliferation in vitro.Conclusion These results indicate that treatment with SPD promotes skin wound healing through activation of the uPA/uPAR pathway and induction of the inflammatory response in wound sites. The administration of SPD might contribute to new effective treatments to accelerate skin wound healing.

scholarly journals Overexpression of BQ323636.1 Modulated AR/IL-8/CXCR1 Axis to Confer Tamoxifen Resistance in ER-Positive Breast Cancer

Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Ho Tsoi ◽  
Ling Shi ◽  
Man-Hong Leung ◽  
Ellen P. S. Man ◽  
Zi-Qing So ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Tamoxifen Resistance ◽  
In Silico Analysis ◽  
Luciferase Reporter ◽  
Androgen Response Element ◽  
Er Positive

NCOR2 is a co-repressor for estrogen receptor (ER) and androgen receptor (AR). Our group previously identified a novel splice variant of NCOR2, BQ323636.1 (BQ), that mediates tamoxifen resistance via interference of NCOR2 repression on ER. Luciferase reporter assay showed BQ overexpression could enhance the transcriptional activity of androgen response element (ARE). We proposed that BQ employs both AR and ER to confer tamoxifen resistance. Through in silico analysis, we identified interleukin-8 (IL-8) as the sole ERE and ARE containing gene responsiveness to ER and AR activation. We confirmed that BQ overexpression enhanced the expression of IL-8 in ER+ve breast cancer cells, and AR inhibition reduced IL-8 expression in the BQ overexpressing cell lines, suggesting that AR was involved in the modulation of IL-8 expression by BQ. Moreover, we demonstrated that IL-8 could activate both AKT and ERK1/2 via CXCR1 to confer tamoxifen resistance. Targeting CXCR1/2 by a small inhibitor repertaxin reversed tamoxifen resistance of BQ overexpressing breast cancer cells in vitro and in vivo. In conclusion, BQ overexpression in ER+ve breast cancer can enhance IL-8 mediated signaling to modulate tamoxifen resistance. Targeting IL-8 signaling is a promising approach to overcome tamoxifen resistance in ER+ve breast cancer.

scholarly journals Heterogeneity of murine periosteum osteochondroprogenitors involved in fracture healing

2020 ◽  
Author(s):  
Brya G Matthews ◽  
Francesca V Sbrana ◽  
Sanja Novak ◽  
Jessica L. Funnell ◽  
Ye Cao ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Progenitor Cells ◽  
Progenitor Cell ◽  
Callus Formation ◽  
Lineage Tracing ◽  
Fracture Callus ◽  
Stem And Progenitor Cells ◽  
Periosteal Cells ◽  
Osteoblast Lineage

AbstractThe periosteum is the major source of cells involved in fracture healing. We sought to characterize differences in progenitor cell populations between periosteum and other bone compartments, and identify periosteal cells involved in fracture healing. The periosteum is highly enriched for progenitor cells, including Sca1+ cells, CFU-F and label-retaining cells. Lineage tracing with αSMACreER identifies periosteal cells that contribute to >80% of osteoblasts and ~40% of chondrocytes following fracture. A subset of αSMA+ cells are quiescent long-term injury-responsive progenitors. Ablation of αSMA+ cells impairs fracture callus formation. In addition, committed osteoblast-lineage cells contributed around 10% of osteoblasts, but no chondrocytes in fracture calluses. Most periosteal progenitors, particularly those that form osteoblasts, can be targeted by αSMACreER. We have demonstrated that the periosteum is highly enriched for skeletal stem and progenitor cells and there is heterogeneity in the populations of cells that contribute to mature lineages during periosteal fracture healing.

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