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Objective: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease that affects 63 in every 100,000 Americans. Its etiology remains unknown, although inflammatory pathways appear...

Adhesions are fibrotic scars that form between abdominal organs following surgery or infection, and may cause bowel obstruction, chronic pain, or infertility. Our understanding of adhesion biology is limited, which explains the paucity of anti-adhesion treatments. Here we present a systematic analysis of mouse and human adhesion tissues. First, we show that adhesions derive primarily from the visceral peritoneum, consistent with our clinical experience that adhesions form primarily following laparotomy rather than laparoscopy. Second, adhesions are formed by poly-clonal proliferating tissue-resident fibroblasts. Third, using single cell RNA-sequencing, we identify heterogeneity among adhesion fibroblasts, which is more pronounced at early timepoints. Fourth, JUN promotes adhesion formation and results in upregulation of PDGFRA expression. With JUN suppression, adhesion formation is diminished. Our findings support JUN as a therapeutic target to prevent adhesions. An anti-JUN therapy that could be applied intra-operatively to prevent adhesion formation could dramatically improve the lives of surgical patients., Abdominal adhesions are a common cause of bowel obstruction, but knowledge regarding adhesion biology and anti-adhesion therapies remains limited. Here the authors report a systematic analysis of mouse and human adhesion tissues demonstrating that visceral fibroblast JUN and associated PDGFRA expression promote adhesions, and JUN suppression can prevent adhesion formation.

Description, Vitamin D–activated Trem2+ macrophages provide a novel strategy to develop advanced cell therapies for complex wounds., Skin allo- and xenotransplantation are the standard treatment for major burns when donor sites for autografts are not available. The relationship between the immune response to foreign grafts and their impact on wound healing has not been fully elucidated. Here, we investigated changes in collagen architecture after xenogeneic implantation of human biologic scaffolds. We show that collagen deposition in response to the implantation of human split-thickness skin grafts (hSTSGs) containing live cells recapitulates normal skin architecture, whereas human acellular dermal matrix (ADM) grafts led to a fibrotic collagen deposition. We show that macrophage differentiation in response to hSTSG implantation is driven toward regenerative Trem2+ subpopulations and found that hydrogel delivery of these cells significantly accelerated wound closure. Our study identifies the preclinical therapeutic potential of Trem2+ macrophages to mitigate fibrosis and promote wound healing, providing a novel effective strategy to develop advanced cell therapies for complex wounds.

Pathologic skin scarring presents a vast economic and medical burden. Unfortunately, the molecular mechanisms underlying scar formation remain to be elucidated. We used a hypertrophic scarring (HTS) mouse model in which Jun is overexpressed globally or specifically in α-smooth muscle or collagen type I–expressing cells to cause excessive extracellular matrix deposition by skin fibroblasts in the skin after wounding. Jun overexpression triggered dermal fibrosis by modulating distinct fibroblast subpopulations within the wound, enhancing reticular fibroblast numbers, and decreasing lipofibroblasts. Analysis of human scars further revealed that JUN is highly expressed across the wide spectrum of scars, including HTS and keloids. CRISPR-Cas9–mediated JUN deletion in human HTS fibroblasts combined with epigenomic and transcriptomic analysis of both human and mouse HTS fibroblasts revealed that JUN initiates fibrosis by regulating CD36. Blocking CD36 with salvianolic acid B or CD36 knockout model counteracted JUN-mediated fibrosis efficacy in both human fibroblasts and mouse wounds. In summary, JUN is a critical regulator of pathological skin scarring, and targeting its downstream effector CD36 may represent a therapeutic strategy against scarring.

Cranial sutures are major growth centers for the calvarial vault, and their premature fusion leads to a pathologic condition called craniosynostosis. This study investigates whether skeletal stem/progenitor cells are resident in the cranial sutures. Prospective isolation by FACS identifies this population with a significant difference in spatio-temporal representation between fusing versus patent sutures. Transcriptomic analysis highlights a distinct signature in cells derived from the physiological closing PF suture, and scRNA sequencing identifies transcriptional heterogeneity among sutures. Wnt-signaling activation increases skeletal stem/progenitor cells in sutures, whereas its inhibition decreases. Crossing Axin2LacZ/+ mouse, endowing enhanced Wnt activation, to a Twist1+/− mouse model of coronal craniosynostosis enriches skeletal stem/progenitor cells in sutures restoring patency. Co-transplantation of these cells with Wnt3a prevents resynostosis following suturectomy in Twist1+/− mice. Our study reveals that decrease and/or imbalance of skeletal stem/progenitor cells representation within sutures may underlie craniosynostosis. These findings have translational implications toward therapeutic approaches for craniosynostosis., Cranial sutures are major growth centers for the skull vault and premature fusion leads to pathological fusion, craniosynostosis. Here the authors isolate Wnt responsive skeletal stem and progenitor cells from sutures, that can be transplanted together with Wnt3a protein to repair craniosynostosis in a mouse model.

Purpose: The longevity of biomedical implants is limited by adverse implant-tissue interactions leading to implant failure. In almost all cases, implant failure occurs due to a phenomenon known as the foreign body response (FBR). FBR is characterized by fibrous capsule formation around implanted devices, leading to implant malfunction as well as distortion of the surrounding tissue. In the context of breast implants, FBR leads to capsular contracture, which is the cause of a significant proportion of all breast implant failures. Despite the high prevalence of FBR-mediated implant failure, the underlying mechanisms of FBR are incompletely understood. Our work utilizing mass spectrometry has demonstrated that when compared to healthy subcutaneous tissue, foreign body capsules in mice and humans display an up-regulation of IQ Motif Containing GTPase Activating Protein 1 (IQGAP1), a scaffolding protein involved in multiple mechanotransduction pathways. Based on these findings, we sought to investigate which cellular subpopulations express IQGAP1 as well as its role in mechanotransduction pathways mediating the development of FBR. Methods: To verify the importance of IQGAP1-mediated signaling in FBR, we employed a murine model of mechanically stimulated silicone implants (MSI), which were implanted subcutaneously in wildtype (WT) and IQGAP1+/- haplo-insufficient mice to compare the effect of human levels of mechanical stress on FBR. Homozygous IQGAP1 KO mice have been previously reported to harbor a fragile phenotype, more prone to pulmonary vascular damage and gastric pathologies. Haplo-insufficient mice were utilized in these experiments in order to prevent potential systemic complications from elevated levels of mechanical stimulation produced by the MSI model. We explanted the foreign body capsules from IQGAP1+/- haplo-insufficient and WT mice and performed single-cell RNA sequencing (sc-RNA-seq) on cells isolated from the capsules. We histologically assessed the quantity as well as maturity of collagen deposition using Masson’s Trichrome and Herovici staining of tissue sections from explanted foreign body capsules. Moreover, immunostaining for the mechanotransduction related proteins alpha-smooth muscle actin (α-SMA), phosphorylated focal adhesion kinase (p-FAK), phosphorylated cell division control protein 42 (p-cdc42), and phosphorylated extracellular signal-regulated kinase (p-ERK1/2) was performed to assess the impact of IQGAP1-deficiency on the protein level. Results: We found that IQGAP1-deficient mice displayed a significantly reduced FBR as evidenced by thinner capsules, lower levels of collagen deposition, collagen maturity, and myofibroblast activation. Our scRNA-seq analysis revealed a depletion of mechanoresponsive myeloid cells in IQGAP1-deficient mice. This was confirmed on the protein level by a significantly reduced expression of a-SMA, p-FAK, p-cdc42, and p-ERK1/2 in foreign body capsule tissue from IQGAP1-deficient mice compared to WT mice. Conclusion: Our results highlight the important role of IQGAP1 as a critical early stage mediator of mechanotransduction pathways contributing to the development of FBR. Further, we show that IQGAP1 plays a role in modulating the innate immune response to synthetic implants. Therefore, IQGAP1 may be a promising target for the development of novel therapeutics to limit the development of FBR around biomedical implants.

Purpose: Dendritic cells (DCs) are a heterogeneous cell population which critically regulates the adaptive immune response. Depending on their activation status, DCs can also promote peripheral immune tolerance, thus limiting the activation of the immune system and tissue damage. The N-myc downregulated gene 2 (Ndrg2) is highly expressed in DCs and limits the secretion of vascular endothelial growth factor (VEGF), which is critical for wound healing. Cell based therapy approaches using DCs have been approved by the FDA and clinical trials using DC immunotherapy are being performed against a variety of cancer types. However, the role of DC therapy for wound healing has not yet been investigated. Methods: Hematopoietic progenitor cells were isolated from the bone marrow of mice and differentiated into DCs over a 7-day in vitro culture period. Pharmacologic down-regulation of Ndrg2 was performed by treatment of cultures with 1,25-dihydroxyvitamin D3 (VD3) and the angiogenic potential of the treated cells was evaluated by endothelial cell (EC) tube formation assays. Cytokine secretion of DCs was measured in the conditioned media using Luminex multiplex assays. To permanently knock out Ndrg2 in DCs, a CRISPR/Cas9 gene editing approach was developed, using Cas9/sgRNA-ribonucleoproteins and electroporation. The determine the impact of genetically edited DCs on wound healing, splinted excisional wounds in C57BL6/J (wild-type) mice were treated weekly with pullulan-collagen hydrogels seeded with Ndrg2-knockout (KO) DCs, control DCs which had undergone electroporation only, or blank hydrogels. The transcriptomic impact of Ndrg2 downregulation on DC fate was evaluated by microfluidic single-cell RNA sequencing (scRNA seq) of Ndrg2-KO DCs, VD3-treated DCs and control DCs. Results: Ndrg2 down-regulation lead to a significantly stronger EC tube formation in co-cultures with VD3-treated DCs, and strongly enhanced VEGF secretion compared to untreated DCs in vitro. A CRISPR/Cas9 editing pipeline was developed for KO of Ndrg2 in DCs with a transfection rate and editing efficiency of > 90% shown by Sanger Sequencing. Excisional wounds treated with Ndrg2-KO DCs demonstrated significantly accelerated healing compared to control DCs and blank hydrogels. scRNA seq revealed that Ndrg2 downregulation strongly induced Vegfa expression and anti-oxidant transcriptomic signatures. Conclusion: Our data indicate that KO of Ndrg2 in DCs strongly enhances their secretion of VEGF, thus promoting angiogenesis and accelerating wound healing. Given the ready availability of DCs from the human blood through established leukapheresis protocols and easy multiplication in vitro, CRISPR/Cas9 editing of DCs is a promising new approach to induce wound healing and soft-tissue regeneration.

Cutaneous wounds are a growing global health burden as a result of an aging population coupled with increasing incidence of diabetes, obesity, and cancer. Cell-based approaches have been used to treat wounds due to their secretory, immunomodulatory, and regenerative effects, and recent studies have highlighted that delivery of stem cells may provide the most benefits. Delivering these cells to wounds with direct injection has been associated with low viability, transient retention, and overall poor efficacy. The use of bioactive scaffolds provides a promising method to improve cell therapy delivery. Specifically, hydrogels provide a physiologic microenvironment for transplanted cells, including mechanical support and protection from native immune cells, and cell–hydrogel interactions may be tailored based on specific tissue properties. In this review, we describe the current and future directions of various cell therapies and usage of hydrogels to deliver these cells for wound healing applications.

Burn scars and scar contractures cause significant morbidity for patients. Recently, cell-based therapies have been proposed as an option for improving healing and reducing scarring after burn injury, through their known proangiogenic and immunomodulatory paracrine effects. Our laboratory has developed a pullulan-collagen hydrogel that, when seeded with mesenchymal stem cells (MSCs), improves cell viability and augments their proangiogenic capacity

In diabetes, stromal cell-derived factor-1 (SDF-1) expression and progenitor cell recruitment are reduced. Dipeptidyl peptidase-4 (DPP-4) inhibits SDF-1 expression and progenitor cell recruitment. Here we examined the impact of the DPP-4 inhibitor, MK0626, on progenitor cell kinetics in the context of wound healing. Wildtype (WT) murine fibroblasts cultured under high-glucose to reproduce a diabetic microenvironment were exposed to MK0626, glipizide, or no treatment, and SDF-1 expression was measured with ELISA. Diabetic mice received MK0626, glipizide, or no treatment for 6 weeks and then were wounded. Immunohistochemistry was used to quantify neovascularization and SDF-1 expression. Gene expression was measured at the RNA and protein level using quantitative polymerase chain reaction and ELISA, respectively. Flow cytometry was used to characterize bone marrow-derived mesenchymal progenitor cell (BM-MPC) population recruitment to wounds. BM-MPC gene expression was assayed using microfluidic single cell analysis. WT murine fibroblasts exposed to MK0626 demonstrated increased SDF-1 expression. MK0626 treatment significantly accelerated wound healing and increased wound vascularity, SDF-1 expression, and dermal thickness in diabetic wounds. MK0626 treatment increased the number of BM-MPCs present in bone marrow and in diabetic wounds. MK0626 had no effect on BM-MPC population dynamics. BM-MPCs harvested from MK0626-treated mice exhibited increased chemotaxis in response to SDF-1 when compared to diabetic controls. Treatment with a DPP-4 inhibitor significantly improved wound healing, angiogenesis, and endogenous progenitor cell recruitment in the setting of diabetes.

Skin allo- and xenotransplantation are the standard treatment for major burns when donor sites for autografts are not available and have been shown to significantly accelerate wound healing. Although the cellular elements of foreign grafts are rejected, the extracellular matrix components integrate into the wound and may underlie their beneficial effects on wound healing. The molecular mechanisms defining the relationship between the immune response to foreign grafts and their impact on wound healing have not been fully elucidated. Here, we investigated changes in collagen architecture after xenogeneic implantation of clinically available human biologic scaffolds. We show that collagen deposition in response to the implantation of human split-thickness skin grafts (hSTSG) containing live cells recapitulates normal skin architecture, whereas human acellular dermal matrix (ADM) grafts led to highly aligned collagen deposition, characteristic of fibrosis and scar. Using single-cell RNA-sequencing, we show that macrophage differentiation in response to hSTSG is driven by vitamin D (VD) signaling toward Trem2+ subpopulations with an enrichment of pro-angiogenic and anti-fibrotic transcriptomic programs. We subsequently induced this regenerative subpopulation in vitro by treating bone marrow-derived cells with vitamin D3 and found that hydrogel delivery of Trem2+ macrophages significantly accelerated wound closure in a human-like murine excisional wound model. Our study identifies the preclinical therapeutic potential of Trem2+ macrophages to mitigate fibrosis and promote wound healing and provides a novel effective strategy to develop advanced cell therapies for complex wounds.One Sentence SummaryVitamin D-activated Trem2+ macrophages promote angiogenesis and mitigate fibrosis, providing a novel effective strategy to develop advanced cell therapies for complex wounds.

Background:. Autologous breast reconstruction is widely regarded as the gold standard approach following mastectomy. However, the lack of sensation continues to present a reconstructive challenge. In this study, clinical outcomes following abdominal flap neurotization with processed human nerve allograft were investigated. Methods:. In this prospective analysis, patients who underwent microsurgical breast reconstruction with (Group 1) or without (Group 2) abdominal flap neurotization at a single institution were investigated. Processed human nerve allograft (Avance, AxoGen, Alachua, Fla.) was used in all cases of flap neurotization. Only patients with a follow-up of ≥12 months were included. Cutaneous pressure threshold was tested using Semmes-Weinstein monofilaments (SWMF) at 9 pre-defined locations. Results:. A total of 59 patients (96 breasts) were enrolled into the registry. Of these, 22 patients (Group 1: N = 15, 22 breasts; Group 2: N = 7, 14 breasts) had a complete data set with ≥12 months follow-up. Measuring cutaneous pressure thresholds, we observed a greater likelihood for return of protective sensation (SWMF ≤ 4.31) in neurotized breasts in 8 of the 9 examined zones. Additionally, flap neurotization was associated with a greater likelihood for return of protective sensation in the majority of the reconstructed breast—that is, ≥5 zones (55% versus 7%; P < 0.01). Conclusion:. Flap neurotization using processed nerve allograft resulted in a greater degree of return of protective sensation to the reconstructed breast than reconstructions without neurotization at ≥12 months.

Purpose: Scarring in the mouse dorsal dermis is mediated by pro-fibrotic, Engrailed-1 lineage-positive fibroblasts (EPFs). We recently showed that mechanotransduction blockade (YAP inhibition, using the drug verteporfin), results in complete wound regeneration, with full recovery of normal dermal appendages (hair follicles, glands), extracellular matrix (ECM) architecture, and tensile strength. This regenerative outcome following verteporfin treatment is mediated by Engrailed-1 lineage-negative fibroblasts (ENFs). The complex milieu of cell types and molecular signals involved in wound repair makes it difficult to study using any single data modality. Thus, we sought to use a holistic approach, incorporating multiple high-throughput, high-dimensional analyses, to define the divergent molecular events distinguishing typical scarring healing from verteporfin-induced wound regeneration. Methods: C57BL/6J mice underwent dorsal splinted excisional wounding per standard protocol. Wounds were treated with local injection of either verteporfin or vehicle control (PBS) on POD 0. We harvested unwounded skin and wounds at POD 2, 7, 14, and 30 (n=5 mice/timepoint and treatment) and subjected wound cells to three analyses: single-cell RNA-sequencing (scRNA-seq, using 10X Genomics Chromium); timsTOF, a recently-developed, high-throughput proteomic sequencing platform; and a novel machine learning algorithm for quantitatively comparing ECM ultrastructure. Results: Pseudotime analysis (Monocle3) of pooled scRNA-seq data revealed that fibroblasts followed two distinct transcriptional trajectories, one characterized by mechanical activation (En-1 lineage-positive, “fibrotic” trajectory) and the other characterized by developmental and regenerative pathways (En-1 lineage-negative; Rspo1, Dkk2/3, Trps1). Cross-platform data integration confirmed that fibroblasts in the fibrotic trajectory correlated with myofibroblast proteomic signatures (Col1a1/2, Fn1, etc.) and fibrotic/scar ECM features. In contrast, fibroblasts in the regenerative trajectory negatively correlated with myofibroblast markers and were associated with a “basket-weave” ECM pattern quantitatively indistinguishable from that of unwounded skin. Our integrated dataset suggested an important role for Wnt pathway proteins in ENF-mediated skin regeneration, so we compared POD 14 scars and regenerated wounds by multiplexed in situ hybridization (RNAScope) for Rspo1 (Wnt agonist), Trps1 (master hair follicle regulator), Ank1 (YAP target gene), and Dpp4 (EPF marker). Quantification of RNA granules across thousands of cells using a custom image analysis pipeline revealed that ENF-mediated healing (low Dpp4) in YAP-inhibited (low Ank1) wounds yielded regeneration of functional hair follicles through Wnt-mediated pathway activation (high Rpos1, Trps1). These data suggest that YAP inhibition unlocks wound regeneration via Wnt-active, En-1 lineage-negative fibroblasts. Conclusion: By studying regenerating (verteporfin-treated) versus scarring wounds across multiple healing timepoints and high-dimensional data modalities, we were able to profile fibrotic versus regenerative healing at unprecedented depth. Our integrated analysis revealed that dermal fibroblasts in these two wound settings exhibit distinct molecular trajectories defined by divergent transcriptomic, proteomic, and ultrastructural properties. Further, we found that wound regeneration in the context of verteporfin treatment is associated with suppression of mechanical signaling and activation of key Wnt pathway members including Trps1 (a gene with known hair follicle developmental roles). These results could have important implications for both the fundamental study of wound healing and potential anti-scarring therapeutic avenues

Radiation therapy can result in pathological fibrosis of healthy soft tissue. The iron chelator deferoxamine (DFO) has been shown to improve skin vascularization when injected into radiated tissue prior to fat grafting. Here, we evaluated whether topical DFO administration using a transdermal drug delivery system prior to and immediately following irradiation (IR) can mitigate the chronic effects of radiation damage to the skin. CD-1 nude immunodeficient mice were split into four experimental groups: (1) IR alone (IR only), (2) DFO treatment for two weeks after recovery from IR (DFO post-IR), (3) DFO prophylaxis with treatment through and post-IR (DFO ppx), or (4) no irradiation or DFO (No IR). Immediately following IR, reactive oxygen species and apoptotic markers were significantly decreased and laser doppler analysis revealed significantly improved skin perfusion in mice receiving prophylactic DFO. Six weeks following IR, mice in the DFO post-IR and DFO ppx groups had improved skin perfusion and increased vascularization. DFO-treated groups also had evidence of reduced dermal thickness and collagen fiber network organization akin to non-irradiated skin. Thus, transdermal delivery of DFO improves tissue perfusion and mitigates chronic radiation-induced skin fibrosis, highlighting a potential role for DFO in the treatment of oncological patients.

Cryopreserved human skin allografts (CHSAs) are used for the coverage of major burns when donor sites for autografts are insufficiently available and have clinically shown beneficial effects on chronic non-healing wounds. However, the biologic mechanisms behind the regenerative properties of CHSA remain elusive. Furthermore, the impact of cryopreservation on the immunogenicity of CHSA has not been thoroughly investigated and raised concerns with regard to their clinical application. To investigate the importance and fate of living cells, we compared cryopreserved CHSA with human acellular dermal matrix (ADM) grafts in which living cells had been removed by chemical processing. Both grafts were subcutaneously implanted into C57BL/6 mice and explanted after 1, 3, 7, and 28 days (n = 5 per group). A sham surgery where no graft was implanted served as a control. Transmission electron microscopy (TEM) and flow cytometry were used to characterise the ultrastructure and cells within CHSA before implantation. Immunofluorescent staining of tissue sections was used to determine the immune reaction against the implanted grafts, the rate of apoptotic cells, and vascularisation as well as collagen content of the overlaying murine dermis. Digital quantification of collagen fibre alignment on tissue sections was used to quantify the degree of fibrosis within the murine dermis. A substantial population of live human cells with intact organelles was identified in CHSA prior to implantation. Subcutaneous pockets with implanted xenografts or ADMs healed without clinically apparent rejection and with a similar cellular immune response. CHSA implantation largely preserved the cellularity of the overlying murine dermis, whereas ADM was associated with a significantly higher rate of cellular apoptosis, identified by cleaved caspase-3 staining, and a stronger dendritic cell infiltration of the murine dermis. CHSA was found to induce a local angiogenic response, leading to significantly more vascularisation of the murine dermis compared with ADM and sham surgery on day 7. By day 28, aggregate collagen-1 content within the murine dermis was greater following CHSA implantation compared with ADM. Collagen fibre alignment of the murine dermis, correlating with the degree of fibrosis, was significantly greater in the ADM group, whereas CHSA maintained the characteristic basket weave pattern of the native murine dermis. Our data indicate that CHSAs promote angiogenesis and collagen-1 production without eliciting a significant fibrotic response in a xenograft model. These findings may provide insight into the beneficial effects clinically observed after treatment of chronic wounds and burns with CHSA.

Human lung single-cell atlas reveals the complexity and diversity of aberrant cellular populations in pulmonary fibrosis., We provide a single-cell atlas of idiopathic pulmonary fibrosis (IPF), a fatal interstitial lung disease, by profiling 312,928 cells from 32 IPF, 28 smoker and nonsmoker controls, and 18 chronic obstructive pulmonary disease (COPD) lungs. Among epithelial cells enriched in IPF, we identify a previously unidentified population of aberrant basaloid cells that coexpress basal epithelial, mesenchymal, senescence, and developmental markers and are located at the edge of myofibroblast foci in the IPF lung. Among vascular endothelial cells, we identify an ectopically expanded cell population transcriptomically identical to bronchial restricted vascular endothelial cells in IPF. We confirm the presence of both populations by immunohistochemistry and independent datasets. Among stromal cells, we identify IPF myofibroblasts and invasive fibroblasts with partially overlapping cells in control and COPD lungs. Last, we confirm previous findings of profibrotic macrophage populations in the IPF lung. Our comprehensive catalog reveals the complexity and diversity of aberrant cellular populations in IPF.

Hand injuries often result in significant functional impairments and are rarely completely restored. The spontaneous regeneration of injured appendages, which occurs in salamanders and newts, for example, has been reported in human fingertips after distal amputation, but this type of regeneration is rare in mammals and is incompletely understood. Here, we study fingertip regeneration by amputating murine digit tips, either distally to initiate regeneration, or proximally, causing fibrosis. Using an unbiased microarray analysis, we found that digit tip regeneration is significantly associated with hair follicle differentiation, Wnt, and sonic hedgehog (SHH) signaling pathways. Viral over-expression and genetic knockouts showed the functional significance of these pathways during regeneration. Using transgenic reporter mice, we demonstrated that, while both canonical Wnt and HH signaling were limited to epidermal tissues, downstream hedgehog signaling (through Gli) occurred in mesenchymal tissues. These findings reveal a mechanism for epidermal/mesenchyme interactions, governed by canonical hedgehog signaling, during digit regeneration. Further research into these pathways could lead to improved therapeutic outcomes after hand injuries in humans.

Background Craniofacial distraction osteogenesis (DO) is a common treatment modality today. Despite its numerous advantages, however, concerns have been expressed regarding the use of DO in the irradiated setting. Methods A systematic review was performed to identify all published reports of patients who underwent DO of the irradiated craniofacial skeleton. The following parameters were of particular interest: postoperative complications, specifically, insufficient bone formation, fracture, and hardware exposure (intraoral and cutaneous), as well as the need for additional bone grafting. Results The initial search retrieved a total of 183 articles of which 20 articles (38 patients) met predetermined inclusion criteria. The most common site of distraction was the mandible (76.3%). The median radiation dose was 50.7 Gy (range, 30-70 Gy). Bone defects ranged from 30 to 80 mm (median, 42.5 mm). Complications were encountered in 19 patients (50%), with insufficient bone formation being most common (9 patients; 23%). The overall incidence of complications was not significantly associated with radiation dosage (P = 0.79). The remaining procedural and demographic variables also failed to meet statistical significance when compared against the overall complication rate (P = 0.27-0.97). Conclusion The complication rate associated with craniofacial DO of the irradiated skeleton does not appear to be substantially higher than what is reported for DO in the nonirradiated setting. As such, patients should be offered this treatment modality, particularly in light of the fact, that it offers the option to decrease patient morbidity as well as treatment complexity.

Background:A hallmark of diabetes mellitus is the breakdown of almost every reparative process in the human body, leading to critical impairments of wound healing. Stabilization and activity of the transcription factor hypoxia-inducible factor (HIF)-1α is impaired in diabetes, leading to deficits in

Despite substantial advances in the management of craniofacial trauma, numerous clinical questions remain. These are increasingly being answered using systematic reviews (SRs). However, caution is warranted as their validity and role in influencing clinical practice has been called into question.A PubMed search was performed in October 2014 to identify SRs published up to and including September 2014 in 35 scientific journals. Two authors independently reviewed the literature and extracted data from included studies. Discrepancies were resolved by consensus. Assessment of multiple systematic reviews (AMSTAR) was used to determine the quality of SRs.The initial search retrieved 3080 articles of which 3051 articles were excluded after screening title and abstract. After full-text review of the remaining 29 articles, 3 additional articles were excluded, thus, leaving 26 SRs for final analysis. Regression analysis demonstrated that the overall number of published SRs increased significantly throughout the period analyzed (P = 0.022). The median AMSTAR score of all SRs was 4.5, consistent with a "poor-to-fair" quality. The interobserver agreement was high, as evidenced by a mean κ of 0.91. Although there appeared to be a trend toward an increase in AMSTAR score by year over the period analyzed, this failed to reach statistical significance in terms of median (P = 0.36) or absolute (P = 0.26) counts.A tremendous opportunity exists for improvements in the quality of SRs focusing on craniofacial trauma. In addition to familiarizing authors with quality criteria for SRs, adoption of strict reporting criteria by scientific journals may result in long-term improvements in the quality of reporting.

Background:Medial thigh lift procedures in the massive weight loss population have been associated with significant complication rates. Liposuction-assisted medial thighplasty has recently been introduced as a technical advancement to improve outcomes. To date, no study is available directly compari

Advanced age is characterized by impairments in wound healing, and evidence is accumulating that this may be due in part to a concomitant increase in oxidative stress. Extended exposure to reactive oxygen species (ROS) is thought to lead to cellular dysfunction and organismal death via the destructive oxidation of intra-cellular proteins, lipids and nucleic acids. Extracellular superoxide dismutase (ecSOD/SOD3) is a prime antioxidant enzyme in the extracellular space that eliminates ROS. Here, we demonstrate that reduced SOD3 levels contribute to healing impairments in aged mice. These impairments include delayed wound closure, reduced neovascularization, impaired fibroblast proliferation and increased neutrophil recruitment. We further establish that SOD3 KO and aged fibroblasts both display reduced production of TGF-β1, leading to decreased differentiation of fibroblasts into myofibroblasts. Taken together, these results suggest that wound healing impairments in ageing are associated with increased levels of ROS, decreased SOD3 expression and impaired extracellular oxidative stress regulation. Our results identify SOD3 as a possible target to correct age-related cellular dysfunction in wound healing.

Significance: Chronic wounds remain a significant public health problem. Alterations in normal physiological processes caused by aging or diabetes lead to impaired tissue repair and the development of chronic and nonhealing wounds. Understanding the unique features of the wound environment will be required to develop new therapeutics that impact these disabling conditions. New drug-delivery systems (DDSs) may enhance current and future therapies for this challenging clinical problem. Recent Advances: Historically, physical barriers and biological degradation limited the efficacy of DDSs in wound healing. In aiming at improving and optimizing drug delivery, recent data suggest that combinations of delivery mechanisms, such as hydrogels, small molecules, RNA interference (RNAi), as well as growth factor and stem cell-based therapies (biologics), could offer exciting new opportunities for improving tissue repair. Critical Issues: The lack of effective therapeutic approaches to combat the significant disability associated with chronic wounds has become an area of increasing clinical concern. However, the unique challenges of the wound environment have limited the development of effective therapeutic options for clinical use. Future Directions: New platforms presented in this review may provide clinicians and scientists with an improved understanding of the alternatives for drug delivery in wound care, which may facilitate the development of new therapeutic approaches for patients.

Chronic nonhealing wounds have a prevalence of 2% in the United States, and cost an estimated $50 billion annually. Accurate stratification of wounds for risk of slow healing may help guide treatment and referral decisions. We have applied modern machine learning methods and feature engineering to develop a predictive model for delayed wound healing that uses information collected during routine care in outpatient wound care centers. Patient and wound data was collected at 68 outpatient wound care centers operated by Healogics Inc. in 26 states between 2009 and 2013. The dataset included basic demographic information on 59,953 patients, as well as both quantitative and categorical information on 180,696 wounds. Wounds were split into training and test sets by randomly assigning patients to training and test sets. Wounds were considered delayed with respect to healing time if they took more than 15 weeks to heal after presentation at a wound care center. Eleven percent of wounds in this dataset met this criterion. Prognostic models were developed on training data available in the first week of care to predict delayed healing wounds. A held out subset of the training set was used for model selection, and the final model was evaluated on the test set to evaluate discriminative power and calibration. The model achieved an area under the curve of 0.842 (95% confidence interval 0.834–0.847) for the delayed healing outcome and a Brier reliability score of 0.00018. Early, accurate prediction of delayed healing wounds can improve patient care by allowing clinicians to increase the aggressiveness of intervention in patients most at risk.

Background: Hematopoietic malignancies represent a broad category of diseases that originate in blood or lymphoid tissues and will account for roughly 10 percent of the estimated 1.7 million new cancer diagnoses in 2019. Traditional treatment options include chemotherapy, radiation therapy, and bone marrow transplant. With the recent explosion in -omics level data platforms and increased patient opt-ins for electronic medical record usage, we have entered a new phase of drug development that focuses on utilizing data-driven approaches to identify targeted therapeutics. Here we apply artificial intelligence and machine learning principles to publicly available datasets to identify candidates for drug repurposing. Methods: A meta-analysis was performed using more than 500 publicly available single cell RNA-seq (scRNA-seq) datasets spanning multiple species, platforms, and capture techniques. Fifteen unique sets of study data examining human or mouse-modeled malignancies of hematopoietic and lymphoid origin were identified. Data were downloaded using the most upstream format available (ie fastq > bam > mtx > h5/rdata). Mappings from fastqbam format were performed using STAR v2.5.3a, mapping from bam files to mtx were performed using Cell Ranger v3.0, and mappings from mtx files to h5 were performed using Scanpy v 1.4. Data were denoised using variational inference to account for study, species, disease, tissue, and subject-specific batch effects using scVI v0.4.1. Meta data from each study was extracted and binned by inspection into classification of ‘severe', ‘moderate', ‘mild', or ‘no disease'. Disease severity signatures were constructed accordingly using EdgeR v3.9, and paired with chemical perturbation signatures for more than 10,000 drug compounds, to identify and score therapeutic candidates. Results: A total of 588 datasets were evaluated using curations provided in Svensson et al 2019, yielding fifteen relevant human (n = 9) and mouse (n = 6) studies published in pubmed-indexed journals. These spanned 11 unique journals, the most common of which was Nature Immunology (n=3). Datasets were obtained from GEO (n = 10), ArrayExpress (n = 2), or laboratory/group-specific web servers (n = 3). Studies evaluated between 63 and 10,260 individual cells (mean 1763, median 362), across six different sequencing platforms. From the 12,442 distinct compounds profiled across 71 cell lines in the LINCS database, we identified 20 top candidates with perturbation profiles most correlated with the decreasing disease severity signatures generated through our scRNA-Seq meta-analysis. Conclusion: This represents a novel method for cancer drug discovery and repurposing using exclusively publicly available datasets. Citation Format: Bei Jiang, Michael Januszyk. An artificial intelligence based meta-analysis of publicly available single cell RNA-seq datasets for hematopoietic and lymphoid malignancies identifies repurposable cancer drug targets [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4166A.