Malignant melanoma arising in a burn scar.

Secondary malignancies are rare but devastating complications of longstanding burn scars. Squamous cell carcinoma is the most common, followed by basal cell carcinoma and melanomas. There are fewer than 50 total reported cases of malignant melanomas arising in burn scars. We report a case of malignant melanoma arising within a longstanding burn scar confirmed by histology, FISH, and PRAME staining to further characterize melanomas arising in burn scars and to illustrate the diagnostic challenges they present.

Long-Term Protective Effects of Succinate Dehydrogenase Inhibition during Reperfusion with Malonate on Post-Infarction Left Ventricular Scar and Remodeling in Mice.

Succinate dehydrogenase inhibition with malonate during initial reperfusion reduces myocardial infarct size in both isolated mouse hearts subjected to global ischemia and in in situ pig hearts subjected to transient coronary ligature. However, the long-term effects of acute malonate treatment are unknown. Here, we investigated whether the protective effects of succinate dehydrogenase inhibition extend to a reduction in scar size and adverse left ventricular remodeling 28 days after myocardial infarction. Initially, ten wild-type mice were subjected to 45 min of left anterior descending coronary artery (LAD) occlusion, followed by 24 h of reperfusion, and were infused during the first 15 min of reperfusion with saline with or without disodium malonate (10 mg/kg/min, 120 µL/kg/min). Malonate-treated mice depicted a significant reduction in infarct size (15.47 ± 3.40% of area at risk vs. 29.34 ± 4.44% in control animals, p < 0.05), assessed using triphenyltetrazolium chloride. Additional animals were then subjected to a 45 min LAD ligature, followed by 28 days of reperfusion. Treatment with a single dose of malonate during the first 15 min of reperfusion induced a significant reduction in scar area, measured using Picrosirius Red staining (11.94 ± 1.70% of left ventricular area (n = 5) vs. 23.25 ± 2.67% (n = 9), p < 0.05), an effect associated with improved ejection fraction 28 days after infarction, as determined using echocardiography, and an attenuated enhancement in expression of the pro-inflammatory and fibrotic markers NF-κB and Smad2/3 in remote myocardium. In conclusion, a reversible inhibition of succinate dehydrogenase with a single dose of malonate at the onset of reperfusion has long-term protective effects in mice subjected to transient coronary occlusion.

TANGO1 inhibitors reduce collagen secretion and limit tissue scarring.

Uncontrolled secretion of ECM proteins, such as collagen, can lead to excessive scarring and fibrosis and compromise tissue function. Despite the widespread occurrence of fibrotic diseases and scarring, effective therapies are lacking. A promising approach would be to limit the amount of collagen released from hyperactive fibroblasts. We have designed membrane permeant peptide inhibitors that specifically target the primary interface between TANGO1 and cTAGE5, an interaction that is required for collagen export from endoplasmic reticulum exit sites (ERES). Application of the peptide inhibitors leads to reduced TANGO1 and cTAGE5 protein levels and a corresponding inhibition in the secretion of several ECM components, including collagens. Peptide inhibitor treatment in zebrafish results in altered tissue architecture and reduced granulation tissue formation during cutaneous wound healing. The inhibitors reduce secretion of several ECM proteins, including collagens, fibrillin and fibronectin in human dermal fibroblasts and in cells obtained from patients with a generalized fibrotic disease (scleroderma). Taken together, targeted interference of the TANGO1-cTAGE5 binding interface could enable therapeutic modulation of ERES function in ECM hypersecretion, during wound healing and fibrotic processes.

Synchronous carcinoma and sarcoma in a burn scar: a treatment conundrum.

Marjolijn's ulcer is a malignant ulcer in a burn scar. Types of malignancy are squamous cell carcinoma, basal cell carcinoma and malignant melanoma. Soft tissue sarcoma case reports indicate only one type of cancer. We present a patient in her 60s with a 10-year-old burn scar developing a biopsy-proven squamous cell carcinoma on the lateral aspect of the left thigh with metastatic superficial inguinal node. A wide excision and grafting of ulcer with ilioinguinal dissection done on left side. On the 12th postoperative day 2, subcutaneous swellings adjacent to the grafted area developed, on biopsy revealed to be pleomorphic sarcoma. PET CT scan revealed tumour deposits in the muscles of the left lower limb, liver and lung. There are no case reports of synchronous carcinoma and sarcoma in a burn scar. The case is reported for its rarity and the decision-making dilemma.

The Two-Stage Folded Paramedian Forehead Flap Without Cartilage Grafts for Full Thickness Distal Nasal Defects: A Review of 35 Patients.

BACKGROUND: Full thickness defects of the ala, soft triangle, and nasal tip involving the nasal lining have traditionally been repaired with the three-stage folded paramedian forehead flap (FPFF), with a cartilage graft for support. For similar defects, the authors utilize the two-stage FPFF without cartilaginous support which provides reproducible functional and aesthetic results.  Objective: To describe the authors’ experience with the two-stage FPFF, including outcomes, complications, and design modifications to enhance functional and aesthetic success.  Methods: An IRB-approved retrospective database review of FPFF was performed at two sites. Using postoperative photographs, outcomes were assessed by blinded non-investigator dermatologist raters using a modified observer scar assessment scale. RESULTS: Thirty-five patients were reconstructed using the two-stage FPFF without cartilage grafts. Subjective assessment of scar vascularity, pigment, relief, and thickness by 3 independent reviewers yielded an overall cosmesis score of 8.4±1.9 (out of 40). CONCLUSION: The two-stage FPFF without cartilage grafts is a reliable, cosmetically elegant repair that can provide optimal functional and aesthetic results for complex unilateral distal nose defects.J Drugs Dermatol. 2024;23(4): doi:10.36849/JDD.7358.

[Exploring the causality between intestinal flora and hyperplastic scars of human based on two-sample Mendelian randomization analysis].

Objective: To investigate the causality between intestinal flora and hypertrophic scars (HS) of human. Methods: This study was a study based on two-sample Mendelian randomization (TSMR) analysis. The data on intestinal flora (n=18 473) and HS (n=208 248) of human were obtained from the genome-wide association study database. Genetically variable genes at five levels (phylum, class, order, family, and genus) of known intestinal flora, i.e., single nucleotide polymorphisms (SNPs), were extracted as instrumental variables for linkage disequilibrium (LD) analysis. Human genotype-phenotype association analysis was performed using PhenoScanner V2 database to exclude SNPs unrelated to HS in intestinal flora and analyze whether the selected SNPs were weak instrumental variables. The causal relationship between intestinal flora SNPs and HS was analyzed through four methods of TSMR analysis, namely inverse variance weighted (IVW), MR-Egger regression, weighted median, and weighted mode. Scatter plots of significant results from the four aforementioned analysis methods were plotted to analyze the correlation between intestinal flora SNPs and HS. Both IVW test and MR-Egger regression test were used to assess the heterogeneity of intestinal flora SNPs, MR-Egger regression test and MR-PRESSO outlier test were used to assess the horizontal multiplicity of intestinal flora SNPs, and leave-one-out sensitivity analysis was used to determine whether HS was caused by a single SNP in the intestinal flora. Reverse TSMR analyses were performed for HS SNPs and genus Intestinimonas or genus Ruminococcus2, respectively, to detect whether there was reverse causality between them. Results: A total of 196 known intestinal flora, belonging to 9 phyla, 16 classes, 20 orders, 32 families, and 119 genera, were obtained, and multiple SNPs were obtained from each flora as instrumental variables. LD analysis showed that the SNPs of the intestinal flora were consistent with the hypothesis that genetic variation was strongly associated with exposure factors, except for rs1000888, rs12566247, and rs994794. Human genotype-phenotype association analysis showed that none of the selected SNPs after LD analysis was excluded and there were no weak instrumental variables. IVW, MR-Egger regression, weighted median, and weighted mode of TSMR analysis showed that both genus Intestinimonas and genus Ruminococcus2 were causally associated with HS. Among them, forest plots of IVW and MR-Egger regression analyses also showed that 16 SNPs (the same SNPs number of this genus below) of genus Intestinimonas and 15 SNPs (the same SNPs number of this genus below) of genus Ruminococcus2 were protective factors for HS. Further, IVW analysis showed that genus Intestinimonas SNPs (with odds ratio of 0.62, 95% confidence interval of 0.41-0.93, P<0.05) and genus Ruminococcus2 SNPs (with odds ratio of 0.62, 95% confidence interval of 0.40-0.97, P<0.05) were negatively correlated with the risk of HS. Scatter plots showed that SNPs of genus Intestinimonas and genus Ruminococcus2 were protective factors of HS. Both IVW test and MR-Egger regression test showed that SNPs of genus Intestinimonas (with Q values of 5.73 and 5.76, respectively, P>0.05) and genus Ruminococcus2 (with Q values of 13.67 and 15.61, respectively, P>0.05) were not heterogeneous. MR-Egger regression test showed that the SNPs of genus Intestinimonas and genus Ruminococcus2 had no horizontal multiplicity (with intercepts of 0.01 and 0.06, respectively, P>0.05); MR-PRESSO outlier test showed that the SNPs of genus Intestinimonas and genus Ruminococcus2 had no horizontal multiplicity (P>0.05). Leave-one-out sensitivity analysis showed that no single intestinal flora SNP drove the occurrence of HS. Reverse TSMR analysis showed no reverse causality between HS SNPs and genus Intestinimonas or genus Ruminococcus2 (with odds ratios of 1.01 and 0.99, respectively, 95% confidence intervals of 0.97-1.06 and 0.96-1.04, respectively, P>0.05). Conclusions: There is a causal relationship between intestinal flora and HS of human, in which genus Intestinimonas and genus Ruminococcus2 have a certain effect on inhibiting HS.

Rapid formed temperature-sensitive hydrogel for the multi-effective wound healing of deep second-degree burn with shikonin based scar prevention.

Burns are a significant public health issue worldwide, resulting in prolonged hospitalization, disfigurement, disability and, in severe cases, death. Among them, deep second-degree burns are often accompanied by bacterial infections, insufficient blood flow, excessive skin fibroblasts proliferation and collagen deposition, all of which contribute to poor wound healing and scarring following recovery. In this study, SNP/MCNs-SKN-chitosan-ß-glycerophosphate hydrogel (MSSH), a hydrogel composed of a temperature-sensitive chitosan-ß-glycerophosphate hydrogel matrix (CGH), mesoporous carbon nanospheres (MCNs), nitric oxide (NO) donor sodium nitroprusside (SNP) and anti-scarring substance shikonin (SKN), is intended for use as a biomedical material. In vitro tests have revealed that MSSH has broad-spectrum antibacterial abilities and releases NO in response to near-infrared (NIR) laser to promote angiogenesis. Notably, MSSH can inhibit excessive proliferation of fibroblasts and effectively reduce scarring caused by deep second-degree burns, as demonstrated by in vitro and in vivo tests.

Irgm proteins attenuate inflammatory disease in mouse models of genital Chlamydia infection.

Chlamydiae are obligate intracellular bacterial pathogens that may cause genital pathology via induction of destructive host immune responses. Human-adapted Chlamydia trachomatis causes inflammatory disease in human hosts but is easily cleared in mice, and mouse-adapted Chlamydia muridarum establishes a productive and pathogenic infection in murine hosts. While numerous anti-chlamydial host resistance factors have been discovered in mice and humans alike, little is known about host factors promoting host fitness independent of host resistance. Here, we show that interferon-inducible immunity-related GTPase M (Irgm) proteins function as such host factors ameliorating infection-associated sequalae in the murine female genital tract, thus characterizing Irgm proteins as mediators of disease tolerance. Specifically, we demonstrate that mice deficient for all three murine Irgm paralogs (pan-Irgm-/-) are defective for cell-autonomous immunity to C. trachomatis, which correlates with an early and transient increase in bacterial burden and sustained hyperinflammation in vivo. In contrast, upon infection of pan-Irgm-/- mice with C. muridarum, bacterial burden is unaffected, yet genital inflammation and scarring pathology are nonetheless increased, demonstrating that Irgm proteins can promote host fitness without altering bacterial burden. Additionally, pan-Irgm-/- mice display increased granulomatous inflammation in genital Chlamydia infection, implicating Irgm proteins in the regulation of granuloma formation and maintenance. These findings demonstrate that Irgm proteins regulate pathogenic immune responses to Chlamydia infection in vivo, establishing an effective infection model to examine the immunoregulatory functions and mechanisms of Irgm proteins. IMPORTANCE: In response to genital Chlamydia infection, the immune system mounts a proinflammatory response to resist the pathogen, yet inflammation must be tightly controlled to avoid collateral damage and scarring to host genital tissue. Variation in the human IRGM gene is associated with susceptibility to autoinflammatory diseases but its role in ameliorating inflammatory diseases caused by infections is poorly defined. Here, we use mice deficient for all three murine Irgm paralogs to demonstrate that Irgm proteins not only provide host resistance to Chlamydia infections but also limit associated inflammation in the female genital tract. In particular, we find that murine Irgm expression prevents granulomatous inflammation, which parallels inflammatory diseases associated with variants in human IRGM. Our findings therefore establish genital Chlamydia infection as a useful model to study the roles for Irgm proteins in both promoting protective immunity and limiting pathogenic inflammation.

Botulinum toxin type A inhibits M1 macrophage polarization by deactivation of JAK2/STAT1 and IκB/NFκB pathway and contributes to scar alleviation in aseptic skin wound healing.

The non-neuronal and non-muscular effects of botulinum toxin type A (BTXA) on scar reduction has been discovered. This study was designed to investigate the effects of BTXA on macrophages polarization during the early stage of skin repair. A skin defect model was established on the dorsal skin of SD rats. BTXA was intracutaneous injected into the edge of wound immediately as the model was established. Histological examinations were performed on scar samples. Raw 264.7 was selected as the cell model of recruited circulating macrophages, and was induced for M1 polarization by LPS. Identify the signaling pathways that primarily regulated M1 polarization and respond to BTXA treatment. Application of BTXA at early stage of injury significantly reduced the scar diameter without delaying wound closure. BTXA treatment improved fiber proliferation and arrangement, and inhibited angiogenesis in scar granular tissue. The number of M1 macrophages and the levels of pro-inflammation were decreased after treated with BTXA in scar tissues. LPS activated JAK2/STAT1 and IκB/NFκB pathways were downregulated by BTXA, as well as LPS induced M1 polarization. At early stage of skin wound healing, injection of BTXA effectively reduced the number of M1 macrophages and the levels of pro-inflammatory mediators which contributes to scar alleviation. BTXA resisted the M1 polarization of macrophages induced by LPS via deactivating the JAK2/STAT1 and IκB/NFκB pathways.

Natural Compounds and Biomimetic Engineering to Influence Fibroblast Behavior in Wound Healing.

Throughout history, natural products have played a significant role in wound healing. Fibroblasts, acting as primary cellular mediators in skin wound healing, exhibit behavioral responses to natural compounds that can enhance the wound healing process. Identifying bioactive natural compounds and understanding their impact on fibroblast behavior offers crucial translational opportunities in the realm of wound healing. Modern scientific techniques have enabled a detailed understanding of how naturally derived compounds modulate wound healing by influencing fibroblast behavior. Specific compounds known for their wound healing properties have been identified. Engineered biomimetic compounds replicating the natural wound microenvironment are designed to facilitate normal healing. Advanced delivery methods operating at micro- and nano-scales have been developed to effectively deliver these novel compounds through the stratum corneum. This review provides a comprehensive summary of the efficacy of natural compounds in influencing fibroblast behavior for promoting wound regeneration and repair. Additionally, it explores biomimetic engineering, where researchers draw inspiration from nature to create materials and devices mimicking physiological cues crucial for effective wound healing. The review concludes by describing novel delivery mechanisms aimed at enhancing the bioavailability of natural compounds. Innovative future strategies involve exploring fibroblast-influencing pathways, responsive biomaterials, smart dressings with real-time monitoring, and applications of stem cells. However, translating these findings to clinical settings faces challenges such as the limited validation of biomaterials in large animal models and logistical obstacles in industrial production. The integration of ancient remedies with modern approaches holds promise for achieving effective and scar-free wound healing.

Impact of prior axonal injury on subsequent injury during brain tissue stretching - A mesoscale computational approach.

Epidemiology studies of traumatic brain injury (TBI) show individuals with a prior history of TBI experience an increased risk of future TBI with a significantly more detrimental outcome. But the mechanisms through which prior head injuries may affect risks of injury during future head insults have not been identified. In this work, we show that prior brain tissue injury in the form of mechanically induced axonal injury and glial scar formation can facilitate future mechanically induced tissue injury. To achieve this, we use finite element computational models of brain tissue and a history-dependent pathophysiology-based mechanically-induced axonal injury threshold to determine the evolution of axonal injury and scar tissue formation and their effects on future brain tissue stretching. We find that due to the reduced stiffness of injured tissue and glial scars, the existence of prior injury can increase the risk of future injury in the vicinity of prior injury during future brain tissue stretching. The softer brain scar tissue is shown to increase the strain and strain rate in its vicinity by as much as 40% in its vicinity during dynamic stretching that reduces the global strain required to induce injury by 20% when deformed at 15 s-1 strain rate. The results of this work highlight the need to account for patient history when determining the risk of brain injury.

Value of early pregnancy ultrasound combined with ultrasound score in the evaluation of placenta accreta in scar uterus: A retrospective cohort study.

The objective of this study is to investigate the value of early pregnancy ultrasound combined with ultrasound score (USS) for the evaluation of placenta accreta (PA) in scar uteri. Thirty cases of PA in scar uteri diagnosed by ultrasound at our hospital between June 2021 and June 2022 were selected retrospectively (observation group). In addition, 30 patients had placenta attached to the anterior wall of the uterus and covered the internal orifice of the cervix; however, no PA was selected in the same period (control group). The results of surgical pathology and ultrasound examination in the first trimester of pregnancy (11-14 weeks of pregnancy, fetal top hip length 4.5-8.4 cm) were analyzed. Ultrasonic image characteristics of the 2 groups were scored using an ultrasonic scoring scale. The ultrasonic signs and ultrasonic scores of the 2 groups were analyzed. The diagnostic value of ultrasound and USS for PA in the scarred uterus alone and in combination was analyzed based on the gold standard of surgical and pathological results. The rich blood flow signal at the junction of the uterine serosa and bladder, the rate of blood flow in the cavity of the placental parenchyma, the thinning rate of the myometrium after placenta, and the abnormal rate of the low echo area after placenta in the observation group were significantly higher than those in the control group (P < .05). The USS of the observation group was significantly higher than that of the control group (P < .05). The sensitivity (93.33%) and accuracy (95.00%) of the combined examinations were significantly higher than those of ultrasound (70.00% and 83.33%, respectively) (P < .05). The sensitivity and accuracy of combined examination were slightly higher than those of USS examination (83.33% and 90.00%), but the difference was not statistically significant (P > .05). There was no significant difference between the specificity of combined examination (93.33%) and ultrasound (96.67%) and USS (96.67%) (P > .05). Early pregnancy ultrasound and USS evaluation have high application value in the diagnosis and evaluation of early scar uterine PA. The combination of the 2 methods can further improve the sensitivity and accuracy of diagnosis.

Timing of surgery in acute deep partial-thickness burns: A study protocol.

For deep partial-thickness burns no consensus on the optimal treatment has been reached due to conflicting study outcomes with low quality evidence. Treatment options in high- and middle-income countries include conservative treatment with delayed excision and grafting if needed; and early excision and grafting. The majority of timing of surgery studies focus on survival rather than on quality of life. This study protocol describes a study that aims to compare long-term scar quality, clinical outcomes, and patient-reported outcomes between the treatment options. A multicentre prospective study will be conducted in the three Dutch burn centres (Rotterdam, Beverwijk, and Groningen). All adult patients with acute deep-partial thickness burns, based on healing potential with Laser Doppler Imaging, are eligible for inclusion. During a nine-month baseline period, standard practice will be monitored. This includes conservative treatment with dressings and topical agents, and excision and grafting of residual defects if needed 14-21 days post-burn. The subsequent nine months, early surgery is advocated, involving excision and grafting in the first week to ten days post-burn. The primary outcome compared between the two groups is long-term scar quality assessed by the Patient and Observer Scar Assessment Scale 3.0 twelve months after discharge. Secondary outcomes include clinical outcomes and patient-reported outcomes like quality of life and return to work. The aim of the study is to assess long-term scar quality in deep partial-thickness burns after conservative treatment with delayed excision and grafting if needed, compared to early excision and grafting. Adding to the ongoing debate on the optimal treatment of these burns. The broad range of studied outcomes will be used for the development of a decision aid for deep partial-thickness burns, to fully inform patients at the point of consent to surgery and support optimal person-centred care.

Evaluation of combining ultrapulse CO2 with fractional CO2 laser for the treatment of atrophic scars in Asians.

Various treatment modalities have been applied to atrophic scars. Fractional CO2 laser treatment has attracted increasingly more attention because of its quicker recovery time and fewer side effects. However, its limitation of sculpting the edge is an urgent shortcoming. In order to achieve a more effective result with fewer complications, we have integrated ultrapulse CO2 and fractional CO2 lasers to for the treatment of facial atrophic scars. The study included 25 patients (10 males and 15 females) diagnosed with moderate to severe atrophic scars between August 2020 and July 2022. All subjects underwent the same surgical treatment. The effects were assessed at baseline, 1 week, 1 month, and 3 months using photographic evidence. Objective evaluation of the results was conducted using a quartile grading scale, while the subjects' satisfaction and any adverse events were also recorded. The patients in the study underwent more than two laser sessions (2-5), resulting in substantial improvement in their appearance. The time interval between each session was 3-6 months. The majority of the patients (19/25, 76%) had a significant or even excellent improvement. Any adverse events observed, such as erythema, superficial crusting, and PIH, were of a mild nature and temporary in duration. This treatment combined two CO2 lasers is an effective and safe choice for atrophic scars in Asians.

Neurotropin® ameliorates chronic pain associated with scar formation in a mouse model: A gene expression analysis of the inflammatory response.

Background: Scar formation after trauma and surgery involves an inflammatory response and can lead to the development of chronic pain. Neurotropin® (NTP) is a nonprotein extract of inflamed skin of rabbits inoculated with vaccinia virus. It has been widely used for the treatment of chronic pain. However, the in vivo effects of NTP on painful scar formation have not been determined. To investigate the molecular mechanisms underlying the effects of NTP on the inflammatory response, we evaluated gene expression in the scar tissues and dorsal root ganglions (DRGs) of mice administered NTP and control mice. Methods and results: Mice injected with saline or NTP were used as controls; other mice were subjected to surgery on the left hind paw to induce painful scar formation, and then injected with saline or NTP. Hind paw pain was evaluated by measuring the threshold for mechanical stimulation using the von Frey test. The paw withdrawal threshold gradually returned to pre-operative levels over 4 weeks post-operation; NTP-treated mice showed a significantly shortened recovery time of approximately 3 weeks, suggesting that NTP exerted an analgesic effect in this mouse model. Total RNA was extracted from the scarred hind paw tissues and DRGs were collected 1 week post-operation for a microarray analysis. Gene set enrichment analysis revealed that the expression of some gene sets related to inflammatory responses was activated or inhibited following surgery and NTP administration. Quantitative real-time reverse transcription-polymerase chain reaction analysis results for several genes were consistent with the microarray results. Conclusion: The administration of NTP to the hind paws of mice with painful scar formation following surgery diminished nociceptive pain and reduced the inflammatory response. NTP inhibited the expression of some genes involved in the response to surgery-induced inflammation. Therefore, NTP is a potential therapeutic option for painful scar associated with chronic pain.

Modern techniques in addressing facial acne scars: A thorough analysis.

BACKGROUND: Facial acne scars are a prevalent concern, leading to the development of various treatment modalities. OBJECTIVES: This review aims to explore the latest advancements in the treatment of facial acne scars, focusing on both surgical and non-surgical methods. METHODS: The non-surgical treatments reviewed include topical medications (such as retinoids and alpha hydroxy acids) and non-invasive procedures (like microdermabrasion and chemical peels). Surgical options discussed are punch excision, subcision, and fractional laser treatments. RESULTS: Combination therapy, integrating both surgical and non-surgical approaches, is frequently utilized to achieve optimal results in scar improvement. CONCLUSION: Recent advancements in the treatment of facial acne scars provide promising options for individuals seeking improvement. However, these treatments have associated risks and potential adverse effects, highlighting the importance of consulting a dermatologist before beginning any treatment regimen.

Electrophysiological Characterization of Subclinical and Overt Hypertrophic Cardiomyopathy by Magnetic Resonance Imaging-Guided Electrocardiography.

BACKGROUND: Ventricular arrhythmia in hypertrophic cardiomyopathy (HCM) relates to adverse structural change and genetic status. Cardiovascular magnetic resonance (CMR)-guided electrocardiographic imaging (ECGI) noninvasively maps cardiac structural and electrophysiological (EP) properties. OBJECTIVES: The purpose of this study was to establish whether in subclinical HCM (genotype [G]+ left ventricular hypertrophy [LVH]-), ECGI detects early EP abnormality, and in overt HCM, whether the EP substrate relates to genetic status (G+/G-LVH+) and structural phenotype. METHODS: This was a prospective 211-participant CMR-ECGI multicenter study of 70 G+LVH-, 104 LVH+ (51 G+/53 G-), and 37 healthy volunteers (HVs). Local activation time (AT), corrected repolarization time, corrected activation-recovery interval, spatial gradients (GAT/GRTc), and signal fractionation were derived from 1,000 epicardial sites per participant. Maximal wall thickness and scar burden were derived from CMR. A support vector machine was built to discriminate G+LVH- from HV and low-risk HCM from those with intermediate/high-risk score or nonsustained ventricular tachycardia. RESULTS: Compared with HV, subclinical HCM showed mean AT prolongation (P = 0.008) even with normal 12-lead electrocardiograms (ECGs) (P = 0.009), and repolarization was more spatially heterogenous (GRTc: P = 0.005) (23% had normal ECGs). Corrected activation-recovery interval was prolonged in overt vs subclinical HCM (P < 0.001). Mean AT was associated with maximal wall thickness; spatial conduction heterogeneity (GAT) and fractionation were associated with scar (all P < 0.05), and G+LVH+ had more fractionation than G-LVH+ (P = 0.002). The support vector machine discriminated subclinical HCM from HV (10-fold cross-validation accuracy 80% [95% CI: 73%-85%]) and identified patients at higher risk of sudden cardiac death (accuracy 82% [95% CI: 78%-86%]). CONCLUSIONS: In the absence of LVH or 12-lead ECG abnormalities, HCM sarcomere gene mutation carriers express an aberrant EP phenotype detected by ECGI. In overt HCM, abnormalities occur more severely with adverse structural change and positive genetic status.

Pericardial delta like non-canonical NOTCH ligand 1 (Dlk1) augments fibrosis in the heart through epithelial to mesenchymal transition.

BACKGROUND: Heart failure due to myocardial infarction (MI) involves fibrosis driven by epicardium-derived cells (EPDCs) and cardiac fibroblasts, but strategies to inhibit and provide cardio-protection remains poor. The imprinted gene, non-canonical NOTCH ligand 1 (Dlk1), has previously been shown to mediate fibrosis in the skin, lung and liver, but very little is known on its effect in the heart. METHODS: Herein, human pericardial fluid/plasma and tissue biopsies were assessed for DLK1, whereas the spatiotemporal expression of Dlk1 was determined in mouse hearts. The Dlk1 heart phenotype in normal and MI hearts was assessed in transgenic mice either lacking or overexpressing Dlk1. Finally, in/ex vivo cell studies provided knowledge on the molecular mechanism. RESULTS: Dlk1 was demonstrated in non-myocytes of the developing human myocardium but exhibited a restricted pericardial expression in adulthood. Soluble DLK1 was twofold higher in pericardial fluid (median 45.7 [34.7 (IQR)) µg/L] from cardiovascular patients (n = 127) than in plasma (median 26.1 µg/L [11.1 (IQR)]. The spatial and temporal expression pattern of Dlk1 was recapitulated in mouse and rat hearts. Similar to humans lacking Dlk1, adult Dlk1-/- mice exhibited a relatively mild developmental, although consistent cardiac phenotype with some abnormalities in heart size, shape, thorax orientation and non-myocyte number, but were functionally normal. However, after MI, scar size was substantially reduced in Dlk1-/- hearts as compared with Dlk1+/+ littermates. In line, high levels of Dlk1 in transgenic mice Dlk1fl/fl xWT1GFPCre and Dlk1fl/fl xαMHCCre/+Tam increased scar size following MI. Further mechanistic and cellular insight demonstrated that pericardial Dlk1 mediates cardiac fibrosis through epithelial to mesenchymal transition (EMT) of the EPDC lineage by maintaining Integrin ß8 (Itgb8), a major activator of transforming growth factor ß and EMT. CONCLUSIONS: Our results suggest that pericardial Dlk1 embraces a, so far, unnoticed role in the heart augmenting cardiac fibrosis through EMT. Monitoring DLK1 levels as well as targeting pericardial DLK1 may thus offer new venues for cardio-protection.

Inhibition of CK2 Diminishes Fibrotic Scar Formation and Improves Outcomes After Ischemic Stroke via Reducing BRD4 Phosphorylation.

Fibrotic scars play important roles in tissue reconstruction and functional recovery in the late stage of nervous system injury. However, the mechanisms underlying fibrotic scar formation and regulation remain unclear. Casein kinase II (CK2) is a protein kinase that regulates a variety of cellular functions through the phosphorylation of proteins, including bromodomain-containing protein 4 (BRD4). CK2 and BRD4 participate in fibrosis formation in a variety of tissues. However, whether CK2 affects fibrotic scar formation remains unclear, as do the mechanisms of signal regulation after cerebral ischemic injury. In this study, we assessed whether CK2 could modulate fibrotic scar formation after cerebral ischemic injury through BRD4. Primary meningeal fibroblasts were isolated from neonatal rats and treated with transforming growth factor-ß1 (TGF-ß1), SB431542 (a TGF-ß1 receptor kinase inhibitor) or TBB (a highly potent CK2 inhibitor). Adult SD rats were intraperitoneally injected with TBB to inhibit CK2 after MCAO/R. We found that CK2 expression was increased in vitro in the TGF-ß1-induced fibrosis model and in vivo in the MCAO/R injury model. The TGF-ß1 receptor kinase inhibitor SB431542 decreased CK2 expression in fibroblasts. The CK2 inhibitor TBB reduced the increases in proliferation, migration and activation of fibroblasts caused by TGF-ß1 in vitro, and it inhibited fibrotic scar formation, ameliorated histopathological damage, protected Nissl bodies, decreased infarct volume and alleviated neurological deficits after MCAO/R injury in vivo. Furthermore, CK2 inhibition decreased BRD4 phosphorylation both in vitro and in vivo. The findings of the present study suggested that CK2 may control BRD4 phosphorylation to regulate fibrotic scar formation, to affecting outcomes after ischemic stroke.