Adipose tissue sensitivity to radiation exposure

Obesity and Colorectal Cancer: A Narrative Review

Background and Objectives: Cancer is a multicausal disease, and environmental, cultural, socioeconomic, lifestyle, and genetic factors can influence the risk of developing cancer. Colorectal cancer (CRC) stands as the third most common cancer globally. Some countries have observed a rise in the incidence of CRC, especially among young people. This increase is associated with lifestyle changes over the last few decades, including changes in diet patterns, a sedentary lifestyle, and obesity. Currently, obesity and overweight account for approximately 39% of the world's population and increase the risk of overall mortality of certain cancer types. This study aims to conduct a literature review examining the association between obesity and CRC. Materials and Methods: This narrative review explored the pathophysiological mechanisms, treatment strategies, and challenges related to obesity and CRC. Results: Several studies have established a clear causal relationship between obesity and CRC, showing that individuals with morbid obesity are at a higher risk of developing colorectal cancer. The adipose tissue, particularly the visceral, secretes proinflammatory cytokines, such as TNF-alpha, interleukin-6, and C-reactive protein. Chronic inflammation is closely linked to cancer initiation and progression, with a complex interplay of molecular mechanisms underlying this association. Obesity can complicate the treatment of CRC due to several factors, reducing the therapeutic effectiveness and increasing the risk for adverse events during treatment. Dietary modification, calorie restriction, and other types of weight-control strategies can reduce the risk of CRC development and improve treatment outcomes. Conclusions: Obesity is intricately linked to CRC development and progression, making it a crucial target for intervention, whether through diet therapy, physical exercises, medical therapy, or bariatric surgery.

Lactobacillus reuteri's multifaceted role in mitigating ionizing radiation-induced injury in Drosophila melanogaster

The numerous beneficial probiotic properties of Lactobacillus reuteri (L. reuteri) include decreasing metabolic syndrome, preventing disorders linked to oxidative stress, improving gut flora imbalances, controlling immunological function, and extending life span. Exposure to ionizing radiation is closely associated with several disorders. We examined the protective and salvaging effects of L. reuteri on ionizing radiation-induced injury to the intestinal tract, reproductive system, and nervous system of Drosophila melanogaster. We also examined its effects on lifespan, antioxidant capacity, progeny development, and behavioral aspects to assess the interaction between L. reuteri and ionizing radiation-induced injury. The findings demonstrated that L. reuteri improved the median survival time following irradiation and greatly extended its lifespan. In addition, it raised SOD activity, reduced ROS levels in intestinal epithelial cells, and increased the quantity of intestinal stem cells. Furthermore, L. reuteri enhanced the adult male flies' capacity to move. It also successfully safeguarded the generations' growth and development. L. reuteri dramatically enhanced expression of the AMPKα gene and regulated expression of its pathway-related gene, mTOR, as well as the autophagy-related genes Atg1 and Atg5 in female Drosophila exposed to irradiation. Notably, no prior reports have been made on the possible effects of L. reuteri on injuries caused by irradiation. As a result, our research offers important new information regarding L. reuteri's possible role as a shield against ionizing radiation-induced injury.

Adolescent and young adult Hodgkin lymphoma patients at risk for subcutaneous fat gain during early cancer treatment: a brief report

Computed tomography scans were assessed for subcutaneous fat area and density at thoracic vertebra 4 in 65 adolescent and young adult (AYA) patients with Hodgkin lymphoma. Subcutaneous fat was quantified over 3 timepoints; (1) baseline, (2) end of initial anthracycline treatment (EOT) and (3) 1 year. Fat area increased at EOT (62.3 ± 5.4 cm/m2 vs 53.5 ± 5.0 cm/m2, p < 0.01) and 1 year (65.8 ± 5.6 cm/m2 vs 53.5 ± 5.0 cm/m2, p < 0.01) compared to baseline. Fat density significantly decreased at EOT (-91.2 ± 1.4 HU vs -86.5 ± 1.4 HU, p < 0.01) and at 1 year (-90.3 ± 1.6 HU vs -86.5 ± 1.4 HU, p = 0.01) compared to baseline. Female, radiation receiving, and anthracycline dosage >250mg/m2subgroups experienced significant fat gain (p < 0.05 for all). Female AYA Hodgkin lymphoma patients receiving radiation, and/or high-dose anthracyclines may be at higher risk of subcutaneous fat gain during therapy.

Activation of cell adhesion and migration is an early event of platelet-rich plasma (PRP)-dependent stimulation of human adipose-derived stem/stromal cells

Stem cell therapy is a promising treatment in regenerative medicine. Human adipose-derived stem/stromal cells (hASCs), a type of mesenchymal stem cell, are easy to harvest. In plastic and aesthetic surgery, hASC may be applied in the treatment of fat grafting, wound healing, and scar remodeling. Platelet-rich plasma (PRP) contains various growth factors, including platelet-derived growth factor (PDGF), which accelerates wound healing. We previously reported that PRP promotes the proliferation of hASC via multiple signaling pathways, and we evaluated the effect of PRP on the stimulation of hASC adhesion and migration, leading to the proliferation of these cells. When hASCs were treated with PRP, AKT, ERK1/2, paxillin and RhoA were rapidly activated. PRP treatment led to the formation of F-actin stress fibers. Strong signals for integrin β1, paxillin and RhoA at the cell periphery of RPR-treated cells indicated focal adhesion. PRP promoted cell adhesion and movement of hASC, compared with the control group. Imatinib, an inhibitor of the PDGF receptor tyrosine kinase, inhibited the promotion of PRP-dependent cell migration. PDGF treatment of hASCs also stimulated cell adhesion and migration but to a lesser extent than PRP treatment. PRP promoted the adhesion and the migration of hASC, mediated by the activation of AKT in the integrin signaling pathway. PRP treatment was more effective than PDGF treatment in enhancing cell migration. Thus, the ability of PRPs to promote migration of hASC to enhance cell growth is evident.

Diabetes in childhood cancer survivors: emerging concepts in pathophysiology and future directions

With advancements in cancer treatment and supportive care, there is a growing population of childhood cancer survivors who experience a substantial burden of comorbidities related to having received cancer treatment at a young age. Despite an overall reduction in the incidence of most chronic health conditions in childhood cancer survivors over the past several decades, the cumulative incidence of certain late effects, in particular diabetes mellitus (DM), has increased. The implications are significant, because DM is a key risk factor for cardiovascular disease, a leading cause of premature death in childhood cancer survivors. The underlying pathophysiology of DM in cancer survivors is multifactorial. DM develops at younger ages in survivors compared to controls, which may reflect an "accelerated aging" phenotype in these individuals. The treatment-related exposures (i.e., chemotherapy, radiation) that increase risk for DM in childhood cancer survivors may be more than additive with established DM risk factors (e.g., older age, obesity, race, and ethnicity). Emerging research also points to parallels in cellular processes implicated in aging- and cancer treatment-related DM. Still, there remains marked inter-individual variability regarding risk of DM that is not explained by demographic and therapeutic risk factors alone. Recent studies have highlighted the role of germline genetic risk factors and epigenetic modifications that are associated with risk of DM in both the general and oncology populations. This review summarizes our current understanding of recognized risk factors for DM in childhood cancer survivors to help inform targeted approaches for disease screening, prevention, and treatment. Furthermore, it highlights the existing scientific gaps in understanding the relative contributions of individual therapeutic exposures and the mechanisms by which they exert their effects that uniquely predispose this population to DM following cancer treatment.

Piezo inhibition prevents and rescues scarring by targeting the adipocyte to fibroblast transition

While past studies have suggested that plasticity exists between dermal fibroblasts and adipocytes, it remains unknown whether fat actively contributes to fibrosis in scarring. We show that adipocytes convert to scar-forming fibroblasts in response to Piezo -mediated mechanosensing to drive wound fibrosis. We establish that mechanics alone are sufficient to drive adipocyte-to- fibroblast conversion. By leveraging clonal-lineage-tracing in combination with scRNA-seq, Visium, and CODEX, we define a "mechanically naïve" fibroblast-subpopulation that represents a transcriptionally intermediate state between adipocytes and scar-fibroblasts. Finally, we show that Piezo1 or Piezo2 -inhibition yields regenerative healing by preventing adipocytes' activation to fibroblasts, in both mouse-wounds and a novel human-xenograft-wound model. Importantly, Piezo1 -inhibition induced wound regeneration even in pre-existing established scars, a finding that suggests a role for adipocyte-to-fibroblast transition in wound remodeling, the least-understood phase of wound healing. Adipocyte-to-fibroblast transition may thus represent a therapeutic target for minimizing fibrosis via Piezo -inhibition in organs where fat contributes to fibrosis.

Irradiation-Induced Dysbiosis: The Compounding Effect of High-Fat Diet on Metabolic and Immune Functions in Mice

The negative impact of irradiation or diet on the metabolic and immune profiles of cancer survivors have been previously demonstrated. The gut microbiota plays a critical role in regulating these functions and is highly sensitive to cancer therapies. The aim of this study was to investigate the effect of irradiation and diet on the gut microbiota and metabolic or immune functions. We exposed C57Bl/6J mice to a single dose of 6 Gy radiation and after 5 weeks, fed them a chow or high-fat diet (HFD) for 12 weeks. We characterised their faecal microbiota, metabolic (whole body and adipose tissue) functions, and systemic (multiplex cytokine, chemokine assay, and immune cell profiling) and adipose tissue inflammatory profiles (immune cell profiling). At the end of the study, we observed a compounding effect of irradiation and diet on the metabolic and immune profiles of adipose tissue, with exposed mice fed a HFD displaying a greater inflammatory signature and impaired metabolism. Mice fed a HFD also showed altered microbiota, irrespective of irradiation status. An altered diet may exacerbate the detrimental effects of irradiation on both the metabolic and inflammatory profiles. This could have implications for the diagnosis and prevention of metabolic complications in cancer survivors exposed to radiation.

Mesenchymal stem cell therapy for neurological disorders: The light or the dark side of the force?

Neurological disorders are recognized as major causes of death and disability worldwide. Because of this, they represent one of the largest public health challenges. With awareness of the massive burden associated with these disorders, came the recognition that treatment options were disproportionately scarce and, oftentimes, ineffective. To address these problems, modern research is increasingly looking into novel, more effective methods to treat neurological patients; one of which is cell-based therapies. In this review, we present a critical analysis of the features, challenges, and prospects of one of the stem cell types that can be employed to treat numerous neurological disorders-mesenchymal stem cells (MSCs). Despite the fact that several studies have already established the safety of MSC-based treatment approaches, there are still some reservations within the field regarding their immunocompatibility, heterogeneity, stemness stability, and a range of adverse effects-one of which is their tumor-promoting ability. We additionally examine MSCs' mechanisms of action with respect to in vitro and in vivo research as well as detail the findings of past and ongoing clinical trials for Parkinson's and Alzheimer's disease, ischemic stroke, glioblastoma multiforme, and multiple sclerosis. Finally, this review discusses prospects for MSC-based therapeutics in the form of biomaterials, as well as the use of electromagnetic fields to enhance MSCs' proliferation and differentiation into neuronal cells.

Regulation and coordination of the different DNA damage responses in Drosophila

Cells have evolved mechanisms that allow them to respond to DNA damage to preserve genomic integrity and maintain tissue homeostasis. These responses include the activation of the cell cycle checkpoints and the repair mechanisms or the induction of apoptosis that eventually will eliminate damaged cells. These “life” vs. “death” decisions differ depending on the cell type, stages of development, and the proliferation status of the cell. The apoptotic response after DNA damage is of special interest as defects in its induction could contribute to tumorigenesis or the resistance of cancer cells to therapeutic agents such as radiotherapy. Multiples studies have elucidated the molecular mechanisms that mediate the activation of the DNA damage response pathway (DDR) and specifically the role of p53. However, much less is known about how the different cellular responses such as cell proliferation control and apoptosis are coordinated to maintain tissue homeostasis. Another interesting question is how the differential apoptotic response to DNA damage is regulated in distinct cell types. The use of Drosophila melanogaster as a model organism has been fundamental to understand the molecular and cellular mechanisms triggered by genotoxic stress. Here, we review the current knowledge regarding the cellular responses to ionizing radiation as the cause of DNA damage with special attention to apoptosis in Drosophila: how these responses are regulated and coordinated in different cellular contexts and in different tissues. The existence of intrinsic mechanisms that might attenuate the apoptotic pathway in response to this sort of DNA damage may well be informative for the differences in the clinical responsiveness of tumor cells after radiation therapy.

Prognostic factors and related complications/sequalae of squamous cell carcinoma located in the gingivobuccal complex

Background

Gingivobuccal complex (GBC) was a relatively new concept of oral subsite that was comprises of the upper and/or lower gingiva, gingival buccal sulcus, and adjacent buccal mucosa. Squamous cell carcinoma (SCC) of the GBC had a poor prognosis, with few studies analyzing this particular entity. The objective of this study was to analyze the risk factors affecting the prognosis and complications/sequalae of gingivobuccal complex cancer.

Methods

Between December 2014 and August 2019, a total of 122 patients diagnosed with primary gingivobuccal complex cancer in Beijing Stomatological Hospital, Capital Medical University were enrolled in the study. Through outpatient reviewed and telephone followed-up for 2-5 years postoperatively, postoperative relapse and complications/sequalae were assessed. The primary outcome parameter was 2-year disease-free survival.

Results

The most common central site of the tumor was the buccal mucosa (45.1%), followed by the lower gingiva (36.9%). The most diseases were pT4a (45.1%) and there was lymph node invasion (pN+) in 41.8% of patients. Moderate differentiated squamous carcinoma (77.9%) accounted for the vast majority of the histopathological differentiation. A total of 62.3% of tumors invaded the bone, while, 5.7% invaded the skin layer. Survival analysis found that 44.3% of patients experienced relapse within two years postoperatively and the mortality rate after relapse was 75.9%. Almost 60.0% of the tumors involving the maxilla and/or mandible developed relapse. Cox proportional hazards model found that pN stage (p= 0.002) and bone invasion (p= 0.007) were significant independent predictors of 2-year disease-free survival. Importantly, 63.1% of patients had postoperative (and postradiotherapy) complications/sequalae. It was noteworthy that 18 of 43 patients (41.9%) who implanted with titanium plates had hardware-related complications/sequalae, and the most of them were titanium plate exposure (61.1%).

Conclusions

Squamous cell carcinoma of the gingivobuccal complex cancer, as a new subsite worthy of attention in oral cancer, has a high complication/sequalae rate, high relapse rate and poor prognosis.

Trial registration

Prospective, Observational, Real-world Oral Malignant Tumors Study (clinicaltrials.gov identifier: NCT02395367). The approval of the Institutional Review Board of the Beijing Stomatological Hospital of Capital Medical University (Approval number: CMUSH-IRB-KJPJ-2015-08)

Radiomitigation by Melatonin in C57BL/6 Mice: Possible Implications as Adjuvant in Radiotherapy and Chemotherapy

BACKGROUND/AIM

Melatonin (N-acetyl-5-methoxytryptamine), a chief secretory molecule of the pineal gland, has multiple properties, and numerous clinical investigations regarding its actions are in progress. This study investigated the radiomitigative role of melatonin in C57BL/6 mice.

MATERIALS AND METHODS

Melatonin (100 mg/kg) was orally administered once daily starting at 1 h on day 1 and subsequently every 24 h until day 7 after whole-body irradiation (WBI) and survival was monitored for 30 days. The bone marrow, spleen, and intestine were studied to evaluate the mitigative potential of melatonin after radiation-induced damage.

RESULTS

Melatonin significantly improved the survival upto 60% and 90% after 9 Gy (lethal) and 7.5 Gy (sub-lethal) WBI, respectively. Melatonin alleviated WBI-induced myelosuppression and pancytopenia, and increased white blood cell, red blood cell, platelet, and lymphocyte (CD4⁺ and CD8⁺) counts in peripheral blood. Bone marrow and spleen cellularity were restored through enhanced haematopoiesis. Melatonin ameliorated the damage in the small intestine, and promoted recovery of villi length, crypts number, and goblet cell count.

CONCLUSION

Melatonin mitigates the radiation-induced injury in the gastrointestinal and haematopoietic systems. The observed radiomitigative properties of melatonin can also be useful in the context of adjuvant therapy for cancer and radiotherapy.

Bone marrow transplantation induces changes in the gut microbiota that chronically increase the cytokine response pattern of splenocytes

Bone marrow transplantation (BMT) involves conditioning regimens which acutely induce side effects, including systemic inflammation, intestinal damage and shifts in the gut microbial composition, some of which may persist chronically. As the gut microbiota affect systemic immune responses, we aimed to investigate whether, post-BMT, the peripheral immune system is modulated as a direct consequence of alterations in the gut microbiota. We show that 24 weeks post-BMT, splenocytes but not peritoneal macrophages display increased cytokine response patterns upon ex-vivo stimulation with various pathogens as compared to untreated controls. The pattern of BMT-induced cytokine responses was transferred to splenocytes, and not to peritoneal macrophages, of healthy controls via co-housing and transferred to germfree mice via transplantation of cecum content. Thus, BMT induces changes in gut microbiota that in their turn increase cytokine responsiveness of splenocytes. Thus, BMT establishes a dominant microbiota that attenuates normalization of the immune-response.

Female Mice are More Resistant to the Mixed-Field (67% Neutron + 33% Gamma) Radiation-Induced Injury in Bone Marrow and Small Intestine than Male Mice due to Sustained Increases in G-CSF and the Bcl-2/Bax Ratio and Lower miR-34a and MAPK Activation

In nuclear and radiological incidents, overexposure to ionizing radiation is life-threatening. It is evident that radiation depletes blood cells and increases circulating cytokine/chemokine concentrations as well as mortality. While microglia cells of female mice have been observed to be less damaged by radiation than in male mice, it is unclear whether sex affects physio-pathological responses in the bone marrow (BM) and gastrointestinal system (GI). We exposed B6D2F1 male and female mice to 0, 1.5, 3, or 6 Gy with mixed-field radiation containing 67% neutron and 33% gamma at a dose rate of 0.6 Gy/min. Blood and tissues were collected on days 1, 4, and 7 postirradiation. Radiation increased cytokines/chemokines in the femurs and ilea of female and male mice in a dose-dependent manner. Cytokines and chemokines reached a peak on day 4 and declined on day 7 with the exception of G-CSF which continued to increase on day 7 in female mice but not in male mice. MiR-34a (a Bcl-2 inhibitor), G-CSF (a miR-34a inhibitor), MAPK activation (pro-cell death), and citrulline (a biomarker of entro-epithelial proliferation), active caspase-3 (a biomarker of apoptosis) and caspase-1activated gasdermin D (a pyroptosis biomarker) were measured in the sternum, femur BM and ileum. Sternum histopathology analysis with H&E staining and femur BM cell counts as well as Flt-3L showed that BM cellularity was not as diminished in females, with males showing a 50% greater decline on day 7 postirradiation, mainly mediated by pyroptosis as indicated by increased gasdermin D in femur BM samples. Ileum injury, such as villus height and crypt depth, was also 43% and 30%, respectively, less damaged in females than in males. The severity of injury in both sexes was consistent with the citrulline and active caspase-3 measurements as well as active caspase-1 and gasdermin D measurements, suggesting apoptosis and pyroptosis occurred. On day 7, G-CSF in the ileum of female mice continued to be elevated by sevenfold, whereas G-CSF in the ileum of male mice returned to baseline. Furthermore, G-CSF is known to inhibit miR-34a expression, which in ileum on day 1 displayed a 3- to 4-fold increase in female mice after mixed-field (67% neutron + 33% gamma) irradiation, as compared to a 5- to 9-fold increase in male mice. Moreover, miR-34a blocked Bcl-2 expression. Mixed-field (60% neutron + 33% gamma) radiation induced more Bcl-2 in females than in males. On day 7, AKT activation was found in the ileums of females and males. However, MAPK activation including ERK, JNK, and p38 showed no changes in the ileum of females (by 0-fold; P > 0.05), whereas the MAPK activation was increased in the ileum of males (by 100-fold; P < 0.05). Taken together, the results suggest that organ injury from mixed-field (67% neutron + 33% gamma) radiation is less severe in females than in males, likely due to increased G-CSF, less MAPK activation, low miR-34a and increased Bcl-2/Bax ratio.

Therapeutic radiation exposure of the abdomen during childhood induces chronic adipose tissue dysfunction

BACKGROUNDChildhood cancer survivors who received abdominal radiotherapy (RT) or total body irradiation (TBI) are at increased risk for cardiometabolic disease, but the underlying mechanisms are unknown. We hypothesize that RT-induced adipose tissue dysfunction contributes to the development of cardiometabolic disease in the expanding population of childhood cancer survivors.METHODSWe performed clinical metabolic profiling of adult childhood cancer survivors previously exposed to TBI, abdominal RT, or chemotherapy alone, alongside a group of healthy controls. Study participants underwent abdominal s.c. adipose biopsies to obtain tissue for bulk RNA sequencing. Transcriptional signatures were analyzed using pathway and network analyses and cellular deconvolution.RESULTSIrradiated adipose tissue is characterized by a gene expression signature indicative of a complex macrophage expansion. This signature includes activation of the TREM2-TYROBP network, a pathway described in diseases of chronic tissue injury. Radiation exposure of adipose is further associated with dysregulated adipokine secretion, specifically a decrease in insulin-sensitizing adiponectin and an increase in insulin resistance-promoting plasminogen activator inhibitor-1. Accordingly, survivors exhibiting these changes have early signs of clinical metabolic derangement, such as increased fasting glucose and hemoglobin A1c.CONCLUSIONChildhood cancer survivors exposed to abdominal RT or TBI during treatment exhibit signs of chronic s.c. adipose tissue dysfunction, manifested as dysregulated adipokine secretion that may negatively impact their systemic metabolic health.FUNDINGThis study was supported by Rockefeller University Hospital; National Institute of General Medical Sciences (T32GM007739); National Center for Advancing Translational Sciences (UL1 TR001866); National Cancer Institute (P30CA008748); American Cancer Society (133831-CSDG-19-117-01-CPHPS); American Diabetes Association (1-17-ACE-17); and an anonymous donor (MSKCC).

Estimating Absorbed Dose to Breast Adipose Tissue from Mammograms

Purpose

Breast cancer usually originates in the glandular tissue of the breast. However, inflamed adipose tissue surrounding glandular tissue may expedite the local growth of cancerous cells. Exposing adipose tissue to radiation during mammography might cause inflammation in adipose tissue. This inflammation depends on the dose, and thus on the energy deposited from the X-ray mammography. Therefore, estimating the absorbed dose to adipose tissue during mammography is essential in breast cancer research.

Materials and Methods

Absorbed dose to adipose tissue in the breast is determined using a new geometrical (semi-elliptical) model and Monte Carlo N-Particle transport code (MCNP6). X-ray mammogram images of patient breasts were taken as the basis of the new compressed breast geometry. The source probability density used in the MCNP6 code was generated from a published X-ray spectrum corresponding to tube voltage and air kerma. The relationship between various mammogram parameters such as peak tube voltage, compressed breast thickness, and adipose tissue weight fraction versus estimated absorbed dose is established for analysis.

Results

Significant influences of adipose tissue weight fraction on absorbed dose were observed.

Conclusion

Estimating the absorbed dose to breast adipose tissue during mammography and patients' degree of obesity are important factors in breast cancer research.

Adipose-derived stromal cells for nonhealing wounds: Emerging opportunities and challenges

Wound healing complications affect thousands of people each year, thus constituting a profound economic and medical burden. Chronic wounds are a highly complex problem that usually affects elderly patients as well as patients with comorbidities such as diabetes, cancer (surgery, radiotherapy/chemotherapy) or autoimmune diseases. Currently available methods of their treatment are not fully effective, so new solutions are constantly being sought. Cell-based therapies seem to have great potential for use in stimulating wound healing. In recent years, much effort has been focused on characterizing of adipose-derived mesenchymal stromal cells (AD-MSCs) and evaluating their clinical use in regenerative medicine and other medical fields. These cells are easily obtained in large amounts from adipose tissue and show a high proregenerative potential, mainly through paracrine activities. In this review, the process of healing acute and nonhealing (chronic) wounds is detailed, with a special attention paid to the wounds of patients with diabetes and cancer. In addition, the methods and technical aspects of AD-MSCs isolation, culture and transplantation in chronic wounds are described, and the characteristics, genetic stability and role of AD-MSCs in wound healing are also summarized. The biological properties of AD-MSCs isolated from subcutaneous and visceral adipose tissue are compared. Additionally, methods to increase their therapeutic potential as well as factors that may affect their biological functions are summarized. Finally, their therapeutic potential in the treatment of diabetic and oncological wounds is also discussed.

Murine models of clonal hematopoiesis to assess mechanisms of cardiovascular disease

Clonal hematopoiesis (CH) is a phenomenon whereby somatic mutations confer a fitness advantage to hematopoietic stem and progenitor cells (HSPC) and thus facilitate their aberrant clonal expansion. These mutations are carried into progeny leukocytes leading to a situation whereby a substantial fraction of an individual's blood cells originate from the HSPC mutant clone. Although this condition rarely progresses to a hematological malignancy, circulating blood cells bearing the mutation have the potential to affect other organ systems as they infiltrate into tissues under both homeostatic and disease conditions. Epidemiological and clinical studies have revealed that CH is highly prevalent in the elderly and is associated with an increased risk of cardiovascular disease and mortality. Recent experimental studies in murine models have assessed the most commonly mutated "driver" genes associated with CH, and have provided evidence for mechanistic connections between CH and cardiovascular disease. A deeper understanding of the mechanisms by which specific CH mutations promote disease pathogenesis is of importance, as it could pave the way for individualized therapeutic strategies targeting the pathogenic CH gene mutations in the future. Here, we review the epidemiology of CH and the mechanistic work from studies using murine disease models, with a particular focus on the strengths and limitations of these experimental systems. We intend for this review to help investigators select the most appropriate models to study CH in the setting of cardiovascular disease.

Obesity induces gut microbiota alterations and augments acute graft-versus-host disease after allogeneic stem cell transplantation

The efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is limited by acute and chronic graft-versus-host disease (GVHD). The impact of obesity on allo-HSCT outcomes is poorly understood. Here, we report that obesity had a negative and selective impact on acute gut GVHD after allo-HSCT in mice with diet-induced obesity (DIO). These animals exhibited increased gut permeability, endotoxin translocation across the gut, and radiation-induced gastrointestinal damage after allo-HSCT. After allo-HSCT, both male and female DIO mouse recipients showed increased proinflammatory cytokine production and expression of the GVHD marker ST2 (IL-33R) and MHC class II molecules; they also exhibited decreased survival associated with acute severe gut GVHD. This rapid-onset, obesity-associated gut GVHD depended on donor CD4⁺ T cells and occurred even with a minor MHC mismatch between donor and recipient animals. Retrospective analysis of clinical cohorts receiving allo-HSCT transplants from unrelated donors revealed that recipients with a high body mass index (BMI, >30) had reduced survival and higher serum ST2 concentrations compared with nonobese transplant recipients. Assessment of both DIO mice and allo-HSCT recipients with a high BMI revealed reduced gut microbiota diversity and decreased Clostridiaceae abundance. Prophylactic antibiotic treatment protected DIO mouse recipients from endotoxin translocation across the gut and increased inflammatory cytokine production, as well as gut pathology and mortality, but did not protect against later development of chronic skin GVHD. These results suggest that obesity-induced alterations of the gut microbiota may affect GVHD after allo-HSCT in DIO mice, which could be ameliorated by prophylactic antibiotic treatment.

Leptin, Both Bad and Good Actor in Cancer

Leptin is an important regulator of basal metabolism and food intake, with a pivotal role in obesity. Leptin exerts many different actions on various tissues and systems, including cancer, and is considered as a linkage between metabolism and the immune system. During the last decades, obesity and leptin have been associated with the initiation, proliferation and progression of many types of cancer. Obesity is also linked with complications and mortality, irrespective of the therapy used, affecting clinical outcomes. However, some evidence has suggested its beneficial role, called the "obesity paradox", and the possible antitumoral role of leptin. Recent data regarding the immunotherapy of cancer have revealed that overweight leads to a more effective response and leptin may probably be involved in this beneficial process. Since leptin is a positive modulator of both the innate and the adaptive immune system, it may contribute to the increased immune response stimulated by immunotherapy in cancer patients and may be proposed as a good actor in cancer. Our purpose is to review this dual role of leptin in cancer, as well as trying to clarify the future perspectives of this adipokine, which further highlights its importance as a cornerstone of the immunometabolism in oncology.

Chronological flap volume and distribution changes after reconstruction of total maxillectomy defect using a rectus abdominis myocutaneous flap

BACKGROUND/PURPOSE

After total or subtotal maxillectomy, reconstruction using a free rectus abdominis myocutaneous (RAMC) flap is a fundamental and useful option. The purpose of the present study was to clarify the degree of flap volume change and volume distribution change with time after total or subtotal maxillectomy and free RAMC flap reconstruction and to examine the factors affecting the results.

METHODS

A total of 20 patients who underwent total or subtotal maxillectomy with free RAMC flap reconstruction were examined, and the flap volume change rate (volume at final evaluation [POD 181-360] / volume at initial evaluation [POD 5-30]) was investigated using the results of imaging tests. Moreover, the flap was divided into four blocks (A-D) in the cranio-caudal direction, and the volume change of each block was individually analyzed.

RESULTS

The overall volume change rate of fat/muscle/total was 0.84 ± 0.21/0.36 ± 0.08/0.67 ± 0.15, at the mean follow-up period of 309±35 days after the operation. The multiple regression analysis revealed that weight loss (for fat), postoperative RT (for fat and muscle), and young age (for muscle) were independently associated with flap volume loss. The results also indicated that the fat volume was stable, whereas the muscle volume decreased to <40% over time, assuming there were no influencing factors. Regarding flap volume distribution change, the fat volume tended to gather toward the central-cranial direction, while the muscle volume gathered toward the cranial direction, and total flap volume gathered toward the central direction.

Sclerostin antibody increases trabecular bone and bone mechanical properties by increasing osteoblast activity damaged by whole-body irradiation in mice

Irradiation therapy causes bone deterioration and increased risk for skeletal-related events. Irradiation interferes with trabecular architecture through increased osteoclastic activity, decreased osteoblastic activity, and increased adipocyte expansion in the bone marrow (BM), which further compounds bone-related disease. Neutralizing antibodies to sclerostin (Scl-Ab) increase bone mass and strength by increasing bone formation and reducing bone resorption. We hypothesized that treatment with Scl-Ab would attenuate the adverse effects of irradiation by increasing bone volume and decreasing BM adipose tissue (BMAT), resulting in better quality bone. In this study, 12-week-old female C57BL/6J mice were exposed to 6 Gy whole-body irradiation or were non-irradiated, then administered Scl-Ab (25 mg/kg) or vehicle weekly for 5 weeks. Femoral μCT analysis confirmed that the overall effect of IR significantly decreased trabecular bone volume/total volume (Tb.BV/TV) (2-way ANOVA, p < 0.0001) with a -43.8% loss in Tb.BV/TV in the IR control group. Scl-Ab independently increased Tb.BV/TV by 3.07-fold in non-irradiated and 3.6-fold in irradiated mice (2-way ANOVA, p < 0.0001). Irradiation did not affect cortical parameters, although Scl-Ab increased cortical thickness and area significantly in both irradiated and non-irradiated mice (2-way ANOVA, p < 0.0001). Femoral mechanical testing confirmed Scl-Ab significantly increased bending rigidity and ultimate moment independently of irradiation (2-way ANOVA, p < 0.0001). Static and dynamic histomorphometry of the femoral metaphysis revealed osteoblast vigor, not number, was significantly increased in the irradiated mice treated with Scl-Ab. Systemic alterations were assessed through serum lipidomic analysis, which showed that Scl-Ab normalized lipid profiles in the irradiated group. This data supports the theory of sclerostin as a novel contributor to the regulation of osteoblast activity after irradiation. Overall, our data support the hypothesis that Scl-Ab ameliorates the deleterious effects of whole-body irradiation on bone and adipose tissue in a mouse model. Our findings suggest that future research into localized and systemic therapies after irradiation exposure is warranted.

Volume Change of Muscle and Fat Portions of Latissimus Dorsi Myocutaneous Flap after Breast Reconstruction

Background

Myocutaneous flaps are composed of muscle and fat portions, and exhibit volume changes with time. However, no consideration is generally given to volume changes of muscle and fat portions occurring in the flap. Therefore, we conducted this study to analyze the volume changes of muscle and fat portions of pedicled latissimus dorsi myocutaneous flaps over time.

Methods

Sixteen patients who underwent breast reconstruction using a latissimus dorsi myocutaneous flap between 2009 and 2017 were enrolled in this study. Using their postoperative computed tomography scan data, we measured the volume of muscle and fat portions of the flap, and performed a statistical analysis of volume changes over time. We also measured the volume of latissimus dorsi muscle on the opposite side and compared the difference in muscle volume.

Results

The volume of the muscle portion of latissimus dorsi myocutaneous flap decreased by approximately 24%, from 6 months to postoperative year 2; from the third year, it shrank with a decrease rate similar to that of normal muscle. The fat portion of the flap showed no regular volume changes.

Conclusions

Atrophy of the muscle portion is the primary cause of volume change of latissimus dorsi myocutaneous flaps over time. it is necessary to understand the difference in the volume change patterns of the muscle and fat. To maintain a long-term satisfactory result, it is better to make the maximum possible use of the relatively stable fat portion rather than the muscle portion.

Lipodystrophy as a Late Effect after Stem Cell Transplantation

Survivors of childhood cancer are at high risk of developing metabolic diseases in adulthood. Recently, several patients developing partial lipodystrophy following hematopoietic stem cell transplantation (HSCT) have been described. In this review, we summarize the cases described so far and discuss potential underlying mechanisms of the disease. The findings suggest that HSCT-associated lipodystrophies may be seen as a novel form of acquired lipodystrophy.

Breast edema, from diagnosis to treatment: state of the art

Introduction

Breast edema can arise from different etiologies; however, it is mostly seen after breast conserving surgery and/or radiotherapy. Combining breast conserving surgery and radiotherapy can cause damage to the lymphatic system and reactions to surrounding tissues, which can lead to breast edema; hereby, the breast size can increase by more than one cup size. Swelling of the breast is not the only criterion associated with breast edema. Other common criteria found in literature are peau d’orange, heaviness of the breast, skin thickening, breast pain, redness of the skin, hyperpigmented skin pores and a positive pitting sign. Despite the benefits of breast conserving surgery, breast edema can be uncomfortable, and can negatively influence quality of life in suffering patients. In contrast to lymphedema of the arm, which is well known in clinical practice and in research, breast edema is often underestimated and far less explored in literature. Currently, many aspects still need to be reviewed.

Purpose and importance to practice

This masterclass aims at providing the state of the art of breast edema for all health care workers and researchers involved in the treatment and monitoring of breast cancer patients. It includes current and future perspectives on its diagnosis, longitudinal course and treatment. Furthermore, recommendations for clinical practice and future research are discussed.

Clinical implications

It is recommended to closely monitor those patients in whom breast edema symptoms do not decline within 6 months after termination of radiotherapy and provide them with the appropriate therapy. Since evidence concerning the treatment of breast edema is currently lacking, we recommend the complex decongestive therapy (CDT) to the utmost extent, by analogy with the lymphedema treatment of the extremities. This treatment involves skin care, exercise therapy and compression. Additionally, all patients should be informed about the normal course of breast edema development.

Future research priorities

A consensus should be reached among clinicians and researchers concerning the definition, assessment methods and best treatment of breast edema. Furthermore, high quality studies are necessary to prove the effectiveness of the CDT for breast edema.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40945-021-00103-4.

Ionizing radiation-induced circulatory and metabolic diseases

Risks to health are the prime consideration in all human situations of ionizing radiation exposure and therefore of relevance to radiation protection in all occupational, medical, and public exposure situations. Over the past few decades, advances in therapeutic strategies have led to significant improvements in cancer survival rates. However, a wide range of long-term complications have been reported in cancer survivors, in particular circulatory diseases and their major risk factors, metabolic diseases. However, at lower levels of exposure, the evidence is less clear. Under real-life exposure scenarios, including radiotherapy, radiation effects in the whole organism will be determined mainly by the response of normal tissues receiving relatively low doses, and will be mediated and moderated by systemic effects. Therefore, there is an urgent need for further research on the impact of low-dose radiation. In this article, we review radiation-associated risks of circulatory and metabolic diseases in clinical, occupational or environmental exposure situations, addressing epidemiological, biological, risk modelling, and systems biology aspects, highlight the gaps in knowledge and discuss future directions to address these gaps.

[Current review of factors in the stem cell donor that influence the regenerative potential of adipose tissue-derived stem cells]

BACKGROUND

Regenerative therapies like cell-assisted lipotransfer or preclinical experimental studies use adipose tissue-derived stem cells (ASCs) as the main therapeutic agent. But there are also factors depending on the clinical donor that influence the cell yield and regenerative potential of human ASCs and stromal vascular fraction (SVF). Therefore, the aim of this review was to identify and evaluate these factors according to current literature.

METHODS

For this purpose, a systematic literature review was performed with focus on factors affecting the regenerative potential of ASCs and SVF using the National Library of Medicine.

RESULTS

Currently, there is an abundance of studies regarding clinical donor factors influencing ASCs properties. But there is some contradiction and need for further investigation. Nevertheless, we identified several recurrent factors: age, sex, weight, diabetes, lipoedema, use of antidepressants, anti-hormonal therapy and chemotherapy.

CONCLUSION

We recommend characterisation of the ASC donor cohort in all publications, regardless of whether they are experimental studies or clinical trials. By these means, donor factors that influence experimental or clinical findings can be made transparent and results are more comparable. Moreover, this knowledge can be used for study design to form a homogenous donor cohort by precise clinical history and physical examination.

Musashi expression in intestinal stem cells attenuates radiation-induced decline in intestinal permeability and survival in Drosophila

Exposure to genotoxic stress by environmental agents or treatments, such as radiation therapy, can diminish healthspan and accelerate aging. We have developed a Drosophila melanogaster model to study the molecular effects of radiation-induced damage and repair. Utilizing a quantitative intestinal permeability assay, we performed an unbiased GWAS screen (using 156 strains from the Drosophila Genetic Reference Panel) to search for natural genetic variants that regulate radiation-induced gut permeability in adult D. melanogaster. From this screen, we identified an RNA binding protein, Musashi (msi), as one of the possible genes associated with changes in intestinal permeability upon radiation. The overexpression of msi promoted intestinal stem cell proliferation, which increased survival after irradiation and rescued radiation-induced intestinal permeability. In summary, we have established D. melanogaster as an expedient model system to study the effects of radiation-induced damage to the intestine in adults and have identified msi as a potential therapeutic target.

Analysis of the effects of mEHT on the treatment-related toxicity and quality of life of HIV-positive cervical cancer patients

Introduction: HIV infection is associated with increased treatment-related toxicity and worse outcomes in locally advanced cervical cancer patients (LACC), especially in resource-constrained settings. Local control (LC) in a phase III randomized, controlled trial investigating modulated electro-hyperthermia (mEHT) on LACC patients in South Africa (ethics registration: M120477/M190295), was significantly higher in participants randomized to receive chemoradiotherapy (CRT) with mEHT compared to CRT alone (stratum: HIV status, accounting for age and stage). This analysis investigates whether mEHT adds to the toxicity profile of CRT in HIV-positive LACC participants.Methods: Inclusion criteria: signed informed consent; International Federation of Gynecology and Obstetrics stages IIB to IIIB squamous cell carcinoma of the cervix; HIV-positive patients: CD4 count >200 cell/µL/on antiretroviral treatment for >6 months; eligible for CRT with radical intent. Recruitment: January 2014 to November 2017 (ClinicalTrials.gov: NCT03332069). Acute toxicity (evaluated using CTCAE v4 criteria) and quality of life (according to EORTC forms) in 206 participants randomized for treatment were evaluated alongside the LC results to determine safety and efficacy in HIV-positive participants.Results: Compliance to mEHT treatment was high (97% completed ≥8 treatments) with no significant differences in CRT-related toxicity between treatment groups or between HIV-positive and -negative participants. Adverse events attributed to mEHT were minor, even in obese patients, and did not affect CRT compliance. Participants treated with mEHT reported improved fatigue, pain, emotional and cognitive functioning.Conclusion: mEHT did not cause unexpected CRT-related toxicities and is a safe treatment modality for HIV-positive patients, with minor limitations regarding body weight, even in a low-resource setting.

Organoids as Complex In Vitro Models for Studying Radiation-Induced Cell Recruitment

Patients with triple negative breast cancer (TNBC) typically receive chemotherapy, surgery, and radiation therapy. Although this treatment improves prognosis for most patients, some patients continue to experience recurrence within 5 years. Preclinical studies have shown that immune cell infiltration at the irradiated site may play a significant role in tumor cell recruitment; however, little is known about the mechanisms that govern this process. This lack of knowledge highlights the need to evaluate radiation-induced cell infiltration with models that have controllable variables and maintain biological integrity. Mammary organoids are multicellular three-dimensional (3D) in vitro models, and they have been used to examine many aspects of mammary development and tumorigenesis. Organoids are also emerging as a powerful tool to investigate normal tissue radiation damage. In this review, we evaluate recent advances in mammary organoid technology, consider the advantages of using organoids to study radiation response, and discuss future directions for the applications of this technique.

Adipocytes protect fibroblasts from radiation-induced damage by adiponectin secretion

Prostate and colon cancers are among the most common cancers diagnosed annually, and both often require treatment with radiation therapy. Advancement in radiation delivery techniques has led to highly accurate targeting of tumor and sparing of normal tissue; however, in the pelvic region it is anatomically difficult to avoid off-target radiation exposure to other organs. Chronically the effects of normal urogenital tissue exposure can lead to urinary frequency, urinary incontinence, proctitis, and erectile dysfunction. Most of these symptoms are caused by radiation-induced fibrosis and reduce the quality of life for cancer survivors. We have observed in animal models that the severity of radiation-induced fibrosis in normal tissue correlates to damaged fat reservoirs in the pelvic region. We hypothesize that adipocytes may secrete a factor that prevents the induction of radiation-associated fibrosis in normal tissues. In these studies we show that the adipokine, adiponectin, is secreted by primary mouse adipocytes and protects fibroblasts from radiation-induced cell death, myofibroblast formation, and senescence. Further, we demonstrated that adiponectin does not protect colorectal or prostate cancer cells from radiation-induced death. Thus, we propose that adiponectin, or its downstream pathway, would provide a novel target for adjuvant therapy when treating pelvic cancers with radiation therapy.

Therapeutic Reversal of Radiotherapy Injury to Pro-fibrotic Dysfunctional Fibroblasts In Vitro Using Adipose-derived Stem Cells

Cancer patients often require radiotherapy (RTx) to enhance their survival. Unfortunately, RTx also damages nearby healthy non-cancer tissues, leading to progressive fibrotic soft-tissue injury, consisting of pain, contracture, tissue-breakdown, infection, and lymphoedema. Mechanisms underlying the clinically observed ability of fat grafting to ameliorate some of these effects, however, are poorly understood. It was hypothesized that RTx significantly alters fibroblast cell function and the paracrine secretome of adipose-derived stem cells (ADSC) may mitigate these changes.

Methods

To investigate cellular changes resulting in the fibrotic side-effects of RTx, cultured normal human dermal fibroblasts (NHDF) were irradiated (10Gy), then studied using functional assays that reflect key fibroblast functions, and compared with unirradiated controls. RNA-Seq and targeted microarrays (with specific examination of TGFβ) were performed to elucidate altered gene pathways. Finally, conditioned-media from ADSC was used to treat irradiated fibroblasts and model fat graft surgery.

Results

RTx altered NHDF morphology, with cellular functional changes reflecting transition into a more invasive phenotype: increased migration, adhesion, contractility, and disordered invasion. Changes in genes regulating collagen and MMP homeostasis and cell-cycle progression were also detected. However, TGFβ was not identified as a key intracellular regulator of the fibroblast response. Finally, treatment with ADSC-conditioned media reversed the RTx-induced hypermigratory state of NHDF.

Conclusions

Our findings regarding cellular and molecular changes in irradiated fibroblasts help explain clinical manifestations of debilitating RTx-induced fibrosis. ADSC-secretome-mediated reversal indicated that these constituents may be used to combat the devastating side-effects of excessive unwanted fibrosis in RTx and other human fibrotic diseases.

Irradiation impairs mitochondrial function and skeletal muscle oxidative capacity: significance for metabolic complications in cancer survivors

BACKGROUND

Metabolic complications are highly prevalent in cancer survivors treated with irradiation but the underlying mechanisms remain unknown.

METHODS

Chow or high fat-fed C57Bl/6J mice were irradiated (6Gy) before investigating the impact on whole-body or skeletal muscle metabolism and profiling their lipidomic signature. Using a transgenic mouse model (Tg:Pax7-nGFP), we isolated muscle progenitor cells (satellite cells) and characterised their metabolic functions. We recruited childhood cancer survivors, grouped them based on the use of total body irradiation during their treatment and established their lipidomic profile.

RESULTS

In mice, irradiation delayed body weight gain and impaired fat pads and muscle weights. These changes were associated with impaired whole-body fat oxidation in chow-fed mice and altered ex vivo skeletal muscle fatty acid oxidation, potentially due to a reduction in oxidative fibres and reduced mitochondrial enzyme activity. Irradiation led to fasting hyperglycaemia and impaired glucose uptake in isolated skeletal muscles. Cultured satellite cells from irradiated mice showed decreased fatty acid oxidation and reduced glucose uptake, recapitulating the host metabolic phenotype. Irradiation resulted in a remodelling of lipid species in skeletal muscles, with the extensor digitorum longus muscle being particularly affected. A large number of lipid species were reduced, with several of these species showing a positive correlation with mitochondrial enzymes activity. In cancer survivors exposed to irradiation, we found a similar decrease in systemic levels of most lipid species, and lipid species that increased were positively correlated with insulin resistance (HOMA-IR).

CONCLUSION

Irradiation leads to long-term alterations in body composition, and lipid and carbohydrate metabolism in skeletal muscle, and affects muscle progenitor cells. Such changes result in persistent impairment of metabolic functions, providing a new mechanism for the increased prevalence of metabolic diseases reported in irradiated individuals. In this context, changes in the lipidomic signature in response to irradiation could be of diagnostic value.

Lipodystrophic syndromes: From diagnosis to treatment

Lipodystrophic syndromes are acquired or genetic rare diseases, characterised by a generalised or partial lack of adipose tissue leading to metabolic alterations linked to strong insulin resistance. They encompass a variety of clinical entities due to primary defects in adipose differentiation, in the structure and/or regulation of the adipocyte lipid droplet, or due to immune-inflammatory aggressions, chromatin deregulations and/or mitochondrial dysfunctions affecting adipose tissue. Diagnosis is based on clinical examination, pathological context and comorbidities, and on results of metabolic investigations and genetic analyses, which together determine management and genetic counselling. Early lifestyle and dietary measures focusing on regular physical activity and avoiding excess energy intake are crucial. They are accompanied by multidisciplinary follow-up adapted to each clinical form. In case of hyperglycemia, antidiabetic medications, with metformin as a first-line therapy in adults, are used in addition to lifestyle and dietary modifications. When standard treatments have failed to control metabolic disorders, the orphan drug metreleptin, an analog of leptin, can be effective in certain forms of lipodystrophy syndrome. Metreleptin therapy indications, prescription and monitoring were recently defined in France, representing a major improvement in patient care.

Melatonin Modulation of Radiation and Chemotherapeutics-induced Changes on Differentiation of Breast Fibroblasts

Melatonin exerts oncostatic actions and sensitizes tumor cells to chemotherapeutics or radiation. In our study, we investigated the effects of docetaxel, vinorelbine, and radiation on human breast fibroblasts and its modulation by melatonin. Docetaxel or vinorelbine inhibits proliferation and stimulates the differentiation of breast preadipocytes, by increasing C/EBPα and PPARγ expression and by downregulating tumor necrosis factor α (TNFα), interleukin 6 (IL-6), and IL-11 expression. Radiation inhibits both proliferation and differentiation through the downregulation of C/EBPα and PPARγ and by stimulating TNFα expression. In addition, docetaxel and radiation decrease aromatase activity and expression by decreasing aromatase promoter II and cyclooxygenases 1 and 2 (COX-1 and COX-2) expression. Melatonin potentiates the stimulatory effect of docetaxel and vinorelbine on differentiation and their inhibitory effects on aromatase activity and expression, by increasing the stimulatory effect on C/EBPα and PPARγ expression and the downregulation of antiadipogenic cytokines and COX expression. Melatonin also counteracts the inhibitory effect of radiation on differentiation of preadipocytes, by increasing C/EBPα and PPARγ expression and by decreasing TNFα expression. Melatonin also potentiates the inhibitory effect exerted by radiation on aromatase activity and expression by increasing the downregulation of promoter II, and COX-1 and COX-2 expression. Our findings suggest that melatonin modulates regulatory effects induced by chemotherapeutic drugs or radiation on preadipocytes, which makes it a promising adjuvant for chemotherapy and radiotherapy sensibilization.

Challenges in Clinical Development of Mesenchymal Stromal/Stem Cells: Concise Review

Identified 50 years ago, mesenchymal stromal/stem cells (MSCs) immediately generated a substantial interest among the scientific community because of their differentiation plasticity and hematopoietic supportive function. Early investigations provided evidence of a relatively low engraftment rate and a transient benefit for challenging congenital and acquired diseases. The reasons for these poor therapeutic benefits forced the entire field to reconsider MSC mechanisms of action together with their ex vivo manipulation procedures. This phase resulted in advances in MSCs processing and the hypothesis that MSC‐tissue supportive functions may be prevailing their differentiation plasticity, broadening the spectrum of MSCs therapeutic potential far beyond their lineage‐restricted commitments. Consequently, an increasing number of studies have been conducted for a variety of clinical indications, revealing additional challenges and suggesting that MSCs are still lagging behind for a solid clinical translation. For this reason, our aim was to dissect the current challenges in the development of still promising cell types that, after more than half a century, still need to reach their maturity. stem cells translational medicine2019;8:1135–1148

Acquired partial lipodystrophy with metabolic disease in children following hematopoietic stem cell transplantation: a report of two cases and a review of the literature

Hematopoietic stem cell transplantation (HSCT) has been newly identified as an etiology underlying acquired lipodystrophy (ALD). We report about two children with leukemia who underwent HSCT and later manifested aberrant fat distributions consistent with acquired partial lipodystrophy (APL). Both patients manifested graft-versus-host disease (GVHD), suggesting that GVHD may trigger lipodystrophy. The patients exhibited diabetic blood glucose patterns in the oral glucose tolerance test (OGTT) with high homeostasis model assessment ratios (HOMA-Rs), hypertriglyceridemia, fatty liver, and decreased serum leptin and adiponectin levels. Both patients were diagnosed with APL with metabolic disease. A review of the data of patients with ALD after HSCT revealed common clinical features, including aberrant fat distribution, impaired glucose tolerance (IGT) or diabetes and dyslipidemia. Based on previous reports and our two cases, we speculate that GVHD in the adipose tissue supports the development of ALD after HSCT. In conclusion, children may develop APL after HSCT. Therefore, evaluations of fat distribution and metabolic disease may be important during the long-term follow-up of these patients.

Lipodystrophy-like features after total body irradiation among survivors of childhood acute leukemia

BACKGROUND/OBJECTIVE

The number of long-term survivors of childhood acute leukemia (AL) is substantially growing. These patients are at high risk for metabolic syndrome (MS), especially those who received total body irradiation (TBI). The consequences of children's irradiation on adipose tissue (AT) development in adulthood are currently unknown. The objective of this study is to assess the impact of TBI on AT of childhood AL survivors.

DESIGN

We compared the morphological and functional characteristics of AT among survivors of childhood AL who developed MS and received (n = 12) or not received (n = 12) TBI.

SUBJECTS/METHODS

Body fat distribution and ectopic fat stores (abdominal visceral and liver fat) were evaluated by DEXA, MRI and 1H-spectroscopy. Functional characteristics of subcutaneous AT were investigated by studying gene expression and pre-adipocyte differentiation in culture.

RESULTS

Patients who have received TBI exhibited a lower BMI (minus 5 kg/m2) and a lower waist circumference (minus 14 cm), especially irradiated women. Despite the lower quantity of intra-abdominal AT, irradiated patient displayed a nearly two-fold greater content of liver fat when compared to non-irradiated patient (17 vs 9%, P = 0.008). These lipodystrophic-like features are supplemented by molecular abnormalities in subcutaneous AT of irradiated patients: decrease of gene expression of SREBP1 (minus 39%, P = 0.01) and CIDEA (minus 36%, P = 0.004) and a clear alteration of pre-adipocyte differentiation.

CONCLUSIONS

These results strongly support the direct effect of irradiation on AT, especially in women, leading to specific nonalcoholic fatty liver disease, despite lower BMI. A long-term appropriate follow-up is necessary for these patients.

Autologous fat transplantation alters gene expression patterns related to inflammation and hypoxia in the irradiated human breast

BACKGROUND

Radiation-induced fibrosis, an adverse effect of breast cancer treatment, is associated with functional and cosmetic impairment as well as surgical complications. Clinical reports suggest improvement following autologous fat transplantation, but the mechanisms underlying this effect are unknown. A global gene expression analysis was undertaken to identify genetic pathways dysregulated by radiation and evaluate the impact of autologous fat transplantation on gene expression.

METHODS

Adipose tissue biopsies were taken synchronously from irradiated and contralateral non-irradiated breasts, before and 1 year after autologous fat transplantation. Whole-genome gene expression analyses were performed, and Hallmark gene set analysis used to explore the effect of radiotherapy and autologous fat transplantation on gene expression.

RESULTS

Forty microarrays were analysed, using bilateral biopsies taken from ten patients before and after autologous fat transplantation. Forty-five pathways were identified among the 3000 most dysregulated transcripts after radiotherapy in irradiated compared with non-irradiated breast (P ≤ 0·023; false discovery rate (FDR) no higher than 0·026). After autologous fat transplantation, 575 of the 3000 genes were again altered. Thirteen pathways (P ≤ 0·013; FDR 0·050 or less) were identified; the top two canonical pathways were interferon-γ response and hypoxia. Correlative immunohistochemistry showed increased macrophage recruitment in irradiated tissues.

CONCLUSION

The present findings contribute to understanding of how autologous fat transplantation can ameliorate radiation-induced fibrosis. This further supports the use of autologous fat transplantation in the treatment of radiation-induced fibrosis. Surgical relevance Clinical studies have indicated that autologous fat transplantation (AFT) stimulates regression of chronic inflammation and fibrosis caused by radiotherapy in skin and subcutaneous fat. However, there is a paucity of biological evidence and the underlying processes are poorly understood. Human data are scarce, whereas experimental studies have focused mainly either on the effect of irradiation or AFT alone. The present results indicate that radiotherapy causes dysregulated gene expression in fibrosis-related pathways in adipose tissues in humans. They also show that AFT can cause a reversal of this, with several dysregulated genes returning to nearly normal expression levels. The study provides biological evidence for the impact of AFT on radiation-induced dysregulated gene expression in humans. It supports the use of AFT in the treatment of radiation-induced fibrosis, associated with severe morbidity and surgical challenges.

Spred2 Regulates High Fat Diet-Induced Adipose Tissue Inflammation, and Metabolic Abnormalities in Mice

Chronic low-grade inflammation in visceral adipose tissues triggers the development of obesity-related insulin resistance, leading to the metabolic syndrome, a serious health condition with higher risk of cardiovascular disease, diabetes, and stroke. In the present study, we investigated whether Sprouty-related EVH1-domain-containing protein 2 (Spred2), a negative regulator of the Ras/Raf/ERK/MAPK pathway, plays a role in the development of high fat diet (HFD)-induced obesity, adipose tissue inflammation, metabolic abnormalities, and insulin resistance. Spred2 knockout (KO) mice, fed with HFD, exhibited an augmented body weight gain, which was associated with enhanced adipocyte hypertrophy in mesenteric white adipose tissue (mWAT) and deteriorated dyslipidemia, compared with wild-type (WT) controls. The number of infiltrating macrophages with a M1 phenotype, and the crown-like structures, composed of macrophages surrounding dead or dying adipocytes, were more abundant in Spred2 KO-mWAT compared to in WT-mWAT. Exacerbated adipose tissue inflammation in Spred2 KO mice led to aggravated insulin resistance and fatty liver disease. To analyze the mechanism(s) that caused adipose tissue inflammation, cytokine response in mWAT was investigated. Stromal vascular fraction that contained macrophages from Spred2 KO-mWAT showed elevated levels of tumor necrosis factor α (TNFα) and monocyte chemoattractant protein-1 (MCP-1/CCL2) compared with those from WT-mWAT. Upon stimulation with palmitate acid (PA), bone marrow-derived macrophages (BMDMs) derived from Spred2 KO mice secreted higher levels of TNFα and MCP-1 than those from WT mice with enhanced ERK activation. U0126, a MEK inhibitor, reduced the PA-induced cytokine response. Taken together, these results suggested that Spred2, in macrophages, negatively regulates high fat diet-induced obesity, adipose tissue inflammation, metabolic abnormalities, and insulin resistance by inhibiting the ERK/MAPK pathway. Thus, Spred2 represents a potential therapeutic tool for the prevention of insulin resistance and resultant metabolic syndrome.

Impact of X-ray Exposure on the Proliferation and Differentiation of Human Pre-Adipocytes

Radiotherapy is a widely used treatment option for cancer patients as well as for patients with musculoskeletal disorders. Adipocytes, the dominant cell type of adipose tissue, are known to constitute an active part of the tumor microenvironment. Moreover, adipocytes support inflammatory processes and cartilage degradation in chronic inflammatory diseases, i.e., rheumatoid and osteoarthritis. Since the production of inflammatory factors is linked to their differentiation stages, we set out to explore the radiation response of pre-adipocytes that may influence their inflammatory potential and differentiation capacity. This is the first study investigating the effects of X-ray irradiation on the proliferation and differentiation capacity of human primary pre-adipocytes, in comparison to Simpson–Golabi–Behmel Syndrome (SGBS) pre-adipocytes, an often-used in vitro model of human primary pre-adipocytes. Our results demonstrate a dose-dependent reduction of the proliferation capacity for both cell strains, whereas the potential for differentiation was mostly unaffected by irradiation. The expression of markers of adipogenic development, such as transcription factors (PPARγ, C/EBPα and C/EBPβ), as well as the release of adipokines (visfatin, adiponectin and leptin) were not significantly changed upon irradiation. However, after irradiation with high X-ray doses, an increased lipid accumulation was observed, which suggests a radiation-induced response of adipocytes related to inflammation. Our results indicate that pre-adipocytes are radio-resistant, and it remains to be elucidated whether this holds true for the overall inflammatory response of adipocytes upon irradiation.

Platelet-rich plasma enhances the proliferation of human adipose stem cells through multiple signaling pathways

BACKGROUND

Platelet-rich plasma (PRP) is an autologous blood product that contains a high concentration of several growth factors. Platelet-derived growth factor (PDGF)-BB is a potential mitogen for human adipose-derived stem cells (hASCs). PRP stimulates proliferation of hASCs; however, the signaling pathways activated by PRP remain unclear.

METHODS

hASCs were cultured with or without PRP or PDGF-BB, and proliferation was assessed. hASCs were also treated with PRP or PDGF-BB with or without imatinib, which is a PDGF receptor tyrosine kinase inhibitor, or sorafenib, which is a multikinase inhibitor. Inhibition of cell proliferation was examined using anti-PDGF antibody (Abcam, Cambridge, UK), by cell counting. We assessed the effects of inhibitors of various protein kinases such as ERK1/2, JNK, p38, and Akt on the proliferation of hASCs.

RESULTS

The proliferation was remarkably promoted in cells treated with either 1% PRP or 10 ng/ml PDGF-BB, and both imatinib and sorafenib inhibited this proliferation. Anti-PDGF antibody (0.5 and 2 μg/ml) significantly decreased the proliferation of hASCs compared with control. PRP-mediated hASC proliferation was blocked by inhibitors of ERK1/2, Akt, and JNK, but not by an inhibitor of p38.

CONCLUSIONS

PRP promotes hASC proliferation, and PDGF-BB in PRP plays a major role in inducing the proliferation of hASCs. PRP promotes hASC proliferation via ERK1/2, PI3K/Akt, and JNK signaling pathways.

Prevalence and characteristics of metabolic syndrome in adults from the French childhood leukemia survivors' cohort: a comparison with controls from the French population

The prevalence of the metabolic syndrome among adults from the French LEA childhood acute leukemia survivors' cohort was prospectively evaluated considering the type of anti-leukemic treatment received, and compared with that of controls. The metabolic profile of these patients was compared with that of controls. A total of 3203 patients from a French volunteer cohort were age- and sex-matched 3:1 to 1025 leukemia survivors (in both cohorts, mean age: 24.4 years; females: 51%). Metabolic syndrome was defined according to the National Cholesterol Education Program's Adult Treatment Panel III criteria. Metabolic syndrome was found in 10.3% of patients (mean follow-up duration: 16.3±0.2 years) and 4.5% of controls, (OR=2.49; P<0.001). Patients transplanted with total body irradiation presented the highest risk (OR=6.26; P<0.001); the other treatment groups also showed a higher risk than controls, including patients treated with chemotherapy only. Odd Ratios were 1.68 (P=0.005) after chemotherapy only, 2.32 (P=0.002) after chemotherapy and cranial irradiation, and 2.18 (P=0.057) in patients transplanted without irradiation. Total body irradiation recipients with metabolic syndrome displayed a unique profile compared with controls: smaller waist circumference (91 vs 99.6 cm; P=0.01), and increased triglyceride levels (3.99 vs 1.5 mmol/L; P<0.001), fasting glucose levels (6.2 vs 5.6 mmol/L; P=0.049), and systolic blood pressure (137.9 vs 132.8 mmHg; P=0.005). By contrast, cranial irradiation recipients with metabolic syndrome had a larger waist circumference (109 vs 99.6 cm; P=0.007) than controls. Regardless of the anti-leukemic treatment, metabolic syndrome risk was higher among childhood leukemia survivors. Its presentation differed depending on the treatment type, thus suggesting a divergent pathophysiology. This study is registered at clinicaltrials.gov identifier: 01756599.

Total body irradiation tremendously impair the proliferation, differentiation and chromosomal integrity of bone marrow-derived mesenchymal stromal stem cells

Total body irradiation (TBI) is frequently used in hematopoietic stem cell transplantation (HSCT) and is associated with many complications due to radiation injury to the normal cells, including normal stem cells. Nevertheless, the effects of TBI on the mesenchymal stromal stem cell (MSC) are not fully understood. Bone marrow-derived MSCs (BM-MSCs) isolated from normal adults were irradiated with 200 cGy twice daily for consecutive 3 days, a regimen identical to that used in TBI-conditioning HSCT. The characteristics, differentiation potential, cytogenetics, hematopoiesis-supporting function, and carcinogenicity of the irradiated BM-MSCs were then compared to the non-irradiated control. The irradiated and non-irradiated MSCs shared similar morphology, phenotype, and hematopoiesis-supporting function. However, irradiated MSCs showed much lower proliferative and differentiative potential. Irradiation also induced clonal cytogenetic abnormalities of MSCs. Nevertheless, the carcinogenicity of irradiated MSCs is low in vitro and in vivo. In parallel with the ex vivo irradiation experiments, decreased proliferative and differentiative abilities and clonal cytogenetic abnormalities can also be found in MSCs isolated from transplant recipients who had received TBI-based conditioning previously. Thus, TBI used in HSCT drastically injury MSCs and may contribute to the development of some long-term complications associated with clonal cytogenetic abnormality and poor adipogenesis and osteogenesis after TBI.

The SOD Mimic, MnTE-2-PyP, Protects from Chronic Fibrosis and Inflammation in Irradiated Normal Pelvic Tissues

Pelvic radiation for cancer therapy can damage a variety of normal tissues. In this study, we demonstrate that radiation causes acute changes to pelvic fibroblasts such as the transformation to myofibroblasts and the induction of senescence, which persist months after radiation. The addition of the manganese porphyrin, MnTE-2-PyP, resulted in protection of these acute changes in fibroblasts and this protection persisted months following radiation exposure. Specifically, at two months post-radiation, MnTE-2-PyP inhibited the number of α-smooth muscle actin positive fibroblasts induced by radiation and at six months post-radiation, MnTE-2-PyP significantly reduced collagen deposition (fibrosis) in the skin and bladder tissues of irradiated mice. Radiation also resulted in changes to T cells. At two months post-radiation, there was a reduction of Th1-producing splenocytes, which resulted in reduced Th1:Th2 ratios. MnTE-2-PyP maintained Th1:Th2 ratios similar to unirradiated mice. At six months post-radiation, increased T cells were observed in the adipose tissues. MnTE-2-PyP treatment inhibited this increase. Thus, MnTE-2-PyP treatment maintains normal fibroblast function and T cell immunity months after radiation exposure. We believe that one of the reasons MnTE-2-PyP is a potent radioprotector is due to its protection of multiple cell types from radiation damage.

Cellular Therapies for Treatment of Radiation Injury: Report from a NIH/NIAID and IRSN Workshop

In recent years, there has been increasing concern over the possibility of a radiological or nuclear incident occurring somewhere in the world. Intelligence agencies frequently report that terrorist groups and rogue nations are seeking to obtain radiological or nuclear weapons of mass destruction. In addition, there exists the real possibility that safety of nuclear power reactors could be compromised by natural (such as the tsunami and subsequent Fukushima accident in Japan in March, 2011) or accidental (Three Mile Island, 1979 and Chernobyl, 1986) events. Although progress has been made by governments around the world to prepare for these events, including the stockpiling of radiation countermeasures, there are still challenges concerning care of patients injured during a radiation incident. Because the deleterious and pathological effects of radiation are so broad, it is desirable to identify medical countermeasures that can have a beneficial impact on several tissues and organ systems. Cellular therapies have the potential to impact recovery and tissue/organ regeneration for both early and late complications of radiation exposure. These therapies, which could include stem or blood progenitor cells, mesenchymal stromal cells (MSCs) or cells derived from other tissues (e.g., endothelium or placenta), have shown great promise in treating other nonradiation injuries to and diseases of the bone marrow, skin, gastrointestinal tract, brain, lung and heart. To explore the potential use of these therapies in the treatment of victims after acute radiation exposure, the National Institute of Allergy and Infectious Diseases co-sponsored an international workshop in July, 2015 in Paris, France with the Institut de Radioprotection et de Sûreté Nucléaire. The workshop included discussions of data available from testing in preclinical models of radiation injury to different organs, logistics associated with the practical use of cellular therapies for a mass casualty incident, as well as international regulatory requirements for authorizing such drug products to be legally and readily used in such incidents. This report reviews the data presented, as well as key discussion points from the meeting.

BMT decreases HFD-induced weight gain associated with decreased preadipocyte number and insulin secretion

Experimental bone marrow transplantation (BMT) in mice is commonly used to assess the role of immune cell-specific genes in various pathophysiological settings. The application of BMT in obesity research is hampered by the significant reduction in high-fat diet (HFD)-induced obesity. We set out to characterize metabolic tissues that may be affected by the BMT procedure and impair the HFD-induced response. Male C57BL/6 mice underwent syngeneic BMT using lethal irradiation. After a recovery period of 8 weeks they were fed a low-fat diet (LFD) or HFD for 16 weeks. HFD-induced obesity was reduced in mice after BMT as compared to HFD-fed control mice, characterized by both a reduced fat (-33%; p<0.01) and lean (-11%; p<0.01) mass, while food intake and energy expenditure were unaffected. As compared to control mice, BMT-treated mice had a reduced mature adipocyte volume (approx. -45%; p<0.05) and reduced numbers of preadipocytes (-38%; p<0.05) and macrophages (-62%; p<0.05) in subcutaneous, gonadal and visceral white adipose tissue. In BMT-treated mice, pancreas weight (-46%; p<0.01) was disproportionally decreased. This was associated with reduced plasma insulin (-68%; p<0.05) and C-peptide (-37%; p<0.01) levels and a delayed glucose clearance in BMT-treated mice on HFD as compared to control mice. In conclusion, the reduction in HFD-induced obesity after BMT in mice is at least partly due to alterations in the adipose tissue cell pool composition as well as to a decreased pancreatic secretion of the anabolic hormone insulin. These effects should be considered when interpreting results of experimental BMT in metabolic studies.

Partial lipodystrophy in patients who have undergone hematopoietic stem cell transplantation during childhood: an institutional cross-sectional survey

Partial lipodystrophy (PD), a condition similar to metabolic syndrome without obesity, is one of the late complications of hematopoietic stem cell transplantation (HSCT) performed during childhood. We aimed to investigate the prevalence and risk factors of PD. A cross-sectional survey was performed in a children’s hospital, targeting patients treated for a malignancy or hematological disorder, and who were disease-free for > 24 mo. PD was defined as gluteal lipoatrophy and lipohypertrophy of the cheeks or neck associated with diabetes and/or fatty liver disease. In total, 65 patients were enrolled. Six patients (9.2%) were judged to have PD, all of whom had received 10–14 Gy total body irradiation. Compared with the patients without PD, patients with PD were older at investigation (P < 0.01), had a longer elapsed time following HSCT (P < 0.01), had more frequent disease recurrence (P < 0.05), and were more likely to have undergone multiple HSCT (P < 0.05). In addition, they had higher blood pressure and showed higher levels of low-density lipoprotein-cholesterol and triglycerides, whereas their adiponectin levels were significantly lower. In conclusion, a large number of patients developed PD following HSCT, with unfavorable metabolic profiles at a later age, especially when they experienced a complex disease course.