Focal Damage Research Articles

Abstract TP297: Focused Mouse Brain Irradiation Model to Define the Neurovascular Unit

Purpose: This project aimed to develop a stereotactic radiosurgery mouse model of radiation-induced brain injury to study endothelial damage within the neurovascular unit (NVU). Classification of focal endothelial damage and the resulting inflammatory cascade has never been cataloged for assessing intrinsic changes versus extrinsic factors of inflammation at the NVU. The study of endothelial damage with invasive models, such as open transcranial injury or vessel occlusion, introduces multiple variables into the system that our model can help overcome to study secondary or systemic insults of the NVU. Methods: Using an X-ray image-guided radiation therapy system, mice were focally irradiated with 30, 45, and 70 Gy to a 5 mm brain target. Mice were followed up at 2, 4, 6, 12 and 18 weeks after irradiation with contrast-enhanced CT imaging for volumetric quantification of radiation effects. Brains were harvested for characterization by histology and immune-multiplexing of reactionary and inflammatory changes to the NVU. Whole coronal slides were scanned and analyzed using machine learning classifiers to quantify cell types within the NVU in the radiated vs. control hemispheres. Results: Radiation-induced changes such as telangiectasias, vessel hyalinization, and white matter necrosis were observed. An inflammatory response with a predominance of T cells was observed, as well as an increase in microglial cells and reactive astrogliosis. These changes were time and dose-dependent after radiation. Serial CTs allowed for determining the development of radiation damage, and the contrast enhancement was proportional to the degree of radiation-induced changes. Conclusions: This radiation model allows precise image-guided targeting with a steep radiation fall-off into surrounding tissues. The NVU’s response to focal insult of endothelial damage presents a novel method of brain injury to specifically study diseases associated with endothelial dysfunction.

Ex vivo radiation sensitivity assessment for individual head and neck cancer patients using deep learning-based automated nuclei and DNA damage foci detection

IntroductionTumor biopsy tissue response to ex vivo irradiation is potentially an interesting biomarker for in vivo tumor response, therefore, for treatment personalization. Tumor response ex vivo can be characterized by DNA damage response, expressed by the large-scale presence of DNA damage foci in tumor nuclei. Currently, characterizing tumor nuclei and DNA damage foci is a manual process that takes hours per patient and is subjective to inter-observer variability, which is not feasible in for clinical decision making. Therefore, our goal was to develop a method to automatically segment nuclei and DNA damage foci in tumor tissue samples treated with radiation ex vivo to characterize the DNA damage response, as potential biomarker for in vivo radio-sensitivity. MethodsOral cavity tumor tissue of 21 patients was irradiated ex vivo (5 or 0 Gy), fixated 2 h post-radiation, and used to develop our method for automated nuclei and 53BP1 foci segmentation. The segmentation model used both deep learning and conventional image-analysis techniques. The training (22 %), validation (22 %), and test set (56 %) consisted of thousands of manually segmented nuclei and foci. The segmentations and number of foci per nucleus in the test set were compared to their ground truths. ResultsThe automatic nuclei and foci segmentations were highly accurate (Dice = 0.901 and Dice = 0.749, respectively). An excellent correlation (R2 = 0.802) was observed for the foci per nucleus that outperformed reported inter-observation variation. The analysis took ∼ 8 s per image. ConclusionThis model can replace manual foci analysis for ex vivo irradiation of head-and-neck squamous cell carcinoma tissue, reduces the image-analysis time from hours to minutes, avoids the problem of inter-observer variability, enables assessment of multiple images or conditions, and provides additional information about the foci size. Thereby, it allows for reliable and rapid ex vivo radio-sensitivity assessment, as potential biomarker for response in vivo and treatment personalization.

FLIP(C1orf112)-FIGNL1 complex regulates RAD51 chromatin association to promote viability after replication stress

Homologous recombination (HR) plays critical roles in repairing lesions that arise during DNA replication and is thus essential for viability. RAD51 plays important roles during replication and HR, however, how RAD51 is regulated downstream of nucleofilament formation and how the varied RAD51 functions are regulated is not clear. We have investigated the protein c1orf112/FLIP that previously scored in genome-wide screens for mediators of DNA inter-strand crosslink (ICL) repair. Upon ICL agent exposure, FLIP loss leads to marked cell death, elevated chromosomal instability, increased micronuclei formation, altered cell cycle progression and increased DNA damage signaling. FLIP is recruited to damage foci and forms a complex with FIGNL1. Both proteins have epistatic roles in ICL repair, forming a stable complex. Mechanistically, FLIP loss leads to increased RAD51 amounts and foci on chromatin both with or without exogenous DNA damage, defective replication fork progression and reduced HR competency. We posit that FLIP is essential for limiting RAD51 levels on chromatin in the absence of damage and for RAD51 dissociation from nucleofilaments to properly complete HR. Failure to do so leads to replication slowing and inability to complete repair.

Mesenchymal Stem Cell-Induced Neuroprotection in Pediatric Neurological Diseases: Recent Update of Underlying Mechanisms and Clinical Utility.

Pediatric neurological diseases refer to a group of disorders that affect the nervous system in children. These conditions can have a significant impact on a child's development, cognitive function, motor skills, and overall quality of life. Stem cell therapy is a new and innovative approach to treat various neurological conditions by repairing damaged neurons and replacing those that have been lost. Mesenchymal stem cells (MSCs) have gained significant recognition in this regard due to their ability to differentiate into different cell types. MSCs are multipotent self-replicating stem cells known to render promising results in the treatment of stroke and spinal cord injury in adults. When delivered to the foci of damage in the central nervous system, stem cells begin to differentiate into neural cells under the stimulation of paracrine factors and secrete various neurotrophic factors (NTFs) like nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) that expedite the repair process in injured neurons. In the present review, we will focus on the therapeutic benefits of the MSC-based therapies in salient pediatric neurological disorders including cerebral palsy, stroke, and autism.

Abstract A022: Poly (ADP-Ribose) glycohydrolase (PARG) removes repressive Poly-ADP Ribose marks from DNA polymerase theta (polq) to stimulate DNA double-strand breaks repair in myeloid malignancies

Abstract Poly (ADP-ribose) polymerase 1 (PARP1) dependent poly-(ADP)-ribosylation (PARylation) of proteins is one of the major post-translational modification events involved in the DNA damage response (DDR). PARylation is tightly controlled by the glycohydrolase activity of poly (ADP-ribose) glycohydrolase (PARG). Thus, interplay between PARP1 and PARG is thought to regulate the PARylation status of relevant DDR proteins and multiple studies demonstrated that both PARP1 and PARG contribute to DDR. Here, we investigated whether the interplay of PARP1 and PARG is important for the regulation of TMEJ and the specific activities of Polq in myeloid malignancies harboring OTKs. We found that upon DNA damage OTKs exerted temporal effect on Polq, PARP1 and PARG detection in chromatin fractions. While both Polq and PARG displayed continuous time-dependent accumulation during 120 min. after irradiation, PARP1 levels sharply increased at 20 min. and dissipated at 120 min. post-irradiation confocal microscopy detected spatiotemporal changes of Polq - PARP1 – PARG colocalization and PARylation of Polq. Polq - PARP1 interaction and PARylation of Polq was detected early followed by dissipation of that interaction and enhanced colocalization of Polq and PARG and dePARylation of Polq. At the time when Polq was PARylated by PARP1, it was not detected at DSBs marked by gH2AX whereas PARG-mediated dePARylation of Polq was associated with its colocalization with DSBs. We find that PARP1 binds to and directly PEGylates Polq in vitro and in cells. Biochemical assays revealed that PARP1 recruits Polq to the vicinity of DNA damage via PARylation-dependent formation of biomolecular condensates containing Polq. However, PARylated Polq is unable to perform TMEJ due to its inability to bind directly to DNA. Hence, PARG is needed to reactivate Polq DNA binding and its TMEJ activity by removing repressive PAR marks on Polq. In support of this, cellular studies show that PARP1-PARG – regulated spatiotemporal recruitment of Polq to DSBs is essential for TMEJ activity. In conclusion, using intracellular and biochemical approaches we show here that both PARP1 and PARG are required for TMEJ despite their counteracting enzymatic activities. We also pinpointed a unique dynamic spatiotemporal interplay between Polq, PARP1 and PARG to regulate TMEJ activity in OTK-positive myeloid malignant cells. Our studies support a two-step mechanism of a PARP1-PARG regulatory axis of Polq and TMEJ. In the first step, the rate of PARP1-Polq spatiotemporal recruitment to DNA damage foci supports a rapid step whereby PARP1 PARylates Polq and facilitates its recruitment to the vicinity of DNA damage in an inactive state. The rate of PARG spatiotemporal recruitment supports a second step whereby subsequent recruitment of PARG corresponds to dissipation of PARP1 and PAR at DNA damage sites, PARG-mediated removal of PAR repressive marks on Polq, and activation of TMEJ. Citation Format: Umeshkumar Vekariya, Leonid Minakhin, Mrityunjay Tyagi, Tatiana Kent, Gurushankar Chandramouly, Katherine Sullivan-Reed, Jessica Atkins, Margaret Nieborowska-Skorska, Anna-Mariya Kukuyan, Richard Pomerantz, Tomasz Skorski. Poly (ADP-Ribose) glycohydrolase (PARG) removes repressive Poly-ADP Ribose marks from DNA polymerase theta (polq) to stimulate DNA double-strand breaks repair in myeloid malignancies [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr A022.

Drawing improves memory in patients with hippocampal damage.

The hippocampus plays a critical role in the formation of declarative memories, and hippocampal damage leads to significant impairments in new memory formation. Drawing can serve as a form of multi-modal encoding that improves declarative memory performance relative to other multimodal encoding strategies such as writing. We examined whether, and to what extent, patients with hippocampal damage could benefit from the mnemonic strategy of drawing. Three patients with focal hippocampal damage, and one patient with both hippocampal and cortical lesions, in addition to 22 age-, sex-, and education-matched controls, were shown a list of words one at a time during encoding and instructed to either draw a picture or repeatedly write each word for 40 s. Following a brief filled delay, free recall and recognition memory for words from both encoding trial types were assessed. Controls showed enhanced recall and recognition memory for words drawn versus those that were written, an effect that was even more pronounced in patients with focal hippocampal damage. By contrast, the patient with both hippocampal and cortical lesions showed no drawing-mediated boost in either recall or recognition memory. These findings demonstrate that drawing is an effective encoding strategy, likely accruing from the engagement of extra-hippocampal processes including the integration of cortical-based motor, visual, and semantic processing, enabling more elaborative encoding.

The central vein sign in the differential diagnosis of multiple sclerosis

To carry out a clinical and radiological assessment of the central vein sign (CVS) as a diagnostic marker for multiple sclerosis (MS) and other demyelinating and non-demyelinating diseases with focal brain damage, using clinical and laboratory examination data, as well as MRI. The results of clinical and neuroradiological examination of 107 patients diagnosed with MS or with other diseases accompanied by focal brain damage according to MRI data were analyzed. CVS is a sensitive but low-specific diagnostic marker of MS. According to our data, the sensitivity and specificity of 40 and 50% of the threshold of perivenular lesions in the diagnosis of MS are the same and amount to 100% and 39.4%, respectively. Neither the type of MS course, nor the severity of the course, nor the intake of DMT (disease modifying treatment), affect the proportion of foci with CVS. The spread of the proportion of foci with CVS in patients with MS was 60-100%. The proportion of foci with CVS is below 40 and 50% of the threshold in patients with demyelinating and non-demyelinating diseases (NMOSD, migraine, systemic lupus erythematosus, Susak disease, CLIPPERS), which allows for differential diagnosis with MS. The proportion of foci with CVS comparable to MS in patients with acute disseminated encephalomyelitis, small vessel disease, as well as in patients with radiologically isolated syndrome does not allow using this symptom in the differential diagnosis of these conditions. The use of CVS as a diagnostic marker of MS is possible only in combination with the already existing diagnostic criteria of MS.

Mechanism of exacerbation of traumatic brain injury under warfarin anticoagulation in male mice.

Traumatic brain injury (TBI) is exacerbated in patients on antithrombotic medications, with warfarin leading to increased bleeding in some cases. However, the extent to which this bleeding increases lethality and its long-term effects remain unclear. This study aimed to investigate the exacerbation of TBI by warfarin treatment and comprehensively evaluate the impact of TBI on the anticoagulant effects of warfarin. We induced TBI in mice after pre-treatment with warfarin and analyzed TBI exacerbation based on the prothrombin time-international normalized ratio (PT-INR) value, brain hemorrhage volume, blood warfarin and 7-hydroxywarfarin levels, and cytochrome P450 2C9 (CYP2C9) protein expression. C57BL/6J mice fed with a vitamin K-deficient diet received oral warfarin (low dose, 0.35 mg/kg/24 h; high dose, 0.70 mg/kg/24 h), and focal brain damage was induced in the cerebral cortices using a brain contusion device. Warfarin-treated injured mice were compared with sham-treated mice (scalp incision alone or scalp incision + bone window formation). When warfarin was administered, the PT-INR value and brain hemorrhage volume associated with cerebral contusion increased on the first day post-injury. High blood warfarin and 7-hydroxywarfarin levels were observed. However, no significant differences in CYP2C9 expression were observed between the groups. Elevated warfarin levels post-injury can increase cerebral hemorrhage risk, possibly worsening TBI. TBI might also elevate warfarin levels, heightening its anticoagulant effects. Therefore, assessing injury severity levels and PT-INR values in patients with TBI on warfarin is crucial to anticipate delayed bleeding risks.

Neighborhood effects on tree growth in a Fagus sylvatica - Abies alba forest following an ice storm

Ice storms can cause substantial damage to tree crowns and lead to growth reduction. However, in uneven-aged stands, the growth of an individual tree may also increase due to crown release caused by the damage or mortality of neighboring trees. Three years after the devastating ice storm in 2014 in mixed uneven-aged Dinaric forests (Croatia), we cored 156 European beech (Fagus sylvatica) and 85 silver fir (Abies alba) trees across 20 permanent sample plots to study the post-storm growth response as a function of tree, stand, site, spatial arrangement and local competition factors. The ice storm damaged over 84% of trees on the sampled plots. Among the cored trees, 52.7% exhibited growth reduction, which on average amounted to −3.1% relative to the pre-disturbance average. Trees with less than 40% crown damage maintained their pre-disturbance growth rates or experienced only minor growth suppression. While 60% of beech trees suffered a growth reduction at an average rate of −7.2%, the average radial increment of fir after the storm was 14.0% higher compared to the pre-storm rate. A linear mixed-effects model suggests that the growth response can largely be explained by the focal and neighboring tree species identity, tree competition pressure, focal and neighboring tree damage, crown size, slenderness index and stoniness. Growth release was positively associated with fir, inverse distance-weighted crown damage of the nearest neighbor, shorter crowns, slenderness, less stony sites and less damaged trees. The analysis suggests that at the same level of local competition load, trees with a broadleaved and damaged nearest neighbor are more likely to experience growth release than those with a coniferous or undamaged nearest neighbor. This implies that uneven-aged stands with a substantial presence and mingling of both conifers and broadleaves are expected to be more resilient to ice storms and are less likely to suffer growth reduction.

Histological and ultrastructural analysis of biopsy specimens of donor heart under conditions of extended period of pharmaco-cold ischaemia

At the histological and ultramicroscopic level, compare biopsy specimens of donor heart under standard (up to 240 min) and extended (more than 240 min) periods of pharmaco-cold preservation. Biopsy specimens of the left atrium of donor hearts: group 1 - 8 samples after transportation with pharmaco-cold preservation of the graft in Bretschneider solution (Dr. Franz Köhler Chemie GmbH, Germany) up to 240 min, (Me 140), and group 2 - 5 samples after an extended pharmaco-cold period (more than 240 min; Me 375) were examined using light microscopy of semi-thin sections and transmission electron microscopy, followed by stereological and statistical analysis. A comparative study of the myocardium of donor hearts revealed stereotypical dystrophic changes in cardiomyocytes. Semi-thin sections demonstrated a mosaic pattern of myocardial parenchyma in both groups, caused by contracture and less pronounced lytic changes in myocytes, which were accompanied by stromal edema without statistically significant differences according to stereological studies. Ultrathin sections of the perinuclear zones of cardiomyocytes visualized reduction and focal damage to myofibrils and mitochondria in combination with pronounced autophagy; at the same time, with a shorter duration of the pharmaco-cold period, the stereological indicators of cardiomyocyte organelles indicated a relatively better supply of myofibrils with mitochondria. The results obtained suggest a sufficiently high degree of preservation of the tissue and ultrastructural organization of donor hearts with prolonged (more than 240 min) pharmaco-cold ischemia to restore adequate cardiac activity after heart transplantation.

Quantitative analysis of nuclear deformations and DNA damage foci dynamics by live-cell imaging.

The correct repair of DNA Double Strand Breaks (DSBs) is fundamental to prevent the loss of genetic information, mutations, and chromosome rearrangements. An emerging determinant of DNA repair is chromatin mobility. However, how chromatin mobility can influence DSBs repair is still poorly understood. While increased mobility is generally associated with the correct repair by Homologous Recombination (HR) of DSBs generated in heterochromatin, it promotes the mis-repair of multiple distal DSBs by Non-Homologous End Joining (NHEJ). Here we describe a method for detecting and quantifying DSBs mobility by live-cell imaging in the context of multiple DSBs prone to mis-repair by NHEJ. In addition, we discuss a set of parameters that can be used for quantitative and qualitative analysis of nuclear deformations and to discard nuclei where the deformation could affect the analysis of DSBs mobility. While this method is based on the visualization of DSBs with the mCherry-53BP1-2 fusion protein, we believe that it can also be used to analyze the mobility of nuclear foci formed by different fluorescent proteins.

Pragmatic language comprehension: Role of theory of mind, executive functions, and the prefrontal cortex

The specific contribution of focal damage of the prefrontal cortex and the cognitive mechanisms accounting for communicative-pragmatic disorders remains unclear. The objective of the current study was to investigate the impact of focal prefrontal cortex damage on the ability to understand indirect speech or hints and to identify the prefrontal neural mechanisms involved. We also examined the underlying cognitive mechanisms of disorders of indirect speech understanding particularly theory of mind and executive functions. Thirty patients with focal prefrontal cortex damage and 30 control subjects were compared on their performances on the Hinting task assessing pragmatic language skills, the "Faux-Pas" task and the Reading the Mind in the Eyes task assessing Theory of Mind and a battery of executive tasks. Patients were significantly impaired compared with control subjects on all these abilities. Both deficits of executive functions and theory of mind were able to predict impaired ability of patients in understanding non-literal meanings on the Hinting task. Finally, using voxel-based lesion analysis we identified a partially shared neural prefrontal network involved in all these abilities centered on the dorsomedial and ventral regions of the prefrontal cortex.

The effect of hippocampal subfield damage on rapid temporal integration through statistical learning and associative inference

IntroductionThe hippocampus (HPC) supports integration of information across time, often indexed by associative inference (AI) and statistical learning (SL) tasks. In AI, an indirect association between stimuli that never appeared together is inferred, whereas SL involves learning item relationships by extracting regularities across experiences. A recent model of hippocampal function (Schapiro et al., 2017) proposes that the HPC can support temporal integration in both paradigms through its two distinct pathways. MethodsWe tested this models’ predictions in four patients with varying degrees of bilateral HPC damage and matched healthy controls, with two patients with complementary damage to either the monosynaptic or trisynaptic pathway. During AI, participants studied overlapping paired associates (AB, BC) and their memory was tested for premise pairs (AB) and for inferred pairs (AC). During SL, participants passively viewed a continuous picture sequence that contained an underlying structure of triplets that later had to be recognized. ResultsBinomial distributions were used to calculate above chance performance at the individual level. For AI, patients with focal HPC damage were impaired at inference but could correctly infer pairs above chance once premise pair acquisition was equated to controls; however, the patient with HPC and cortical damage showed severe impairment at recalling premise and inferred pairs, regardless of accounting for premise pair performance. For SL, none of the patients performed above chance, but notably neither did most controls. ConclusionsAssociative inference of indirect relationships can be intact with HPC damage to either hippocampal pathways or the HPC more broadly, provided premise pairs can first be formed. Inference may remain intact through residual HPC tissue supporting premise pair acquisition, and/or through extra-hippocampal structures supporting inference at retrieval. Clear conclusions about hippocampal contributions to SL are precluded by low performance in controls, which we caution is not dissimilar to previous amnesic studies using the same task. This complicates interpretations of studies claiming necessity of hippocampal contributions to SL and warrants the use of a common and reliable task before conclusions can be drawn.

MYSM1 attenuates DNA damage signals triggered by physiologic and genotoxic DNA breaks

Patients with deleterious variants in MYSM1 have an immune deficiency characterized by B-cell lymphopenia, hypogammaglobulinemia, and increased radiosensitivity. MYSM1 is a histone deubiquitinase with established activity in regulating gene expression. MYSM1 also localizes to sites of DNA injury but its function in cellular responses to DNA breaks has not been elucidated. This study sought to determine the activity of MYSM1 in regulating DNA damage responses (DDRs) to DNA double-stranded breaks (DSBs) generated during immunoglobulin receptor gene (Ig) recombination and by ionizing radiation. MYSM1-deficient pre- and non-B cells were used to determine the role of MYSM1 in DSB generation, DSB repair, and termination of DDRs. Genetic testing in a newborn with abnormal screen for severe combined immune deficiency, T-cell lymphopenia, and near absence of B cells identified a novel splice variant in MYSM1 that results in nearly absent protein expression. Radiosensitivity testing in patient's peripheral blood lymphocytes showed constitutive γH2AX, a marker of DNA damage, in B cells in the absence of irradiation, suggesting a role for MYSM1 in response to DSBs generated during Ig recombination. Suppression of MYSM1 in pre-B cells did not alter generation or repair of Ig DSBs. Rather, loss of MYSM1 resulted in persistent DNA damage foci and prolonged DDR signaling. Loss of MYSM1 also led to protracted DDRs in U2OS cells with irradiation induced DSBs. MYSM1 regulates termination of DNA damage responses but does not function in DNA break generation and repair.

Predictive underestimation of difficult direct laryngoscopy in a patient with rheumatoid arthritis-associated immobilized craniocervical junction

BackgroundThe upper cervical spine is a major focus of damage by rheumatoid arthritis (RA). Specific screening for mobility of the upper cervical spine, which is essential for direct laryngoscopy, is lacking. Herein, we present a case of RA with Cormack-Lehane grade IV, which was not predicted by preoperative examination.Case presentationA 66-year-old woman with RA was scheduled for a right total knee arthroplasty and right elbow synovectomy. She had a long history of RA without symptoms related to the cervical spine or spinal cord. Although physical examination suggested moderate risk of difficult intubation with preserved cervical retroflexion, her Cormack-Lehane classification was grade IV under muscle relaxation. Bony integration of the occiput to axis was considered to be the main cause of difficult direct laryngoscopy, and restricted neck rotation was found postoperatively.ConclusionsRA patients may have limited upper cervical spine motion despite normal cervical retroflexion.

Neutrophil Extracellular Traps (NETs) in Kidney Disease: Role in Pathogenesis and Possibilities of NET Regulatory Therapy

Excessive uncontrolled inflammatory and immune reactions often lead to the development of acute and chronic forms of damage to various organs, including the kidneys. Neutrophils are the cells of the innate immune system, which are the first cellular effectors in protecting the host from a variety of pathogens, including bacteria, fungi and protozoa. As the most numerous leukocytes present in human blood, neutrophils migrate early to the foci of inflammation or tissue damage, where they play a significant role in the development of inflammation, recruitment of immune cells, removal of pathogens and tissue repair. Neutrophils also produce pro-inflammatory cytokines and release, in a process called netosis, a network of DNA and granular proteins known as neutrophil extracellular traps (NETs). NETs are potentially toxic, contribute to glomerular damage, activate autoimmune processes, cause vascular damage, and promote renal fibrosis. Numerous studies show that an imbalance between NET production and clearance is detrimental to kidney function. Therefore, strategies aimed at modulating the processes associated with NET may have a favorable prognostic effect. The review discusses the role of the netosis in the pathogenesis of kidney diseases, describes the mechanisms of tissue damage associated with NET, and the therapeutic potential of NET regulatory therapy.

Micro-Vessels-Like 3D Scaffolds for Studying the Proton Radiobiology of Glioblastoma-Endothelial Cells Co-Culture Models.

Glioblastoma (GBM) is a devastating cancer of the brain with an extremely poor prognosis. While X-ray radiotherapy and chemotherapy remain the current standard, proton beam therapy is an appealing alternative as protons can damage cancer cells while sparing the surrounding healthy tissue. However, the effects of protons on in vitro GBM models at the cellular level, especially when co-cultured with endothelial cells, the building blocks of brain micro-vessels, are still unexplored. In this work, novel 3D-engineered scaffolds inspired by the geometry of brain microvasculature are designed, where GBM cells cluster and proliferate. The architectures are fabricated by two-photon polymerization (2PP), pre-cultured with endothelial cells (HUVECs), and then cultured with a human GBM cell line (U251). The micro-vessel structures enable GBM in vivo-like morphologies, and the results show a higher DNA double-strand breakage in GBM monoculture samples when compared to the U251/HUVECs co-culture, with cells in 2D featuring a larger number of DNA damage foci when compared to cells in 3D. The discrepancy in terms of proton radiation response indicates a difference in the radioresistance of the GBM cells mediated by the presence of HUVECs and the possible induction of stemness features that contribute to radioresistance and improved DNA repair.

The role of cognitive estimation in understanding the mental states of others

ABSTRACT Previous studies have emphasized the critical role of the prefrontal cortex in cognitive estimation and theory of mind, however, none of them has questioned the possible role of cognitive estimation processes in understanding the mental states of others. In this study, we compared 30 patients with focal prefrontal cortex damage and 30 control subjects matched by gender, age, and education level on their performances on a cognitive estimation task and two tasks assessing theory of mind: the “Faux-Pas” task and the Reading the Mind in the Eyes task. The results showed that patients were significantly impaired compared with control subjects on both abilities of cognitive estimation and theory of mind. Moreover, regression analyses showed that performance on theory of mind was predicted by the scores on cognitive estimation. Finally, using voxel-based lesion analysis, we identified a partially common bilaterally distributed prefrontal network involved in both these domains centred within the ventral and dorsomedial areas with extension to the dorsolateral prefrontal cortex.

Symmetry differences of structural connectivity in multiple sclerosis and healthy state

Focal and diffuse cerebral damages occur in Multiple Sclerosis (MS) that promotes profound shifts in local and global structural connectivity parameters, mainly derived from diffusion tensor imaging. Most of the reconstruction analyses have applied conventional tracking algorithms largely based on the controversial streamline count. For a more credible explanation of the diffusion MRI signal, we used convex optimization modeling for the microstructure-informed tractography2 (COMMIT2) framework. All multi-shell diffusion data from 40 healthy controls (HCs) and 40 relapsing-remitting MS (RRMS) patients were transformed into COMMIT2-weighted matrices based on the Schefer-200 parcels atlas (7 networks) and 14 bilateral subcortical regions. The success of the classification process between MS and healthy state was efficiently predicted by the left DMN-related structures and visual network-associated pathways. Additionally, the lesion volume and age of onset were remarkably correlated with the components of the left DMN. Using complementary approaches such as global metrics revealed differences in WM microstructural integrity between MS and HCs (efficiency, strength). Our findings demonstrated that the cutting-edge diffusion MRI biomarkers could hold the potential for interpreting brain abnormalities in a more distinctive way.

Role and new insights of microfibrillar-associated protein 4 in fibrotic diseases.

Fibrosis is one of the most worrisome complications of chronic inflammatory diseases, leading to tissue damage, organ failure, and ultimately, death. The most notable pathological characteristic of fibrosis is the excessive accumulation of extracellular matrix (ECM) components such as collagen and fibronectin adjacent to foci of inflammation or damage. The human microfibrillar-associated protein 4 (MFAP4), an important member of the superfamily of fibrinogen-related proteins, is considered to have an extremely important role in ECM transformation of fibrogenesis. This review summarizes the structure, characteristics, and physiological functions of MFAP4 and the importance of MFAP4 in various fibrotic diseases. Meanwhile, we elaborated the underlying actions and mechanisms of MFAP4 in the development of fibrosis, suggesting that a better understand of MFAP4 broadens novel perspective for early screening, diagnosis, prognostic risk assessment, and treatment of fibrotic diseases.