Distribution Analysis of Iron and Copper by STEM-EDX Spectroscopy of Hemosiderin Particles in the Liver of Rats Overloaded With Iron.

BACKGROUND/AIM: Our recent studies have indicated that trace copper co-existed with iron in hemosiderin particles of human genetic iron overload. To understand this phenomenon, we analyzed hemosiderin particles in iron-overloaded rat liver by using scanning transmission electron microscopy - energy-dispersive X-ray (STEM-EDX) spectroscopy. MATERIALS AND METHODS: Samples for STEM-EDX spectroscopy were prepared from the liver of rats administered an intraperitoneal injection of dextran iron. RESULTS: The micro-domain analysis with STEM-EDX spectroscopy showed that dense bodies contained high levels of iron and trace copper. Quantitative analysis of copper levels in the liver specimen using atomic spectrophotometry showed that copper concentration in the liver was not increased by iron overload. These findings suggest that the overload of iron induced distribution of trace copper to hemosiderin particles without changing cellular copper levels. CONCLUSION: Co-existence of copper with iron was observed in hemosiderin particles of the liver of an experimental model of iron overload, suggesting that iron overload induced distribution of trace copper into hemosiderin particles.

Assessment of Imaging Findings of Renal Carcinoma Subtypes with 3.0T MRI.

BACKGROUND: The prevalence of renal masses has escalated as a result of the augmented utilization of cross-sectional imaging techniques. The approach to managing renal masses may exhibit variability contingent upon the subtype of renal cell carcinoma (RCC). AIM: This research aimed to distinguish between clear cell and papillary RCCs, utilizing dynamic contrast magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI). MATERIALS AND METHODS: The study assessed the MR images of 112 patients with RCC. Two radiologists independently analyzed tumor size, vascular involvement, signal characteristics in T1- and T2-weighted sequences, the presence of hemosiderin, both microscopic and macroscopic fat content, enhancement patterns, and apparent diffusion coefficient (ADC) values derived from b-values of 1000 s/mm². RESULTS: Seventy patients had clear cell RCC, and 42 had papillary. In the clear cell RCC, microscopic fat content was significantly higher than the papillary RCC (P < 0.001). However, in papillary RCC, hemosiderin content was substantially greater (P = 0.001). On T2-weighted MR images, clear cell RCCs were usually hyperintense, while papillary RCCs were hypointense (P < 0.001). Even though the rapid enhancement pattern was observed in clear cell RCCs, the progressive enhancement pattern was more prevalent in papillary RCCs (P < 0.001). CONCLUSION: Hyperintensity on T2-weighted images, microscopic fat content, and rapid enhancement pattern may be indicative of clear cell RCC, whereas hypointensity on T2-weighted images, hemosiderin content, and a progressive contrast pattern may be diagnostic for papillary RCC.

Comparison of four different displays for identification of select pathologic features extracted from whole slide images of surgical pathology cases.

BACKGROUND: The establishment of minimum standards for display selection for the whole slide image (WSI) interpretation has not been fully defined. Recently, pathologists have increasingly preferred using remote displays for clinical diagnostics. Our study aims to assess and compare the performance of three fixed work displays and one remote personal display in accurately identifying ten selected pathologic features integrated into WSIs. DESIGN: Hematoxylin and eosin-stained glass slides were digitized using Philips scanners. Seven practicing pathologists and three residents reviewed ninety WSIs to identify ten pathologic features using the LG, Dell, and Samsung and an optional consumer-grade display. Ten pathologic features included eosinophils, neutrophils, plasma cells, granulomas, necrosis, mucin, hemosiderin, crystals, nucleoli, and mitoses. RESULTS: The accuracy of the identification of ten features on different types of displays did not significantly differ among the three types of "fixed" workplace displays. The highest accuracy was observed for the identification of neutrophils, eosinophils, plasma cells, granuloma, and mucin. On the other hand, a lower accuracy was observed for the identification of crystals, mitoses, necrosis, hemosiderin, and nucleoli. Participant pathologists and residents preferred the use of larger displays (>30″) with a higher pixel count, resolution, and luminance. CONCLUSION: Most features can be identified using any display. However, certain features posed more challenges across the three fixed display types. Furthermore, the use of a remote personal consumer-grade display chosen according to the pathologists' preference showed similar feature identification accuracy. Several factors of display characteristics seemed to influence pathologists' display preferences such as the display size, color, contrast ratio, pixel count, and luminance calibration. This study supports the use of standard "unlocked" vendor-agnostic displays for clinical digital pathology workflow rather than purchasing "locked" and more expensive displays that are part of a digital pathology system.

Hemosiderin induced acute kidney injury requiring hemodialysis in patients with paroxysmal nocturnal hemoglobinuria: A case report.

RATIONALE: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematopoietic stem cell disease with features of hemolytic anemia, thrombosis, and bone marrow failure. Due to intravascular hemolysis and hemoglobinuria, renal dysfunction is often accompanied in PNH patients. PATIENT CONCERNS: A 25-year old woman presenting gross hematuria after coronavirus disease 2019 infection was admitted to our medical center. She had mild nausea and headache. She was diagnosed with iron deficiency anemia few years ago and had no other underlying disease. Her laboratory findings showed acute kidney injury (AKI) and severe anemia, with evidences of hemolysis. DIAGNOSIS: Renal biopsy was done to determine the cause of renal failure and the result was acute tubular necrosis with deposition of golden pigments, hemosiderin. With pathologic result and laboratory finding of hemolysis, we did flow cytometry for PNH, and the patient was finally diagnosed with PNH. INTERVENTIONS: With AKI and oliguria, the patient started to take hemodialysis. OUTCOMES: After taking 5 sessions of hemodialysis, the patient's renal function was recovered from AKI. With diagnosis of PNH, the patient is now being treated with complement C5 inhibitor. LESSONS: This challenging case tells us that we should consider the first manifestation of PNH as a cause of severe AKI requiring hemodialysis in a patient with anemia and evidence of hemolysis.

Case report: a case of primary intracranial parasagittal meningeal angiosarcoma.

BACKGROUND: Angiosarcoma, also known as malignant hemangioendothelioma, is a rare vasogenic malignant tumor, commonly found on the skin of the head and neck, rarely occurring in the intracranial region. As for intracranial meningeal angiosarcoma, only 8 cases have been reported before and there is no clinical study with large sample size. We report here a case of parasagittal meningeal angiosarcoma. CASE DESCRIPTION: A 48-year-old Chinese male patient was admitted to our hospital due to headache accompanied by bilateral lower limb weakness. On admission, CT showed a high-density mass on both sides of the sagittal sinus at the top of the frontal lobe. We performed exploratory surgical resection of the tumor. During the operation, it was found that the tumor originated from the dura mater and extensively invaded the surrounding brain tissue and skull, and the surrounding hemosiderin deposition was observed. Postoperative pathology suggested angiosarcoma. CONCLUSIONS: Intracranial meningeal angiosarcoma is difficult to accurately diagnose before surgery, so radiologists and neurosurgeons need to strengthen their understanding of this disease. The presence of extensive superficial hemosiderin deposition during operation may contribute to the diagnosis, and immunohistochemistry is very important for the diagnosis of intracranial angiosarcoma.

Chronic kidney disease in a giant panda (Ailuropoda melanoleuca): a case report.

BACKGROUND: Chronic kidney disease (CKD) is a common cause of morbidity and mortality in captive wildlife species. However, CKD has been rarely documented in giant pandas. CASE PRESENTATION: The following report describes a case of an eight-year-old female giant panda showing clinical signs of epistaxis, bloody diarrhea, polyuria, azotemia and anemia. The animal died despite of supportive treatments. Necropsy was performed. Grossly, both kidneys were shrunken and scarred with pallor. Subcutis edema and petechia on the epicardium of the heart were observed. The tissue samples were made into paraffin sections and stained by H.E and special staining including Periodic Acid-Schiff (PAS), von Kossa, Masson's trichrome, Phosphotungstic acid-hematoxylin (PTAH), and Congo red. Histopathology examination revealed severe chronic tubulointerstitial nephritis with marked interstitial fibrosis, glomerulosclerosis, tubular atrophy and calcification in kidneys, and acute necrotizing hemorrhagic myocarditis with calcification in heart. Other lesions included intestinal hemorrhage, hepatic fatty degeneration and necrosis with hemosiderin, and splenic hemosiderin. CONCLUSIONS: In summary, chronic kidney disease was finally diagnosed based on the association of clinical, gross, and histopathological findings. Heart failure secondary to CKD is the leading cause of death in this giant panda. The potential cause of CKD in this animal is possibly due to long term and uncontrolled hypertension. Blood pressure monitoring is essential in establishing the diagnosis and management of hypertension in giant panda.

Pigmentation of lower limbs: Contribution of haemosiderin and melanin in chronic venous insufficiency and related disorders.

BACKGROUND: To determine the composition of skin pigmentation in chronic venous insufficiency (CVI) and other less common vascular conditions of lower limbs. METHODS: Forty-five skin biopsies were obtained from 17 patients. Samples were taken from pigmented regions and compared with control non-lesional samples from the same patient. Perl's Prussian Blue was used to identify haemosiderin and Schmorl's for melanin. RESULTS: Seven patients presented with CVI, one with concurrent livedo vasculopathy (LV). One patient had LV only. Two patients had acroangiodermatitis (AAD). Six patients had post-sclerotherapy pigmentation (PSP), one with concurrent post-inflammatory hyperpigmentation (PIH). One patient had PIH only. The predominant pigment in CVI samples was haemosiderin. C5-C6 patients showed increased epidermal melanin. LV, AAD, and PSP samples showed dermal haemosiderin but no increase in epidermal melanin. PIH samples showed prominent epidermal melanin whilst no haemosiderin was detected. CONCLUSION: The predominant pigment in CVI and other vascular conditions was haemosiderin. Melanin was present in later stages of CVI (C5-C6) and in PIH.

Histotripsy Treatment of Murine Brain and Glioma: Temporal Profile of Magnetic Resonance Imaging and Histological Characteristics Post-treatment.

OBJECTIVE: Currently, there is a knowledge gap in our understanding of the magnetic resonance imaging (MRI) characteristics of brain tumors treated with histotripsy to evaluate treatment response as well as treatment-related injuries. Our aim was to bridge this gap by investigating and correlating MRI with histological analysis after histotripsy treatment of mouse brain with and without brain tumors and evaluating the evolution of the histotripsy ablation zone on MRI over time. METHODS: An eight-element, 1 MHz histotripsy transducer with a focal distance of 32.5 mm was used to treat orthotopic glioma-bearing mice and normal mice. The tumor burden at the time of treatment was ∼5 mm3. T2, T2*, T1 and T1-gadolinium (Gd) MR images and histology of the brain were acquired on days 0, 2 and 7 for tumor-bearing mice and days 0, 2, 7, 14, 21 and 28 post-histotripsy for normal mice. RESULTS: T2 and T2* sequences most accurately correlated with histotripsy treatment zone. The treatment-induced blood products, T1 along with T2, revealed blood product evolution from oxygenated, de-oxygenated blood and methemoglobin to hemosiderin. And T1-Gd revealed the state of the blood-brain barrier arising from the tumor or histotripsy ablation. Histotripsy leads to minor localized bleeding, which resolves within the first 7 d as evident on hematoxylin and eosin staining. By day 14, the ablation zone could be distinguished only by the macrophage-laden hemosiderin, which resides around the ablation zone, rendering the treated zone hypo-intense on all MR sequences. CONCLUSION: These results provide a library of radiological features on MRI sequences correlated to histology, thus allowing for non-invasive evaluation of histotripsy treatment effects in in vivo experiments.

Cytopathological findings of intranodal palisaded myofibroblastoma: Case report and review of the literature.

INTRODUCTION: Intranodal palisaded myofibroblastoma (IPM) is an exceedingly rare benign mesenchymal tumor of the lymph nodes. Magnetic resonance imaging (MRI) findings are unspecific, which may present diagnostic challenges to fine-needle aspiration cytology (FNAC). The histological and immunohistochemical features of IPM are unique. CASE REPORT: A previously healthy 40-year-old male patient presented a slow-growing solitary left inguinal mass. FNAC revealed clustered cells within a metachromatic stroma, single spindle cells without atypia, hemosiderin pigment, and siderophages. An MRI showed a central hyperintense septum in fat-suppressed, T2-weighted sequences. The excised lymph node contained central haphazard fascicles of spindle cells with focal nuclear palisading, hemosiderin pigment, extravasated erythrocytes, and hemorrhagic areas. Vimentin and smooth muscle actin were diffusely positive. Amianthoid collagen fibers were not clearly observed. CONCLUSION: IPM is an extremely rare mesenchymal benign intranodal tumor that should be included in the differential diagnosis of spindle cell lesions in the inguinal region.

Corneal Perforation as a Rare and Late Manifestation of Choroidal Melanoma.

PURPOSE: To report a case of corneal perforation as a rare and late manifestation of choroidal melanoma and to highlight the major histopathological findings of this unusual combined clinical presentation. METHODS: A 74-year-old male patient presented to our department due to corneal perforation of the right eye with the absence of light perception for 6 months. The intraocular pressure was hard on palpation. Because of the protracted finding and reduced visual prognosis, primary enucleation was performed. RESULTS: The histopathological examination revealed choroidal melanoma with epithelioid and spindle cell components at the posterior pole, which was positive for Melan-A, Human Melanoma Black 45 (HMB45), BAP1, and SOX10. The anterior segment showed complete anterior chamber hemorrhage and blood remnants in the trabecular meshwork. The cornea displayed diffuse blood staining with hemosiderin and hemosiderin-loaded macrophages and keratocytes. No inflammatory cells were present near the corneal perforation, which had a width of 3 mm. Intraocular heterotopic ossification was indicative of a long-standing condition. Postoperative cancer staging was normal. CONCLUSION: Corneal perforation should be considered as a very rare and late manifestation of advanced choroidal melanoma and may result from interaction between intraocular hemorrhage, elevated IOP, and its secondary signs such as corneal blood staining.

Technical note: Improved differentiation of calcification from hemosiderin using paramagnetic- and diamagnetic-specific magnetic resonance susceptibility weighted imaging (p-SWI, d-SWI).

INTRODUCTION: Differentiation of calcification and calcium-containing tissue from blood products remains challenging using magnetic resonance imaging (MRI). We developed a novel post-processing algorithm which creates both paramagnetic- and diamagnetic-specific SWI images generated from T2* weighted images using distinct "positive" and "negative" phase masks. METHODS: 10 patients who had undergone clinical MRI scanning of the brain with a rapid echo planar based T2*-weighted EPI-GRE pulse sequence with evidence for either hemosiderin and/or calcifications were retrospectively identified. Complex raw k-space data from individual imaging coils were then extracted, reconstructed, and appropriately combined to produce magnitude and phase images using a phase preserving method. The final reconstructed images included the T2* EPI-GRE magnitude images, p-SWI and d-SWI images. Filtered phase images were also available for review. Correlation with CT scans and MR imaging appearance over time corroborated the composition of the voxels. RESULTS: Differential "blooming" of diamagnetic and paramagnetic foci was readily identified on the corresponding p-SWI and d-SWI images and provided fast and reliable visual differentiation of diamagnetic from paramagnetic susceptibility effects by ascertaining which of the two images depicted the greatest "blooming" effect. Correlation with the available filtered phase maps was not necessary for differentiation of paramagnetic from diamagnetic image components. CONCLUSION: Clinical interpretation of SWI images can be further enhanced by creating specific p-SWI and d-SWI image pairs which contain greater visual information than the combination of standard p-SWI images and phase image.

Bronchoalveolar lavage hemosiderosis in lightly active or sedentary horses.

BACKGROUND: Hemosiderophages in bronchoalveolar lavage fluid (BALF) are commonly ascribed to exercise-induced pulmonary hemorrhage (EIPH). Little information exists regarding the presence of these cells in horses that perform light or no work and that are referred for respiratory problems. OBJECTIVES: Evaluate the presence of hemosiderophages in BALF of horses suspected of respiratory disease without history of or risk factors for EIPH and determine predictors of hemosiderophages in BALF in this population. METHODS: Observational retrospective cross-sectional study using STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Bronchoalveolar lavage fluid cytology reports of 353 horses evaluated for respiratory disease between 2012 and 2022 at the Cummings School for Veterinary Medicine were reviewed retrospectively. Horses with a history or likelihood of having performed past strenuous exercise were removed, and the remaining 91 horses were divided into hemosiderin-positive (HSD-POS) and hemosiderin-negative groups based on Perls' Prussian blue staining. Potential predictors for the presence of hemosiderophages in BALF (history, clinical evaluation, baseline lung function, airway reactivity, BALF cytology, and hemosiderin score) were compared between the 2 groups, using univariate and multivariate analyses. RESULTS: Horses with a diagnosis of severe equine asthma (sEA; odds ratio, 11.1; 95% confidence interval, 3.2-38.5; P < .001) were significantly more likely to be HSD-POS than horses with mild-to-moderate equine asthma. CONCLUSIONS AND CLINICAL IMPORTANCE: Hemosiderophages were found in the BALF cytology in a subset of horses that perform light or no work and presented for respiratory signs; these cells were found more frequently in horses with sEA. The link between hemosiderophages and sEA highlights previously unstudied pathology associated with this common disease.

Pediatric Cerebral Cavernous Malformation: A Single-Centered Experience of 23 Cases.

AIM: To describe, and to evaluate the clinical and radiological characteristics of pediatric cavernous malformations (CMs) and the surgical approaches and their outcomes in a single center. MATERIAL AND METHODS: We retrospectively reviewed pediatric patients with CMs that were treated in our center between 2010 and 2020. Radiological, clinical, and demographic features, as well as treatment details were evaluated. RESULTS: Of 23 patients, 12 were male, and 11 were female. Two patients with multiple CMs had a family history. The most common symptoms were headaches (9/23, 39.1%) and seizures (9/23, 39.1%). Twenty patients had single lesions and three patients had multiple lesions. According to Zabramski classification, eight (34.7%) patients had type 1, 11 (47.8%) had type 2 and four (17.3%) had type 3 lesions. Thirteen patients had recurrent preoperative hemorrhages and nine had increased lesion size. Seven patients (30.4%) had coexisting deep venous anomalies in the CM vicinity. Twenty-one patients underwent microsurgical resection (5/23 simple lesionectomy, 16/23 lesionectomy + resection of the surrounding hemosiderin ring). All lesions were completely resected. No surgical mortalities or major complications occurred. CONCLUSION: Since pediatric CMs are more aggressive than adult CMs, they should not be underestimated. Microsurgical total resection should be the first treatment choice where possible. We concluded that early surgical treatment and resection of perilesional hemosiderin-stained tissue, when feasible, yield the most favorable results at long-term follow-up including seizure outcomes.

Magnetic resonance imaging evidence for subclinical joint bleeding in a Dutch population of people with severe hemophilia on prophylaxis.

BACKGROUND: Previous studies suggest that subclinical bleeding occurs in persons with hemophilia. OBJECTIVES: The aim of this study was to investigate whether patients with lifelong access to prophylaxis showed signs of previous subclinical bleeding on magnetic resonance imaging (MRI) in joints without a history of joint bleeding. METHODS: This single-center cross-sectional study included persons with severe hemophilia A on prophylaxis, aged 16 to 33 years, with lifetime bleeding records available. Per participant, 1 index joint without a history of joint bleeding was evaluated with 3-Tesla MRI, including hemosiderin sensitive sequences. MRI scans were reviewed according to the International Prophylaxis Study Group (IPSG) additive MRI scale (range, 0-17/joint). Hemosiderin deposits with/without synovial hypertrophy were considered signs of previous subclinical bleeding. Additionally, physical examination was performed, followed by ultrasound examination according to the Hemophilia Early Arthropathy Detection with Ultrasound protocol. RESULTS: In 43 patients with a median age of 23.5 years, 43 joints (16 elbows, 13 knees, 14 ankles) without reported bleeds were evaluated with MRI. The median IPSG MRI score was 1 (range, 0-9). Signs of previous subclinical bleeding were observed in 7 of 43 joints (16%; 95% CI, 7-30): 7 of 7 joints showed hemosiderin deposits, with concomitant synovial hypertrophy in 2 of 7 joints. MRI changes were accompanied by swelling and ultrasound-detected synovial hypertrophy in 1 ankle only. None of the other joints showed abnormalities at physical examination and ultrasound. CONCLUSION: In this study, 16% of the joints without reported bleeds showed signs of previous subclinical bleeding, providing evidence for subclinical bleeding in people with severe hemophilia with lifelong access to prophylaxis.

Extrastriatal 99m Tc-TRODAT-1 Uptake in the Previous Hemorrhage With Hemosiderin Deposition.

ABSTRACT: We reported a 91-year-old man who was suspected of having parkinsonism, and brain 99m Tc-TRODAT-1 scan revealed an extrastriatal uptake in the left side of brainstem, which was correlated to a previously hemorrhagic lesion with hemosiderin deposition. Macrophage or microglia might accumulate in the previous hemorrhagic lesion to phagocytize hemosiderin. We assumed that the 99m Tc-TRODAT-1 uptake in the hemosiderin deposition might be partially mediated by macrophage expressing dopamine transporter.

Clinical characteristics and risk factors of cerebral cavernous malformation-related epilepsy.

PURPOSE: This study aimed to summarize the clinical characteristics and explore the risk factors for cerebral cavernous malformation (CCM)-related epilepsy (CRE). METHODS: We retrospectively analyzed the clinical data of patients with CCM in our cerebral vascular malformations database. Descriptive statistics were used to present the clinical characteristics of CRE patients. Patients were divided into a CRE and a non-CRE group according to clinical presentation. Binary logistic regression analysis was used to analyze the risk factors of CRE. RESULTS: A total of 199 patients with CCM confirmed by postoperative pathological examination were enrolled, 93 of whom were diagnosed with CRE, and 34 patients had drug-resistant epilepsy. The most common seizure type of CRE patients was focal to bilateral tonic-clonic seizure (FBTCS), followed by focal impaired awareness motor seizure. All CCM lesions were supratentorial, 97.8% of which involved the cerebral cortex, 86.0% of lesions had hemosiderin rim, and 50.5% of lesions were located in the temporal lobe. Binary logistic regression analysis indicated that CCM diagnosis age ≤ 44 years (odds ratio [OR] 2.79, p = 0.010), temporal lobe lesion location (OR = 9.07, p = 0.042), medial temporal lobe lesion (OR = 14.09, p = 0.002), cortical involvement of the lesion (OR = 32.77, p = 0.010), and hemosiderin rim around the lesion (OR = 16.48, p = 0.001) significantly increased the risk of CRE. CONCLUSIONS: The most common seizure type of CRE was FBTCS. Those whose CCM diagnosis age was ≤ 44 years, having a temporal lobe lesion location, especially the medial temporal lobe lesion, cortical involvement, and hemosiderin rim around the lesion had a higher risk of developing CRE.

Neuropathology of microbleeds in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

Cerebral microbleeds (CMBs) detected on magnetic resonance imaging are common in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). The neuropathologic correlates of CMBs are unclear. In this study, we characterized findings relevant to CMBs in autopsy brain tissue of 8 patients with genetically confirmed CADASIL and 10 controls within the age range of the CADASIL patients by assessing the distribution and extent of hemosiderin/iron deposits including perivascular hemosiderin leakage (PVH), capillary hemosiderin deposits, and parenchymal iron deposits (PID) in the frontal cortex and white matter, basal ganglia and cerebellum. We also characterized infarcts, vessel wall thickening, and severity of vascular smooth muscle cell degeneration. CADASIL subjects had a significant increase in hemosiderin/iron deposits compared with controls. This increase was principally seen with PID. Hemosiderin/iron deposits were seen in the majority of CADASIL subjects in all brain areas. PVH was most pronounced in the frontal white matter and basal ganglia around small to medium sized arterioles, with no predilection for the vicinity of vessels with severe vascular changes or infarcts. CADASIL subjects have increased brain hemosiderin/iron deposits but these do not occur in a periarteriolar distribution. Pathogenesis of these lesions remains uncertain.

Iron cycle disruption by heme oxygenase-1 activation leads to a reduced breast cancer cell survival.

Heme oxygenase-1 (HO-1), which catalyzes heme degradation releasing iron, regulates several processes related to breast cancer. Iron metabolism deregulation is also connected with several tumor processes. However the regulatory relationship between HO-1 and iron proteins in breast cancer remains unclear. Using human breast cancer biopsies, we found that high HO-1 levels significantly correlated with low DMT1 levels. Contrariwise, high HO-1 levels significantly correlated with high ZIP14 and prohepcidin expression, as well as hemosiderin storage. At mRNA level, we found that high HO-1 expression significantly correlated with low DMT1 expression but high ZIP14, L-ferritin and hepcidin expression. In in vivo experiments in mice with genetic overexpression or pharmacological activation of HO-1, we detected the same expression pattern observed in human biopsies. In in vitro experiments, HO-1 activation induced changes in iron proteins expression leading to an increase of hemosiderin, ROS levels, lipid peroxidation and a decrease of the growth rate. Such low growth rate induced by HO-1 activation was reversed when iron levels or ROS levels were reduced. Our findings demonstrate an important role of HO-1 on iron homeostasis in breast cancer. The changes in iron proteins expression when HO-1 is modulated led to the iron accumulation deregulating the iron cell cycle, and consequently, generating oxidative stress and low viability, all contributing to impair breast cancer progression.

Low-temperature Mössbauer spectroscopy of organs from 57Fe-enriched HFE(-/-) hemochromatosis mice: an iron-dependent threshold for generating hemosiderin.

Hereditary hemochromatosis is an iron-overload disease most often arising from a mutation in the Homeostatic Fe regulator (HFE) gene. HFE organs become overloaded with iron which causes damage. Iron-overload is commonly detected by NMR imaging, but the spectroscopic technique is insensitive to diamagnetic iron. Here, we used Mössbauer spectroscopy to examine the iron content of liver, spleen, kidney, heart, and brain of 57Fe-enriched HFE(-/-) mice of ages 3-52 wk. Overall, the iron contents of all investigated HFE organs were similar to the same healthy organ but from an older mouse. Livers and spleens were majorly overloaded, followed by kidneys. Excess iron was generally present as ferritin. Iron-sulfur clusters and low-spin FeII hemes (combined into the central quadrupole doublet) and nonheme high-spin FeII species were also observed. Spectra of young and middle-aged HFE kidneys were dominated by the central quadrupole doublet and were largely devoid of ferritin. Collecting and comparing spectra at 5 and 60 K allowed the presence of hemosiderin, a decomposition product of ferritin, to be quantified, and it also allowed the diamagnetic central doublet to be distinguished from ferritin. Hemosiderin was observed in spleens and livers from HFE mice, and in spleens from controls, but only when iron concentrations exceeded 2-3 mM. Even in those cases, hemosiderin represented only 10-20% of the iron in the sample. NMR imaging can identify iron-overload under non-invasive room-temperature conditions, but Mössbauer spectroscopy of 57Fe-enriched mice can detect all forms of iron and perhaps allow the process of iron-overloading to be probed in greater detail.

Arteriolosclerosis differs from venular collagenosis in relation to cerebrovascular parenchymal damages: an autopsy-based study.

BACKGROUND AND PURPOSE: Cerebrovascular parenchymal damage is prevalent in ageing brains; however, its vascular aetiology has not been fully elucidated. In addition to the underlying role of sclerotic arterioles, the correlation between collagenised venules has not been clarified. Here, we aimed to investigate the associations between microvascular injuries, including arteriolosclerosis and venular collagenosis, and related parenchymal damages in ageing brains, to investigate the underlying correlations. METHODS: We evaluated arteriolosclerosis and venular collagenosis in 7 regions from 27 autopsy cases with no history of stroke or brain tumour. The correlations between the ratio of arteriolosclerosis, venular collagenosis and the severity of cerebrovascular parenchymal damage, including lacunes, microinfarcts, myelin loss, and parenchymal and perivascular haemosiderin deposits, were assessed. RESULTS: Arteriolosclerosis and venular collagenosis became more evident with age. Arteriolosclerosis was associated with lacunes (p=0.004) and brain parenchymal haemosiderin deposits in the superior frontal cortex (p=0.024) but not with leukoaraiosis severity. Venular collagenosis was not associated with the number of lacunes or haemosiderin, while white matter generally became paler with severe venular collagenosis in the periventricular (ß=-0.430, p=0.028) and deep white matter (ß=-0.437, p=0.025). CONCLUSION: Our findings imply an important role for venular lesions in relation to microvessel-related parenchymal damage which is different from that for arteriolosclerosis. Different underlying mechanisms of both cerebral arterioles and venules require further investigation.