Morphological analysis of astrocytes in the hippocampus in mechanical asphyxiation

Differential Glial Chitotriosidase 1 and Chitinase 3-like Protein 1 Expression in the Human Primary Visual Cortex and Cerebellum after Global Hypoxia-Ischemia

Here, we studied the neuroinflammation- and ischemia-related glial markers chitotriosidase 1 (CHIT1) and chitinase-3-like protein 1 (CHI3L1, alias YKL-40) in the human striate cortex and cerebellum at different time points after global hypoxic-ischemic brain injury (HIBI). Both regions differ considerably in their glial cell population but are supplied by the posterior circulation. CHIT1 and CHI3L1 expression was compared to changes in microglial (IBA1, CD68), astrocytic (GFAP, S100β), and neuronal markers (H&E, neurofilament heavy chain, NfH; calretinin, CALR) using immunohistochemistry and multiple-label immunofluorescence. Initial striatal cortical and cerebellar Purkinje cell damage, detectable already 1/2 d after HIBI, led to delayed neuronal death, whereas loss of cerebellar NfH-positive stellate and CALR-positive granule cells was variable. During the first week post-HIBI, a transient reduction of IBA1-positive microglia was observed in both regions, and fragmented/clasmatodendritic cerebellar Bergmann glia appeared. In long-term survivors, both brain regions displayed high densities of activated IBA1-positive cells and CD68-positive macrophages, which showed CHIT1 co-localization in the striate cortex. Furthermore, enlarged GFAP- and S100β-positive astroglia emerged in both regions around 9-10 d post-HIBI, i.e., along with clearance of dead neurons from the neuropil, although GFAP-/S100β-positive gemistocytic astrocytes that co-expressed CHI3L1 were found only in the striate cortex. Thus, only GFAP-/S100β-positive astrocytes in the striate cortex, but not cerebellar Bergmann glia, differentiated into CHI3L1-positive gemistocytes. CHIT1 was co-expressed almost entirely in macrophages in the striate cortex and not cerebellum of long-term survivors, thereby indicating that CHIT1 and CHI3L1 could be valuable biomarkers for monitoring the outcome of global HIBI.

Thyroid-related hormones as potential markers of hypoxia/ischemia

This study aimed to investigate the usefulness of the thyroid-related hormones as markers of acute systemic hypoxia/ischemia to identify deaths caused by asphyxiation due to neck compression in human autopsy cases. The following deaths from pathophysiological conditions were examined: mechanical asphyxia and acute/subacute blunt head injury; acute/subacute non-head blunt injury; sharp instrument injury as the hemorrhagic shock condition; drowning as alveolar injury; burn; and death due to cardiac dysfunction. Blood samples were collected from the left and right cardiac chambers and iliac veins, and serum triiodothyronine (T3), thyroxine (T4), thyroglobulin (Tg), and thyroid-stimulating hormone (TSH) levels were measured using electrochemiluminescence immunoassays. Two types of thyroid cell lines were used to confirm independent thyroid function under the condition of hypoxia (3% O₂). The human thyroid carcinoma cell line (HOTHC) cell line derived from human anaplastic thyroid carcinoma and the UD-PTC (sample of the second resection papillary thyroid carcinoma) cell line derived from human thyroid papillary adenoma, which forms Tg retention follicles, were used to examine the secretion levels of T3, T4, and Tg hormones. The results showed a strong correlation between T3 and T4 levels in all blood sampling sites, while the TSH and Tg levels were not correlated with the other markers. Serum T3 and T4 levels were higher in cases of mechanical asphyxia and acute/subacute blunt head injury, representing hypoxic and ischemic conditions of the brain as compared to those in other causes of death. In the thyroid gland cell line, T4, T3, and Tg levels were stimulated after exposure to hypoxia for 10-30 min. These findings suggest that systemic advanced hypoxia/ischemia may cause a rapid and TSH-independent release of T3 and T4 thyroid hormones in autopsy cases. These findings demonstrate that increased thyroid-related hormone (T3 and T4) levels in the pathophysiological field may indicate systemic hypoxia/ischemia.

The combination of two-dimensional and three-dimensional analysis methods contributes to the understanding of glioblastoma spatial heterogeneity

Heterogeneity is regarded as the major factor leading to the poor outcomes of glioblastoma (GBM) patients. However, conventional two-dimensional (2D) analysis methods, such as immunohistochemistry and immunofluorescence, have limited capacity to reveal GBM spatial heterogeneity. Thus, we sought to develop an effective analysis strategy to increase the understanding of GBM spatial heterogeneity. Here, 2D and three-dimensional (3D) analysis methods were compared for the examination of cell morphology, cell distribution and large intact structures, and both types of methods were employed to dissect GBM spatial heterogeneity. The results showed that 2D assays showed only cross-sections of specimens but provided a full view. To visualize intact GBM specimens in 3D without sectioning, the optical tissue clearing methods CUBIC and iDISCO+ were used to clear opaque specimens so that they would become more transparent, after which the specimens were imaged with a two-photon microscope. The 3D analysis methods showed specimens at a large spatial scale at cell-level resolution and had overwhelming advantages in comparison to the 2D methods. Furthermore, in 3D, heterogeneity in terms of cell stemness, the microvasculature, and immune cell infiltration within GBM was comprehensively observed and analysed. Overall, we propose that 2D and 3D analysis methods should be combined to provide much greater detail to increase the understanding of GBM spatial heterogeneity.

New astroglial injury-defined biomarkers for neurotrauma assessment

Traumatic brain injury (TBI) is an expanding public health epidemic with pathophysiology that is difficult to diagnose and thus treat. TBI biomarkers should assess patients across severities and reveal pathophysiology, but currently, their kinetics and specificity are unclear. No single ideal TBI biomarker exists. We identified new candidates from a TBI CSF proteome by selecting trauma-released, astrocyte-enriched proteins including aldolase C (ALDOC), its 38kD breakdown product (BDP), brain lipid binding protein (BLBP), astrocytic phosphoprotein (PEA15), glutamine synthetase (GS) and new 18-25kD-GFAP-BDPs. Their levels increased over four orders of magnitude in severe TBI CSF. First post-injury week, ALDOC levels were markedly high and stable. Short-lived BLBP and PEA15 related to injury progression. ALDOC, BLBP and PEA15 appeared hyper-acutely and were similarly robust in severe and mild TBI blood; 25kD-GFAP-BDP appeared overnight after TBI and was rarely present after mild TBI. Using a human culture trauma model, we investigated biomarker kinetics. Wounded (mechanoporated) astrocytes released ALDOC, BLBP and PEA15 acutely. Delayed cell death corresponded with GFAP release and proteolysis into small GFAP-BDPs. Associating biomarkers with cellular injury stages produced astroglial injury-defined (AID) biomarkers that facilitate TBI assessment, as neurological deficits are rooted not only in death of CNS cells, but also in their functional compromise.

S100β is associated with cognitive impairment in childhood-onset systemic lupus erythematosus patients

Objective

To investigate serologic S100β protein levels in childhood-onset SLE patients (cSLE) and to elucidate their association with disease activity and neuropsychiatric (NP) manifestations.

Methods

We included 71 cSLE patients (67 females; median age 18 years; range 9–37 and 53 (47 females; median age of 20 years; range 6–29) age and sex matched healthy controls. Neurological manifestations were analysed according to the American College of Rheumatology (ACR) criteria. Cognitive evaluation was performed in all participants using Wechsler Intelligence Scale for Children (WISC-III) and Wechsler Adult Intelligence Scale (WAIS), according to age, and validated in Portuguese. SLE patients were further assessed for clinical and laboratory SLE manifestations, disease activity (SLE Disease Activity Index (SLEDAI)), damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI)) and current drug exposures. Sera S100β protein levels were measured by enzyme-linked immunosorbent assay using commercial kits.

Results

The median S100β protein level was 116.55 pg/mL (range 1.53–468.50) in cSLE and 54.98 pg/mL (range 0.69–181.00) in healthy controls ( p < 0.001). An association was observed between S100β protein and NP manifestations ( p = 0.03). The S100β protein levels was associated with cognitive impairment in cSLE patients ( p = 0.006).

Conclusions

S100β protein levels are increased in cSLE with cognitive impairment. S100β may be considered a potential biomarker that underlies central nervous system (CNS) dysfunction, especially cognitive impairment.

Expression of Glucose-Regulated Protein 78 and miR-199a in Rat Brain After Fatal Ligature Strangulation

The roles of endoplasmic reticulum (ER) stress and microRNA in the brain tissue after fatal mechanical asphyxia have not been clearly elucidated. We examined the expression of glucose-regulated protein 78 (GRP78), the key regulator of unfolded protein response, and miR-199a in the brain tissues of rats subjected to fatal ligature strangulation to understand the roles of ER stress and microRNA in ligature strangulation. The expressions of GRP78 and miR-199a in rat cortex, hippocampi, and midbrain were measured by immunohistochemistry and Western blot analysis in a rat model of ligature strangulation. Furthermore, the levels of miR-199a-3p and miR-199a-5p were detected by real-time fluorescent quantitative polymerase chain reaction. Glucose-regulated protein 78 was highly expressed in the cortex and midbrain in the ligature strangulation group (P < 0.01) when compared with the control group. The expression of GRP78 in the hippocampi showed no significant difference between the 2 groups. miR-199a-3p in the cortex and midbrain was significantly down-regulated in the ligature strangulation group (P < 0.01). However, miR-199a-5p in each brain region showed no significant difference between the 2 groups. In conclusion, ER stress was involved in the physiological and pathological processes of ligature strangulation. Furthermore, upstream miR-199a may play an important regulatory role in mechanical asphyxia.

Forensic molecular pathology: its impacts on routine work, education and training

The major role of forensic pathology is the investigation of human death in relevance to social risk management to determine the cause and process of death, especially in violent and unexpected sudden deaths, which involve social and medicolegal issues of ultimate, personal and public concerns. In addition to the identification of victims and biological materials, forensic molecular pathology contributes to general explanation of the human death process and assessment of individual death on the basis of biological molecular evidence, visualizing dynamic functional changes involved in the dying process that cannot be detected by morphology (pathophysiological or molecular biological vital reactions); the genetic background (genomics), dynamics of gene expression (up-/down-regulation: transcriptomics) and vital phenomena, involving activated biological mediators and degenerative products (proteomics) as well as metabolic deterioration (metabolomics), are detected by DNA analysis, relative quantification of mRNA transcripts using real-time reverse transcription-PCR (RT-PCR), and immunohisto-/immunocytochemistry combined with biochemistry, respectively. Thus, forensic molecular pathology involves the application of omic medical sciences to investigate the genetic basis, and cause and process of death at the biological molecular level in the context of forensic pathology, that is, 'advanced molecular autopsy'. These procedures can be incorporated into routine death investigations as well as guidance, education and training programs in forensic pathology for 'dynamic assessment of the cause and process of death' on the basis of autopsy and laboratory data. Postmortem human data can also contribute to understanding patients' critical conditions in clinical management.