An arylthiazyne derivative is a potent inhibitor of lipid peroxidation and ferroptosis providing neuroprotection in vitro and in vivo.

Lipid peroxidation-initiated ferroptosis is an iron-dependent mechanism of programmed cell death taking place in neurological diseases. Here we show that a condensed benzo[b]thiazine derivative small molecule with an arylthiazine backbone (ADA-409-052) inhibits tert-Butyl hydroperoxide (TBHP)-induced lipid peroxidation (LP) and protects against ferroptotic cell death triggered by glutathione (GSH) depletion or glutathione peroxidase 4 (GPx4) inhibition in neuronal cell lines. In addition, ADA-409-052 suppresses pro-inflammatory activation of BV2 microglia and protects N2a neuronal cells from cell death induced by pro-inflammatory RAW 264.7 macrophages. Moreover, ADA-409-052 efficiently reduces infarct volume, edema and expression of pro-inflammatory genes in a mouse model of thromboembolic stroke. Targeting ferroptosis may be a promising therapeutic strategy in neurological diseases involving severe neuronal death and neuroinflammation.

Susceptibility to focal and global brain ischemia of Alzheimer mice displaying aß deposits: effect of immunoglobulin.

Cerebral ischemia is a risk factor for Alzheimer's disease (AD). Moreover, recent evidence indicates that it is a two-way street as the incidence rate of stroke is significantly higher in AD patients than those without the disease. Here we investigated the interaction of ischemic brain insults and AD in 9-month-old ApdE9 mice, which show full-blown accumulation of Aß deposits and microgliosis in the brain. Permanent occlusion of the middle cerebral artery (pMCAo) resulted in 36% larger infarct in ApdE9 mice compared to their wild-type (wt) controls. This was not due to differences in endothelium-dependent vascular reactivity. Treatment with human intravenous immunoglobulin (IVIG) reduced the infarct volumes and abolished the increased vulnerability of ApdE9 mice to pMCAo induced brain ischemia. When the mice were exposed to global brain ischemia (GI), an insult of hippocampal cells, ApdE9 mice showed increased neuronal loss in CA2 and CA3 subregions compared to their wt controls. GI was associated with increased microgliosis, astrogliosis, infiltration of blood-derived monocytic cells, and neurogenesis without clear differences between the genotypes. IVIG treatment prevented the GI-induced neuron loss in hippocampal CA1 and CA3 regions in ApdE9 mice. IVIG treatment increased microgliosis in wt but not in ApdE9 mice. Finally, GI induced 60% reduction in the hippocampal Aß burden in ApdE9 mice, which was not affected by IVIG treatment. The results indicate that the AD pathology with Aß deposits and microgliosis increases ischemic vulnerability in various brain areas. Moreover, IVIG treatment may be beneficial especially in patients suffering from both acute ischemic insult and AD.

Production of monocytic cells from bone marrow stem cells: therapeutic usage in Alzheimer's disease.

Accumulation of amyloid ß (Aß) is a major hallmark in Alzheimer's disease (AD). Bone marrow derived monocytic cells (BMM) have been shown to reduce Aß burden in mouse models of AD, alleviating the AD pathology. BMM have been shown to be more efficient phagocytes in AD than the endogenous brain microglia. Because BMM have a natural tendency to infiltrate into the injured area, they could be regarded as optimal candidates for cell-based therapy in AD. In this study, we describe a method to obtain monocytic cells from BM-derived haematopoietic stem cells (HSC). Mouse or human HSC were isolated and differentiated in the presence of macrophage colony stimulating factor (MCSF). The cells were characterized by assessing the expression profile of monocyte markers and cytokine response to inflammatory stimulus. The phagocytic capacity was determined with Aß uptake assay in vitro and Aß degradation assay of natively formed Aß deposits ex vivo and in a transgenic APdE9 mouse model of AD in vivo. HSC were lentivirally transduced with enhanced green fluorescent protein (eGFP) to determine the effect of gene modification on the potential of HSC-derived cells for therapeutic purposes. HSC-derived monocytic cells (HSCM) displayed inflammatory responses comparable to microglia and peripheral monocytes. We also show that HSCM contributed to Aß reduction and could be genetically modified without compromising their function. These monocytic cells could be obtained from human BM or mobilized peripheral blood HSC, indicating a potential therapeutic relevance for AD.

Lack of collagen XV impairs peripheral nerve maturation and, when combined with laminin-411 deficiency, leads to basement membrane abnormalities and sensorimotor dysfunction.

Although the Schwann cell basement membrane (BM) is required for normal Schwann cell terminal differentiation, the role of BM-associated collagens in peripheral nerve maturation is poorly understood. Collagen XV is a BM zone component strongly expressed in peripheral nerves, and we show that its absence in mice leads to loosely packed axons in C-fibers and polyaxonal myelination. The simultaneous lack of collagen XV and another peripheral nerve component affecting myelination, laminin α4, leads to severely impaired radial sorting and myelination, and the maturation of the nerve is permanently compromised, contrasting with the slow repair observed in Lama4-/- single knock-out mice. Moreover, the Col15a1-/-;Lama4-/- double knock-out (DKO) mice initially lack C-fibers and, even over 1 year of age have only a few, abnormal C-fibers. The Lama4-/- knock-out results in motor and tactile sensory impairment, which is exacerbated by a simultaneous Col15a1-/- knock-out, whereas sensitivity to heat-induced pain is increased in the DKO mice. Lack of collagen XV results in slower sensory nerve conduction, whereas the Lama4-/- and DKO mice exhibit increased sensory nerve action potentials and decreased compound muscle action potentials; x-ray diffraction revealed less mature myelin in the sciatic nerves of the latter than in controls. Ultrastructural analyses revealed changes in the Schwann cell BM in all three mutants, ranging from severe (DKO) to nearly normal (Col15a1-/-). Collagen XV thus contributes to peripheral nerve maturation and C-fiber formation, and its simultaneous deletion from neural BM zones with laminin α4 leads to a DKO phenotype distinct from those of both single knock-outs.

The role and therapeutic potential of monocytic cells in Alzheimer's disease.

Alzheimer's disease (AD) is a dementing neurodegenerative disorder without a cure. The abnormal parenchymal accumulation of beta-amyloid (Abeta) is associated with inflammatory reactions involving microglia and astrocytes. Increased levels of Abeta and Abeta deposition in the brain are thought to cause neuronal dysfunction and underlie dementia. Microglia, the brain resident cells of monocytic origin, have a potential ability to phagocytose Abeta but they also react to Abeta by increased production of proinflammatory toxic agents. Microglia originate from hemangioblastic mesoderm during early embryonic stages and from bone marrow (BM)-derived monocytic cells that home the brain throughout the neonatal stage of development. Recent studies indicate that BM or blood-derived monocytes are recruited to the diseased AD brain, associate with the Abeta depositions, and are more efficient phagocytes of Abeta compared with resident microglia. The clearance of Abeta deposition by these cells has been recently under intensive investigation and can occur through several different mechanisms. Importantly, peripheral monocytic cells of patients with AD appear to be deficient in clearing Abeta. This review will summarize the findings on the role of blood-derived cells in AD and discuss their therapeutic potential for treating patients suffering from this devastating disease.

Double knockout mice reveal a lack of major functional compensation between collagens XV and XVIII.

Generation of double knockout mice for collagen types XV and XVIII indicated surprisingly that the mice are viable and do not suffer from any new major defects. Although the two collagens are closely related molecules sharing similarities in tissue expression, we conclude that their biological roles are essentially separate, that of type XV in muscle and type XVIII in the eye. Detailed comparisons of the null mice eyes indicated that type XV collagen seems to be involved in the tunica vasculosa lentis regression process, whereas type XVIII is in the regression of vasa hyaloidea propria, and only minor compensatory effects could be detected. Furthermore, the essential role of type XVIII collagen in the eye is highlighted by the occurrence of this collagen in the epithelial basement membranes of the iris and the ciliary body and in the inner limiting membrane of the retina, sites lacking type XV.

Developmentally regulated expression of type XV collagen correlates with abnormalities in Col15a1(-/-) mice.

Lack of type XV collagen in mice results in mild skeletal myopathy and increases vulnerability to exercise-induced skeletal muscle and cardiac injury [Proc. Natl. Acad. Sci. USA 98 (2001), 1194]. The expression of type XV collagen was studied during murine fetal development from 10.5 to 18.5 dpc using immunofluorescence. The first sign of type expression was seen in the capillaries of many tissues at 10.5 dpc, some of them showing developmental transitions in the expression. Interestingly, capillaries forming the blood-brain barrier and those of the sinusoidal type were essentially lacking in this collagen. Early expression was also detected in the skeletal muscle and peripheral nerves, while expression in the heart, kidney and lung appeared to be developmentally regulated. In addition, distinct staining was found in the perichondrium of the cartilage. Collectively, the dynamics of its expression during development, its localization in the basement membrane--fibrillar matrix interface and the consequences of its absence in mice suggest a structural role in providing stability at least in skeletal muscle and capillaries. The early prominent expression of type XV collagen in newly forming blood vessels could also indicate a possible role in angiogenic processes.