Anti-CD163 Antibody [K20-T] (A8196)

OBJECTIVE:

Although the underlying cause of Huntington's disease (HD) is well established, the actual pathophysiological processes involved remain to be fully elucidated. In other proteinopathies such as Alzheimer's and Parkinson's diseases, there is evidence for impairments of the cerebral vasculature as well as the blood-brain barrier (BBB), which have been suggested to contribute to their pathophysiology. We investigated whether similar changes are also present in HD.

METHODS:

We used 3- and 7-Tesla magnetic resonance imaging as well as postmortem tissue analyses to assess blood vessel impairments in HD patients. Our findings were further investigated in the R6/2 mouse model using in situ cerebral perfusion, histological analysis, Western blotting, as well as transmission and scanning electron microscopy.

RESULTS:

We found mutant huntingtin protein (mHtt) aggregates to be present in all major components of the neurovascular unit of both R6/2 mice and HD patients. This was accompanied by an increase in blood vessel density, a reduction in blood vessel diameter, as well as BBB leakage in the striatum of R6/2 mice, which correlated with a reduced expression of tight junction-associated proteins and increased numbers of transcytotic vesicles, which occasionally contained mHtt aggregates. We confirmed the existence of similar vascular and BBB changes in HD patients.

INTERPRETATION:

Taken together, our results provide evidence for alterations in the cerebral vasculature in HD leading to BBB leakage, both in the R6/2 mouse model and in HD patients, a phenomenon that may, in turn, have important pathophysiological implications.

© 2015 American Neurological Association.

OBJECTIVE:

Huntington disease (HD) is caused by a genetically encoded pathological protein (mutant huntingtin [mHtt]), which is thought to exert its effects in a cell-autonomous manner. Here, we tested the hypothesis that mHtt is capable of spreading within cerebral tissue by examining genetically unrelated fetal neural allografts within the brains of patients with advancing HD.

METHODS:

The presence of mHtt aggregates within the grafted tissue was confirmed using 3 different types of microscopy (bright-field, fluorescence, and electron), 2 additional techniques consisting of Western immunoblotting and infrared spectroscopy, and 4 distinct antibodies targeting different epitopes of mHtt aggregates.

RESULTS:

We describe the presence of mHtt aggregates within intracerebral allografts of striatal tissue in 3 HD patients who received their transplants approximately 1 decade earlier and then died secondary to the progression of their disease. The mHtt(+) aggregates were observed in the extracellular matrix of the transplanted tissue, whereas in the host brain they were seen in neurons, neuropil, extracellular matrix, and blood vessels.

INTERPRETATION:

This is the first demonstration of the presence of mHtt in genetically normal and unrelated allografted neural tissue transplanted into the brain of affected HD patients. These observations raise questions on protein spread in monogenic neurodegenerative disorders of the central nervous system characterized by the formation of mutant protein oligomers/aggregates.

© 2014 American Neurological Association.

BACKGROUND:

Liver macrophages are a heterogeneous cell population that produces factors involved in fibrogenesis and matrix turnover, including matrix metalloproteinase (MMP) -9. During liver injury, their close proximity to hepatic progenitor cells and the ductular reaction may enable them to regulate liver repair and fibrosis.

AIMS:

To enumerate and characterise liver macrophages in patients with chronic hepatitis C, to determine whether a distinct population of macrophages is associated with the ductular reaction and portal fibrosis.

METHODS:

Immunostaining for macrophage markers (CD68, CD163, CCR2), the ductular reaction (keratin-7) and MMP-9 was performed in liver biopsy sections from patients with chronic hepatitis C virus (HCV) (n = 85).

RESULTS:

Portal tracts were more densely populated with macrophages (10.5 ± 0.36 macrophages/HPF) than lobules (7.2 ± 0.16 macrophages/HPF, P < 0.001) and macrophages were found in close proximity to the ductular reaction. ≥30% of portal and periductal macrophages expressed MMP-9 and these were significantly associated with increasing stage of fibrosis (rs  = 0.58, 0.68, respectively, both P < 0.001). In contrast, MMP-9(+) macrophages were largely absent in lobular regions and non-diseased liver. Hepatic MMP-9 mRNA levels and gelatinolytic activity were significantly associated with stage of fibrosis (rs  = 0.47, rs  = 0.89, respectively, both P < 0.001). Furthermore, a second distinct CCR2(+) macrophage population was localised to the centrilobular regions and was predominantly absent from portal and periductal areas.

CONCLUSIONS:

These findings demonstrate significant regional differences in macrophage phenotypes, suggesting that there are at least two populations of liver macrophages. We propose that these populations have distinct contributions to the pathogenesis of chronic HCV-related liver disease.

© 2012 John Wiley & Sons A/S.