Weekly glatiramer acetate immunization of transgenic mice modelling Alzheimer's disease resulted in retained cognition (Morris water maze test), decreased amyloid-β plaque burden, and regulation of local inflammation through a mechanism involving enhanced recruitment of monocytes. Ablation of bone marrow-derived myeloid cells exacerbated plaque pathology, whereas weekly administration of glatiramer acetate enhanced cerebral recruitment of innate immune cells, which dampened the pathology. Here, we assessed the therapeutic potential of grafted CD115(+) monocytes, injected once monthly into the peripheral blood of transgenic APPSWE/PS1ΔE9 Alzheimer's disease mouse models, with and without weekly immunization of glatiramer acetate, as compared to glatiramer acetate alone. All immune-modulation treatment groups were compared with age-matched phosphate-buffered saline-injected control transgenic and untreated non-transgenic mouse groups. Two independent cohorts of mice were assessed for behavioural performance (6-8 mice/group); treatments started in 10-month-old symptomatic mice and spanned a total of 2 months. For all three treatments, our data suggest a substantial decrease in cognitive deficit as assessed by the Barnes maze test (P < 0.0001-0.001). Improved cognitive function was associated with synaptic preservation and reduction in cerebral amyloid-β protein levels and astrogliosis (P < 0.001 and P < 0.0001), with no apparent additive effects for the combined treatment. The peripherally grafted, green fluorescent protein-labelled and endogenous monocytes, homed to cerebral amyloid plaques and directly engulfed amyloid-β; their recruitment was further enhanced by glatiramer acetate. In glatiramer acetate-immunized mice and, moreover, in the combined treatment group, monocyte recruitment to the brain was coupled with greater elevation of the regulatory cytokine IL10 surrounding amyloid-β plaques. All treated transgenic mice had increased cerebral levels of MMP9 protein (P < 0.05), an enzyme capable of degrading amyloid-β, which was highly expressed by the infiltrating monocytes. In vitro studies using primary cultures of bone marrow monocyte-derived macrophages, demonstrated that glatiramer acetate enhanced the ability of macrophages to phagocytose preformed fibrillar amyloid-β1-42 (P < 0.0001). These glatiramer acetate-treated macrophages exhibited increased expression of the scavenger receptors CD36 and SCARA1 (encoded by MSR1), which can facilitate amyloid-β phagocytosis, and the amyloid-β-degrading enzyme MMP9 (P < 0.0001-0.001). Overall, our studies indicate that increased cerebral infiltration of monocytes, either by enrichment of their levels in the circulation or by weekly immunization with glatiramer acetate, resulted in substantial attenuation of disease progression in murine Alzheimer's models by mechanisms that involved enhanced cellular uptake and enzymatic degradation of toxic amyloid-β as well as regulation of brain inflammation.
Cognitive decline in patients with Alzheimer's disease (AD) is associated with elevated brain levels of amyloid β protein (Aβ), particularly neurotoxic Aβ 1-42 . Angiotensin-converting enzyme (ACE) can degrade Aβ 1-42 , and ACE overexpression in myelomonocytic cells enhances their immune function. To examine the effect of targeted ACE overexpression on AD, we crossed ACE 10/10 mice, which overexpress ACE in myelomonocytes using the c-fms promoter, with the transgenic APP SWE /PS1 ΔE9 mouse model of AD (AD + ). Evaluation of brain tissue from these AD + ACE 10/10 mice at 7 and 13 months revealed that levels of both soluble and insoluble brain Aβ 1-42 were reduced compared with those in AD + mice. Furthermore, both plaque burden and astrogliosis were drastically reduced. Administration of the ACE inhibitor ramipril increased Aβ levels in AD + ACE 10/10 mice compared with the levels induced by the ACE-independent vasodilator hydralazine. Overall, AD + ACE 10/10 mice had less brain-infiltrating cells, consistent with reduced AD-associated pathology, though ACE-overexpressing macrophages were abundant around and engulfing Aβ plaques. At 11 and 12 months of age, the AD + ACE 10/WT and AD + ACE 10/10 mice were virtually equivalent to non-AD mice in cognitive ability, as assessed by maze-based behavioral tests. Our data demonstrate that an enhanced immune response, coupled with increased myelomonocytic expression of catalytically active ACE, prevents cognitive decline in a murine model of AD.
Background-The extent to which the prognosis for AIDS and death of patients initiating highly active antiretroviral therapy (HAART) continues to be affected by their characteristics at the time of initiation (baseline) is unclear.Methods-We analyzed data on 20,379 treatment-naive HIV-1-infected adults who started HAART in 1 of 12 cohort studies in Europe and North America (61,798 person-years of followup, 1844 AIDS events, and 1005 deaths).Results-Although baseline CD4 cell count became less prognostic with time, individuals with a baseline CD4 count <25 cells/µL had persistently higher progression rates than individuals with a baseline CD4 count >350 cells/µL (hazard ratio for AIDS = 2.3, 95% confidence interval [CI]: 1.0 to 2.3; mortality hazard ratio = 2.5, 95% CI: 1.2 to 5.5, 4 to 6 years after starting HAART). Rates of AIDS were persistently higher in individuals who had experienced an AIDS event before starting HAART. Individuals with presumed transmission by means of injection drug use experienced substantially higher rates of AIDS and death than other individuals throughout follow-up (AIDS hazard ratio = 1.6, 95% CI: 0.8 to 3.0; mortality hazard ratio = 3.5, 95% CI: 2.2 to 5.5, 4 to 6 years after starting HAART).Conclusions-Compared with other patient groups, injection drug users and patients with advanced immunodeficiency at baseline experience substantially increased rates of AIDS and death up to 6 years after starting HAART.
Switching from a virologically successful first-line boosted PI-containing cART regimen to a non-nucleoside reverse transcriptase inhibitor-containing cART regimen containing either efavirenz or nevirapine is virologically safe, while switching to abacavir-containing cART should be avoided.
The cognitive decline in Alzheimer's disease (AD) is associated with elevated brain levels of amyloid β-protein (Aβ), particularly Aβ 1-42 . Angiotensin-converting enzyme (ACE) can enzymatically degrade Aβ 1-42 and its overexpression in myelomonocytic cells enhances their immune function. To examine the effect of targeted ACE overexpression on AD, we crossed ACE 10/10 mice, which over express ACE in myelomonocytic cells, with the double-transgenic APP SWE /PS1 ΔE9 mouse model of AD (AD + ). At 7 months, soluble Aβ 1-42 was reduced by 44% (136 vs 245 pg/mg) and Aβ 1-40 was reduced by 32% (21 vs 31 pg/mg). Plaque burden was reduced by as much as 79% (13 vs 62 10 3 mm 2 ) and insoluble Aβ 1-42 by 64% (189 vs 521 pg/mg). There was also a substantial reduction in astrogliosis (49-57% at 7 months, 50% at 13 months). AD + ACE 10/10 mice demonstrated less overall brain infiltrating cells, consistent with less AD pathology, though ACE-overexpressing monocytes and macrophages were increasingly abundant surrounding and engulfing Aβ plaque. At 11 and 12 months, AD + ACE 10/WT and AD + ACE 10/10 mice were virtually equivalent to non-AD mice in cognitive ability as assessed by maze-based behavioral tests. This study shows that an enhanced immune response, coupled with increased myelomonocytic cell expression of ACE, resulted in essentially complete prevention of the cognitive decline observed in a murine model of AD.
development of experimental autoimmune encephalomyelitis (EAE) in rats and to elucidate its underlying mechanisms. Methods: EAE model was induced by immunization of adult female Lewis rats with purified guineapig myelin basic protein (MBP)68-86. CIG and EF were administrated intragastrically once a day after immunization until day 21 post immunization (p.i.). Histopathological staining, enzyme-linked immunosorbent assay (ELISA), biochemical methods and western blotting approaches were used to evaluate the disease incidence and severity, neuroinflammatory and neurotrophic response in the central nervous system (CNS). Results: CIG or EF intragastrical administration significantly reduced clinical score of neurological deficit in EAE rats; alleviated demyelination and inflammatory infiltration; and inhibited glias activation, nuclear transcription factor (NF-kB) expression in the spinal cord of EAE rats. Treatment with CIG or EF also enhanced neurotrophic factors such as nerve growth factor (NGF) or brain-derived nerve factor (BDNF) expression, increased the number of oligodendrocytes and protected the ultrastructure of myelin sheaths and axons in the spinal cord of EAE rats. Conclusions: Our results showed that CIG and EF could inhibit the development of MBP-induced EAE in rats and our findings suggest that traditional Chinese medicine with reinforcing kidney activity may be useful for the treatment of multiple sclerosis. This effect involved reducing neuroinflammation and enhancing myelination and neurotrophins.
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