The effects of enhancing angiotensin converting enzyme in myelomonocytes on ameliorating Alzheimer's-related disease and preserving cognition

Cognitive impairment in patients with heart failure: Physiopathology, clinical implications, and therapeutic considerations

Cognitive impairment (CI) is a significant comorbidity in individuals with heart failure (HF). A substantial number of patients with HF may experience CI, which can present as deficits in attention, memory, executive function, and processing speed. HF patients with CI tend to have reduced functional independence, self-care capabilities, medication adherence and decision-making ability, along with more frequent rehospitalizations, and an increased risk of mortality. Currently, there is no established gold standard diagnostic tool or follow-up strategy for assessing CI in patients with HF. There has been an increasing recognition of the complex bidirectional relationship between HF and CI. However, the exact pathological mechanisms of CI in HF need further in-depth investigation. This review aims to explore the current epidemiological status of CI in patients with HF, the relationship between HF and cognitive dysfunction, the pathological mechanisms involved, as well as the early screening, diagnosis, and management issues for HF patients with CI. It also discusses prevention and intervention strategies. The objective is to provide a scientific basis for the clinical diagnosis, management, and treatment of CI in HF, while proposing future research directions to advance this field.

Dimerization and dynamics of angiotensin-I converting enzyme revealed by cryoEM and MD simulations

Angiotensin-I converting enzyme (ACE) regulates the levels of disparate bioactive peptides, notably converting angiotensin-I to angiotensin-II and degrading amyloid beta. ACE is a heavily glycosylated dimer, containing 4 analogous catalytic sites, and exists in membrane bound and soluble (sACE) forms. ACE inhibition is a frontline, FDA-approved, therapy for cardiovascular diseases yet is associated with significant side effects, including higher rates of lung cancer. To date, structural studies have been confined to individual domains or partially denatured cryoEM structures. Here we report the cryoEM structure of the full-length, glycosylated, sACE dimer. We resolved four structural states at 2.99 to 3.65 Å resolution which are primarily differentiated by varying degrees of solvent accessibility to the active sites and reveal the full dimerization interface. We also employed all-atom molecular dynamics (MD) simulations and heterogeneity analysis in cryoSPARC, cryoDRGN, and RECOVAR to elucidate the conformational dynamics of sACE and identify key regions mediating conformational change. We identify differences in the mechanisms governing the conformational dynamics of individual domains that have implications for the design of domain-specific sACE modulators.

Peripheral blood amyloid-β involved in the pathogenesis of Alzheimer's disease via impacting on peripheral innate immune cells

A key pathological factor of Alzheimer's disease (AD), the most prevalent form of age-related dementia in the world, is excessive β-amyloid protein (Aβ) in extracellular aggregation in the brain. And in the peripheral blood, a large amount of Aβ is derived from platelets. So far, the causality between the levels of peripheral blood Aβ and its aggregation in the brain, particularly the role of the peripheral blood Aβ in the pathology of AD, is still unclear. And the relation between the peripheral blood Aβ and tau tangles of brain, another crucial pathologic factor contributing to the pathogenesis of AD, is also ambiguous. More recently, the anti-Aβ monoclonal antibodies are approved for treatment of AD patients through declining the peripheral blood Aβ mechanism of action to enhance plasma and central nervous system (CNS) Aβ clearance, leading to a decrease Aβ burden in brain and improving cognitive function, which clearly indicates that the levels of the peripheral blood Aβ impacted on the Aβ burden in brain and involved in the pathogenesis of AD. In addition, the role of peripheral innate immune cells in AD remains mostly unknown and the results obtained were controversial. In the present review, we summarize recent studies on the roles of peripheral blood Aβ and the peripheral innate immune cells in the pathogenesis of AD. Finally, based on the published data and our own work, we believe that peripheral blood Aβ plays an important role in the development and progression of AD by impacting on the peripheral innate immune cells.