Increased MANF Expression in the Inferior Temporal Gyrus in Patients With Alzheimer Disease

Predicting cognitive dysfunction and regional hubs using Braak staging amyloid-beta biomarkers and machine learning

Mild cognitive impairment (MCI) is a transitional stage between normal aging and early Alzheimer's disease (AD). The presence of extracellular amyloid-beta (Aβ) in Braak regions suggests a connection with cognitive dysfunction in MCI/AD. Investigating the multivariate predictive relationships between regional Aβ biomarkers and cognitive function can aid in the early detection and prevention of AD. We introduced machine learning approaches to estimate cognitive dysfunction from regional Aβ biomarkers and identify the Aβ-related dominant brain regions involved with cognitive impairment. We employed Aβ biomarkers and cognitive measurements from the same individuals to train support vector regression (SVR) and artificial neural network (ANN) models and predict cognitive performance solely based on Aβ biomarkers on the test set. To identify Aβ-related dominant brain regions involved in cognitive prediction, we built the local interpretable model-agnostic explanations (LIME) model. We found elevated Aβ in MCI compared to controls and a stronger correlation between Aβ and cognition, particularly in Braak stages III-IV and V-VII (p < 0.05) biomarkers. Both SVR and ANN, especially ANN, showed strong predictive relationships between regional Aβ biomarkers and cognitive impairment (p < 0.05). LIME integrated with ANN showed that the parahippocampal gyrus, inferior temporal gyrus, and hippocampus were the most decisive Braak regions for predicting cognitive decline. Consistent with previous findings, this new approach suggests relationships between Aβ biomarkers and cognitive impairment. The proposed analytical framework can estimate cognitive impairment from Braak staging Aβ biomarkers and delineate the dominant brain regions collectively involved in AD pathophysiology.

Navigating the Landscape of MANF Research: A Scientometric Journey with CiteSpace Analysis

This study employs bibliometric analysis through CiteSpace to comprehensively evaluate the status and trends of MANF (mesencephalic astrocyte-derived neurotrophic factor) research spanning 25 years (1997-2022). It aims to fill the gap in objective and comprehensive reviews of MANF research. MANF-related studies were extracted from the Web of Science database. MANF publications were quantitatively and qualitatively analyzed for various factors by CiteSpace, including publication volume, journals, countries/regions, institutions, and authors. Keywords and references were visually analyzed to unveil research evolution and hotspot. Analysis of 353 MANF-related articles revealed escalating annual publications, indicating growing recognition of MANF's importance. High-impact journals such as the International Journal of Molecular Sciences and Journal of Biological Chemistry underscored MANF's interdisciplinary significance. Collaborative networks highlighted China and the USA's pivotal roles, while influential figures and partnerships drove understanding of MANF's mechanisms. Co-word analysis of MANF-related keywords exposed key evolutionary hotspots, encompassing neurotrophic effects, cytoprotective roles, MANF-related diseases, and the CDNF/MANF family. This progression from basic understanding to clinical potential showcased MANF's versatility from cellular protection to therapy. Bibliometric analysis reveals MANF's diverse research trends and pathways, from basics to clinical applications, driving medical progress. This comprehensive assessment enriches understanding and empowers researchers for dynamic evolution, advancing innovation, and benefiting patients. Bibliometric analysis of MANF research. The graphical abstract depicts the bibliometric analysis of MANF research, highlighting its aims, methods, and key results.

CDNF and MANF in the brain dopamine system and their potential as treatment for Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by gradual loss of midbrain dopamine neurons, leading to impaired motor function. Preclinical studies have indicated cerebral dopamine neurotrophic factor (CDNF) and mesencephalic astrocyte-derived neurotrophic factor (MANF) to be potential therapeutic molecules for the treatment of PD. CDNF was proven to be safe and well tolerated when tested in Phase I-II clinical trials in PD patients. Neuroprotective and neurorestorative effects of CDNF and MANF were demonstrated in animal models of PD, where they promoted the survival of dopamine neurons and improved motor function. However, biological roles of endogenous CDNF and MANF proteins in the midbrain dopamine system have been less clear. In addition to extracellular trophic activities, CDNF/MANF proteins function intracellularly in the endoplasmic reticulum (ER), where they modulate protein homeostasis and protect cells against ER stress by regulating the unfolded protein response (UPR). Here, our aim is to give an overview of the biology of endogenous CDNF and MANF in the brain dopamine system. We will discuss recent studies on CDNF and MANF knockout animal models, and effects of CDNF and MANF in preclinical models of PD. To elucidate possible roles of CDNF and MANF in human biology, we will review CDNF and MANF tissue expression patterns and regulation of CDNF/MANF levels in human diseases. Finally, we will discuss novel findings related to the molecular mechanism of CDNF and MANF action in ER stress, UPR, and inflammation, all of which are mechanisms potentially involved in the pathophysiology of PD.

Mesencephalic Astrocyte-Derived Neurotrophic Factor (MANF): An Emerging Therapeutic Target for Neurodegenerative Disorders

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a member of the new family of neurotrophic factors (NTFs) with a unique structure and functions compared to other conventionally known NTFs. MANF is broadly expressed in developing and mature tissues, including the central nervous system and peripheral nervous system tissues. Growing research demonstrated that MANF protects neurons from endoplasmic reticulum (ER) stress-associated complications by restoring ER homeostasis and regulating unfolded protein response. This review discusses MANF signaling in neurodegenerative conditions with specific emphasis given to its overall effect and mechanisms of action in experimental models of Parkinson’s disease, Alzheimer’s disease, and stroke. Additional perspectives on its potential unexplored roles in other neurodegenerative conditions are also given.

The Role of the Mesencephalic Astrocyte-Derived Neurotrophic Factor in Patients in Intensive Care Units Receiving Voriconazole Therapy

Recent publications regarding the role of mesencephalic astrocyte-derived neurotrophic factor (MANF) in various metabolic and degenerative disorders suggest that MANF is both a marker of disease and a possible therapeutic agent. We investigate the role of plasma MANF levels in patients in intensive care units (ICUs) receiving voriconazole (VCZ) therapy while also comparing MANF levels in healthy individuals. A single-center prospective study was conducted. The plasma MANF level in patients in ICU was found to have high interindividual variability and was significantly higher than that in healthy controls (P < .01). Compared with patients using VCZ only, patients using both VCZ and amikacin had 3-fold lower MANF concentrations (P < .05). The MANF concentrations also decreased when alkaline phosphatase (ALP) and serum creatinine levels were above the upper limits of the normal range (P < .05) and the estimated glomerular filtration rate (eGFR) was below the lower limit of the normal range (P < .01). Receiver operating characteristic curve analysis indicated that low MANF levels were associated with high ALP levels, high creatinine levels, and low eGFR. The cut-off value of MANF for ALP levels higher than 126 U/L was 0.35 ng/mL (area under curve, AUC = 0.62, 95%CI = 0.50-0.74, P = .044); for serum creatinine levels higher than 104 μmol/L, the cut-off value was 0.41 ng/mL (AUC = 0.74, 95%CI = 0.62-0.87, P = .001); and for eGFR below 80 mL/min, the cut-off value was 0.75 ng/mL (AUC = 0.70, 95%CI = 0.59-0.81, P = .002). Monitoring plasma MANF levels may be of value for clinical decision-making regarding the choice of antibiotics and the prediction of impaired liver function and renal function in patients admitted to an ICU.

MANF/EWSR1/ANXA6 pathway might as the bridge between hypolipidemia and major depressive disorder

Major depressive disorder (MDD) involves changes in lipid metabolism, but previous findings are contradictory. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is considered to be a regulator of lipid metabolism. To date, the function of MANF has been studied in many brain disorders, but not in MDD. Therefore, to better understand the role of lipids in MDD, this study was conducted to examine lipid levels in the serum of MDD patients and to investigate the potential function of MANF in MDD. First, the data on total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) in serum from 354 MDD patients and 360 healthy controls (HCs) were collected and analyzed. The results showed that there were significantly lower concentrations of TC and LDL-C in MDD patients compared with HCs, and TC levels were positively correlated with LDL-C levels. Bioinformatics analysis indicated that MANF/EWSR1/ANXA6 pathway might serve as the connecting bridge through which hypolipidemia played a functional role in MDD. Second, to verify this hypothesis, serum samples were collected from 143 MDD patients, and 67 HCs to measure the levels of MANF, EWSR1, and ANXA6 using ELISA kits. The results showed that compared to HCs, MDD patients had a significantly lower level of MANF and higher levels of ANXA6 and EWSR1, and these molecules were significantly correlated with both TC level and Hamilton Depression Rating Scales (HDRS) score. In addition, a discriminative model consisting of MANF, EWSR1, and ANXA6 was identified. This model was capable of distinguishing MDD subjects from HCs, yielded an area under curve of 0.9994 in the training set and 0.9569 in the testing set. Taken together, our results suggested that MANF/EWSR1/ANXA6 pathway might act as the bridge between hypolipidemia and MDD, and these molecules held promise as potential biomarkers for MDD.

Amyloidogenesis and Neurotrophic Dysfunction in Alzheimer’s Disease: Do They have a Common Regulating Pathway?

The amyloid cascade hypothesis has predominately been used to describe the pathogenesis of Alzheimer’s disease (AD) for decades, as Aβ oligomers are thought to be the prime cause of AD. Meanwhile, the neurotrophic factor hypothesis has also been proposed for decades. Accumulating evidence states that the amyloidogenic process and neurotrophic dysfunction are mutually influenced and may coincidently cause the onset and progress of AD. Meanwhile, there are intracellular regulators participating both in the amyloidogenic process and neurotrophic pathways, which might be the common original causes of amyloidogenesis and neurotrophic dysfunction. In this review, the current understanding regarding the role of neurotrophic dysfunction and the amyloidogenic process in AD pathology is briefly summarized. The mutual influence of these two pathogenesis pathways and their potential common causal pathway are further discussed. Therapeutic strategies targeting the common pathways to simultaneously prevent amyloidogenesis and neurotrophic dysfunction might be anticipated for the disease-modifying treatment of AD.

Potential Role of MANF, an ER Stress Responsive Neurotrophic Factor, in Protecting Against Alcohol Neurotoxicity

Alcohol exposure during pregnancy is harmful to the fetus and causes a wide range of long-lasting physiological and neurocognitive impairments, collectively referred to as fetal alcohol spectrum disorders (FASD). The neurobehavioral deficits observed in FASD result from structural and functional damages in the brain, with neurodegeneration being the most destructive consequence. Currently, there are no therapies for FASD. It is exigent to delineate the underlying mechanisms of alcohol neurotoxicity and develop an effective strategy of treatment. ER stress, caused by the accumulation of unfolded/misfolded proteins in the ER, is the hallmark of many neurodegenerative diseases, including alcohol-induced neurodegeneration. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a newly discovered endoplasmic reticulum (ER) stress responsive neurotrophic factor that regulates diverse neuronal functions. This review summarizes the recent findings revealing the effects of MANF on the CNS and its protective role against neurodegeneration. Particularly, we focus the role of MANF on alcohol-induced ER stress and neurodegeneration and discuss the therapeutic potential of MANF in treating alcohol neurotoxicity such as FASD.