Autophagy is a crucial biological process of eukaryotes, which is involved in cell growth, survival and energy metabolism, while the premise of the autophagy function is activated autophagic flux. It has been confirmed that impaired autophagic flux promotes pathogenesis of many chronic inflammatory diseases, especially cancer, neurodegenerative disease and tissue fibrosis, therefore the analysis of autophagic flux state is important for revealing autophagy function and the mechanism of autophagy related diseases. Given that autophagy is a dynamic process with multiple steps, it is very hard to observe the real state of autophagic flux. Summarized here is the novel concept and current approach to detect autophagic flux. This knowledge is crucial for the researching of the biological function of autophagy, and may provide some strategies for developing autophagy-related drug.
Autophagy ; Fibrosis ; Humans ; Inflammation ; pathology ; Neoplasms ; pathology ; Neurodegenerative Diseases ; pathology

Humans ; Cerebral Cortex ; Hallucinations/pathology* ; Neurodegenerative Diseases/pathology* ; Atrophy/pathology* ; Magnetic Resonance Imaging

Neurodegenerative diseases (NDs) have become a significant threat to an aging human society. Numerous studies have been conducted in the past decades to clarify their pathologic mechanisms and search for reliable biomarkers. Magnetic resonance imaging (MRI) is a powerful tool for investigating structural and functional brain alterations in NDs. With the advantages of being non-invasive and non-radioactive, it has been frequently used in both animal research and large-scale clinical investigations. MRI may serve as a bridge connecting micro- and macro-level analysis and promoting bench-to-bed translational research. Nevertheless, due to the abundance and complexity of MRI techniques, exploiting their potential is not always straightforward. This review aims to briefly introduce research progress in clinical imaging studies and discuss possible strategies for applying MRI in translational ND research.
Animals ; Humans ; Neurodegenerative Diseases/pathology* ; Translational Research, Biomedical ; Magnetic Resonance Imaging/methods* ; Brain/pathology* ; Head/pathology*

Exosomes are extracellular membranous vesicles with a diameter of 30-100 nm derived from a variety of eukaryocytes. The cargo of exosomes includes proteins, lipids, nucleic acids, and substances of the cells from which they originate. They can transfer functional cargo to neighboring and distal cells, therefore contributing to intercellular communication in both physiological and pathological processes. In recent years, it was shown that exosomes in several neurodegenerative diseases are closely related to the transmission of disease-related misfolded proteins (such as α-synuclein, tau, amyloid β-protein, etc). These proteins are transported by exosomes, thus promoting the propagation to unaffected cells or areas and accelerating the progression of neurodegenerative diseases. This review focuses on the origin and composition, biological synthesis, secretion, function of exosomes, as well as their roles in the pathogenesis and progression of neurodegenerative diseases. In addition, we also discuss that exosomes can serve as biomarkers and drug delivery vehicles, and play a role in the diagnosis and treatment of neurodegenerative diseases.
Amyloid beta-Peptides ; Biomarkers ; Cell Communication ; Exosomes ; pathology ; Humans ; Neurodegenerative Diseases ; pathology ; alpha-Synuclein ; tau Proteins

Animal models are essential for investigating the pathogenesis and developing the treatment of human diseases. Identification of genetic mutations responsible for neurodegenerative diseases has enabled the creation of a large number of small animal models that mimic genetic defects found in the affected individuals. Of the current animal models, rodents with genetic modifications are the most commonly used animal models and provided important insights into pathogenesis. However, most of genetically modified rodent models lack overt neurodegeneration, imposing challenges and obstacles in utilizing them to rigorously test the therapeutic effects on neurodegeneration. Recent studies that used CRISPR/Cas9-targeted large animal (pigs and monkeys) have uncovered important pathological events that resemble neurodegeneration in the patient's brain but could not be produced in small animal models. Here we highlight the unique nature of large animals to model neurodegenerative diseases as well as the limitations and challenges in establishing large animal models of neurodegenerative diseases, with focus on Huntington disease, Amyotrophic lateral sclerosis, and Parkinson diseases. We also discuss how to use the important pathogenic insights from large animal models to make rodent models more capable of recapitulating important pathological features of neurodegenerative diseases.
Amyotrophic Lateral Sclerosis/genetics* ; Animals ; Brain/pathology* ; Disease Models, Animal ; Gene Editing ; Neurodegenerative Diseases/pathology* ; Swine

Adult polyglucosan body disease (APBD) is a rare neurological disease, characterized by adult onset (fifth to seventh decades), progressive sensorimotor or pure motor peripheral neuropathy, upper motor neuron symptoms, neurogenic bladder, and cognitive impairment. APBD is confirmed by a sural nerve biopsy that shows the widespread presence of polyglucosan bodies in the nerve. We report a 70 year old male patient who exhibited progressive weakness in all extremities and dementia. His electrodiagnostic studies showed sensorimotor polyneuropathy and muscle pathology that consisted of polyglucosan bodies located in small peripheral nerves. This is the first case of APBD reported in Korea.
Aged ; Biopsy ; *Glucans/metabolism ; Humans ; Inclusion Bodies ; Male ; Neurodegenerative Diseases/metabolism/*pathology

No disease-modifying therapies (DMT) for neurodegenerative diseases (NDs) have been established, particularly for Alzheimer's disease (AD) and Parkinson's disease (PD). It is unclear why candidate drugs that successfully demonstrate therapeutic effects in animal models fail to show disease-modifying effects in clinical trials. To overcome this hurdle, patients with homogeneous pathologies should be detected as early as possible. The early detection of AD patients using sufficiently tested biomarkers could demonstrate the potential usefulness of combining biomarkers with clinical measures as a diagnostic tool. Cerebrospinal fluid (CSF) biomarkers for NDs are being incorporated in clinical trials designed with the aim of detecting patients earlier, evaluating target engagement, collecting homogeneous patients, facilitating prevention trials, and testing the potential of surrogate markers relative to clinical measures. In this review we summarize the latest information on CSF biomarkers in NDs, particularly AD and PD, and their use in clinical trials. The large number of issues related to CSF biomarker measurements and applications has resulted in relatively few clinical trials on CSF biomarkers being conducted. However, the available CSF biomarker data obtained in clinical trials support the advantages of incorporating CSF biomarkers in clinical trials, even though the data have mostly been obtained in AD trials. We describe the current issues with and ongoing efforts for the use of CSF biomarkers in clinical trials and the plans to harness CSF biomarkers for the development of DMT and clinical routines. This effort requires nationwide, global, and multidisciplinary efforts in academia, industry, and regulatory agencies to facilitate a new era.
Alzheimer Disease ; Biomarkers* ; Cerebrospinal Fluid* ; Humans ; Models, Animal ; Neurodegenerative Diseases ; Parkinson Disease ; Pathology ; Therapeutic Uses

Alzheimer's disease (AD) is a neurodegenerative disorder and its reported pathophysiological features in the brain include the deposition of amyloid beta peptide, chronic inflammation, and cognitive impairment. The incidence of AD is increasing worldwide and researchers have studied various aspects of AD pathophysiology in order to improve our understanding of the disease. Thus far, the onset mechanisms and means of preventing AD are completely unknown. Peroxisome proliferator-activated receptor-γ coactivator (PGC-1α) is a protein related to various cellular mechanisms that lead to the alteration of downstream gene regulation. It has been reported that PGC-1α could protect cells against oxidative stress and reduce mitochondrial dysfunction. Moreover, it has been demonstrated to have a regulatory role in inflammatory signaling and insulin sensitivity related to cognitive function. Here, we present further evidence of the involvement of PGC-1α in AD pathogenesis. Clarifying the relationship between PGC-1α and AD pathology might highlight PGC-1α as a possible target for therapeutic intervention in AD.
Alzheimer Disease* ; Amyloid beta-Peptides ; Brain ; Incidence ; Inflammation ; Insulin Resistance ; Neurodegenerative Diseases ; Oxidative Stress ; Pathology ; Peroxisomes

Alzheimer's disease (AD) is a neurodegenerative disorder associated with extracellular plaques, composed of amyloid-beta (Aβ), in the brain. Although the precise mechanism underlying the neurotoxicity of Aβ has not been established, Aβ accumulation is the primary event in a cascade of events that lead to neurofibrillary degeneration and dementia. In particular, the Aβ burden, as assessed by neuroimaging, has proved to be an excellent predictive biomarker. Positron emission tomography, using ligands such as ¹¹C-labeled Pittsburgh Compound B or ¹⁸F-labeled tracers, such as ¹⁸F-florbetaben, ¹⁸F-florbetapir, and ¹⁸F-flutemetamol, which bind to Aβ deposits in the brain, has been a valuable technique for visualizing and quantifying the deposition of Aβ throughout the brain in living subjects. Aβ imaging has very high sensitivity for detecting AD pathology. In addition, it can predict the progression from mild cognitive impairment to AD, and contribute to the development of disease-specific therapies.
Alzheimer Disease ; Brain ; Dementia ; Ligands ; Mild Cognitive Impairment ; Neurodegenerative Diseases ; Neuroimaging ; Pathology ; Positron-Emission Tomography

The accumulation and spread of prion-like proteins is a key feature of neurodegenerative diseases (NDs) such as Alzheimer's disease, Parkinson's disease, or Amyotrophic Lateral Sclerosis. In a process known as 'seeding', prion-like proteins such as amyloid beta, microtubule-associated protein tau, α-synuclein, silence superoxide dismutase 1, or transactive response DNA-binding protein 43 kDa, propagate their misfolded conformations by transforming their respective soluble monomers into fibrils. Cellular and molecular evidence of prion-like propagation in NDs, the clinical relevance of their 'seeding' capacities, and their levels of contribution towards disease progression have been intensively studied over recent years. This review unpacks the cyclic prion-like propagation in cells including factors of aggregate internalization, endo-lysosomal leaking, aggregate degradation, and secretion. Debates on the importance of the role of prion-like protein aggregates in NDs, whether causal or consequent, are also discussed. Applications lead to a greater understanding of ND pathogenesis and increased potential for therapeutic strategies.
Humans ; Prions ; Neurodegenerative Diseases/pathology* ; Amyloid beta-Peptides ; Alzheimer Disease ; alpha-Synuclein ; tau Proteins ; Parkinson Disease