Cold Spring Harbor perspectives in medicine最新文献

Autophagy is a vital cellular process responsible for the degradation of proteins, organelles, and other cellular components within lysosomes. In neurons, basal autophagy is indispensable for maintaining cellular homeostasis and protein quality control. Accordingly, lysosomal dysfunction has been proposed to be associated with neurodegeneration, and with Parkinson's disease (PD) in particular. Aging, dopamine metabolism, and PD-linked genetic mutations are thought to impair the autophagic-lysosomal pathway, disrupt cellular proteostasis, and contribute to PD pathogenesis. These alterations represent an opportunity to identify potential new therapeutic targets and disease biomarkers, thus laying the groundwork for the development of novel disease-modifying strategies for PD that are aimed at restoring cellular proteostasis and quality control systems.

Research in the last few decades has brought us closer to an understanding of the brain circuit abnormalities that underlie parkinsonian motor signs. This article summarizes the current knowledge in this rapidly emerging field. Traditional observations of activity changes of basal ganglia neurons that accompany akinesia and bradykinesia have been supplemented with new knowledge regarding specific pathophysiologic changes that are associated with other parkinsonian signs, such as tremor and gait impairments. New research also emphasizes the role of non-basal ganglia structures in parkinsonism, including the pedunculopontine nucleus, the cerebellum, and the cerebral cortex, and the role of structural and functional neuroplasticity. A more detailed understanding of the brain network abnormalities that result from Parkinson's disease is necessary to arrive at more effective and specific treatments for these symptoms in parkinsonian patients through circuit interventions reaching from deep brain stimulation to genetic and chemogenetic treatments.

The term "basal ganglia" refers to a group of interconnected subcortical nuclei engaged in motor planning and movement initiation, executive functions, behaviors, and emotions. Dopamine released from the substantia nigra is the underlying driving force keeping the basal ganglia network under proper equilibrium and, indeed, reduction of dopamine levels triggers basal ganglia dysfunction, setting the groundwork for several movement disorders. The canonical basal ganglia model has been instrumental for most of our current understanding of the normal and pathological functioning of this subcortical network. This model explains how cortical information flows through the basal ganglia nuclei back to the cortex by going through two pathways with opposing effects that together lead to the proper execution of a given movement. The basal ganglia model has paved the way for the standard clinical management of Parkinson's disease, where pharmacological and neurosurgical treatments in place collectively afford an impressive symptomatic alleviation. Although much of the model has remained, the canonical model has been enriched with new arrivals gathered from evidence provided in the last three decades. Here, we sought to provide a comprehensive review of the basal ganglia network, with emphasis on structure, connectivity patterns, and basic operational principles, both in normal and pathological conditions.

Rare monogenic forms of disease provide a unique opportunity to understand novel pathways in human biology. With the rapid advances in genomics and next-generation sequencing, we now have the tools to interrogate the genomes of patients on a large scale to identify candidate genes in patients with rare monogenic forms of type 1 diabetes (T1D). These cases are more likely to represent genetic defects in critical pathways of immune tolerance, and the study of these patients provides a high-yield pool in which to discover new mechanisms of disease in T1D. These studies are also expected to have high translational impact for the T1D community by helping to identify at-risk individuals and provide compelling candidate targets for prevention and treatment.

Inherited retinal diseases (IRDs) are the leading cause of blindness in working-age individuals worldwide. Their genetic etiology is especially heterogenous, so the development of gene-specific therapies is unlikely to meet the medical needs of the entire patient community. Considering these challenges, a complementary strategy could be to develop therapies independent of the underlying gene variant causing retinal degeneration. As the retina is a neural tissue, it is in theory amenable to neuroprotective therapies that could help prolong cell survival or promote retinal function. Many neurotrophic factors have shown favorable results in preclinical animal models of neurodegenerative diseases, but unfortunately these findings have not yet translated into successful human clinical trials. The clinical development of these new therapies is mostly impeded by selection of pertinent clinical end points and time-to-readout, as the majority of IRDs show a relatively slow disease progression rate. Despite these challenges, several strategies have moved forward into clinical development.

Growing evidence indicates that childhood cancer is a developmental disease and the oncogenic impact of mutations depends on spatiotemporal developmental contexts. This dependency leads to distinct molecular, genetic, and clinical characteristics across various cancer (sub)types. However, the underlying molecular mechanisms of tumorigenesis are not fully understood, and the development of precision medicine for childhood cancers is still an ongoing effort, partially due to their relative rarity. Therefore, it is crucial to develop and use "developmental models" that replicate both mutations and specific developmental contexts that determine their impact. In this review, we summarize recent advances in the growing field of developmental modeling of childhood cancers, which enhance our understanding of the pathogenic mechanisms and pave the way for the development of new therapeutic approaches.

The contribution of environmental factors to the pathogenesis of type 1 diabetes is considered substantial, but their identification has turned out to be challenging. Large prospective studies are crucial for reliable identification of environmental risk and protective factors. However, only few large prospective birth cohort studies have been carried out. Enterovirus infections have shown quite consistent risk association with the initiation of islet autoimmunity (IA) across these studies. Also, certain dietary factors have been consistently associated with IA risk, omega-3 fatty acids inversely, and childhood cow's milk intake directly. However, the mechanisms of these associations are not fully understood, and possible causality has not been confirmed. Clinical trial programs with enterovirus vaccines and antiviral drugs are in progress to evaluate the causality of enterovirus association. The only nutritional primary prevention randomized trial, TRIGR, did not find a difference between weaning to extensively hydrolyzed versus conventional cow's milk-based infant formula.

Cancer is caused by mutations that drive aberrant growth, proliferation, and invasion, thus overriding regulatory mechanisms that normally link these processes to organismal needs and cellular physiology. This imposes demands for the production of energy and biomass and for survival in microenvironments that are often nonphysiologic and nutrient-poor, which are met by rewiring of cellular metabolism. The resultant dependence of tumor cells on altered metabolism can induce sensitivity to specific metabolic perturbations that can be exploited for cancer therapy. Some cancers are caused by mutations that impart a novel function to metabolic enzymes, leading to the production of a tumor-promoting metabolite that is dispensable in normal cells, representing an ideal therapeutic target. Tumors can also exploit metabolic regulation of cellular immunity to evade antitumor immune responses, and deciphering this biology has revealed potential targets for therapeutic intervention. Here, we discuss a number of illustrative examples highlighting the therapeutic potential and the challenges of targeting metabolism for cancer therapy.

Parkinson's disease (PD) is a common disorder that has, as part of its core pathology, the loss of the nigral dopaminergic nerve cells that project to the striatum. Replacing this loss with dopaminergic drugs has been the mainstay of therapy in PD for more than 50 years and while offering significant clinical benefit, especially in early-stage disease, leads to side effects over time. A conceptually more effective way to treat this aspect of the PD pathology would be to replace the missing dopaminergic system with grafts of new dopamine cells. This approach has been investigated for nearly 40 years using a variety of different dopamine cell sources. To date, a proof-of-principle has been shown using human fetal dopamine cells in patients with PD, but the more widespread adoption of this approach has been hampered by logistical reasons around tissue supply, the ethics of the cell source, and, most importantly, by the inconsistent results shown across trials, which in some cases have reported worrying side effects. Reasons for all this have been discussed extensively in the literature and one solution may lie in the development of new human stem cell-derived dopamine cells, which are now just entering first in human clinical trials.

Cancer cells undergo changes in metabolism that distinguish them from non-malignant tissue. These may provide a growth advantage by promoting oncogenic signaling and redirecting intermediates to anabolic pathways that provide building blocks for new cellular components. Cancer metabolism is far from uniform, however, and recent work has shed light on its heterogenity within and between tumors. This work is also revealing how cancer metabolism adapts to the tumor microenvironment, as well as ways in which we may capitalize on metabolic changes in cancer cells to create new therapies.