Jordanvestergaard8596

Inhibitory neurons orchestrate the activity of excitatory neurons and play key roles in circuit function. Although individual interneurons have been studied extensively, little is known about their properties at the population level. Using random-access 3D two-photon microscopy, we imaged local populations of cerebellar Golgi cells (GoCs), which deliver inhibition to granule cells. We show that population activity is organized into multiple modes during spontaneous behaviors. A slow, network-wide common modulation of GoC activity correlates with the level of whisking and locomotion, while faster ( less then 1 s) differential population activity, arising from spatially mixed heterogeneous GoC responses, encodes more precise information. A biologically detailed GoC circuit model reproduced the common population mode and the dimensionality observed experimentally, but these properties disappeared when electrical coupling was removed. Our results establish that local GoC circuits exhibit multidimensional activity patterns that could be used for inhibition-mediated adaptive gain control and spatiotemporal patterning of downstream granule cells.Generation of induced oligodendrocyte progenitor cells (iOPCs) from somatic fibroblasts is a strategy for cell-based therapy of myelin diseases. However, iOPC generation is inefficient, and the resulting iOPCs exhibit limited expansion and differentiation competence. Here we overcome these limitations by transducing an optimized transcription factor combination into a permissive donor phenotype, the pericyte. Pericyte-derived iOPCs (PC-iOPCs) are stably expandable and functionally myelinogenic with high differentiation competence. Unexpectedly, however, we found that PC-iOPCs are metastable so that they can produce myelination-competent oligodendrocytes or revert to their original identity in a context-dependent fashion. Phenotypic reversion of PC-iOPCs is tightly linked to memory of their original transcriptome and epigenome. Phenotypic reversion can be disconnected from this donor cell memory effect, and in vivo myelination can eventually be achieved by transplantation of O4+ pre-oligodendrocytes. Our data show that donor cell source and memory can contribute to the fate and stability of directly converted cells.Decline in hematopoietic stem cell (HSC) function with age underlies limited health span of our blood and immune systems. In order to preserve health into older age, it is necessary to understand the nature and timing of initiating events that cause HSC aging. By performing a cross-sectional study in mice, we discover that hallmarks of aging in HSCs and hematopoiesis begin to accumulate by middle age and that the bone marrow (BM) microenvironment at middle age induces and is indispensable for hematopoietic aging. Using unbiased approaches, we find that decreased levels of the longevity-associated molecule IGF1 in the local middle-aged BM microenvironment are a factor causing HSC aging. Direct stimulation of middle-aged HSCs with IGF1 rescues molecular and functional hallmarks of aging, including restored mitochondrial activity. Thus, although decline in IGF1 supports longevity, our work indicates that this also compromises HSC function and limits hematopoietic health span.A remarkable feature of tissue stem cells is their ability to regenerate the structure and function of host tissue following transplantation. However, the dynamics of donor stem cells during regeneration remains largely unknown. Here we conducted quantitative clonal fate studies of transplanted mouse spermatogonial stem cells in host seminiferous tubules. We found that, after a large population of donor spermatogonia settle in host testes, through stochastic fate choice, only a small fraction persist and regenerate over the long term, and the rest are lost through differentiation and cell death. Further, based on these insights, we showed how repopulation efficiency can be increased to a level where the fertility of infertile hosts is restored by transiently suppressing differentiation using a chemical inhibitor of retinoic acid synthesis. These findings unlock a range of potential applications of spermatogonial transplantation, from fertility restoration in individuals with cancer to conservation of biological diversity.Stem cell dysfunction drives many age-related disorders. Identifying mechanisms that initially compromise stem cell behavior represent early targets to promote tissue function later in life. Here, we pinpoint multiple factors that disrupt neural stem cell (NSC) behavior in the adult hippocampus. Clonal tracing showed that NSCs exhibit asynchronous depletion by identifying short-term NSCs (ST-NSCs) and long-term NSCs (LT-NSCs). ST-NSCs divide rapidly to generate neurons and deplete in the young brain. Meanwhile, multipotent LT-NSCs are maintained for months but are pushed out of homeostasis by lengthening quiescence. Single-cell transcriptome analysis of deep NSC quiescence revealed several hallmarks of molecular aging in the mature brain and identified tyrosine-protein kinase Abl1 as an NSC aging factor. Treatment with the Abl inhibitor imatinib increased NSC activation without impairing NSC maintenance in the middle-aged brain. Our study indicates that hippocampal NSCs are particularly vulnerable and adaptable to cellular aging.Parkinson's disease is a recognisable clinical syndrome with a range of causes and clinical presentations. Parkinson's disease represents a fast-growing neurodegenerative condition; the rising prevalence worldwide resembles the many characteristics typically observed during a pandemic, except for an infectious cause. In most populations, 3-5% of Parkinson's disease is explained by genetic causes linked to known Parkinson's disease genes, thus representing monogenic Parkinson's disease, whereas 90 genetic risk variants collectively explain 16-36% of the heritable risk of non-monogenic Parkinson's disease. Additional causal associations include having a relative with Parkinson's disease or tremor, constipation, and being a non-smoker, each at least doubling the risk of Parkinson's disease. The diagnosis is clinically based; ancillary testing is reserved for people with an atypical presentation. Current criteria define Parkinson's disease as the presence of bradykinesia combined with either rest tremor, rigidity informed by new insights in genetic causes and mechanisms of neuronal death, several promising strategies are being tested for disease-modifying potential. With the perspective of people with Parkinson's disease as a so-called red thread throughout this Seminar, we will show how personalised management of Parkinson's disease can be optimised.

We explored public opinion about using telemedicine to provide medication abortion during the COVID-19 pandemic in 2020. We also investigated the associations between socio-demographic characteristics and support for using telemedicine in this context and explored factors that influenced respondents' attitudes on the topic.

In a nationally representative, web-based survey of US adults (n = 711), we asked open- and closed-ended questions about using telemedicine to prescribe medication abortion during COVID-19. We used multinomial logistic regression to assess the relationship between socio-demographic characteristics, endorsement of abortion labels, and political affiliation and support for telemedicine in this circumstance. Then, we conducted content and thematic analyses with the open-ended data to explore what influenced respondents' opinions.

Overall, 332 (44%) of respondents supported using telemedicine for medication abortion during the pandemic; 237 (35%) opposed and 138 (21%) were unsure. Responong US adults for the provision of medication abortion via telemedicine during COVID-19. Policymakers may consider public sentiment as well as clinical evidence when considering legislation about abortion.Necroptosis is a form of cell death characterized by receptor-interacting protein kinase activity and plasma membrane permeabilization via mixed-lineage kinase-like protein (MLKL). This permeabilization is responsible for the inflammatory properties of necroptosis. We previously showed that very long chain fatty acids (VLCFAs) are functionally involved in necroptosis, potentially through protein fatty acylation. Here, we define the scope of protein acylation by saturated VLCFAs during necroptosis. We show that MLKL and phosphoMLKL, key for membrane permeabilization, are exclusively acylated during necroptosis. Reducing the levels of VLCFAs decreases their membrane recruitment, suggesting that acylation by VLCFAs contributes to their membrane localization. Acylation of phosphoMLKL occurs downstream of phosphorylation and oligomerization and appears to be, in part, mediated by ZDHHC5 (a palmitoyl transferase). We also show that disruption of endosomal trafficking increases cell viability during necroptosis, possibly by preventing recruitment, or removal, of phosphoMLKL from the plasma membrane.A fundamental challenge in synthetic biology is to create molecular circuits that can program complex cellular functions. Because proteins can bind, cleave, and chemically modify one another and interface directly and rapidly with endogenous pathways, they could extend the capabilities of synthetic circuits beyond what is possible with gene regulation alone. However, the very diversity that makes proteins so powerful also complicates efforts to harness them as well-controlled synthetic circuit components. Recent work has begun to address this challenge, focusing on principles such as orthogonality and composability that permit construction of diverse circuit-level functions from a limited set of engineered protein components. These approaches are now enabling the engineering of circuits that can sense, transmit, and process information; dynamically control cellular behaviors; and enable new therapeutic strategies, establishing a powerful paradigm for programming biology.Receptor tyrosine kinase (RTK)-mediated activation of downstream effector pathways such as the RAS GTPase/MAP kinase (MAPK) signaling cascade is thought to occur exclusively from lipid membrane compartments in mammalian cells. Here, we uncover a membraneless, protein granule-based subcellular structure that can organize RTK/RAS/MAPK signaling in cancer. Chimeric (fusion) oncoproteins involving certain RTKs including ALK and RET undergo de novo higher-order assembly into membraneless cytoplasmic protein granules that actively signal. These pathogenic biomolecular condensates locally concentrate the RAS activating complex GRB2/SOS1 and activate RAS in a lipid membrane-independent manner. RTK protein granule formation is critical for oncogenic RAS/MAPK signaling output in these cells. We identify a set of protein granule components and establish structural rules that define the formation of membraneless protein granules by RTK oncoproteins. Our findings reveal membraneless, higher-order cytoplasmic protein assembly as a distinct subcellular platform for organizing oncogenic RTK and RAS signaling.

Copanlisib, an intravenous pan-class I PI3K inhibitor, showed efficacy and safety as monotherapy in patients with relapsed or refractory indolent non-Hodgkin lymphoma who had received at least two therapies. see more The CHRONOS-3 study aimed to assess the efficacy and safety of copanlisib plus rituximab in patients with relapsed indolent non-Hodgkin lymphoma.

CHRONOS-3 was a multicentre, double-blind, randomised, placebo-controlled, phase 3 study in 186 academic medical centres across Asia, Australia, Europe, New Zealand, North America, Russia, South Africa, and South America. Patients aged 18 years and older with an Eastern Cooperative Oncology Group performance status of no more than 2 and histologically confirmed CD20-positive indolent B-cell lymphoma relapsed after the last anti-CD20 monoclonal antibody-containing therapy and progression-free and treatment-free for at least 12 months, or at least 6 months for patients unwilling or unfit to receive chemotherapy, were randomly assigned (21) with an interactive voice-web response system via block randomisation (block size of six) to copanlisib (60 mg given as a 1-h intravenous infusion on an intermittent schedule on days 1, 8, and 15 [28-day cycle]) plus rituximab (375 mg/m

given intravenously weekly on days 1, 8, 15, and 22 during cycle 1 and day 1 of cycles 3, 5, 7, and 9) or placebo plus rituximab, stratified on the basis of histology, progression-free and treatment-free interval, presence of bulky disease, and previous treatment with PI3K inhibitors.