Multidimensional analysis of cortical interneuron synaptic features reveals underlying synaptic heterogeneity.

Cortical interneurons represent a diverse set of neuronal subtypes characterized in part by their striking degree of synaptic specificity. However, little is known about the extent of synaptic diversity because of the lack of unbiased methods to extract synaptic features among interneuron subtypes. Here, we develop an approach to aggregate image features from fluorescent confocal images of interneuron synapses and their post-synaptic targets, in order to characterize the heterogeneity of synapses at fine scale. We started by training a model that recognizes pre- and post-synaptic compartments and then determines the target of each genetically-identified interneuron synapse in vitro and in vivo. Our model extracts hundreds of spatial and intensity features from each analyzed synapse, constructing a multidimensional data set, consisting of millions of synapses, which allowed us to perform an unsupervised analysis on this dataset, uncovering novel synaptic subgroups. The subgroups were spatially distributed in a highly structured manner that revealed the local underlying topology of the postsynaptic environment. Dendrite-targeting subgroups were clustered onto subdomains of the dendrite along the proximal to distal axis. Soma-targeting subgroups were enriched onto different postsynaptic cell types. We also find that the two main subclasses of interneurons, basket cells and somatostatin interneurons, utilize distinct strategies to enact inhibitory coverage. Thus, our analysis of multidimensional synaptic features establishes a conceptual framework for studying interneuron synaptic diversity.

ICPUTRD: Image Cloud Platform for use in tagging and research on decomposition.

Human decomposition studies aim to understand the various factors influencing human decay to assess the deceased and develop postmortem interval (PMI) estimation methods. These types of studies are typically conducted through physical experiments examining the deceased; however, big data systems have the potential to transform how large-scale forensic anthropology research questions can be addressed with curated images of donors with known demographic, climatic, and postmortem historical data. This study introduces ICPUTRD (Image Cloud Platform for Use in Tagging and Research on Decomposition), a web-based software system, which enables forensic scientists to easily access, enhance (or curate), and analyze very large photographic collections documenting the longitudinal process of human decomposition. ICPUTRD, a JavaScript-based application, was designed and built through a combination of the Waterfall and Agile software development life-cycle methods and provides an image search and tagging features with a predefined nomenclature of forensic-related keywords. To evaluate the system, a user study was conducted, involving 27 participants who completed pre- and post-study surveys and three research tasks. Analysis of the study results confirmed the feasibility and practicality of ICPUTRD to facilitate aspects of forensic research and casework involving large collections of digital photographs of human decomposition. It was observed that the nomenclature lacked certain law enforcement keywords, so future work will focus on expanding it to ensure ICPUTRD is suited for all its intended users.

Multicellular communities are perturbed in the aging human brain and Alzheimer's disease.

The role of different cell types and their interactions in Alzheimer's disease (AD) is a complex and open question. Here, we pursued this question by assembling a high-resolution cellular map of the aging frontal cortex using single-nucleus RNA sequencing of 24 individuals with a range of clinicopathologic characteristics. We used this map to infer the neocortical cellular architecture of 638 individuals profiled by bulk RNA sequencing, providing the sample size necessary for identifying statistically robust associations. We uncovered diverse cell populations associated with AD, including a somatostatin inhibitory neuronal subtype and oligodendroglial states. We further identified a network of multicellular communities, each composed of coordinated subpopulations of neuronal, glial and endothelial cells, and we found that two of these communities are altered in AD. Finally, we used mediation analyses to prioritize cellular changes that might contribute to cognitive decline. Thus, our deconstruction of the aging neocortex provides a roadmap for evaluating the cellular microenvironments underlying AD and dementia.

A cellular taxonomy of the adult human spinal cord.

The mammalian spinal cord functions as a community of cell types for sensory processing, autonomic control, and movement. While animal models have advanced our understanding of spinal cellular diversity, characterizing human biology directly is important to uncover specialized features of basic function and human pathology. Here, we present a cellular taxonomy of the adult human spinal cord using single-nucleus RNA sequencing with spatial transcriptomics and antibody validation. We identified 29 glial clusters and 35 neuronal clusters, organized principally by anatomical location. To demonstrate the relevance of this resource to human disease, we analyzed spinal motoneurons, which degenerate in amyotrophic lateral sclerosis (ALS) and other diseases. We found that compared with other spinal neurons, human motoneurons are defined by genes related to cell size, cytoskeletal structure, and ALS, suggesting a specialized molecular repertoire underlying their selective vulnerability. We include a web resource to facilitate further investigations into human spinal cord biology.

Human disease-specific cell signatures in non-lesional tissue in Multiple Sclerosis detected by single-cell and spatial transcriptomics.

Recent investigations of cell type changes in Multiple Sclerosis (MS) using single-cell profiling methods have focused on active lesional and peri-lesional brain tissue, and have implicated a number of peripheral and central nervous system cell types. However, an important question is the extent to which so-called "normal-appearing" non-lesional tissue in individuals with MS accumulate changes over the lifespan. Here, we compared post-mortem non-lesional brain tissue from donors with a pathological or clinical diagnosis of MS from the Religious Orders Study or Rush Memory and Aging Project (ROSMAP) cohorts to age- and sex-matched brains from persons without MS (controls). We profiled three brain regions using single-nucleus RNA-seq: dorsolateral prefrontal cortex (DLPFC), normal appearing white matter (NAWM) and the pulvinar in thalamus (PULV), from 15 control individuals, 8 individuals with MS, and 5 individuals with other detrimental pathologies accompanied by demyelination, resulting in a total of 78 samples. We identified region- and cell type-specific differences in non-lesional samples from individuals diagnosed with MS and/or exhibiting secondary demyelination with other neurological conditions, as compared to control donors. These differences included lower proportions of oligodendrocytes with expression of myelination related genes MOBP, MBP, PLP1, as well as higher proportions of CRYAB+ oligodendrocytes in all three brain regions. Among microglial signatures, we identified subgroups that were higher in both demyelination (TMEM163+/ERC2+), as well as those that were specifically higher in MS donors (HIF1A+/SPP1+) and specifically in donors with secondary demyelination (SOCS6+/MYO1E+), in both white and grey matter. To validate our findings, we generated Visium spatial transcriptomics data on matched tissue from 13 donors, and recapitulated our observations of gene expression differences in oligodendrocytes and microglia. Finally, we show that some of the differences observed between control and MS donors in NAWM mirror those previously reported between control WM and active lesions in MS donors. Overall, our investigation sheds additional light on cell type- and disease-specific differences present even in non-lesional white and grey matter tissue, highlighting widespread cellular signatures that may be associated with downstream pathological changes.

St18 specifies globus pallidus projection neuron identity in MGE lineage.

The medial ganglionic eminence (MGE) produces both locally-projecting interneurons, which migrate long distances to structures such as the cortex as well as projection neurons that occupy subcortical nuclei. Little is known about what regulates the migratory behavior and axonal projections of these two broad classes of neurons. We find that St18 regulates the migration and morphology of MGE neurons in vitro. Further, genetic loss-of-function of St18 in mice reveals a reduction in projection neurons of the globus pallidus pars externa. St18 functions by influencing cell fate in MGE lineages as we observe a large expansion of nascent cortical interneurons at the expense of putative GPe neurons in St18 null embryos. Downstream of St18, we identified Cbx7, a component of Polycomb repressor complex 1, and find that it is essential for projection neuron-like migration but not morphology. Thus, we identify St18 as a key regulator of projection neuron vs. interneuron identity.

Cell type-specific changes identified by single-cell transcriptomics in Alzheimer's disease.

The rapid advancement of single-cell transcriptomics in neurology has allowed for profiling of post-mortem human brain tissue across multiple diseases. Over the past 3 years, several studies have examined tissue from donors with and without diagnoses of Alzheimer's disease, highlighting key changes in cell type composition and molecular signatures associated with pathology and, in some cases, cognitive decline. Although all of these studies have generated single-cell/nucleus RNA-seq or ATAC-seq data from the full array of major cell classes in the brain, they have each focused on changes in specific cell types. Here, we synthesize the main findings from these studies and contextualize them in the overall space of large-scale omics studies of Alzheimer's disease. Finally, we touch upon new horizons in the field, in particular advancements in high-resolution spatial interrogation of tissue and multi-modal efforts-and how they are likely to further advance mechanistic and target-selection studies on Alzheimer's disease.

Resilience in Older Adults During the COVID-19 Pandemic: A Socioecological Approach.

OBJECTIVES: We examined sources of vulnerability and resilience among older adults early in the coronavirus disease 2019 (COVID-19) pandemic. METHODS: We surveyed 235 respondents, 51-95 years old (M = 71.35; SD = 7.39; 74% female), including 2 open-ended questions concerning COVID-19-related difficulties and positive experiences during the past week. Using inductive coding, we found 9 final codes for difficulties and 12 for positives and grouped them into socioecological levels: personal, interpersonal, and societal. RESULTS: Difficulties were reported by 94% of the sample, while 63% described positives. Difficulties and positive responses were made at all socioecological levels and illustrated a dialectic between personal-level constraints and opportunities, interpersonal-level social isolation and integration, and societal-level outrage, sorrow, and social optimism. DISCUSSION: Respondents described sources of vulnerabilities and resilience that supported a socioecological approach to understand resilience during this pandemic. A notable example was resilience derived from witnessing and contributing to the community and social solidarity, highlighting the potential of older adults as resources to their communities during the global pandemic.

Life satisfaction of Korean Vietnam War Veterans in later life: A lifespan approach.

The current study examined correlates of life satisfaction among Korean Vietnam War Veterans. The sample included 450 male Veterans from the Korean Vietnam War Veterans Study, surveyed by mail in 2013 (Mean age = 67.4 years old, SD = 3.0). A hierarchical analysis was conducted by entering four blocks of variables: first demographic factors, and then pre-military service, military service, and post-military service variables. Each successive regression analysis showed a significant additional contribution to the variance in life satisfaction. In the final model, Korean Veterans had higher life satisfaction when they were married, had higher monthly income and poorer childhood family environment, appraised their military service in a positive light, and had less stressors after homecoming and better perceived physical health. However, combat exposure and social support after homecoming were not independently associated with life satisfaction in the final model. These results imply that both pre- and post-military service factors, as well as cognitive appraisals of military service, should be considered in understanding the subjective well-being of Korean Vietnam War Veterans in later life.

A harmonized atlas of mouse spinal cord cell types and their spatial organization.

Single-cell RNA sequencing data can unveil the molecular diversity of cell types. Cell type atlases of the mouse spinal cord have been published in recent years but have not been integrated together. Here, we generate an atlas of spinal cell types based on single-cell transcriptomic data, unifying the available datasets into a common reference framework. We report a hierarchical structure of postnatal cell type relationships, with location providing the highest level of organization, then neurotransmitter status, family, and finally, dozens of refined populations. We validate a combinatorial marker code for each neuronal cell type and map their spatial distributions in the adult spinal cord. We also show complex lineage relationships among postnatal cell types. Additionally, we develop an open-source cell type classifier, SeqSeek, to facilitate the standardization of cell type identification. This work provides an integrated view of spinal cell types, their gene expression signatures, and their molecular organization.

DL4-µbeads induce T cell lineage differentiation from stem cells in a stromal cell-free system.

T cells are pivotal effectors of the immune system and can be harnessed as therapeutics for regenerative medicine and cancer immunotherapy. An unmet challenge in the field is the development of a clinically relevant system that is readily scalable to generate large numbers of T-lineage cells from hematopoietic stem/progenitor cells (HSPCs). Here, we report a stromal cell-free, microbead-based approach that supports the efficient in vitro development of both human progenitor T (proT) cells and T-lineage cells from CD34+cells sourced from cord blood, GCSF-mobilized peripheral blood, and pluripotent stem cells (PSCs). DL4-µbeads, along with lymphopoietic cytokines, induce an ordered sequence of differentiation from CD34+ cells to CD34+CD7+CD5+ proT cells to CD3+αß T cells. Single-cell RNA sequencing of human PSC-derived proT cells reveals a transcriptional profile similar to the earliest thymocytes found in the embryonic and fetal thymus. Furthermore, the adoptive transfer of CD34+CD7+ proT cells into immunodeficient mice demonstrates efficient thymic engraftment and functional maturation of peripheral T cells. DL4-µbeads provide a simple and robust platform to both study human T cell development and facilitate the development of engineered T cell therapies from renewable sources.

Hypergammaglobulinemic purpura of Waldenström in children.

BACKGROUND: Hypergammaglobulinemic purpura of Waldenström (HGPW), a rare cutaneous eruption characterized by the triad of recurrent episodes of lower extremity petechiae, symptoms of stinging and burning, and lower extremity edema, is poorly described in children. Some children have been reported to follow a benign course, while others are eventually diagnosed with fulminant rheumatologic disease. OBJECTIVES: To determine the distinguishing features of HGPW including the spectrum of disease manifestations and clinical outcomes. METHODS: This is a multicenter, retrospective case series of six children with HGPW combined with a literature review of 45 previously published pediatric cases. RESULTS: Most children were eventually diagnosed with systemic disease (63%) or developed autoantibody accumulation suggestive of evolving disease (71%). The most common diagnoses were Sjogren's syndrome and systemic lupus erythematosus. The mean duration between onset of cutaneous eruption and diagnosis of systemic disease was 5.6 years, underscoring that HPGW patients often present with a rash that precedes the development of systemic symptoms. CONCLUSIONS: Diagnosis of HGPW should prompt initial screening for rheumatologic disease with long-term rheumatology follow-up, as the majority of patients present with evolving manifestations of systemic disease.

Topical probiotics: the unknowns behind their rising popularity.

OBJECTIVE: Topical probiotics have been used for skin care and treatment since the early 20th century. Over the past decade, there has been a dramatic surge of commercially-available topical probiotic products. We conducted a systematic search of clinical data relating to the use of topical probiotics and identified relevant clinical and regulatory gaps. METHODS: PubMed and Google Scholar searches were conducted for trials and reviews of probiotics. FDA definitions of cosmetics, drugs, and regulation of topical probiotics were reviewed. RESULTS: Topical probiotics have shown efficacy in a number of limited trials, particularly those involving the treatment of acne, atopic dermatitis, and rosacea. However, there is a paucity of literature on the safety profiles, mechanistic action, and therapeutic potential of topical probiotic products. Several regulatory gaps exist, including approval and classification of topical probiotic products by the FDA; currently there are no topical probiotic products the FDA has approved as drugs. CONCLUSION: With increasing popularity among the general public, but insufficient clinical data to demonstrate large-scale effectiveness and a thorough understanding of side effects, there is a need for further mechanistic and clinical investigation, as well as improved regulation and standardization of topical probiotic products.

Current and emerging therapies for hand eczema.

Although hand eczema (HE) and chronic hand eczema (CHE) are common conditions with significant disease burden, they traditionally have had limited treatment options beyond topical and short-term systemic corticosteroids. We reviewed published and preliminary evidence on the current and emerging topical and systemic therapeutic agents for HE and CHE. The etiologies of various HE subtypes are discussed, and remaining knowledge and practice gaps are highlighted to encourage further investigations. A comprehensive search of ClinicalTrials.gov and PubMed was completed for clinical trials that utilized known and emerging treatment options for HE and CHE. Several agents that target IL-4 and IL-13 signaling, keratinocyte proliferation, inflammatory cytokine production, bacterial protein synthesis, and inflammatory mediator (TNF-α, JAK1, JAK2, and JAK3) proliferation are shown to be involved in the pathogenesis of CHE. Systemic agents include dupilumab, alitretinoin, acitretin, cyclosporine, azathioprine, and probiotics. Topical agents include delgocitinib, retapamulin, halometasone/triclosan, calcipotriol/betamethasone, tacrolimus, and pimecrolimus. These modalities have demonstrated varying degrees of clinical efficacy, evaluated by subjective assessments and scoring indexes. Targeted therapies are emerging for HE, but options are still limited, partially due to our narrow understanding of this heterogeneous condition. Additional and targeted therapeutic options are needed to match the rising prevalence and burden of HE. KEYPOINTS: Hand eczema (HE) is a heterogenous dermatosis with limited therapeutic options due to a lack of international guidelines regarding classification of HE subtypes and treatment. This review discusses current and emerging topical and systemic agents and their efficacies in the treatment of different types of hand eczema.

A comparison of international management guidelines for atopic dermatitis.

BACKGROUND/OBJECTIVES: Atopic dermatitis (AD) is a chronic condition that is predominantly found in pediatric patients and commonly presents therapeutic challenges. The management of AD encompasses a variety of factors, and the pillars of optimal management revolve around skin barrier repair and antiinflammatory, antimicrobial, and antipruritic treatment. AD management guidelines exist in various geographic regions globally. The purpose of this review was to compare international guidelines to highlight the similarities and variances among populations and skin types. Comparisons were made for recommendations regarding moisturization, bathing, wet wrap therapy, topical corticosteroids, topical calcineurin inhibitors, antihistamines, antipruritics, antibiotics, systemic immunosuppressants, and biologics. METHODS: A literature search of the PubMed, EMBASE, and MEDLINE databases was performed for published guidelines in each geographic region. Inclusion criteria included publications available in English that were established by a dermatological association or group including dermatologists, pertained to the treatment of AD in humans, were the most recent guidelines available that were published between 2007 and 2018, and included comprehensive treatment recommendations. RESULTS: Publications from Europe, North America, Asia, the Asia-Pacific region, Australia, and Africa were reviewed, encompassing 14 guidelines. Notable diversity exists across these guidelines regarding recommendations for moisturization and bathing, as well as topical and systemic therapies for AD. CONCLUSIONS: Due to the heterogeneity of the disease and regional treatment accessibility, complete standardization of AD management guidelines may be difficult. Nevertheless, more consensus on management guidelines is needed, and recommendations should be updated as new treatment modalities become available.

Hemophagocytic Lymphohistiocytosis in Cutaneous T-Cell Lymphoma.

Importance: Hemophagocytic lymphohistiocytosis (HLH) has been reported as a serious complication of cutaneous T-cell lymphoma (CTCL). Despite available diagnostic guidelines, it remains a diagnostic and therapeutic challenge in this patient population. Objectives: To examine the characteristics of CTCL associated with HLH and analyze the presenting signs and symptoms, therapeutic options, and outcome. Design, Setting, and Participants: In this case series, patients diagnosed with CTCL and HLH who were treated at a single institution from January 1, 2014, through December 31, 2017, were studied. Exposures: The HLH-2004 trial criteria, HScore, and various clinical and histopathologic variables were applied to and analyzed in the cohort. Main Outcomes and Measures: Subtype of CTCL, treatment administered for HLH, and patient outcome were assessed. Results: Seven patients (4 men and 3 women; median age, 50 years; range, 34-77 years) were identified from the database and included in the study. Cytotoxic subtypes of CTCL that involve the deep dermis and subcutaneous tissue were most commonly associated with HLH. Four patients met 5 or more HLH-2004 trial criteria, and 5 had an HScore probability greater than 85% at presentation. Common presenting HLH symptoms were fever and malaise. Cyclosporine, polychemotherapy, and systemic corticosteroids were the most common treatments. Patients receiving allogeneic stem cell transplants had the best outcomes, with all 3 of these patients alive and in complete remission. Conclusions and Relevance: Hemophagocytic lymphohistiocytosis is a life-threatening complication of CTCL associated with rare cytotoxic CTCL subtypes that primarily involve the subcutaneous tissue. Because these cases may resemble a granulomatous or infectious condition, the diagnosis and appropriate management are often delayed. The results of this study demonstrate the need for high awareness of HLH in patients with panniculitic lymphomas and indicate that allogeneic stem cell transplantation may be the best option for a sustained remission.