Intercellular Transfer of Mitochondria between Senescent Cells through Cytoskeleton-Supported Intercellular Bridges Requires mTOR and CDC42 Signalling

Cellular senescence is a state of irreversible cell proliferation arrest induced by various stressors including telomere attrition, DNA damage, and oncogene induction. While beneficial as an acute response to stress, the accumulation of senescent cells with increasing age is thought to contribute adversely to the development of cancer and a number of other age-related diseases, including neurodegenerative diseases for which there are currently no effective disease-modifying therapies. Non-cell-autonomous effects of senescent cells have been suggested to arise through the SASP, a wide variety of proinflammatory cytokines, chemokines, and exosomes secreted by senescent cells. Here, we report an additional means of cell communication utilised by senescent cells via large numbers of membrane-bound intercellular bridges—or tunnelling nanotubes (TNTs)—containing the cytoskeletal components actin and tubulin, which form direct physical connections between cells. We observe the presence of mitochondria in these TNTs and show organelle transfer through the TNTs to adjacent cells. While transport of individual mitochondria along single TNTs appears by time-lapse studies to be unidirectional, we show by differentially labelled co-culture experiments that organelle transfer through TNTs can occur between different cells of equivalent cell age, but that senescent cells, rather than proliferating cells, appear to be predominant mitochondrial donors. Using small molecule inhibitors, we demonstrate that senescent cell TNTs are dependent on signalling through the mTOR pathway, which we further show is mediated at least in part through the downstream actin-cytoskeleton regulatory factor CDC42. These findings have significant implications for the development of senomodifying therapies, as they highlight the need to account for local direct cell-cell contacts as well as the SASP in order to treat cancer and diseases of ageing in which senescence is a key factor.

Data Independent Acquisition Mass Spectrometry of the Human Lens Enhances Spatiotemporal Measurement of Fiber Cell Aging

The ocular lens proteome undergoes post-translational and progressive degradation as fiber cells age. The oldest fiber cells and the proteins therein are present at birth and are retained through death. Transparency of the lens is maintained in part by the high abundance crystallin family proteins (up to 300 mg/mL), which establishes a high dynamic range of protein abundance. As a result, previous Data Dependent Analysis (DDA) measurements of the lens proteome are less equipped to identify the lowest abundance proteins. In an attempt to probe more deeply into the lens proteome, we measured the insoluble lens proteome of an 18-year-old human with DDA and newer Data Independent Analysis (DIA) methods. By applying library free DIA search methods, 4,564 protein groups, 48,474 peptides and 5,577 deamidation sites were detected: significantly outperforming the quantity of identifications in using DDA and Pan-Human DIA library searches. Finally, by segmenting the lens into multiple fiber cell-age related regions, we uncovered cell-age resolved changes in proteome composition and putative function.

A role for the immune system-released activating agent (ISRAA) in the ontogenetic development of brain astrocytes

The Immune System-Released Activating Agent (ISRAA) was discovered as a novel molecule that functions as a mediator between the nervous and immune systems in response to a nervous stimulus following an immune challenge. This research investigated the role of ISRAA) in promoting the ontogeny of the mouse brain astrocytes. Astrocyte cultures were prepared from two-month-old BALB/c mice. Recombinant ISRAA protein was used to stimulate astrocyte cultures. Immunohistochemistry and ELISA were utilized to measure ISRAA and IFN-γ levels, IFN-γR expression and STAT1 nuclear translocation. MTT-assay was used to evaluate cellular survival and proliferation. To assess astrocyte cell lysates and tyrosine-phosphorylated proteins, SDS-PAGE and western blot were used. ISRAA was highly expressed in mouse embryonic astrocytes, depending on cell age. Astrocytes aged seven days (E7) showed increased proliferation and diminished differentiation, while 21-day-old (E21) astrocytes depicted reversed effects. IFN-γ was involved in the ISRAA action as ISRAA induced IFN-γ in both age groups, but only E21 astrocytes expressed IFN-γR. ISRAA stimulation of E21 resulted in tyrosine phosphorylation of numerous cellular proteins and the nuclear translocation of STAT1, a signalling pathway utilized by IFN-γ. The results suggest that ISRAA is involved in mouse brain development through the cytokine network involving IFN-γ.

The Consequences of Budding versus Binary Fission on Adaptation and Aging in Primitive Multicellularity

Early multicellular organisms must gain adaptations to outcompete their unicellular ancestors, as well as other multicellular lineages. The tempo and mode of multicellular adaptation is influenced by many factors including the traits of individual cells. We consider how a fundamental aspect of cells, whether they reproduce via binary fission or budding, can affect the rate of adaptation in primitive multicellularity. We use mathematical models to study the spread of beneficial, growth rate mutations in unicellular populations and populations of multicellular filaments reproducing via binary fission or budding. Comparing populations once they reach carrying capacity, we find that the spread of mutations in multicellular budding populations is qualitatively distinct from the other populations and in general slower. Since budding and binary fission distribute age-accumulated damage differently, we consider the effects of cellular senescence. When growth rate decreases with cell age, we find that beneficial mutations can spread significantly faster in a multicellular budding population than its corresponding unicellular population or a population reproducing via binary fission. Our results demonstrate that basic aspects of the cell cycle can give rise to different rates of adaptation in multicellular organisms.

Automated in vivo Tracking of Cortical Oligodendrocytes

Oligodendrocytes exert a profound influence on neural circuits by accelerating action potential conduction, altering excitability, and providing metabolic support. As oligodendrogenesis continues in the adult brain and is essential for myelin repair, uncovering the factors that control their dynamics is necessary to understand the consequences of adaptive myelination and develop new strategies to enhance remyelination in diseases such as multiple sclerosis. Unfortunately, few methods exist for analysis of oligodendrocyte dynamics, and even fewer are suitable for in vivo investigation. Here, we describe the development of a fully automated cell tracking pipeline using convolutional neural networks (Oligo-Track) that provides rapid volumetric segmentation and tracking of thousands of cells over weeks in vivo. This system reliably replicated human analysis, outperformed traditional analytic approaches, and extracted injury and repair dynamics at multiple cortical depths, establishing that oligodendrogenesis after cuprizone-mediated demyelination is suppressed in deeper cortical layers. Volumetric data provided by this analysis revealed that oligodendrocyte soma size progressively decreases after their generation, and declines further prior to death, providing a means to predict cell age and eventual cell death from individual time points. This new CNN-based analysis pipeline offers a rapid, robust method to quantitatively analyze oligodendrocyte dynamics in vivo, which will aid in understanding how changes in these myelinating cells influence circuit function and recovery from injury and disease.

APLIKASI PEMERIKSAAN KESEHATAN KONSUMEN HERBALIFE BERBASIS ANDROID

Health services are one type of public service that is the spearhead of public health development. People who care about health have started to establish health communities such as healthy homes or nutrition houses such as the Herbalife healthy home. Herbalife's healthy home uses a special scale, the tanita scale, as an indicator of consumer fitness and health. With technological developments, an application is needed that can help carry out consumer health checks. The methodology used in making this application is the prototype model. The programming language used is Kotlin. Meanwhile, the tools and editors used are Android Studio. The method used in data collection in this study is the method of literature, observation, and interviews. With this built application, it can help in determining the health of consumers from several parameters used in this study, including body fat, belly fat, cell age, and health. The output of these parameters is then used as input for the application being built. Layanan kesehatan menjadi salah satu jenis layanan publik yang merupakan ujung tombak dalam pembangunan kesehatan masyarakat. Komunitas masyarakat yang peduli kesehatan mulai mendirikan komunitas kesehatan seperti rumah sehat atau pun rumah nutrisi seperti rumah sehat Herbalife. Rumah sehat Herbalife menggunakan timbangan khusus yakni timbangan tanita sebagai alat indikator kebugaran dan kesehatan konsumen. Dengan perkembangan teknologi, maka dibutuhkan aplikasi yang bisa membantu melakukan pemeriksaan kesehatan konsumen. Metodologi yang digunakan dalam pembuatan aplikasi ini yakni model prototype. Bahasa pemrograman yang digunakan yaitu Kotlin. Sedangkan tools dan editor yang digunakan yakni Android Studio. Metode yang digunakan dalam pengumpulan data dalam penelitian ini yakni metode kepustakaan, observasi, dan wawancara. Dengan adanya pengembangan aplikasi ini, maka dapat membantu dalam menentukan kesehatan konsumen dari beberapa parameter yang digunakan antara lain yakni lemak tubuh, lemak perut, usia sel, dan kadar air. Output dari beberapa parameter tersebut kemudian dijadikan sebagai input untuk aplikasi yang dibangun.

A role for the immune system-released activating agent (ISRAA) in the ontogenetic development of brain astrocytes

The Immune System-Released Activating Agent (ISRAA) was discovered as a novel molecule that functions as a mediator between the nervous and immune systems in response to a nervous stimulus following an immune challenge. This research investigated the role of ISRAA) in promoting the ontogeny of the mouse brain astrocytes. Astrocyte cultures were prepared from two-month-old BALB/c mice. Recombinant ISRAA protein was used to stimulate astrocyte cultures. Immunohistochemistry and ELISA were utilized to measure ISRAA and IFN-γ levels, IFN-γR expression and STAT1 nuclear translocation. MTT-assay was used to evaluate cellular survival and proliferation. To assess astrocyte cell lysates and tyrosine-phosphorylated proteins, SDS-PAGE and western blot were used. ISRAA was highly expressed in mouse embryonic astrocytes, depending on cell age. Astrocytes aged seven days (E7) showed increased proliferation and diminished differentiation, while 21-day-old (E21) astrocytes depicted reversed effects. ISRAA stimulated the tyrosine phosphorylation of numerous cellular proteins and the nuclear translocation of STAT1. IFN-γ was involved in the ISRAA action as ISRAA induced IFN-γ in both age groups, but only E21 astrocytes expressed IFN-γR. The results suggest that ISRAA is involved in mouse brain development through the cytokine network involving IFN-γ.

Automated in vivo tracking of cortical oligodendrocytes

ABSTRACTOligodendrocytes exert a profound influence on neural circuits by accelerating axon potential conduction, altering excitability and providing metabolic support. As oligodendrogenesis continues in the adult brain and is essential for myelin repair, uncovering the factors that control their dynamics is necessary to understand the consequences of adaptive myelination and develop new strategies to enhance remyelination in diseases such as multiple sclerosis. Unfortunately, few methods exist for analysis of oligodendrocyte dynamics, and even fewer are suitable for in vivo investigation. Here, we describe the development of a fully automated cell tracking pipeline using convolutional neural networks (Oligo-Track) that provides rapid volumetric segmentation and tracking of thousands of cells over weeks in vivo. This system reliably replicated human analysis, outperformed traditional analytic approaches, and extracted injury and repair dynamics at multiple cortical depths, establishing that oligodendrogenesis after cuprizone-mediated demyelination is suppressed in deeper cortical layers. Volumetric data provided by this analysis revealed that oligodendrocyte soma size progressively decreases after their generation, and declines further prior to death, providing a means to predict cell age and eventual cell death from individual time points. This new CNN-based analysis pipeline offers a rapid, robust method to quantitatively analyze oligodendrocyte dynamics in vivo, which will aid in understanding how changes in these myelinating cells influence circuit function and recovery from injury and disease.

SCLERODERMA AND MALIGNANCY

Background/ObjectivesDescribe clinical characteristics of malignancy-associated scleroderma in a regional population.MethodsScleroderma patients with current or past malignancy were prospectively identified from a cohort of 125 scleroderma subjects of a largely Hispanic population. Demographic information included scleroderma subtype, serologies, cancer diagnosis, age at diagnosis, co-morbid conditions, therapies, and survival outcomes.Results16.0% (20/125) of scleroderma patients were identified as having a malignancy. The mean age of malignancy onset and scleroderma onset were 55.6±10.3 and 52.7±12.9 years respectively (95% CI of difference: -4.6 <2.9< 10.4, p=0.44). Antinuclear antibody was positive in 70%, anticentromere antibody in 35.0%, and anti-topoisomerase antibodies in 25%. Tumor proportions were adenocarcinomas 55.0% (11/20) (1 gastric, 2 pancreatic, 1 lung, 2 thyroid, 5 breast), 15% (3/20) squamous cell carcinoma (1 skin, 1 uterine cervical, and 1 rectal), and 20% (4/20) benign tumors (2 meningiomas, 1 renal adenoma, 1 plasma cell). Age of onset of scleroderma greater than 42 years respectively accounted for 85% of all cancer cases. The standardized incidence ratio (SIR) was 2.0 (CI at 95%: 1.2<2<3.1), indicating 100% increase in cancer risk. Treatment of the malignancy did not resolve the scleroderma in any of the cases. Five-year survival after cancer diagnosis was 70.0%, although 2 of the survivors had tumor recurrence.ConclusionsMalignancy, especially adenocarcinoma, occurs frequently in scleroderma in minority populations with up to 16% of patients affected. High-risk patients are those with scleroderma-onset greater than 42 years in whom routine screening for common cancers should be undertaken.