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The microenvironment of a cancer stem cell (CSC) niche is often found in coexistence with cancer-associated fibroblasts (CAFs). Here, we show the first in-depth analysis of the interaction between primary triple-negative breast cancer stem cells (BCSCs) with fibroblasts. Using 2D co-culture models with specific seeding ratios, we identified stromal fibroblast aggregation at the BCSC cluster periphery, and, on closer observation, the aggregated fibroblasts was found to encircle BCSC clusters in nematic organization. In addition, collagen type I and fibronectin accumulation were also found at the BCSC-stromal periphery. MACE-Seq analysis of BCSC-encapsulating fibroblasts displayed the transformation of stromal fibroblasts to CAFs and the upregulation of fibrosis regulating genes of which the Interferon Regulatory Factor 6 ( IRF6 ) gene was identified. Loss of function experiments with the IRF6 gene decreased fibroblast encapsulation around BCSC clusters in 2D co-cultures. In BCSC xenografts, fibroblast IRF6 expression led to an increase in the stromal area and fibroblast density in tumors, in addition to a reduction in necrotic growth. Based on our findings, we propose that fibroblast IRF6 function is an important factor in the development of the stromal microenvironment and in sustaining the BCSC tumor niche.

Objective: The aim of the study was to assess the effect of non-surgical periodontal therapy (NSPT) on periodontal and cardiac parameters as well as on the expression of calprotectin and periostin levels in periodontitis patients with and without coronary artery disease (CAD)., Methods: Ninety subjects were categorised into three groups: Group H: periodontally and systemically healthy subjects, Group P: stage III grade B periodontitis subjects with no associated systemic diseases and Group P + CAD: stage III grade B periodontitis subjects diagnosed with CAD. Demographic, periodontal and cardiac parameters were recorded at baseline (0 day) and on the 180th day after NSPT. Gingival crevicular fluid was collected from all participants at baseline (0 day) and after the 180th day. Calprotectin and periostin expression were reassessed., Results: A significant increase in the levels of calprotectin (34.05 ± 11.72) was seen at baseline in the P + CAD group, whereas on the contrary, a decreased periostin (1.59 ± 0.41) was also noted at baseline. The study also showed a significant improvement in periodontal and cardiac parameters on the 180th day following NSPT., Conclusion: Detection of calprotectin and periostin expression in GCF samples could represent a link to the association of periodontitis and CAD., (© 2023 Wiley Periodicals LLC.)

Background and Aims: The prevalence of acute coronary syndrome (ACS) has been rising in the younger population worldwide. To fully comprehend the effects of the condition, it is crucial to examine the evolving characteristics and treatment options. The purpose of this study is to evaluate the characteristics and treatment analysis for young ACS patients in a tertiary care setting., Methods: This cross-sectional, retrospective, single-center study included a random sample of patients who had been hospitalized for ACS over the period of a year. We collected and analyzed data on risk factors, diagnoses, angiographic patterns, and potential treatments., Results: The study involved 198 young ACS patients in total. The majority of patients (57%) had no risk factors, and the majority of them (44%) had ST-elevation myocardial infarction (STEMI) as their diagnosis. The most common type (48%) was single-vessel disease (SVD). Statins and antiplatelet medications made up the majority of the patients' nonsurgical treatments (88% and 87%, respectively). A statistically significant difference exists between young and older ACS patients with gender ( p  < 0.01). However, it is not clinically relevant., Conclusion: Men were the majority of young ACS patients, and STEMI, SVD were more prevalent. The majority of young ACS patients had no significant risk factors. To determine the risk factors of young ACS patients, a more thorough case-control study is critically needed., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors. Health Science Reports published by Wiley Periodicals LLC.)

Background: Health care professionals (HCPs) have been using drugs and poison information centre (DIC) less frequently in recent years. The purpose of this study was to identify the barriers that inhibit HCPs from using the DIC service in a tertiary care hospital, as well as the factors that assist HCPs in using DIC more effectively., Methods: A cross-sectional study was conducted among HCPs in Sri Ramachandra Institute of Higher Education and Research, Chennai. HCPs were given a semi-structured questionnaire that was developed and validated by a subject expert, a public health expert, and a clinical psychologist, and their barriers and facilitators in accessing drug information services were recorded., Findings: A total of 405 HCPs responded to the survey. Among the identified barriers, the top 3 were: HCPs found it easier to use mobile internet (31%) and the department's reference library (25%) instead of contacting DIC for any drug/poison information. In addition, 17% of HCPs stated that they were too busy. The factors that may assist HCPs utilize DIC more effectively were more awareness is required to demonstrate the functionalities of DIC (24%), and a mobile application is required (23%)., Conclusion: Today's HCPs have easy access to a variety of drug information resources, and many prefer to do their own drug/poison research. As current generation HCPs find it more convenient to use mobile internet than contacting DIC, the creation of a mobile application for drug information service may enhance the number of questions from HCPs., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

During neuronal migration, forces generated by cytoplasmic dynein yank on microtubules extending from the centrosome into the leading process and move the nucleus along microtubules that extend behind the centrosome. Scaffolds, such as radial glia, guide neuronal migration outward from the ventricles, but little is known about the internal machinery that ensures that the soma migrates along its proper path rather than moving backward or off the path. Here we report that depletion of KIFC1, a minus-end-directed kinesin called HSET in humans, causes neurons to migrate off their appropriate path, suggesting that this molecular motor is what ensures fidelity of the trajectory of migration. For these studies, we used rat migratory neurons in vitro and developing mouse brain in vivo , together with RNA interference and ectopic expression of mutant forms of KIFC1. We found that crosslinking of microtubules into a nonsliding mode by KIFC1 is necessary for dynein-driven forces to achieve sufficient traction to thrust the soma forward. Asymmetric bouts of microtubule sliding driven by KIFC1 thereby enable the soma to tilt in one direction or another, thus providing midcourse corrections that keep the neuron on its appropriate trajectory. KIFC1-driven sliding of microtubules further assists neurons in remaining on their appropriate path by allowing the nucleus to rotate directionally as it moves, which is consistent with how we found that KIFC1 contributes to interkinetic nuclear migration at an earlier stage of neuronal development. SIGNIFICANCE STATEMENT Resolving the mechanisms of neuronal migration is medically important because many developmental disorders of the brain involve flaws in neuronal migration and because deployment of newly born neurons may be important in the adult for cognition and memory. Drugs that inhibit KIFC1 are candidates for chemotherapy and therefore should be used with caution if they are allowed to enter the brain., (Copyright © 2022 the authors.)

Three-dimensional cell cultures using patient-derived stem cells are essential in vitro models for a more efficient and individualized cancer therapy. Currently, culture conditions and metabolite concentrations, especially hypoxia, are often not accessible continuously and in situ within microphysiological systems. However, understanding and standardizing the cellular microenvironment are the key to successful in vitro models. We developed a microfluidic organ-on-chip platform for matrix-based, heterogeneous 3D cultures with fully integrated electrochemical chemo- and biosensor arrays for the energy metabolites oxygen, lactate, and glucose. Advanced microstructures allow straightforward cell matrix integration with standard laboratory equipment, compartmentalization, and microfluidic access. Single, patient-derived, triple-negative breast cancer stem cells develop into tumour organoids in a heterogeneous spheroid culture on-chip. Our system allows unprecedented control of culture conditions, including hypoxia, and simultaneous verification by integrated sensors. Beyond previous works, our results demonstrate precise and reproducible on-chip multi-analyte metabolite monitoring under dynamic conditions from a matrix-based culture over more than one week. Responses to alterations in culture conditions and cancer drug exposure, such as metabolite consumption and production rates, could be accessed quantitatively and in real-time, in contrast to endpoint analyses. Our approach highlights the importance of continuous, in situ metabolite monitoring in 3D cell cultures regarding the standardization and control of culture conditions, and drug screening in cancer research. Overall, the results underline the potential of microsensors in organ-on-chip systems for successful application, e.g. in personalized medicine.

Microtubule sliding is an underappreciated mechanism that contributes to the establishment, organization, preservation, and plasticity of neuronal microtubule arrays. Powered by molecular motor proteins and regulated in part by static crosslinker proteins, microtubule sliding is the movement of microtubules relative to other microtubules or to non-microtubule structures such as the actin cytoskeleton. In addition to other important functions, microtubule sliding significantly contributes to the establishment and maintenance of microtubule polarity patterns in different regions of the neuron. The purpose of this article is to review the state of knowledge on microtubule sliding in the neuron, with emphasis on its mechanistic underpinnings as well as its functional significance., (Copyright © 2021 Elsevier B.V. All rights reserved.)

KIFC1 (also called HSET or kinesin-14a) is best known as a multifunctional motor protein essential for mitosis. The present studies are the first to explore KIFC1 in terminally postmitotic neurons. Using RNA interference to partially deplete KIFC1 from rat neurons (from animals of either gender) in culture, pharmacologic agents that inhibit KIFC1, and expression of mutant KIFC1 constructs, we demonstrate critical roles for KIFC1 in regulating axonal growth and retraction as well as growth cone morphology. Experimental manipulations of KIFC1 elicit morphological changes in the axon as well as changes in the organization, distribution, and polarity orientation of its microtubules. Together, the results indicate a mechanism by which KIFC1 binds to microtubules in the axon and slides them into alignment in an ATP-dependent fashion and then cross-links them in an ATP-independent fashion to oppose their subsequent sliding by other motors. SIGNIFICANCE STATEMENT Here, we establish that KIFC1, a molecular motor well characterized in mitosis, is robustly expressed in neurons, where it has profound influence on the organization of microtubules in a number of different functional contexts. KIFC1 may help answer long-standing questions in cellular neuroscience such as, mechanistically, how growth cones stall and how axonal microtubules resist forces that would otherwise cause the axon to retract. Knowledge about KIFC1 may help researchers to devise strategies for treating disorders of the nervous system involving axonal retraction given that KIFC1 is expressed in adult neurons as well as developing neurons., (Copyright © 2019 the authors.)

Mutations of the SPAST gene, which encodes the microtubule-severing protein spastin, are the most common cause of hereditary spastic paraplegia (HSP). Haploinsufficiency is the prevalent opinion as to the mechanism of the disease, but gain-of-function toxicity of the mutant proteins is another possibility. Here, we report a new transgenic mouse (termed SPASTC448Y mouse) that is not haploinsufficient but expresses human spastin bearing the HSP pathogenic C448Y mutation. Expression of the mutant spastin was documented from fetus to adult, but gait defects reminiscent of HSP (not observed in spastin knockout mice) were adult onset, as is typical of human patients. Results of histological and tracer studies on the mouse are consistent with progressive dying back of corticospinal axons, which is characteristic of the disease. The C448Y-mutated spastin alters microtubule stability in a manner that is opposite to the expectations of haploinsufficiency. Neurons cultured from the mouse display deficits in organelle transport typical of axonal degenerative diseases, and these deficits were worsened by depletion of endogenous mouse spastin. These results on the SPASTC448Y mouse are consistent with a gain-of-function mechanism underlying HSP, with spastin haploinsufficiency exacerbating the toxicity of the mutant spastin proteins. These findings reveal the need for a different therapeutic approach than indicated by haploinsufficiency alone., (© The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

It is widely believed that tau stabilizes microtubules in the axon [1-3] and, hence, that disease-induced loss of tau from axonal microtubules leads to their destabilization [3-5]. An individual microtubule in the axon has a stable domain and a labile domain [6-8]. We found that tau is more abundant on the labile domain, which is inconsistent with tau's proposed role as a microtubule stabilizer. When tau is experimentally depleted from cultured rat neurons, the labile microtubule mass of the axon drops considerably, the remaining labile microtubule mass becomes less labile, and the stable microtubule mass increases. MAP6 (also called stable tubule-only polypeptide), which is normally enriched on the stable domain [9], acquires a broader distribution across the microtubule when tau is depleted, providing a potential explanation for the increase in stable microtubule mass. When MAP6 is depleted, the labile microtubule mass becomes even more labile, indicating that, unlike tau, MAP6 is a genuine stabilizer of axonal microtubules. We conclude that tau is not a stabilizer of axonal microtubules but is enriched on the labile domain of the microtubule to promote its assembly while limiting the binding to it of genuine stabilizers, such as MAP6. This enables the labile domain to achieve great lengths without being stabilized. These conclusions are contrary to tau dogma., (Copyright © 2018 Elsevier Ltd. All rights reserved.)