The role of mechanobiology in bone and cartilage model systems in characterizing initiation and progression of osteoarthritis

: The development of colorectal cancer (CRC) is a multi-stage process. The inflammation of the colon as in inflammatory bowel disease (IBD) such as ulcerative colitis (UC) or Crohn’s disease (CD) is often regarded as the initial trigger for the development of CRC. Many cytokines such as tumor necrosis factor alpha (TNF-α) and several interleukins (ILs) are known to exert proinflammatory actions, and inflammation initiates or promotes tumorigenesis of various cancers, including CRC through differential regulation of microRNAs (miRNAs/miRs). miRNAs can be oncogenic miRNAs (oncomiRs) or anti-oncomiRs/tumor suppressor miRNAs, and they play key roles during colorectal carcinogenesis. However, the functions and molecular mechanisms of regulation of miRNAs involved in inflammation-associated CRC are still anecdotal and largely unknown. Consolidating the published results and offering perspective solutions to circumvent CRC, the current review is focused on the role of miRNAs and their regulation in the development of CRC. We have also discussed the model systems adapted by researchers to delineate the role of miRNAs in inflammation-associated CRC.

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Role of inflammation in the development of colorectal cancer

Endocrine Metabolic & Immune Disorders - Drug Targets ◽

10.2174/1871530320666200909092908 ◽

2020 ◽

Vol 20 ◽

Author(s):

Sridhar Muthusami ◽

R. Ileng Kumaran ◽

Kokelavani Nampalli Babu ◽

Sneha Krishnamoorthy ◽

Akash Guruswamy ◽

...

Keyword(s):

Colorectal Cancer ◽

Chronic Inflammation ◽

Interleukin 1 ◽

Cell Types ◽

Model Systems ◽

Cytokine Gene Expression ◽

Necrosis Factor Alpha ◽

Tnf Α ◽

Proinflammatory Molecules

: Chronic inflammation can lead to the development of many diseases including cancer. Inflammatory bowel disease (IBD) that includes both ulcerative colitis (UC) and Crohn's disease (CD) are risk factors for the development of colorectal cancer (CRC). Many cytokines produced primarily by the gut immune cells either during or in response to localized inflammation in the colon and rectum are known to stimulate the complex interactions between the different cell types in the gut environment resulting in acute inflammation. Subsequently, chronic inflammation together with genetic and epigenetic changes has been shown to lead to the development and progression of CRC. Various cell types present in the colon such as enterocytes, Paneth cells, goblet cells and macrophages express receptors for inflammatory cytokines and respond to tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6 and other cytokines. Among the several cytokines produced, TNF-α and IL-1β are the key proinflammatory molecules that play critical roles in the development of CRC. The current review is intended to consolidate the published findings to focus on the role of proinflammatory cytokines, namely TNF-α and IL-1β, on inflammation (and the altered immune response) in the gut, to better understand the development of CRC in IBD, using various experimental model systems, preclinical and clinical studies. Moreover, this review also highlights the current therapeutic strategies available (monotherapy and combination therapy), to alleviate the symptoms or treat inflammationassociated CRC by using monoclonal antibodies or aptamers to block proinflammatory molecules, inhibitors of tyrosine kinases in inflammatory signaling cascade, competitive inhibitors of proinflammatory molecules, and the nucleic acid drugs like small activating RNAs (saRNAs) or microRNA (miRNA) mimics to activate tumor suppressor or repress oncogene/proinflammatory cytokine gene expression.

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On the Structure of Lead(II) Complexes in Aqueous Solutions. I. Trinuclear Clusters

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19950527 ◽

1995 ◽

Vol 60 (4) ◽

pp. 527-536 ◽

Cited By ~ 10

Author(s):

Martin Breza ◽

Alena Manová

Keyword(s):

Quantum Chemistry ◽

Aqueous Solutions ◽

Electronic Structures ◽

Mndo Method ◽

Model Systems ◽

Trinuclear Clusters ◽

The Stability ◽

Semiempirical Mndo

Using semiempirical MNDO method of quantum chemistry the optimal geometries and corresponding electronic structures of [Pb3(OH)n]6-n model systems as well as of their hydrated [Pb3(OH)n(H2O)8-n]6-n analogues (n = 4, 5) are investigated. The most stable trinuclear lead(II) complexes present in aqueous solutions correspond to cyclo-(μ3-OH)(μ2-OH)3Pb32+, Pb(μ-OH)2Pb(μ-OH)2Pb2+, cyclo-(μ3-OH)2(μ2-OH)3Pb3+, Pb(OH)(μ-OH)2Pb(μ-OH)Pb(OH)+ and Pb(OH)(μ-OH)2Pb(μ-OH)2Pb+ systems. The key role of OH bridges (by vanishing direct Pb-Pb bonds) on the stability of individual isomers is discussed.

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The localized electron: magnetic properties

10.1093/oso/9780198814597.003.0002 ◽

2018 ◽

Author(s):

Jean-Pierre Launay ◽

Michel Verdaguer

Keyword(s):

Single Molecule ◽

Model Systems ◽

Ferromagnetic Coupling ◽

Single Chain ◽

Single Molecule Magnets ◽

Magnetic Systems ◽

Orbital Interactions ◽

Prussian Blue Analogues ◽

Mononuclear Complexes

After preliminaries about electron properties, and definitions in magnetism, one treats the magnetism of mononuclear complexes, in particular spin cross-over, showing the role of cooperativity and the sensitivity to external perturbations. Orbital interactions and exchange interaction are explained in binuclear model systems, using orbital overlap and orthogonality concepts to explain antiferromagnetic or ferromagnetic coupling. The phenomenologically useful Spin Hamiltonian is defined. The concepts are then applied to extended molecular magnetic systems, leading to molecular magnetic materials of various dimensionalities exhibiting bulk ferro- or ferrimagnetism. An illustration is provided by Prussian Blue analogues. Magnetic anisotropy is introduced. It is shown that in some cases, a slow relaxation of magnetization arises and gives rise to appealing single-ion magnets, single-molecule magnets or single-chain magnets, a route to store information at the molecular level.

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Anatomy and Neural Pathways Modulating Distinct Locomotor Behaviors in Drosophila Larva

Biology ◽

10.3390/biology10020090 ◽

2021 ◽

Vol 10 (2) ◽

pp. 90

Author(s):

Swetha B. M. Gowda ◽

Safa Salim ◽

Farhan Mohammad

Keyword(s):

Motor Neurons ◽

Model Systems ◽

Neural Pathways ◽

Animal Movements ◽

Drosophila Larvae ◽

The Central Nervous System ◽

Drosophila Larva ◽

Locomotor Behaviors ◽

Basic Level

The control of movements is a fundamental feature shared by all animals. At the most basic level, simple movements are generated by coordinated neural activity and muscle contraction patterns that are controlled by the central nervous system. How behavioral responses to various sensory inputs are processed and integrated by the downstream neural network to produce flexible and adaptive behaviors remains an intense area of investigation in many laboratories. Due to recent advances in experimental techniques, many fundamental neural pathways underlying animal movements have now been elucidated. For example, while the role of motor neurons in locomotion has been studied in great detail, the roles of interneurons in animal movements in both basic and noxious environments have only recently been realized. However, the genetic and transmitter identities of many of these interneurons remains unclear. In this review, we provide an overview of the underlying circuitry and neural pathways required by Drosophila larvae to produce successful movements. By improving our understanding of locomotor circuitry in model systems such as Drosophila, we will have a better understanding of how neural circuits in organisms with different bodies and brains lead to distinct locomotion types at the organism level. The understanding of genetic and physiological components of these movements types also provides directions to understand movements in higher organisms.

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Impaired eIF5A function causes a Mendelian disorder that is partially rescued in model systems by spermidine

Nature Communications ◽

10.1038/s41467-021-21053-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Víctor Faundes ◽

Martin D. Jennings ◽

Siobhan Crilly ◽

Sarah Legraie ◽

Sarah E. Withers ◽

...

Keyword(s):

De Novo ◽

Model Systems ◽

Yeast Growth ◽

Related Disorder ◽

Optimal Position ◽

Human Phenotype ◽

Mendelian Disorder ◽

Growth Defects ◽

Polysome Profiling

AbstractThe structure of proline prevents it from adopting an optimal position for rapid protein synthesis. Poly-proline-tract (PPT) associated ribosomal stalling is resolved by highly conserved eIF5A, the only protein to contain the amino acid hypusine. We show that de novo heterozygous EIF5A variants cause a disorder characterized by variable combinations of developmental delay, microcephaly, micrognathia and dysmorphism. Yeast growth assays, polysome profiling, total/hypusinated eIF5A levels and PPT-reporters studies reveal that the variants impair eIF5A function, reduce eIF5A-ribosome interactions and impair the synthesis of PPT-containing proteins. Supplementation with 1 mM spermidine partially corrects the yeast growth defects, improves the polysome profiles and restores expression of PPT reporters. In zebrafish, knockdown eif5a partly recapitulates the human phenotype that can be rescued with 1 µM spermidine supplementation. In summary, we uncover the role of eIF5A in human development and disease, demonstrate the mechanistic complexity of EIF5A-related disorder and raise possibilities for its treatment.

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The Relevance of the SH2 Domain for c-Src Functionality in Triple-Negative Breast Cancer Cells

Cancers ◽

10.3390/cancers13030462 ◽

2021 ◽

Vol 13 (3) ◽

pp. 462

Author(s):

Víctor Mayoral-Varo ◽

María Pilar Sánchez-Bailón ◽

Annarica Calcabrini ◽

Marta García-Hernández ◽

Valerio Frezza ◽

...

Keyword(s):

Breast Cancer ◽

Triple Negative Breast Cancer ◽

Triple Negative ◽

Sh2 Domain ◽

Model Systems ◽

System A ◽

Promising Therapeutic Target ◽

Relevant Role ◽

Inactivating Mutation

The role of Src family kinases (SFKs) in human tumors has been always associated with tyrosine kinase activity and much less attention has been given to the SH2 and SH3 adapter domains. Here, we studied the role of the c-Src-SH2 domain in triple-negative breast cancer (TNBC). To this end, SUM159PT and MDA-MB-231 human cell lines were employed as model systems. These cells conditionally expressed, under tetracycline control (Tet-On system), a c-Src variant with point-inactivating mutation of the SH2 adapter domain (R175L). The expression of this mutant reduced the self-renewal capability of the enriched population of breast cancer stem cells (BCSCs), demonstrating the importance of the SH2 adapter domain of c-Src in the mammary gland carcinogenesis. In addition, the analysis of anchorage-independent growth, proliferation, migration, and invasiveness, all processes associated with tumorigenesis, showed that the SH2 domain of c-Src plays a very relevant role in their regulation. Furthermore, the transfection of two different aptamers directed to SH2-c-Src in both SUM159PT and MDA-MB-231 cells induced inhibition of their proliferation, migration, and invasiveness, strengthening the hypothesis that this domain is highly involved in TNBC tumorigenesis. Therefore, the SH2 domain of c-Src could be a promising therapeutic target and combined treatments with inhibitors of c-Src kinase enzymatic activity may represent a new therapeutic strategy for patients with TNBC, whose prognosis is currently very negative.

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The role of spin in the degradation of organic photovoltaics

Nature Communications ◽

10.1038/s41467-020-20601-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Ivan Ramirez ◽

Alberto Privitera ◽

Safakath Karuthedath ◽

Anna Jungbluth ◽

Johannes Benduhn ◽

...

Keyword(s):

Transient Absorption ◽

Bulk Heterojunction ◽

Critical Factor ◽

Model Systems ◽

Transient Absorption Spectroscopy ◽

Triplet States ◽

Paramagnetic Resonance ◽

Time Resolved ◽

A Charge

AbstractStability is now a critical factor in the commercialization of organic photovoltaic (OPV) devices. Both extrinsic stability to oxygen and water and intrinsic stability to light and heat in inert conditions must be achieved. Triplet states are known to be problematic in both cases, leading to singlet oxygen production or fullerene dimerization. The latter is thought to proceed from unquenched singlet excitons that have undergone intersystem crossing (ISC). Instead, we show that in bulk heterojunction (BHJ) solar cells the photo-degradation of C60 via photo-oligomerization occurs primarily via back-hole transfer (BHT) from a charge-transfer state to a C60 excited triplet state. We demonstrate this to be the principal pathway from a combination of steady-state optoelectronic measurements, time-resolved electron paramagnetic resonance, and temperature-dependent transient absorption spectroscopy on model systems. BHT is a much more serious concern than ISC because it cannot be mitigated by improved exciton quenching, obtained for example by a finer BHJ morphology. As BHT is not specific to fullerenes, our results suggest that the role of electron and hole back transfer in the degradation of BHJs should also be carefully considered when designing stable OPV devices.

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TAMI-37. STEAROYL-COA DESATURASE 1 IS ESSENTIAL FOR THE GROWTH OF IDH MUTANT GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noab196.821 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi206-vi206

Author(s):

Tomohiro Yamasaki ◽

Lumin Zhang ◽

Tyrone Dowdy ◽

Adrian Lita ◽

Mark Gilbert ◽

...

Keyword(s):

Glioma Cell ◽

De Novo ◽

Glioma Cells ◽

Model Systems ◽

De Novo Lipogenesis ◽

Wild Type ◽

Knock Out ◽

Stearoyl Coa Desaturase ◽

Scd1 Expression

Abstract BACKGROUND Increased de novo lipogenesis is a hallmark of cancer metabolism. In this study, we interrogated the role of de novo lipogenesis in IDH1 mutated glioma’s growth and identified the key enzyme, Stearoyl-CoA desaturase 1 (SCD1) that provides this growth advantage. MATERIALS ANDMETHODS We prepared genetically engineered glioma cell lines (U251 wild-type: U251WT and U251 IDHR132H mutant: U251RH) and normal human astrocytes (empty vector induced-NHA: NHAEV and IDHR132H mutant: NHARH). Lipid metabolic analysis was conducted by using LC-MS and Raman imaging microscopy. SCD1 expression was investigated by The Cancer Genome Atlas (TCGA) data analysis and Western-blotting method. Knock-out of SCD1 was conducted by using CRISPR/Cas9 and shRNA. RESULTS Previously, we showed that IDH1 mut glioma cells have increased monounsaturated fatty acids (MUFAs). TCGA data revealed IDH mut glioma shows significantly higher SCD1 mRNA expression than wild-type glioma. Our model systems of IDH1 mut (U251RH, NHARH) showed increased expression of this enzyme compared with their wild-type counterpart. Moreover, addition of D-2HG to U251WT increased SCD1 expression. Herein, we showed that inhibition of SCD1 with CAY10566 decreased relative cell number and sphere forming capacity in a dose-dependent manner. Furthermore, addition of MUFAs were able to rescue the SCD1 inhibitor induced-cell death and sphere forming capacity. Knock out of SCD1 revealed decreased cell proliferation and sphere forming ability. Decreasing lipid content from the media did not alter the growth of these cells, suggesting that glioma cells rely on de novo lipid synthesis rather than scavenging them from the microenvironment. CONCLUSION Overexpression of IDH mutant gene altered lipid composition in U251 cells to enrich MUFA levels and we confirmed that D-2HG caused SCD1 upregulation in U251WT. We demonstrated the glioma cell growth requires SCD1 expression and the results of the present study may provide novel insights into the role of SCD1 in IDH mut gliomas growth.

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