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Alzheimer's disease (AD), one of the most common types of chronic neurodegenerative diseases, is pathologically characterized by the formation of amyloid β (Aβ) peptide-containing plaques and neurofibrillary tangles. Among Aβ peptides, Aβ1–42 induces neuronal toxicity and neurodegeneration. In our previous studies, Cdk5 was found to regulate Aβ1–42-induced mitochondrial fission via the phosphorylation of dynamin-related protein 1 (Drp1) at Ser579. However, whether blockage of Drp1 phosphorylation at Ser579 protects neurons against Aβ1–42-induced degeneration remains to be elucidated. Thus, the aim the present study was to examine the effect of mutant Drp1-S579A on neurodegeneration and its underlying mechanism. First, the phosphorylation-defect (phospho-defect) mutant, Lenti-Drp1-S579A was constructed. Phospho-defect Drp1-S579A expression was detected in primary cultures of mouse cortical neurons infected with Lenti-Drp1-S579A using western blotting and it was found to successfully attenuate the phosphorylation of endogenous Drp1 at Ser579. In primary neuronal cultures, the neuronal processes were evaluated under microscopy. Treatment with 10 µM Aβ1–42 significantly decreased dendritic density and length, spine outgrowth and synapse number. As expected, infection of neurons with Lenti-Drp1-S579A efficiently alleviated the inhibitory effect of Aβ1–42 on neurite outgrowth and synapse density. In addition, infection with Lenti-Drp1-S579A abolished the cleavage of caspase-3 and apoptosis in neurons exposed to Aβ1–42. Thus, the current data demonstrated that blockage of Drp1 phosphorylation at Ser579 may be an effective strategy to protect neurons against Aβ1–42-induced degeneration and apoptosis. These findings underline the therapeutic potential of targeting Drp1 in the treatment of AD. [ABSTRACT FROM AUTHOR]

Cisplatin resistance is a major obstacle in the treatment of non-small cell lung cancer (NSCLC). p32 and OPA1 are the key regulators of mitochondrial morphology and function. This study aims to investigate the role of the p32/OPA1 axis in cisplatin resistance in NSCLC and its underlying mechanism. The levels of p32 protein and mitochondrial fusion protein OPA1 are higher in cisplatin-resistant A549/DDP cells than in cisplatin-sensitive A549 cells, which facilitates mitochondrial fusion in A549/DDP cells. In addition, the expression of p32 and OPA1 protein is also upregulated in A549 cells during the development of cisplatin resistance. Moreover, p32 knockdown effectively downregulates the expression of OPA1, stimulates mitochondrial fission, decreases ATP generation and sensitizes A549/DDP cells to cisplatin-induced apoptosis. Furthermore, metformin significantly downregulates the expressions of p32 and OPA1 and induces mitochondrial fission and a decrease in ATP level in A549/DDP cells. The co-administration of metformin and cisplatin shows a significantly greater decrease in A549/DDP cell viability than cisplatin treatment alone. Moreover, D-erythro-Sphingosine, a potent p32 kinase activator, counteracts the metformin-induced downregulation of OPA1 and mitochondrial fission in A549/DDP cells. Taken together, these findings indicate that p32/OPA1 axis-mediated mitochondrial dynamics contributes to the acquired cisplatin resistance in NSCLC and that metformin resensitizes NSCLC to cisplatin, suggesting that targeting p32 and mitochondrial dynamics is an effective strategy for the prevention of cisplatin resistance.

Background/aim: The quantity and the phenotypes of desired T cell receptor engineered T (TCR-T) cells in the final cell product determine their in vivo anti-tumor efficacy. Optimization of key steps in the TCR-T cell production process, such as T cell activation, has been shown to improve cell quality., Materials and Methods: Using a modified TCR (mTCR) derived from mice transducing PBMCs, we assessed the proportions of low-density lipoprotein receptor (LDL-R) and mTCR expressing cells under the various activation conditions of CD3/CD28-Dynabeads or OKT3 via flow cytometry., Results: We demonstrate that the proportion of T cells expressing LDL-R post activation is positively correlated with the percentage of mTCR + CD8 + T cells with their less differentiated subtypes in the final product. In addition, we show that shifting the CD3/CD28-Dynabeads activation duration from a typical 48 h to 24 h can significantly increase the production of the desired mTCR + CD8 + T cells. Importantly, the percentages of TCR-T cells with less-differentiated phenotypes, namely mTCR central memory T cells (T CM ), were found to be preserved with markedly higher efficiency when T cell activation was optimized., Conclusion: Our findings suggest that the proportion of LDL-R + T cells may serve as an early assessment parameter for evaluating TCR-T cell quality, possibly facilitating the functional and economical improvement of current adoptive therapy., (Copyright © 2023, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Alzheimer's disease (AD), one of the most common types of chronic neurodegenerative diseases, is pathologically characterized by the formation of amyloid β (Aβ) peptide‑containing plaques and neurofibrillary tangles. Among Aβ peptides, Aβ 1‑42 induces neuronal toxicity and neurodegeneration. In our previous studies, Cdk5 was found to regulate Aβ 1‑42 ‑induced mitochondrial fission via the phosphorylation of dynamin‑related protein 1 (Drp1) at Ser579. However, whether blockage of Drp1 phosphorylation at Ser579 protects neurons against Aβ 1‑42 ‑induced degeneration remains to be elucidated. Thus, the aim the present study was to examine the effect of mutant Drp1‑S579A on neurodegeneration and its underlying mechanism. First, the phosphorylation‑defect (phospho‑defect) mutant, Lenti‑Drp1‑S579A was constructed. Phospho‑defect Drp1‑S579A expression was detected in primary cultures of mouse cortical neurons infected with Lenti‑Drp1‑S579A using western blotting and it was found to successfully attenuate the phosphorylation of endogenous Drp1 at Ser579. In primary neuronal cultures, the neuronal processes were evaluated under microscopy. Treatment with 10  µ M Aβ1‑42 significantly decreased dendritic density and length, spine outgrowth and synapse number. As expected, infection of neurons with Lenti‑Drp1‑S579A efficiently alleviated the inhibitory effect of Aβ 1‑42 on neurite outgrowth and synapse density. In addition, infection with Lenti‑Drp1‑S579A abolished the cleavage of caspase‑3 and apoptosis in neurons exposed to Aβ 1‑42 . Thus, the current data demonstrated that blockage of Drp1 phosphorylation at Ser579 may be an effective strategy to protect neurons against Aβ 1‑42 ‑induced degeneration and apoptosis. These findings underline the therapeutic potential of targeting Drp1 in the treatment of AD.

Mitochondria are high dynamic organelles with frequent fission and fusion. Here, we found hypoxia stimulated Drp1 expression, mitochondrial fission and migration in metastatic MDA-MB‑231 cells, but not in non-metastatic MCF-7 cells. Inhibition of Drp1-dependent mitochondrial fission by Mdivi-1 or silencing Drp1 attenuated hypoxia-induced mitochondrial fission and migration in MDA-MB‑231 cells. On the other hand, cisplatin induced significant apoptosis and mitochondrial fission in MDA-MB‑231 cells, but not in MCF-7 cells. Mdivi-1 and silencing Drp1 also efficiently prevented cisplatin-induced MMP decrease, ROS production and apoptosis in MDA-MB‑231 cells. Our data suggest that Drp1-dependent mitochondrial fission not only regulates hypoxia-induced migration of breast cancer cells, but also facilitates its sensitivity to chemotherapeutic agents. Thus, targeting Drp1-dependent mitochondrial dynamics may provide a novel strategy to suppress breast cancer metastasis and improve the chemotherapeutic effect in the future.

Cdc42 is a Ras-related small GTP-binding protein. A previous study has shown that Cdc42 binding to the γ subunit of the coatomer protein complex (γCOP) is essential for Cdc42-regulated cellular transformation, but the molecular mechanism involved is not well understood. Here, we demonstrate that constitutively-active Cdc42 binding to γCOP induced the accumulation of epithelial growth factor receptor (EGFR) in the cells, sustained EGF-stimulated extracellular signal-regulated kinase (ERK), JUN amino-terminal kinase (JNK) and phosphoinositide 3-kinase (PI3K) signaling and promoted cell division. Moreover, constitutive Cdc42 activity facilitated the nuclear translocation of EGFR, and this indicates a novel mechanism through which Cdc42 might promote cellular transformation., (Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.)

In this work, drug-loaded fibers and threads were successfully fabricated by combining electrospinning with aligned fibers collection. Two different electrospinning processes, that is, blend and coaxial electrospinning, to incorporate a model drug tetracycline hydrochloride (TCH) into poly(L-lactic acid) (PLLA) fibers have been used and compared with each other. The resulting composite ultrafine fibers and threads were characterized through scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, and tensile testing. It has been shown that average diameters of the fibers made from the same polymer concentration depended on the processing method. The blend TCH/PLLA fibers showed the smallest fiber diameter, whereas neat PLLA fibers and core-shell TCH-PLLA fibers showed a larger proximal average diameter. Higher rotating speed of a wheel collector is helpful for obtaining better-aligned fibers. Both the polymer and the drug in the electrospun fibers have poor crystalline property. In vitro release study indicated that threads made from the core-shell fibers could suppress the initial burst release and provide a sustained drug release useful for the release of growth factor or other therapeutic drugs. On the other hand, the threads from the blend fibers produced a large initial burst release that may be used to prevent bacteria infection. A combination of these results suggests that electrospinning technique provides a novel way to fabricate medical agents-loaded fibrous threads for tissue suturing and tissue regeneration applications., (Copyright 2008 Wiley Periodicals, Inc.)