Journal of Cellular Physiology最新文献

Treatment of osteosarcoma is hampered by tumor hypoxia and requires alternative approaches. Although the CCL2-CCR2 axis is indispensable in tumor-induced inflammation and angiogenesis, its blockade has not been effective to date. This study aimed to characterize how CCR2 inhibition affects the crosstalk of osteosarcoma cells with immune cells to better delineate tumor resistance mechanisms that help withstand such treatment. In this study, 143B cells were exposed to healthy donor PBMC supernatants in a transwell assay lacking direct cell-to-cell contact and subjected to different oxygen concentrations. In addition, mice bearing orthotopic 143B tumors were subjected to CCR2 antagonist treatment. Our findings show that hypoxic conditions alter cytokine and cancer- related protein expression on cells and impair CCR2 antagonist effects in the experimental osteosarcoma model. CCL2-CCR2 axis blockade in the 143B xenografts, which are positive for hypoxia marker CAIX, did not slow 143B tumor growth or metastasis but altered tumor microenvironment by VEGFR downregulation and shift in the CD44-positive cell population towards high CD44 expression. This study highlights differential responses of tumor cells to CCR2 antagonists in the presence of different oxygen saturations and expands our knowledge of compensatory mechanisms leading to CCL2-CCR2 treatment resistance.

The endoplasmic reticulum (ER) is a pivotal organelle responsible for protein and lipid synthesis, calcium homeostasis, and protein quality control within eukaryotic cells. To maintain cellular health, damaged or excess portions of the ER must be selectively degraded via a process known as selective autophagy, or ER-phagy. This specificity is driven by a network of protein receptors and regulatory mechanisms. In this review, we explore the molecular mechanisms governing ER-phagy, with a focus on the FAM134 family of ER-resident ER-phagy receptors. We discuss the molecular pathways and Posttranslational modifications that regulate receptor activation and clustering, and how these modifications fine-tune ER-phagy in response to stress. This review provides a concise understanding of how ER-phagy contributes to cellular homeostasis and highlights the need for further studies in models where ER stress and autophagy are dysregulated.

Breast cancer is a heterogeneous malignant tumor, and its high metastasis rate depends on the abnormal activation of cell dynamics. Formin-like protein 3 (FMNL3) plays an important role in the formation of various cytoskeletons that participate in cell movement. The objective of this study was to explore the function of FMNL3 in breast cancer progression and endeavor to reveal the molecular mechanism of this phenomenon. We found that FMNL3 was abnormally highly expressed in aggressive breast cancer cells and tissues, and it significantly inhibited E-cadherin expression. FMNL3 could specifically interact with Twist1 rather than other epithelial-mesenchymal transition transcription factors (EMT-TFs). We also found that FMNL3 enhanced the repressive effect of Twist1 on CDH1 transcription in breast cancer cells. Further mechanism studies showed that FMNL3 suppressed the ubiquitin degradation of Twist1 by inhibiting the interaction between Twist1 and Rad23B, the ubiquitin transfer protein of Twist1. In vitro functional experiments, it was confirmed that FMNL3 promoted the migration and invasion of breast cancer cells by regulating Twist1. Furthermore, Twist1 could directly bind to the fmnl3 promoter to facilitate FMNL3 transcription. To conclude, this study indicated that FMNL3 acted as a pro-metastasis factor in breast cancer by promoting Twist1 stability to suppress CDH1 transcription.

The development of the salivary gland (SG) is a complex process regulated by multiple signaling pathways in a spatiotemporal manner. Various stem/progenitor cell populations and respective cell lineages are involved in SG morphogenesis and postnatal maturation. Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) has been identified as critical regulator of stem cells by virtue of its ability to restrain stem cell proliferation, indicating its potential role in the development of several maxillofacial tissues and in the regulation of the quiescence in adult tissues. This study aimed to investigate the expression pattern and functions of Lrig1 in the developing and mature murine submandibular gland (SMG). To accomplish this objective, we collected the murine SMGs at different developmental stages and examined the expression pattern and levels of Lrig1 with qRT-PCR, immunofluorescent (IF) and RNAscope staining. We observed that Lrig1 was widely distributed in both epithelial and mesenchymal cells throughout embryonic and neonatal stages, with specific localization in the more mature epithelium. Furthermore, through single-cell RNA sequencing (scRNA-Seq) and IF techniques, we confirmed that LRIG1 is highly concentrated along with SMG progenitor markers in acinar and basal cells. Additionally, transcription factors (TFs) that could regulate LRIG1 expression were predicted from JASPAR databases and their motifs were identified by the UCSC browser's BLAT tool. Gene Ontology (GO) enrichment analyses on postnatal day 5 (PN5) scRNA-Seq data also provided insights into Lrig1's functions in SG development. Finally, we also conducted in vitro experiments on a human salivary gland (HSG) cell line to assess LRIG1's impact on HSG proliferation and migration, as well as its potential upstream regulatory TFs. Taken together, our study reveals that LRIG1 plays a vital role in SG development.

Epithelial to mesenchymal transition (EMT) is highly plastic with a programme where cells lose adhesion and become more motile. EMT heterogeneity is one of the factors for disease progression and chemoresistance in cancer. Omics characterisations are costly and challenging to use. We developed single cell phenomics with easy to use wide-field fluorescence microscopy. We analyse over 70,000 cells and combined 53 features. Our simplistic pipeline allows efficient tracking of EMT plasticity, with a single statistical metric. We discriminate four high EMT plasticity cancer cell lines along the EMT spectrum. We test two cytokines, inducing EMT in all cell lines, alone or in combination. The single cell EMT metrics demonstrate the additive effect of cytokines combination on EMT independently of cell line EMT spectrum. The effects of cytokines are also observed at the front of migration during wound healing assay. Single cell phenomics is uniquely suited to characterise the cellular heterogeneity in response to complex microenvironment and show potential for drug testing assays.

The growth plate is the primary site of longitudinal bone growth with chondrocytes playing a pivotal role in endochondral bone development. Chondrocytes undergo a series of differentiation steps, resulting in the formation of a unique hierarchical columnar structure comprising round, proliferating, pre-hypertrophic, and hypertrophic chondrocytes. Pre-hypertrophic chondrocytes, which exist in the transitional stage between proliferating and hypertrophic stages, are a critical cell population in the growth plate. However, the molecular basis of pre-hypertrophic chondrocytes remains largely undefined. Here, we employed scRNA-seq analysis on fluorescently labeled growth plate chondrocytes for their molecular characterization. Serine incorporator 5 (Serinc5) was identified as a marker gene for pre-hypertrophic chondrocytes. Histological analysis revealed that Serinc5 is specifically expressed in pre-hypertrophic chondrocytes, overlapping with Indian hedgehog (Ihh). Serinc5 represses cell proliferation and Col2a1 and Acan expression by inhibiting the transcriptional activity of Sox9 in primary chondrocytes. Chromatin profiling using ChIP-seq and ATAC-seq revealed an active enhancer of Serinc5 located in intron 1, with its chromatin status progressively activated during chondrocyte differentiation. Collectively, our findings suggest that Serinc5 regulates sequential chondrocyte differentiation from proliferation to hypertrophy by inhibiting Sox9 function in pre-hypertrophic chondrocytes, providing novel insights into the mechanisms underlying chondrocyte differentiation in growth plates.

Retraction: S. Islam, H. Dasgupta, M. Basu, A. Roy, N. Alam, S. Roychoudhury, C. K. Panda, "Reduction of Nuclear Y654-p-β-Catenin Expression Through SH3GL2-Meditated Downregulation of EGFR in Chemotolerance TNBC: Clinical and Prognostic Importance," Journal of Cellular Physiology 235, no. 11 (2020): 8114-8128. https://doi.org/10.1002/jcp.29466. The above article, published online on 20 January 2020, in Wiley Online Library (wileyonlinelibrary.com), and has been retracted by agreement between the journal Editor-in-Chief, Robert Heath; and Wiley Periodicals LLC. The journal received notice of concerns from a third party regarding duplications and rotation of images between Figures 2 C and 2 G in this article as well as concerns that Figures 2 F and 3 C had been re-used in a different article by some of the same authors (Islam, et al. 2020 [https://doi.org/10.1007/s13402-020-00525-5]). Additional investigation by the publisher also confirmed image duplications within Figure 4 F and between Supplementary Figures 1 C and 1 F in this article. In response to an inquiry by the publisher, the authors stated that the duplication between figures 2 C and 2 G was due to the fact that serial sections of tissue were analyzed. The authors acknowledged that the same samples had been used between this article and the article published in a different journal, but reported that they had mislabeled the samples in the other article. Lastly, the authors stated that the duplications in Figure 4 F and between Supplementary Figures 1 C and 1 F were caused by a mistake during figure preparation. The parties agree that the explanation does not account for the multiple duplications and rotations of images both within this article and between this article and the article published in another journal. The parties also agree that the original data as provided does not adequately support the authors' explanation. The retraction has been agreed to because the evidence of image duplication and manipulation fundamentally compromises the conclusions presented in the article. The authors disagree with the retraction.

Bronchopulmonary dysplasia (BPD) is one of the most prevalent complication in preterm infants, primarily characterized by arrested alveolar growth. The involvement of epithelial-mesenchymal transition (EMT) of AECII cells is proposed to have a crucial role in the pathogenesis of BPD; however, the underlying mechanism remains unclear. The present study reveals a significant reduction of WHAMM (WASP homolog associated with actin, membranes, and microtubules) in hyperoxia-induced BPD mice, highlighting its crucial role in suppressing the progression of BPD through the inhibition of EMT in AECIIs. We demonstrated that hyperoxia-induced downregulation of WHAMM leads to the accumulation of TGF-β1 primarily through its mediation of the autophagic degradation pathway. Mechanistically, WHAMM enhanced the autophagosomal localization of TGF-β1 and concurrently promoted the process of autophagy, thereby comprehensively facilitating the autophagic degradation of TGF-β1. These findings reveal the important role of WHAMM in the development of BPD, and the proposed WHAMM/autophagy/TGF-β1/EMT pathway may represent a potential therapeutic strategy for BPD treatment.

Liver fibrosis is one of the leading cause of death worldwide. In liver, hepatic stellate cells are the primary cell type that gets activated during fibrosis. LX-2 cells are human-derived hepatic stellate cell lines typically employed for studying liver fibrosis mechanisms and screening anti-fibrotic lead molecules. Although LX-2 cells are partially activated in culture conditions, numerous stimuli including TGF-β, H₂O₂, hypoxia, LPS were reported to activate LX-2 cells. In this study, for the first time, the effect of cholesterol depletion on LX-2 cells was studied. Under cholesterol-depleted conditions, the mRNA and protein expression of HSC activation markers (α-SMA, GFAP) were significantly increased. Also, the expression of SREBP-2, HMGCR were significantly upregulated in response to cholesterol depletion. Treatment with fatostatin, a reported SREBP inhibitor abolished nuclear SREBP-1 and SREBP-2 expression and regulated the SREBP signaling. Transmission electron microscopic imaging showed distinct ultrastructural changes in response to cholesterol depletion. Furthermore, cholesterol depletion did not affect the cell-cycle profile of LX-2 cells compared with untreated while fatostatin treatment induced G2 cell-cycle arrest. Overall, cholesterol depletion activated LX-2 cells mediated by SREBP-2 signaling and therefore could be further employed as stimuli for LX-2 activation and screening lead molecules targeting SREBPs.

Estrogen is an essential hormone for the development and functional activities of reproductive organs. Recent studies showed that estrogen signaling is also an important regulator of lipid and glucose metabolism in a number of tissues, but the molecular mechanism is not fully understood. We report here that estrogen is a stimulator of brain-derived neurotrophic factor (BDNF) synthesis in the skeletal muscle. Estradiol (E2), but not testosterone, induces a dose- and time-dependent BDNF production in cultured myotubes. Estrogen depletion in ovariectomized mice significantly reduced Bdnf expression in the glycolytic myofibers, which could be rescued after E2 administration. Mechanistically, E2 stimulation triggered the tethering of estrogen receptor (ER) α, but not ERβ, to the estrogen-responsive element on promoter VI of the Bdnf gene in skeletal muscle. When Bdnf production was inhibited by shRNA in C2C12 myotubes, E2-induced mitochondria activation and pyruvate dehydrogenase kinase 4 expressions were jeopardized. Collectively, our results demonstrate that BDNF is an underrecognized effector of estrogen in regulating mitochondrial activity and fuel metabolism in the skeletal muscle.