PTPIP51: a new interaction partner of the insulin receptor and PKA in adipose tissue

Correlation between Mitochondria-Associated Endoplasmic Reticulum Membrane-Related Genes and Cellular Senescence-Related Genes in Osteoarthritis

BACKGROUND

The role of mitochondria-associated endoplasmic reticulum membrane (MAM) formation in the development of osteoarthritis (OA) is yet unclear.

METHODS

A mix of bioinformatics methods and in vitro experimental methodologies was used to study and corroborate the role of MAM-related genes and cellular senescence-related genes in the development of OA. The Gene Expression Omnibus database was used to obtain the microarray information that is relevant to the OA. Several bioinformatic methods were employed to carry out function enrichment analysis and protein-protein correlation analysis, build the correlation regulatory network, and investigate potential relationships between MAM-related genes and cellular senescence-related genes in OA. These methods also served to identify the MAM-related and OA-related genes (MAM-OARGs).

RESULTS

For the additional functional enrichment analysis, a total of 13 MAM-OARGs were detected. The correlation regulatory network was also created. Hub MAM-OARGs were shown to have a strong correlation with genes relevant to cellular senescence in OA. Results of in vitro experiments further demonstrated a positive correlation between MAM-OARGs (PTPN1 and ITPR1) and cellular senescence-related and OA-related genes.

CONCLUSIONS

As a result, our findings can offer new insights into the investigations of MAM-related genes and cellular senescence-related genes, which could be linked to the OA as well as brand-new potential treatment targets.

Paper-based analytical devices for point-of-care blood tests

Blood can be a window to health, and as a result, is the most intensively studied human biofluid. Blood tests can diagnose diseases, monitor therapeutic drugs, and provide information about the health of an individual. Rapid response blood tests are becoming increasingly essential, especially when subsequent treatment is required. Toward this need, paper-based devices have been excellent tools for performing blood tests due to their ability to conduct rapid and low-cost diagnostics and analyses in a non-laboratory environment. In this Perspective, we review recent advances in paper-based blood tests, particularly focusing on the specific techniques and assays applied. Additionally, we discuss the future of these paper-based devices, such as how the signal intensity can be enhanced and how the in situ synthesis of nanomaterials can be used to improve the sensitivity, functionality, and operational simplicity. With these advances, paper-based devices are becoming increasingly valuable tools for point-of-care blood tests in various practical scenarios.

Protein interactions study through proximity-labeling

Introduction: The proteome is a dynamic system in which protein-protein interactions play a crucial part in shaping the cell phenotype. However, given the current limitations of available technologies to describe the dynamic nature of these interactions, the identification of protein-protein interactions has long been a major challenge in proteomics. In recent years, the development of BioID and APEX, two proximity-tagging technologies, have opened-up new perspectives and have already started to change our conception of protein-protein interactions, and more generally, of the proteome. With a broad range of application encompassing health, these new technologies are currently setting milestones crucial to understand fine cellular mechanisms. Area covered: In this article, we describe both the recent and the more conventional available tools to study protein-protein interactions, compare the advantages and the limitations of these techniques, and discuss the recent advancements led by the proximity tagging techniques to refine our conception of the proteome. Expert opinion: The recent development of proximity labeling techniques emphasizes the growing importance of such technologies to decipher cellular mechanism. Although several challenges still need to be addressed, many fields can benefit from these tools and notably the detection of new therapeutic targets for patient care.

Interorganellar calcium signaling in the regulation of cell metabolism: A cancer perspective

Organelles were originally considered to be individual cellular compartments with a defined organization and function. However, recent studies revealed that organelles deeply communicate within each other via Ca²⁺ exchange. This communication, mediated by specialized membrane regions in close apposition between two organelles, regulate cellular functions, including metabolism and cell fate decisions. Advances in microscopy techniques, molecular biology and biochemistry have increased our understanding of these interorganelle platforms. Research findings suggest that interorganellar Ca²⁺ signaling, which is altered in cancer, influences tumorigenesis and tumor progression by controlling cell death programs and metabolism. Here, we summarize the available data on the existence and composition of interorganelle platforms connecting the endoplasmic reticulum with mitochondria, the plasma membrane, or endolysosomes. Finally, we provide a timely overview of the potential function of interorganellar Ca²⁺ signaling in maintaining cellular homeostasis.

Approches nouvelles pour l’étude des interactions protéine-protéine

Le protéome est un système dynamique où les interactions protéine-protéine occupent une place essentielle pour modeler ensemble le phénotype cellulaire. L’identification de ces interactions a toutefois longtemps représenté un obstacle important en protéomique tant les techniques disponibles ne permettaient pas de rendre compte de ces dynamiques d’interactions. Le développement récent du BioID et de l’APEX, deux technologies de marquage de proximité, ouvre aujourd’hui de nouvelles perspectives. Dans cette revue, nous décrivons les outils disponibles pour étudier les interactions protéine-protéine et discutons des progrès récents apportés par les marquages de proximité pour compléter notre vision du protéome et ainsi mieux comprendre les mécanismes cellulaires.

Altered Protein Interactions of the Endogenous Interactome of PTPIP51 towards MAPK Signaling

Protein-protein interactions play a pivotal role in normal cellular functions as well as in carcinogenesis. The protein-protein interactions form functional clusters during signal transduction. To elucidate the fine calibration of the protein-protein interactions of protein tyrosine phosphatase interacting protein 51 (PTPIP51) a small molecule drug, namely LDC-3, directly targeting PTPIP51 is now available. Therefore, LDC-3 allows for the studying of the regulation of the endogenous interactome by modulating PTPIP51 binding capacity. Small interfering ribonucleic acid (siRNA) experiments show that the modification in PTPIP51 binding capacity is induced by LDC-3. Application of LDC-3 annuls the known regulatory phosphorylation mechanisms for PTPIP51 and consequently, significantly alters the assembly of the PTPIP51 associated protein complexes. The treatment of human keratinocytes (HaCaT cells) with LDC-3 induces an altered protein-protein interaction profile of the endogenous interactome of PTPIP51. In addition, LDC-3 stabilizes PTPIP51 within a mitogen activated protein kinase (MAPK) complex composed of Raf-1 and the scaffold protein 14-3-3, independent of the phosphorylation status of PTPIP51. Of note, under LDC-3 treatment the regulatory function of the PTP1B on PTPIP51 fails to impact the PTPIP51 interaction characteristics, as reported for the HaCaT cell line. In summary, LDC-3 gives the unique opportunity to directly modulate PTPIP51 in malignant cells, thus targeting potential dysregulated signal transduction pathways such as the MAPK cascade. The provided data give critical insights in the therapeutic potential of PTPIP51 protein interactions and thus are basic for possible targeted therapy regimens.

Orchestrating cellular signaling pathways-the cellular "conductor" protein tyrosine phosphatase interacting protein 51 (PTPIP51)

The protein tyrosine phosphatase interacting protein 51 (PTPIP51) is thought to regulate crucial cellular functions such as mitosis, apoptosis, migration, differentiation and communication between organelles as a scaffold protein. These diverse functions are modulated by the tyrosine/serine phosphorylation status of PTPIP51. This review interconnects the insights obtained about the action of PTPIP51 in mitogen-activated protein kinase signaling, nuclear factor kB signaling, calcium homeostasis and chromosomal segregation and identifies important signaling hubs. The interference of PTPIP51 in such multiprotein complexes and their PTPIP51-modulated cross-talk makes PTPIP51 an ideal target for novel drugs such as the small molecule LDC-3. Graphical Abstract ᅟ.