Cellular Functions Research Articles

NECTIN2 is a prognostic biomarker and potential therapeutic target in lung adenocarcinoma

IntroductionNECTINs are transmembrane proteins mediating cell-to-cell adhesion. NECTINs interact with integrins or other membrane receptors to trigger multiple cellular functions. Aberrant NECTIN expression is associated with cancer progression and poor outcomes. While NECTIN2 is overexpressed in various cancer types, its role in lung cancer is not well understood. Material and methodsWe investigated the function of NECTIN2 in lung adenocarcinoma (LUAD) using the Cancer Genome Atlas (TCGA) dataset and clinical samples of 105 LUAD patients who had undergone surgical resection. Cell proliferation, apoptosis, migration and invasion were investigated using human lung adenocarcinoma cell lines. ResultsWe found that high NECTIN2 expression correlated with reduced overall survival in LUAD in TCGA database. In clinical samples, high NECTIN2 expression was associated with lower recurrence-free survival in all patients (P < 0.001) and in stage I patients (P = 0.001). Functional analyses demonstrated that NECTIN2 knockout promoted cell apoptosis and diminished cell proliferation and migration capacity. NECTIN2 overexpression did not significantly affect cellular functions. DiscussionOur results suggest that NECTIN2 plays a significant role in cell apoptosis and cancer cell migration, leading to increased postoperative recurrence. Furthermore, NECTIN2 serves as a prognostic indicator and a potential therapeutic target in LUAD. ConclusionsHigh NECTIN2 expression in LUAD was found to be associated with postoperative recurrence, and was observed to play an important role in cell apoptosis and migration.

Long-term adaptation of prefrontal circuits in a mouse model of NMDAR hypofunction

Pharmacological approaches to induce N-methyl-d-aspartate receptor (NMDAR) hypofunction have been intensively used to understand the aetiology and pathophysiology of schizophrenia. Yet, the precise cellular and molecular mechanisms that relate to brain network dysfunction remain largely unknown. Here, we used a set of complementary approaches to assess the functional network abnormalities present in male mice that underwent a 7-day subchronic phencyclidine (PCP 10 mg/kg, subcutaneously, once daily) treatment. Our data revealed that pharmacological intervention with PCP affected cognitive performance and auditory evoked gamma oscillations in the prefrontal cortex (PFC) mimicking endophenotypes of some schizophrenia patients. We further assessed PFC cellular function and identified altered neuronal intrinsic membrane properties, reduced parvalbumin (PV) immunostaining and diminished inhibition onto L5 PFC pyramidal cells. A decrease in the strength of optogenetically-evoked glutamatergic current at the ventral hippocampus to PFC synapse was also demonstrated, along with a weaker shunt of excitatory transmission by local PFC interneurons. On a macrocircuit level, functional ultrasound measurements indicated compromised functional connectivity within several brain regions particularly involving PFC and frontostriatal circuits. Herein, we reproduced a panel of schizophrenia endophenotypes induced by subchronic PCP application in mice. We further recapitulated electrophysiological signatures associated with schizophrenia and provided an anatomical reference to critical elements in the brain circuitry. Together, our findings contribute to a better understanding of the physiological underpinnings of deficits induced by subchronic NMDAR antagonist regimes and provide a test system for characterization of pharmacological compounds.

Two thyroperoxidase-inhibiting chemicals induce shared transcriptional changes in hippocampus of developing rats

Thyroid hormone (TH) system disrupting compounds can impair brain development by perturbing TH action during critical life stages. Human exposure to TH system disrupting chemicals is therefore of great concern. To better protect humans against such chemicals, sensitive test methods that can detect effects on the developing brain are critical. Worryingly, however, current test methods are not sensitive and specific towards TH-mediated effects. To address this shortcoming, we performed RNA-sequencing of rat brains developmentally exposed to two different thyroperoxidase (TPO) inhibiting compounds, the medical drug methimazole (MMI) or the pesticide amitrole. Pregnant and lactating rats were exposed to 8 and 16 mg/kg/day(d) MMI or 25 and 50 mg/kg/d amitrole from gestational day 7 until postnatal day 16. Bulk-RNA-seq was performed on hippocampus from the 16-day old male pups. MMI and amitrole caused pronounced changes to the transcriptomes; 816 genes were differentially expressed, and 425 gene transcripts were similarly affected by both chemicals. Functional terms indicate effects from key cellular functions to changes in cell development, migration and differentiation of several cell populations. Of the total number of DEGs, 106 appeared to form a consistent transcriptional fingerprint of developmental hypothyroidism as they were similarly and dose-dependently expressed across all treatment groups. Using a filtering system, we identified 20 genes that appeared to represent the most sensitive, robust and dose-dependent markers of altered TH-mediated brain development. These markers provide inputs to the adverse outcome pathway (AOP) framework where they, in the context of linking TPO inhibiting compounds to adverse cognitive function, can be used to assess altered gene expression in the hippocampus in rat toxicity studies.

Functional implication of the homotrimeric multidomain vacuolar sorting receptor 1 (VSR1) from Arabidopsis thaliana

The vacuolar sorting receptors (VSRs) are specific to plants and are responsible for sorting and transporting particular proteins from the trans-Golgi network to the vacuole. This process is critically important for various cellular functions, including storing nutrients during seed development. Despite many years of intense studies on VSRs, a complete relation between function and structure has not yet been revealed. Here, we present the crystal structure of the entire luminal region of glycosylated VSR1 from Arabidopsis thaliana (AtVSR1) for the first time. The structure provides insights into the tertiary and quaternary structures of VSR1, which are composed of an N-terminal protease-associated (PA) domain, a unique central region, and one epidermal growth factor (EGF)-like domain followed by two disordered EGF-like domains. The structure of VSR1 exhibits unique characteristics, the significance of which is yet to be fully understood.

Effect of Cigarette Smoking on Selected Coagulation Parameters in Apparently Healthy Male Smokers

Background: Smoking is a significant global health concern associated with increased mortality and morbidity, including cancer development. Tobacco smoke contains carcinogens that can disrupt cellular processes and immune function, potentially affecting coagulation parameters. Objective: This study aimed to investigate the impact of smoking on selected coagulation parameters in apparently healthy male smokers compared to non-smokers. Method: A cross-sectional analytical study was conducted at the Department of Physiology, Sir Salimullah Medical College (SSMC) in Dhaka, Bangladesh, from July 1, 2018, to June 30, 2019. Seventy male participants aged 20 to 40 years were enrolled, comprising 35 healthy non-smokers (Group A) and 35 male smokers (Group B). Smokers (Group B) were further categorized into two groups based on pack-years of smoking (group B1 and group B2). Coagulation parameters including prothrombin time (PT), activated partial thromboplastin time (APTT), bleeding time (BT), and clotting time (CT) were assessed. Results: In this study, age and BMI were almost similar between groups A (healthy non-smokers) and B (smokers), with mean (± SD) ages of 33.17 ± 2.91 and 34.11 ± 3.18 years, and mean (± SD) BMI values of 24.36 ± 2.28 and 24.68 ± 2.33 kg/m2, respectively. There was no statistically significant disparity between the two groups, indicating successful age and BMI matching. Smokers (group B) exhibited significantly lower mean (± SD) prothrombin time (PT) values (11.56 ± 0.87 seconds) compared to non-smokers (13.07 ± 0.77 seconds), with a statistically significant difference (p &lt; 0.001). Similarly, activated partial thromboplastin time (APTT) was significantly decreased in smokers (28.42 ± 2.00 seconds) compared to non-smokers (31.50 ± 1.00 seconds) (p &lt; 0.001). Bleeding time (BT) and clotting time (CT) were also significantly reduced in smokers (2.40 ± 0.24 minutes and 5.35 ± 0.29 minutes, respectively) compared to non-smokers (3.48 ± 0.36 minutes .....

Age-dependent dynamics of neuronal VAPBALS inclusions in the adult brain

Amyotrophic Lateral Sclerosis (ALS) is a relentlessly progressive and fatal disease, caused by the degeneration of upper and lower motor neurons within the brain and spinal cord in the ageing human. The dying neurons contain cytoplasmic inclusions linked to the onset and progression of the disease. Here, we use a Drosophila model of ALS8 (VAPP58S) to understand the modulation of these inclusions in the ageing adult brain.The adult VAPP58S fly shows progressive deterioration in motor function till its demise 25 days post-eclosion. The density of VAPP58S-positive brain inclusions is stable for 5–15 days of age. In contrast, adding a single copy of VAPWT to the VAPP58S animal leads to a large decrease in inclusion density with concomitant rescue of motor function and lifespan. ER stress, a contributing factor in disease, shows reduction with ageing for the disease model. Autophagy, rather than the Ubiquitin Proteasome system, is the dominant mechanism for aggregate clearance.We explored the ability of Drosophila Valosin-containing protein (VCP/TER94), the ALS14 locus, which is involved in cellular protein clearance, to regulate age-dependent aggregation. Contrary to expectation, TER94 overexpression increased VAPP58S punctae density, while its knockdown led to enhanced clearance. Expression of a dominant positive allele, TER94R152H, further stabilised VAPP58S puncta, cementing roles for an ALS8-ALS14 axis. Our results are explained by a mechanism where autophagy is modulated by TER94 knockdown.Our study sheds light on the complex regulatory events involved in the neuronal maintenance of ALS8 aggregates, suggesting a context-dependent switch between proteasomal and autophagy-based mechanisms as the larvae develop into an adult. A deeper understanding of the nucleation and clearance of the inclusions, which affect cellular stress and function, is essential for understanding the initiation and progression of ALS.

Screening and validation of atherosclerosis PAN-apoptotic immune-related genes based on single-cell sequencing.

Carotid atherosclerosis (CAS) is a complication of atherosclerosis (AS). PAN-optosome is an inflammatory programmed cell death pathway event regulated by the PAN-optosome complex. CAS's PAN-optosome-related genes (PORGs) have yet to be studied. Hence, screening the PAN-optosome-related diagnostic genes for treating CAS was vital. We introduced transcriptome data to screen out differentially expressed genes (DEGs) in CAS. Subsequently, WGCNA analysis was utilized to mine module genes about PANoptosis score. We performed differential expression analysis (CAS samples vs. standard samples) to obtain CAS-related differentially expressed genes at the single-cell level. Venn diagram was executed to identify PAN-optosome-related differential genes (POR-DEGs) associated with CAS. Further, LASSO regression and RF algorithm were implemented to were executed to build a diagnostic model. We additionally performed immune infiltration and gene set enrichment analysis (GSEA) based on diagnostic genes. We verified the accuracy of the model genes by single-cell nuclear sequencing and RT-qPCR validation of clinical samples, as well as in vitro cellular experiments. We identified 785 DEGs associated with CAS. Then, 4296 module genes about PANoptosis score were obtained. We obtained the 7365 and 1631 CAS-related DEGs at the single-cell level, respectively. 67 POR-DEGs were retained Venn diagram. Subsequently, 4 PAN-optosome-related diagnostic genes (CNTN4, FILIP1, PHGDH, and TFPI2) were identified via machine learning. Cellular function tests on four genes showed that these genes have essential roles in maintaining arterial cell viability and resisting cellular senescence. We obtained four PANoptosis-related diagnostic genes (CNTN4, FILIP1, PHGDH, and TFPI2) associated with CAS, laying a theoretical foundation for treating CAS.

Convex Representation of Metabolic Networks with Michaelis–Menten Kinetics

Polyhedral models of metabolic networks are computationally tractable and can predict some cellular functions. A longstanding challenge is incorporating metabolites without losing tractability. In this paper, we do so using a new second-order cone representation of the Michaelis–Menten kinetics. The resulting model consists of linear stoichiometric constraints alongside second-order cone constraints that couple the reaction fluxes to metabolite concentrations. We formulate several new problems around this model: conic flux balance analysis, which augments flux balance analysis with metabolite concentrations; dynamic conic flux balance analysis; and finding minimal cut sets of networks with both reactions and metabolites. Solving these problems yields information about both fluxes and metabolite concentrations. They are second-order cone or mixed-integer second-order cone programs, which, while not as tractable as their linear counterparts, can nonetheless be solved at practical scales using existing software.

Mitochondrial transplantation for the treatment of cardiac and non-cardiac diseases: mechanisms, prospective, and challenges

Abstract Mitochondrial transplantation (MT) is a promising therapeutic strategy that involves introducing healthy mitochondria into damaged tissues to restore cellular function. This approach has shown promise in treating cardiac diseases, such as ischemia-reperfusion injury, myocardial infarction, and heart failure, where mitochondrial dysfunction plays a crucial role. Transplanting healthy mitochondria into affected cardiac tissue has resulted in improved cardiac function, reduced IS, and enhanced cell survival in preclinical studies. Beyond cardiac applications, MT is also being explored for its potential in addressing various non-cardiac diseases, including stroke, infertility, and genetic mitochondrial disorders. Ongoing research focused on refining techniques for mitochondrial isolation, preservation, and targeted delivery is bolstering the prospects of MT as a clinical therapy. As the scientific community gains a deeper understanding of mitochondrial dynamics and pathology, the development of MT as a clinical therapy holds significant promise. This review provides an overview of recent research on MT and discusses the methodologies involved, including sources, isolation, delivery, internalization, and distribution of mitochondria. Additionally, it explores the effects of MT and potential mechanisms in cardiac disease, as well as other diseases. Future prospects for MT are also discussed.

Membrane phospholipids activate the inflammatory response in macrophages by various mechanisms.

Exosomes, which are small membrane-encapsulated particles derived from all cell types, are emerging as important mechanisms for intercellular communication. In addition, exosomes are currently envisioned as potential carriers for the delivery of drugs to target tissues. The natural population of exosomes is very variable due to the limited amount of cargo components present in these small vesicles. Consequently, common components of exosomes may play a role in their function. We have proposed that membrane phospholipids could be a common denominator in the effect of exosomes on cellular functions. In this regard, we have previously shown that liposomes made of phosphatidylcholine (PC) or phosphatidylserine (PS) induced a robust alteration of macrophage (Mϕ) gene expression. We herewith report that these two phospholipids modulate gene expression in Mϕs by different mechanisms. PS alters cellular responses by the interaction with surface receptors, particularly CD36. In contrast, PC is captured by a receptor-independent process and likely triggers an activity within endocytic vesicles. Despite this difference in the capture mechanisms, both lipids mounted similar gene expression responses. This investigation suggests that multiple mechanisms mediated by membrane phospholipids could be participating in the alteration of cellular functions by exosomes.

The Satellite DNA PcH-Sat, Isolated and Characterized in the Limpet Patella caerulea (Mollusca, Gastropoda), Suggests the Origin from a Nin-SINE Transposable Element

Satellite DNA (sat-DNA) was previously described as junk and selfish DNA in the cellular economy, without a clear functional role. However, during the last two decades, evidence has been accumulated about the roles of sat-DNA in different cellular functions and its probable involvement in tumorigenesis and adaptation to environmental changes. In molluscs, studies on sat-DNAs have been performed mainly on bivalve species, especially those of economic interest. Conversely, in Gastropoda (which includes about 80% of the currently described molluscs species), studies on sat-DNA have been largely neglected. In this study, we isolated and characterized a sat-DNA, here named PcH-sat, in the limpet Patella caerulea using the restriction enzyme method, particularly HaeIII. Monomeric units of PcH-sat are 179 bp long, AT-rich (58.7%), and with an identity among monomers ranging from 91.6 to 99.8%. Southern blot showed that PcH-sat is conserved in P. depressa and P. ulyssiponensis, while a smeared signal of hybridization was present in the other three investigated limpets (P. ferruginea, P. rustica and P. vulgata). Dot blot showed that PcH-sat represents about 10% of the genome of P. caerulea, 5% of that of P. depressa, and 0.3% of that of P. ulyssiponensis. FISH showed that PcH-sat was mainly localized on pericentromeric regions of chromosome pairs 2 and 4–7 of P. caerulea (2n = 18). A database search showed that PcH-sat contains a large segment (of 118 bp) showing high identity with a homologous trait of the Nin-SINE transposable element (TE) of the patellogastropod Lottia gigantea, supporting the hypothesis that TEs are involved in the rising and tandemization processes of sat-DNAs.

Endoplasmic reticulum stress produced by Thapsigargin affects the occurrence of spike-wave discharge by modulating unfolded protein response pathways and activating immune responses in a dose-dependent manner

The Endoplasmic Reticulum (ER) is associated with many cellular functions, from post-transcriptional modifications to the proper folding of proteins, and disruption of these functions causes ER stress. Although the relationship between epileptic seizures and ER stress has been reported, the contribution of ER stress pathways to epileptogenesis is still unclear. This study aimed to investigate the possible effects of ER stress-related molecular pathways modulated by mild- and high-dose Thapsigargin (Tg) on absence epileptic activity, CACNA1H and immune responses in WAG/Rij rats. For this purpose, rats were divided into four groups; mild-dose (20 ng) Tg, high-dose (200 ng) Tg, saline, and DMSO and drugs administered intracerebroventriculary. EEG activity was recorded for 1 h and 24 h after drug administration following the baseline recording. In cortex and thalamus tissues, GRP78, ERp57, GAD153 protein changes (Western Blot), Eif2ak3, XBP-1, ATF6, CACNA1H mRNA expressions (RT-PCR), NF-κB and TNF-α levels (ELISA) were measured. Mild-dose-Tg administration resulted in increased spike-wave discharge (SWD) activity at the 24th hour compared to administration of saline, and high-dose-Tg and it also significantly increased the amount of GRP78 protein, the expression of Eif2ak3, XBP-1, and CACNA1H mRNA in the thalamus tissue. In contrast, high-dose-Tg administration suppressed SWD activity and significantly increased XBP-1 and ATF6 mRNA expression in the thalamus, and increased NF-κB and TNF-α levels. In conclusion, our findings indicate that Tg affects SWD occurrence by modulating the unfolded protein response pathway and activating inflammatory processes in a dose-dependent manner.

A flow equilibrium of zinc in cells of Cupriavidus metallidurans.

Understanding the biochemical action of a single enzyme or transport protein is the pre-requisite to obtain insight into its cellular function but this is only one half of the coin. The other side concerns the question of how central metabolic functions of a cell emerge from the interplay of different proteins and other macromolecules. This paper demonstrates that a flow equilibrium of zinc uptake and efflux reactions is at the core of cellular zinc homeostasis and identifies the most important contributors to this flow equilibrium: the uptake and efflux systems and metal-binding components of the cytoplasm.

Transcriptome Analysis of Picea crassifolia in Response to Rust Infestation

This study examines the relationship between needle age and rust resistance in Picea crassifolia, focusing on the needle morphology, including size, shape, and physiological traits. One-year-old spruce needles are more susceptible to rust, while two-year-old needles show effective resistance. Using RNA-seq on the Illumina HiSeq500 platform, we analyzed both healthy and diseased one-year-old needles (N and B), as well as healthy one-year-old and two-year-old needles (N and L). We applied a fold change (FC) threshold of ≥2 and a false discovery rate (FDR) of &lt;0.01, alongside GO annotation and KEGG pathway enrichment, to identify differentially expressed genes (DEGs). In N vs. B, DEGs were significantly enriched in processes such as metabolism, cellular function, catalysis, binding, ribosomal function, plant-pathogen interactions, endoplasmic reticulum protein processing, and signal transduction, revealing a polygenic network regulating the rust response. Similarly, in N vs. L, electron microscopy highlighted morphological differences in the wax layers of needles, with subsequent transcriptome sequencing uncovering genes involved in the development of one-year-old and two-year-old needles. DEGs were primarily found in pathways related to cutin, suberin, wax biosynthesis, fatty acid metabolism, photosynthesis, and phenylalanine synthesis. Two-year-old needles displayed reduced stomatal density, higher lignin content, and a thicker wax layer compared to one-year-old needles. Validation of the RNA-seq data through RT-qPCR on 10 DEGs confirmed the consistency of gene expression trends, enhancing our understanding of Picea crassifolia’s genetic response to rust and supporting future research into its disease resistance.

Human P2X7 receptor variants Gly150Arg and Arg276His polymorphisms have differential effects on risk association and cellular functions in pancreatic cancer

BackgroundThe purinergic P2X7 receptor (P2X7R) plays an important role in the crosstalk between pancreatic stellate cells (PSCs) and cancer cells, thus promoting progression of pancreatic ductal adenocarcinoma (PDAC). Single nucleotide polymorphisms (SNPs) in the P2X7R have been reported for several cancers, but have not been explored in PDAC.Materials and methodsBlood samples from PDAC patients and controls were genotyped for 11 non-synonymous SNPs in P2X7R and a risk analysis was performed. Relevant P2X7R-SNP GFP variants were expressed in PSCs and cancer cells and their function was assayed in the following tests. Responses in Ca2+ were studied with Fura-2 and dye uptake with YO-PRO-1. Cell migration was monitored by fluorescence microscopy. Released cytokines were measured with MSD assay.ResultsRisk analysis showed that two SNPs 474G>A and 853G>A (rs28360447, rs7958316), that lead to the Gly150Arg and Arg276His variants, had a significant but opposite risk association with PDAC development, protecting against and predisposing to the disease, respectively. In vitro experiments performed on cancer cells and PSCs expressing the Gly150Arg variant showed reduced intracellular Ca2+ response, fluorescent dye uptake, and cell migration, while the Arg276His variant reduced dye uptake but displayed WT-like Ca2+ responses. As predicted, P2X7R was involved in cytokine release (IL-6, IL-1β, IL-8, TNF-α), but the P2X7R inhibitors displayed varied effects.ConclusionIn conclusion, we provide evidence for the P2X7R SNPs association with PDAC and propose that they could be considered as potential biomarkers.

Smad4 deficiency inhibits lung metastases through enhancing phagocytosis of lung interstitial macrophages

Smad4, a critical mediator of TGF-β signaling, plays a pivotal role in regulating various cellular functions, including immune responses. In this study, we investigated the impact of Smad4 knockout specifically in macrophages on anti-tumor immunity, focusing on lung metastasis of B16 melanoma cells. Using a mouse model with Smad4 knockout in macrophages established via Lyz2-cre mice and Smad4 flox/flox mice, we demonstrated a significant inhibition of B16 metastasis in the lungs. Interestingly, the inhibition of tumor growth was found to be independent of adaptive immunity, as no significant changes were observed in the numbers or activities of T cells, B cells, or NK cells. Instead, Smad4 knockout led to the emergence of an MCHIIlow CD206high subset of lung interstitial macrophages, characterized by enhanced phagocytosis function. Our findings highlight the crucial role of Smad4 in modulating the innate immune response against tumors and provide insights into potential therapeutic strategies targeting lung interstitial macrophages to enhance anti-tumor immunity.

Multiomics Analysis Unravels Alteration in Molecule and Pathways Involved in Nondiabetic Chronic Wounds.

The prevalence of chronic wounds (CW) continues to grow. A thorough knowledge of the mechanism of CW formation remains elusive due to a lack of relevant studies. Furthermore, most previous studies concentrated on diabetic ulcers with relatively few investigations on other types. We performed this multiomics study to investigate the proteomic and metabolomic changes in wound and surrounding tissue from a cohort containing 13 patients with nondiabetic CW. Differentially expressed proteins (DEPs) and metabolites (DEMs) were filtered out and analyzed through multiomic profiling. The DEPs were further confirmed with the use of parallel reaction monitoring. Compared with the surrounding tissue, there were 82 proteins and 214 metabolites altered significantly in wound tissue. The DEPs were mainly enriched in focal adhesion (FA), extracellular matrix-receptor interaction (ERI), and the PI3K-Akt (PA) signaling pathway. Moreover, the DEMs were significantly enriched in amino sugar and nucleotide sugar metabolism and biosynthesis of nucleotide sugar pathways. In correlation analysis, we discovered that the PA signaling pathway, as well as its upstream and downstream pathways, coenriched some DEPs and DEMs. Additionally, we found that FBLN1, FBLN5, and EFEMP1 (FBLN3) proteins dramatically elevated in wound tissue and connected with the above signaling pathways. This multiomics study found that changes in FA, ERI, and PA signaling pathways had an impact on the cellular activities and functions of wound tissue cells. Additionally, increased expression of those proteins in wound tissue may inhibit vascular and skin cell proliferation and degrade the extracellular matrix, which may be one of the causes of CW formation.

Clinical investigation of glucokinase activators for the restoration of glucose homeostasis in diabetes.

As a sensor, glucokinase (GK) controls glucose homeostasis, which progressively declines in patients with diabetes. GK maintains the equilibrium of glucose levels and regulates the homeostatic system set points. Endocrine and hepatic cells can both respond to glucose cooperatively when GK is activated. GK has been under study as a therapeutic target for decades due to the possibility that cellular GK expression and function can be recovered, hence restoring glucose homeostasis in patients with type 2 diabetes. Five therapeutic compounds targeting GK are being investigated globally at the moment. They all have distinctive molecular structures and have been clinically shown to have strong antihyperglycemia effects. The mechanics, classification, and clinical development of GK activators are illustrated in this review. With the recent approval and marketing of the first GK activator (GKA), dorzagliatin, GKA's critical role in treating glucose homeostasis disorder and its long-term benefits in diabetes will eventually become clear.

Comparative analysis of SEC61A1 mutant R236C in two patient-derived cellular platforms

SEC61A1 encodes a central protein of the mammalian translocon and dysfunction results in severe disease. Recently, mutation R236C was identified in patients having autosomal dominant polycystic liver disease (ADPLD). The molecular phenotype of R236C was assessed in two cellular platforms. Cells were immortalized by retroviral transduction of an oncogene (UCi) or reprogrammed to induced pluripotent stem cells (iPSC) that were differentiated to cholangiocyte progenitor-like cells (CPLC). UCi and CPLC were subjected to analyses of molecular pathways that were associated with development of disease. UCi displayed markers of epithelial cells, while CPLCs expressed typical markers of both cholangiocytes and hepatocytes. Cells encoding R236C showed a stable, continuous proliferation in both platforms, however growth rates were reduced as compared to wildtype control. Autophagy, cAMP synthesis, and secretion of important marker proteins were reduced in R236C-expressing cells. In addition, R236C induced increased calcium leakiness from the ER to the cytoplasm. Upon oxidative stress, R236C led to a high induction of apoptosis and necrosis. Although the grade of aberrant cellular functions differed between the two platforms, the molecular phenotype of R236C was shared suggesting that the mutation, regardless of the cell type, has a dominant impact on disease-associated pathways.

Erasing marks: Functions of plant deubiquitylating enzymes in modulating the ubiquitin code.

Plant cells need to respond to environmental stimuli and developmental signals accurately and promptly. Ubiquitylation is a reversible posttranslational modification that enables the adaptation of cellular proteostasis to internal or external factors. The different topologies of ubiquitin linkages serve as the structural basis for the ubiquitin code, which can be interpreted by ubiquitin-binding proteins or readers in specific processes. The ubiquitylation status of target proteins is regulated by ubiquitylating enzymes or writers, and deubiquitylating enzymes (DUBs) or erasers. DUBs can remove ubiquitin molecules from target proteins. Arabidopsis (A. thaliana) DUBs belong to seven protein families and exhibit a wide range of functions and play an important role in regulating selective protein degradation processes, including proteasomal-, endocytic-, and autophagic protein degradation. DUBs also shape the epigenetic landscape and modulate DNA damage repair processes. In this review, we summarize the current knowledge on DUBs in plants, their cellular functions, and the regulatory mechanisms involved in the spatiotemporal regulation of plant DUBs.