Stress Relief Techniques: p38 MAPK Determines the Balance of Cell Cycle and Apoptosis Pathways

Hematopoietic stem cell metabolism within the bone marrow niche - insights and opportunities

Hematopoiesis unfolds within the bone marrow niche where hematopoietic stem cells (HSCs) play a central role in continually replenishing blood cells. The hypoxic bone marrow environment imparts peculiar metabolic characteristics to hematopoietic processes. Here, we discuss the internal metabolism of HSCs and describe external influences exerted on HSC metabolism by the bone marrow niche environment. Importantly, we suggest that the metabolic environment and metabolic cues are intertwined with HSC cell fate, and are crucial for hematopoietic processes. Metabolic dysregulation within the bone marrow niche during acute stress, inflammation, and chronic inflammatory conditions can lead to reduced HSC vitality. Additionally, we raise questions regarding metabolic stresses imposed on HSCs during implementation of stem cell protocols such as allo-SCT and gene therapy, and the potential ramifications. Enhancing our comprehension of metabolic influences on HSCs will expand our understanding of pathophysiology in the bone marrow and improve the application of stem cell therapies.

Small Molecules Targeting Mitochondria: A Mechanistic Approach to Combating Doxorubicin-Induced Cardiotoxicity

Doxorubicin (Dox) is a commonly used chemotherapy drug effective against a range of cancers, but its clinical application is greatly limited by dose-dependent and cumulative cardiotoxicity. Mitochondrial dysfunction is recognized as a key factor in Dox-induced cardiotoxicity, leading to oxidative stress, disrupted calcium balance, and activation of apoptotic pathways. Recent research has emphasized the potential of small molecules that specifically target mitochondria to alleviate these harmful effects. This review provides a comprehensive analysis of small molecules that offer cardioprotection by preserving mitochondrial function in the context of doxorubicin-induced cardiotoxicity (DIC). The mechanisms of action include the reduction of reactive oxygen species (ROS) production, stabilization of mitochondrial membrane potential, enhancement of mitochondrial biogenesis, and modulation of key signaling pathways involved in cell survival and apoptosis. By targeting mitochondria, these small molecules present a promising therapeutic strategy to prevent or reduce the cardiotoxic effects associated with Dox treatment. This review not only discusses the mechanistic actions of these agents but also emphasizes their potential in improving cardiovascular outcomes for cancer patients. Gaining insight into these mechanisms can help in creating more effective strategies to safeguard the heart during chemotherapy, allowing for the ongoing use of Dox with a lower risk to the patient's cardiovascular health. This review highlights the critical role of mitochondria-targeted therapies as a promising approach in addressing DIC.

Integrative Human Genetic and Cellular Analysis of the Pathophysiological Roles of AnxA2 in Alzheimer's Disease

Alzheimer's disease (AD) is an intractable and progressive neurodegenerative disease. Amyloid beta (Aβ) aggregation is the hallmark of AD. Aβ induces neurotoxicity through a variety of mechanisms, including interacting with membrane receptors to alter downstream signaling, damaging cellular or organelle membranes, interfering with protein degradation and synthesis, and inducing an excessive immune-inflammatory response, all of which lead to neuronal death and other pathological changes associated with AD. In this study, we extracted gene expression profiles from the GSE5281 and GSE97760 microarray datasets in the GEO (Gene Expression Omnibus) database, as well as from the Human Gene Database. We identified differentially expressed genes in the brain tissues of AD patients and healthy persons. Through GO, KEGG, and ROC analyses, annexin A2 (AnxA2) was identified as a putative target gene. Notably, accumulating evidence suggests that intracellular AnxA2 is a key regulator in various biological processes, including endocytosis, transmembrane transport, neuroinflammation, and apoptosis. Thus, we conducted a series of cell biology experiments to explore the biological function of AnxA2 in AD. The results indicate that AnxA2 gene knockdown primarily affects oxidative phosphorylation, cell cycle, AD, protein processing in the endoplasmic reticulum, SNARE interactions in vesicular transport, and autophagy. In SH-SY5Y cells secreting Aβ42, AnxA2 gene knockdown exacerbated Aβ42-induced cytotoxicity, including cell death, intracellular ROS levels, and neuronal senescence, altered cell cycle, and reduced ATP levels, suggesting its critical role in mitochondrial function maintenance. AnxA2 gene knockdown also exacerbated the inhibitory effect of Aβ42 on cell migration. AnxA2 overexpression reduced the inflammatory response induced by Aβ42, while its absence increased pro-inflammatory and decreased anti-inflammatory responses. Furthermore, AnxA2 gene knockdown facilitated apoptosis and decreased autophagy. These results indicated potential pathophysiological roles of AnxA2 in AD.

Targeting NUF2 suppresses gastric cancer progression through G2/M phase arrest and apoptosis induction

BACKGROUND

Gastric cancer (GC), a malignant tumor with poor prognosis, is one of the leading causes of cancer-related deaths worldwide; consequently, identifying novel therapeutic targets is crucial for its corresponding treatment. NUF2 , a component of the NDC80 kinetochore complex, promotes cancer progression in multiple malignancies. Therefore, this study aimed to explore the potential of NUF2 as a therapeutic target to inhibit GC progression.

METHODS

Clinical samples were obtained from patients who underwent radical resection of GC at Lanzhou University Second Hospital from 2016 to 2021. Cell count assays, colony formation assays, and cell-derived xenotransplantation (CDX) models were used to determine the effects of NUF2 on GC progression. Flow cytometry was used to detect the effect of NUF2 or quercetin on cell cycle progression and apoptosis. A live-cell time-lapse imaging assay was performed to determine the effect of NUF2 on the regulation of mitotic progression. Transcriptomics was used to investigate the NUF2 -associated molecular mechanisms. Virtual docking and microscale thermophoresis were used to identify NUF2 inhibitors. Finally, CDX, organoid, and patient-derived xenograft (PDX) models were used to examine the efficacy of the NUF2 inhibitor in GC.

RESULTS

NUF2 expression was significantly increased in GC and was negatively correlated with prognosis. The deletion of NUF2 suppressed GC progression both in vivo and in vitro . NUF2 significantly regulated the mitogen-activated protein kinase (MAPK) pathway, promoted G2/M phase transition, and inhibited apoptosis in GC cells. Additionally, quercetin was identified as a selective NUF2 inhibitor with low toxicity that significantly suppressed tumor growth in GC cells, organoids, CDX, and PDX models.

CONCLUSIONS

Collectively, NUF2 -mediated G2/M phase transition and apoptosis inhibition promoted GC progression; additionally, NUF2 inhibitors exhibited potent anti-GC activity. This study provides a new strategy for targeting NUF2 to suppress GC progression in clinical settings.

EtROP38 suppresses apoptosis of host cells infected with Eimeria tenella by inhibition of the p38MAPK pathway

Coccidiosis is an important parasitic disease that has serious adverse effects on the global poultry industry. The mechanism by which the pathogenic factors of Eimeria tenella damage host cells is unknown. Some kinases from the rhoptry compartment can regulate apoptosis of host cells. This study focused on revealing the role and critical nodes of E. tenella rhoptry protein (EtROP) 38 in controlling the apoptosis of host cells via the P38 mitogen-activated protein kinase (MAPK) signaling pathway. The cells were treated with EtROP38 protein, siRNA p38MAPK, or both. The rate of infection, apoptosis, and the dynamic changes in the expression and activation of key factor genes of the P38MAPK signaling pathway in host cells infected with E. tenella were measured. The results showed that the addition of EtROP38 and/or knockdown of the host cells p38 gene reduced the apoptosis rate of cecal epithelial cells (CECS), decreased the mRNA expressions of p38, p53, c-myc, c-fos, and c-jun and increased the expression of p65, decreased the protein expressions of c-myc, c-fos, and c-jun, decreased the p38 protein phosphorylation level, and increased the p65 protein phosphorylation level in CECS. When E. tenella was inoculated for 4-96 h, the addition of Et ROP38 and/or host cell p38 knockdown both increased the infection rate of host cells, and this effect was more pronounced with the addition of EtROP38 with the host cell p38 knockdown. These observations indicate that E. tenella can inhibits the activation of the p38MAPK signaling pathway in host cells via EtROP38, which suppresses apoptosis in host cells.

CDC25B Is a Prognostic Biomarker Associated With Immune Infiltration and Drug Sensitivity in Hepatocellular Carcinoma

Cell division cycle 25B (CDC25B), a member of the CDC25 phosphatase family, plays a key role in cell cycle regulation. Studies have suggested its carcinogenic potential in various cancers, but the role of CDC25B in the development of hepatocellular carcinoma (HCC) remains poorly understood. The aim of this study was to clarify the role of CDC25B in HCC using bioinformatics and experiments. CDC25B expression data of HCC cancer tissues and paracancerous normal samples were obtained from The Cancer Gene Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and the relationship between CDC25B expression and the prognosis and degree of tumor differentiation of HCC patients was analyzed. CDC25B expression was verified in clinical HCC tissue samples using fluorescence quantitative polymerase chain reaction (q-PCR) and protein immunoblotting (Western blot). Gene set enrichment analysis (GSEA) was used to identify signaling pathways enriched in CDC25B expression, and differential genes (DEGs) were used to screen out coexpressed hub genes and construct protein-protein interaction (PPI) networks. 5-Ethynyl-2'-deoxyuridine (EDU) staining was used to compare the proliferation and differentiation ability of the HCC cell line (HCC-LM3) after knockdown of CDC25B. Finally, we investigated the mutation of CDC25B in HCC and the relationship between CDC25B expression and tumor cell infiltration of lymphocytes and some immune checkpoints as well as drug sensitivity. CDC25B was overexpressed in HCC tissues and correlated with poor prognosis and the degree of tumor differentiation in patients with HCC. The GSEA and PPI networks together revealed significantly upregulated signaling pathways, as well as functions, associated with the development of HCC when CDC25B was overexpressed. The EDU assay demonstrated that the ability of cells to differentiate value addedly was markedly reduced following the downregulation of CDC25B expression in HCC-LM3s. CDC25B was also involved in the formation of the tumor microenvironment (TME) and immune processes in HCC, and the high expression of CDC25B made patients less sensitive to some drugs. CDC25B can be used as a biomarker and immunotherapeutic target for poor prognosis and partial drug sensitivity in HCC, providing new ideas for HCC treatment.

PKC-δ Promotes IL-1β-Induced Apoptosis of Rat Chondrocytes and Via Activating JNK and P38 MAPK Pathways

OBJECTIVE

Protein kinase C-delta (PKC-δ) is involved in apoptosis. This study aimed to establish whether PKC-δ can further promote IL-1β-induced chondrocyte apoptosis by mediating the phosphorylation of the JNK and p38 mitogen-activated protein kinase (MAPK) signaling pathways In osteoarthritis (OA).

METHODS

We employed chondrocyte staining to determine the extent of cartilage degeneration. PKC-δ and p38 signal expressions were used in the immunohistochemical (IHC) test and apoptosis was assayed at the TUNEL test in human osteoarthritic and controls. We stimulated rat cartilage cells using IL-1β (10 ng/ml)/rottlerin (10 μM) or lentivirus. To determine the apoptosis rate, we employed flow cytometry. The mRNA of both BCL2-related X (BAX) and cysteine aspartate protease 3 (caspase-3) could be measured via qRT-PCR. Western blot measured the protein levels of BAX, caspase-3, PKC-δ, p-JNK/JNK and p-p38/p38.

RESULTS

The positive rate of PKC-δ and the apoptotic rate of chondrocytes in OA were higher than controls. The manifestation of PKC-δ was positively related to the degree of cartilage degeneration, p38 protein expression, and apoptosis rate. IL-1β exposure upregulated PKC-δ expression in chondrocytes in a dose-dependent manner. Decreasing PKC-δ expression and its phosphorylation in OA can inhibit MAPK signaling pathway activation (phosphorylation) by downregulating JNK and p38 protein phosphorylation and expression. This inhibition decreases caspase-3 and BAX levels, consequently lowering the apoptosis rate in chondrocytes.

CONCLUSION

PKC-δ activation by IL-1β in OA promotes chondrocyte apoptosis via activation of the JNK and p38 MAPK signal pathways, thereby promoting the OA progression.

Digitoxin inhibits ICC cell properties via the NF‑κB/ST6GAL1 signaling pathway

Intrahepatic cholangiocarcinoma (ICC) is a type of liver cancer associated with poor prognosis and increased mortality; the limited treatment strategy highlights the urgent need for investigation. Traditional Chinese Medicine (TCM), used alone or in combination with other treatments, can enhance therapeutic efficacy, improve life quality of patients and extend overall survival. In total, two rounds of screening of a TCM library of 2,538 active compounds were conducted using a Cell Counting Kit‑8 assay and ICC cell lines. Cell proliferation and migration abilities were assessed through colony formation, 5‑ethynyl‑2'‑deoxyuridine, would healing and Transwell assays. The impact of digitoxin (DT) on signaling pathways was initially investigated using RNA sequencing and further validated using reverse transcription‑quantitative PCR, western blotting, lectin blotting and flow cytometry. ICC cells stably overexpressing ST6 β‑galactoside α‑2,6‑sialyltransferase 1 (ST6GAL1) were generated through lentiviral transfection. It was shown that DT emerged as a highly effective anti‑ICC candidate from two rounds high‑throughput library screening. DT could inhibit the proliferation and migration of ICC cells by suppressing NF‑κB activation and reducing nuclear phosphorylated‑NF‑κB levels, along with diminishing ST6GAL1 mRNA and protein expression. The aforementioned biological effects and signal pathways of DT could be counteracted by overexpressing ST6GAL1 in ICC cells. In conclusion, DT suppressed ICC cell proliferation and migration by targeting the NF‑κB/ST6GAL1 signaling axis. The findings of the present study indicated the promising therapeutic effects of DT in managing ICC, offering new avenues for treatment strategies.

MAPK Phosphatase-5 is required for TGF-β signaling through a JNK-dependent pathway

Mitogen-activated protein kinase (MAPK) phosphatases (MKPs) constitute members of the dual-specificity family of protein phosphatases that dephosphorylate the MAPKs. MKP-5 dephosphorylates the stress-responsive MAPKs, p38 MAPK and JNK, and has been shown to promote tissue fibrosis. Here, we provide insight into how MKP-5 regulates the transforming growth factor-β (TGF-β) pathway, a well-established driver of fibrosis. We show that MKP-5-deficient fibroblasts in response to TGF-β are impaired in SMAD2 phosphorylation at canonical and non-canonical sites, nuclear translocation, and transcriptional activation of fibrogenic genes. Consistent with this, pharmacological inhibition of MKP-5 is sufficient to block TGF-β signaling, and that this regulation occurs through a JNK-dependent pathway. By utilizing RNA sequencing and transcriptomic analysis, we identify TGF-β signaling activators regulated by MKP-5 in a JNK-dependent manner, providing mechanistic insight into how MKP-5 promotes TGF-β signaling. This study elucidates a novel mechanism whereby MKP-5-mediated JNK inactivation is required for TGF-β signaling and provides insight into the role of MKP-5 in fibrosis.

Sulfated Laminarin Polysaccharides Reduce the Adhesion of Nano-COM Crystals to Renal Epithelial Cells by Inhibiting Oxidative and Endoplasmic Reticulum Stress

Purpose: Adhesion between calcium oxalate crystals and renal tubular epithelial cells is a vital cause of renal stone formation; however, the drugs that inhibit crystal adhesion and the mechanism of inhibition have yet to be explored. Methods: The cell injury model was constructed using nano-COM crystals, and changes in oxidative stress levels, endoplasmic reticulum (ER) stress levels, downstream p38 MAPK protein expression, apoptosis, adhesion protein osteopontin expression, and cell-crystal adhesion were examined in the presence of Laminarin polysaccharide (DLP) and sulfated DLP (SDLP) under protected and unprotected conditions. Results: Both DLP and SDLP inhibited nano-COM damage to human kidney proximal tubular epithelial cell (HK-2), increased cell viability, decreased ROS levels, reduced the opening of mitochondrial membrane permeability transition pore, markedly reduced ER Ca2+ ion concentration and adhesion molecule OPN expression, down-regulated the expression of ER stress signature proteins including CHOP, Caspase 12, and p38 MAPK, and decreased the apoptosis rate of cells. SDLP has a better protective effect on cells than DLP. Conclusions: SDLP protects HK-2 cells from nano-COM crystal-induced apoptosis by reducing oxidative and ER stress levels and their downstream factors, thereby reducing crystal-cell adhesion interactions and the risks of kidney stone formation.

Delineating the molecular mechanisms of hippocampal neurotoxicity induced by chronic administration of synthetic cannabinoid AB-FUBINACA in mice

Chronic use of synthetic cannabinoids (SCs) has been associated with cognitive and behavioural deficits and an increased risk of neuropsychiatric disorders. The underlying molecular and cellular mechanisms of the neurotoxic effects of long-term use of SCs have not been well investigated in the literature. Herein, we evaluated the in vivo effects of chronic administration of AB-FUBINACA on the hippocampus in mice. Our results revealed that the administration of AB-FUBINACA induced a significant impairment in recognition memory associated with histopathological changes in the hippocampus. These findings were found to be correlated with increased level of oxidative stress, neuroinflammation, and apoptosis markers, and reduced expression of brain-derived neurotrophic factor (BDNF), which plays an essential role in modulating synaptic plasticity integral for promoting learning and memory in the hippocampus. Additionally, we showed that AB-FUBINACA significantly decreased the expression of NR1, an important functional subunit of glutamate/NMDA receptors and closely implicated in the development of toxic psychosis. These findings shed light on the long-term neurotoxic effects of SCs on hippocampus and the underlying mechanisms of these effects. This study provided new targets for possible medical interventions to improve the treatment guidelines for SCs addiction.

Apoptosis and eryptosis: similarities and differences

Eryptosis is a regulated cell death (RCD) of mature erythrocytes initially described as a counterpart of apoptosis for enucleated cells. However, over the recent years, a growing number of studies have emphasized certain differences between both cell death modalities. In this review paper, we underline the hallmarks of eryptosis and apoptosis and highlight resemblances and dissimilarities between both RCDs. We summarize and critically discuss differences in the impact of caspase-3, Ca2+ signaling, ROS signaling pathways, opposing roles of casein kinase 1α, protein kinase C, Janus kinase 3, cyclin-dependent kinase 4, and AMP-activated protein kinase to highlight a certain degree of divergence between apoptosis and eryptosis. This review emphasizes the crucial importance of further studies that focus on deepening our knowledge of cell death machinery and identifying novel differences between cell death of nucleated and enucleated cells. This might provide evidence that erythrocytes can be defined as viable entities capable of programmed cell destruction. Additionally, the revealed cell type-specific patterns in cell death can facilitate the development of cell death-modulating therapeutic agents.

Low-frequency magnetic field therapy for glioblastoma: Current advances, mechanisms, challenges and future perspectives

BACKGROUND

Glioblastoma (GBM) is the most common malignant tumour of the central nervous system. Despite recent advances in multimodal GBM therapy incorporating surgery, radiotherapy, systemic therapy (chemotherapy, targeted therapy), and supportive care, the overall survival (OS) remains poor, and long-term survival is rare. Currently, the primary obstacles hindering the effectiveness of GBM treatment are still the blood-brain barrier and tumor heterogeneity. In light of its substantial advantages over conventional therapies, such as strong penetrative ability and minimal side effects, low-frequency magnetic fields (LF-MFs) therapy has gradually caught the attention of scientists.

AIM OF REVIEW

In this review, we shed the light on the current status of applying LF-MFs in the treatment of GBM. We specifically emphasize our current understanding of the mechanisms by which LF-MFs mediate anticancer effects and the challenges faced by LF-MFs in treating GBM cells. Furthermore, we discuss the prospective applications of magnetic field therapy in the future treatment of GBM. Key scientific concepts of review: The review explores the current progress on the use of LF-MFs in the treatment of GBM with a special focus on the potential underlying mechanisms of LF-MFs in anticancer effects. Additionally, we also discussed the complex magnetic field features and biological characteristics related to magnetic bioeffects. Finally, we proposed a promising magnetic field treatment strategy for future applications in GBM therapy.

Synergy between PEDF and Doxorubicin in Breast Cancer Cells: Effects on Metastatic and Metabolic Pathways

Pigment epithelium-derived factor (PEDF), a serine protease inhibitor (Serpin) family member, shows promise in inhibiting tumour growth. In our study, we explored the effects of PEDF on the efficacy of the frontline chemotherapy agent doxorubicin (Dox) in BC cells. We found that Dox+PEDF treatment significantly reduced glucose uptake in MDA-MB-231 cells compared to the control (p = 0.0005), PEDF (p = 0.0137), and Dox (p = 0.0171) alone but paradoxically increased it in MCF-7 cells. Our findings further revealed that PEDF, Dox, and Dox+PEDF substantially hindered tumour cell migration from tumour spheroids, with Dox+PEDF showing the most significant impact (p < 0.0001). We also observed notable decreases in the expression of metastatic markers (uPAR, uPA, CXCR4, MT1-MMP, TNF-α) across all treatment groups (p < 0.0001) in both cell lines. When it comes to metabolic pathways, PEDF increased phosphorylated IRS-1 (p-IRS1) levels in MDA-MB-231 and MCF-7 (p < 0.0001), while Dox decreased it, and the combination led to an increase. In MDA-MB-231 cells, treatment with PEDF, Dox, and the combination led to a notable decrease in both phosphorylated AKT (p-AKT) and total AKT levels. In MCF-7, while PEDF, Dox, and their combination led to a reduction in p-AKT, total levels of AKT increased in the presence of Dox and Dox+PEDF. Combining PEDF with Dox enhances the targeting of metastatic and metabolic pathways in breast cancer cell lines. This synergy, marked by PEDF's increasing roles in cancer control, may pave the way for more effective cancer treatments.

Suppression of the SLC7A11/glutathione axis causes ferroptosis and apoptosis and alters the mitogen-activated protein kinase pathway in nasopharyngeal carcinoma

SLC7A11 is a unit of the glutamate cystine antiporter Xc- system. It functions to import cystine for glutathione biosynthesis and maintains the redox balance in cells. Sorafenib inhibits the transporter activity of SLC7A11. The use of sorafenib has been approved in the treatment of multiple cancers. However, at present, our understanding of the mechanism of SLC7A11 and sorafenib in nasopharyngeal carcinoma (NPC) remains limited. We found that the expression of SLC7A11 was upregulated in NPC. A high SLC7A11 expression was associated with poor prognosis, metastasis, and an advanced T stage, which can be used as an independent prognostic indicator of NPC. In vitro, we observed that NPC cells relied on cystine for survival. Targeting SLC7A11 resulted in glutathione biosynthesis limitation, intracellular reactive oxygen species accumulation, lipid peroxides, ferroptosis, and apoptosis. Meanwhile, it altered mitogen activated protein kinase pathway, including p38 activation but ERK inhibition in NPC. This limited the proliferation of NPC cells. Sorafenib inhibited the proliferation and induced the death of NPC cells in vivo. In conclusion, SLC7A11 plays an important role in the occurrence and progression of NPC and may be a novel target for NPC treatment.

Delivery of dental pulp stem cells by an injectable ROS-responsive hydrogel promotes temporomandibular joint cartilage repair via enhancing anti-apoptosis and regulating microenvironment

Temporomandibular joint (TMJ) cartilage repair poses a considerable clinical challenge, and tissue engineering has emerged as a promising solution. In this study, we developed an injectable reactive oxygen species (ROS)-responsive multifunctional hydrogel (RDGel) to encapsulate dental pulp stem cells (DPSCs/RDGel in short) for the targeted repair of condylar cartilage defect. The DPSCs/RDGel composite exhibited a synergistic effect in the elimination of TMJ OA (osteoarthritis) inflammation via the interaction between the hydrogel component and the DPSCs. We first demonstrated the applicability and biocompatibility of RDGel. RDGel encapsulation could enhance the anti-apoptotic ability of DPSCs by inhibiting P38/P53 mitochondrial apoptotic signal in vitro. We also proved that the utilization of DPSCs/RDGel composite effectively enhanced the expression of TMJOA cartilage matrix and promoted subchondral bone structure in vivo. Subsequently, we observed the synergistic improvement of DPSCs/RDGel composite on the oxidative stress microenvironment of TMJOA and its regulation and promotion of M2 polarization, thereby confirmed that M2 macrophages further promoted the condylar cartilage repair of DPSCs. This is the first time application of DPSCs/RDGel composite for the targeted repair of TMJOA condylar cartilage defects, presenting a novel and promising avenue for cell-based therapy.

Salt Behind the Scenes of Systemic Lupus Erythematosus and Rheumatoid Arthritis

PURPOSE OF REVIEW

Sodium is vital for human health. High salt intake is a global health problem and is associated with cardiovascular morbidity and mortality. Recent evidence suggests that both innate and adaptive immune systems are affected by sodium. In general, excess salt intake drives immune cells toward a pro-inflammatory phenotype. The incidence of autoimmune diseases, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), is steadily increasing. As excess salt induces a pro-inflammatory state, increased salt intake may have impacts on autoimmune diseases. The relationship between salt intake and autoimmune diseases is most widely studied in patients with SLE or RA. This review aimed to summarize the relationship between salt intake and SLE and RA.

RECENT FINDINGS

Most, but not all, of these studies showed that high salt intake might promote SLE by M1 macrophage shift, increase in Th17/Treg cell ratio, activation of dendritic and follicular helper T cells, and increased secretion of pro-inflammatory cytokines. In RA, apart from driving immune cells toward a pro-inflammatory state, high salt intake also influences cellular signaling pathways, including receptor activator of nuclear factor κB ligand (RANKL), Rho GTPases, and MAPK (mitogen-activated protein kinase). There is now sufficient evidence that excess salt intake may be related to the development and progression of SLE and RA, although there are still knowledge gaps. More studies are warranted to further highlight the relationship between excess salt intake, SLE, and RA. Salt intake may affect cell types and pro-inflammatory cytokines and signaling pathways associated with the development and progression of systemic lupus erythematosus and rheumatoid arthritis. Bcl-6 B-cell lymphoma, 6 Erk extracellular signal-regulated kinases, IFN-γ interferon-gamma, JNK c-Jun N-terminal kinase, IL-4 interleukin 4, IL-6 interleukin 6, MAPK mitogen-activated protein kinase, STAT signal transducer and activator of transcription, Tnf-α tumor necrosis factor, Treg T regulatory cell.

Natural Products for Acetaminophen-Induced Acute Liver Injury: A Review

The liver plays a vital role in metabolism, synthesis, and detoxification, but it is susceptible to damage from various factors such as viral infections, drug reactions, excessive alcohol consumption, and autoimmune diseases. This susceptibility is particularly problematic for patients requiring medication, as drug-induced liver injury often leads to underestimation, misdiagnosis, and difficulties in treatment. Acetaminophen (APAP) is a widely used and safe drug in therapeutic doses but can cause liver toxicity when taken in excessive amounts. This study aimed to investigate the hepatotoxicity of APAP and explore potential treatment strategies using a mouse model of APAP-induced liver injury. The study involved the evaluation of various natural products for their therapeutic potential. The findings revealed that natural products demonstrated promising hepatoprotective effects, potentially alleviating liver damage and improving liver function through various mechanisms such as oxidative stress and inflammation, which cause changes in signaling pathways. These results underscore the importance of exploring novel treatment options for drug-induced liver injury, suggesting that further research in this area could lead to the development of effective preventive and therapeutic interventions, ultimately benefiting patients with liver injury caused by medicine.

Nanoplastics activate a TLR4/p38-mediated pro-inflammatory response in human intestinal and mouse microglia cells

The crescent presence of nanoplastics in the environment raises concerns regarding their potential impact on health. This study exposed human colon adenocarcinoma cells (HT29) and microglia cells (N9) to nanoplastics (25 nm, 50 nm, and 100 nm Polystyrene) to investigate their inflammatory responses, which are vital for body's defence. Although cytotoxicity remained generally low, HT29 cells exhibited a notable upregulation of p50 and p38 expression, concomitant with elevated TLR4 expression, in contrast with N9 cells that showed a less pronounced upregulation of these proteins. Additionally, nanoplastic exposure increased IL-1ß levels, partially attenuated by pre-exposure to TLR4 or p38 inhibitors. Intriguingly, N9 cells exposed to nanoplastics exhibited substantial increases in iNOS mRNA. This effect was entirely prevented by pre-exposure to TLR4 or p38 inhibitors, while TNF-α mRNA levels remained relatively stable. These findings underscore the potential of nanoplastics to activate inflammatory pathways, with response kinetics varying depending on the cell type.

Cyclic fasting bolsters cholesterol biosynthesis inhibitors' anticancer activity

Identifying oncological applications for drugs that are already approved for other medical indications is considered a possible solution for the increasing costs of cancer treatment. Under the hypothesis that nutritional stress through fasting might enhance the antitumour properties of at least some non-oncological agents, by screening drug libraries, we find that cholesterol biosynthesis inhibitors (CBIs), including simvastatin, have increased activity against cancers of different histology under fasting conditions. We show fasting's ability to increase CBIs' antitumour effects to depend on the reduction in circulating insulin, insulin-like growth factor-1 and leptin, which blunts the expression of enzymes from the cholesterol biosynthesis pathway and enhances cholesterol efflux from cancer cells. Ultimately, low cholesterol levels through combined fasting and CBIs reduce AKT and STAT3 activity, oxidative phosphorylation and energy stores in the tumour. Our results support further studies of CBIs in combination with fasting-based dietary regimens in cancer treatment and highlight the value of fasting for drug repurposing in oncology.

MAPK-negative feedback regulation confers dependence to JAK2V617F signaling

Despite significant advances in developing selective JAK2 inhibitors, JAK2 kinase inhibitor (TKI) therapy is ineffective in suppressing the disease. Reactivation of compensatory MEK-ERK and PI3K survival pathways sustained by inflammatory cytokine signaling causes treatment failure. Concomitant inhibition of MAPK pathway and JAK2 signaling showed improved in vivo efficacy compared to JAK2 inhibition alone but lacked clonal selectivity. We hypothesized that cytokine signaling in JAK2V617F induced MPNs increases the apoptotic threshold that causes TKI persistence or refractoriness. Here, we show that JAK2V617F and cytokine signaling converge to induce MAPK negative regulator, DUSP1. Enhanced DUSP1 expression blocks p38 mediated p53 stabilization. Deletion of Dusp1 increases p53 levels in the context of JAK2V617F signaling that causes synthetic lethality to Jak2V617F expressing cells. However, inhibition of Dusp1 by a small molecule inhibitor (BCI) failed to impart Jak2V617F clonal selectivity due to pErk1/2 rebound caused by off-target inhibition of Dusp6. Ectopic expression of Dusp6 and BCI treatment restored clonal selectively and eradicated the Jak2V617F cells. Our study shows that inflammatory cytokines and JAK2V617F signaling converge to induce DUSP1, which downregulates p53 and establishes a higher apoptotic threshold. These data suggest that selectively targeting DUSP1 may provide a curative response in JAK2V617F-driven MPN.

Learning Causal Biological Networks with Parallel Ant Colony Optimization Algorithm

A wealth of causal relationships exists in biological systems, both causal brain networks and causal protein signaling networks are very classical causal biological networks (CBNs). Learning CBNs from biological signal data reliably is a critical problem today. However, most of the existing methods are not excellent enough in terms of accuracy and time performance, and tend to fall into local optima because they do not take full advantage of global information. In this paper, we propose a parallel ant colony optimization algorithm to learn causal biological networks from biological signal data, called PACO. Specifically, PACO first maps the construction of CBNs to ants, then searches for CBNs in parallel by simulating multiple groups of ants foraging, and finally obtains the optimal CBN through pheromone fusion and CBNs fusion between different ant colonies. Extensive experimental results on simulation data sets as well as two real-world data sets, the fMRI signal data set and the Single-cell data set, show that PACO can accurately and efficiently learn CBNs from biological signal data.

FGF19 induces the cell cycle arrest at G2-phase in chondrocytes

Fibroblast growth factor 19 (FGF19) has appeared as a new possible avenue in the treatment of skeletal metabolic disorders. However, the role of FGF19 on cell cycle progression in skeletal system is poorly understood. Here we demonstrated that FGF19 had the ability to reduce the proliferation of chondrocytes and cause cell cycle G2 phase arrest through its interaction with β-Klotho (KLB), an important accessory protein that helps FGF19 link to its receptor. FGF19-mediated cell cycle arrest by regulating the expressions of cdk1/cylinb1, chk1 and gadd45a. We then confirmed that the binding of FGF19 to the membrane receptor FGFR4 was necessary for FGF19-mediated cell cycle arrest, and further proved that FGF19-mediated cell cycle arrest was via activation of p38/MAPK signaling. Through inhibitor experiments, we discovered that inhibition of FGFR4 led to down-regulation of p38 signaling even in the presence of FGF19. Meanwhile, inhibiting p38 signaling reduced the cell cycle arrest of chondrocytes induced by FGF19. Furthermore, blocking p38 signaling facilitated to retain the expression of cdk1 and cyclinb1 that had been reduced in chondrocytes by FGF19 and decreased the expression of chk1 and gadd45a that had been enhanced by FGF19 in chondrocytes. Taking together, this study is the first to demonstrate that FGF19 induces cell cycle arrest at G2 phase via FGFR4-p38/MAPK axis and enlarges our understanding about the role of FGF19 on cell cycle progression in chondrocytes.

Iodine-Biofortified Lettuce Can Promote Mitochondrial Dependent Pathway of Apoptosis in Human Gastrointestinal Cancer Cells

Previously, our research provided evidence that exposure of gastric and colon cancer cells to extracts from iodine-biofortified lettuce leads to a reduction of cell viability and proliferation through cell cycle arrest and upregulation of pro-apoptotic genes. The aim of the present study was to determine the potential cellular mechanisms of induction of cell death in human gastrointestinal cancer cell lines after treatment with iodine-biofortified lettuce. We demonstrated that extracts from lettuce enriched with iodine induce apoptosis in gastric AGS and colon HT-29 cancer cells and the mechanism of programmed cell death may be triggered and executed through different signaling pathways, depending on the type of cells. Western blot analysis revealed that iodine-fortified lettuce leads to cell death through the release of cytochrome c to the cytosolic fraction and activation of the primary drivers of apoptosis: caspase-3, caspase-7, and caspase-9. Furthermore, we have reported that apoptotic effects of lettuce extracts may be mediated by poly (ADP-ribose) polymerase (PARP) and activation of pro-apoptotic Bcl-2 family proteins such as Bad, Bax, and BID. We also observed mitochondrial dysfunction with the dissipation of the mitochondrial membrane potential in cells exposed to lettuce extracts. Taken together, these results indicate that the organic form of iodine such as 5-ISA and 3,5-diISA is an important factor in the activation of intrinsic mitochondrial apoptotic pathway in AGS and HT-29 cancer cells in a p53-independent manner.

A Selective Nano Cell Cycle Checkpoint Inhibitor Overcomes Leukemia Chemoresistance

Cell cycle checkpoint activation promotes DNA damage repair, which is highly associated with the chemoresistance of various cancers including acute myeloid leukemia (AML). Selective cell cycle checkpoint inhibitors are strongly demanded to overcome chemoresistance, but remain unexplored. A selective nano cell cycle checkpoint inhibitor (NCCI: citric acid capped ultra-small iron oxide nanoparticles) that can catalytically inhibit the cell cycle checkpoint of AML to boost the chemotherapeutic efficacy of genotoxic agents is now reported. NCCI can selectively accumulate in AML cells and convert H2 O2 to • OH to cleave heat shock protein 90, leading to the degradation of ataxia telangiectasia and Rad3-related proteinand checkpoint kinase 1, and the subsequent dysfunction of the G2/M checkpoint. Consequently, NCCI revitalizes the anti-AML efficacy of cytarabine that is previously ineffective both in vitro and in vivo. This study offers new insights into designing selective cell cycle checkpoint inhibitors for biomedical applications.

Consequences of poly(ethylene oxide) and poloxamer P188 on transcription in healthy and stressed myoblasts

Poly(ethylene oxide) (PEO) and poloxamers, a class of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, have many personal and medical care applications, including the stabilization of stressed cellular membranes. Despite the widespread use, the cellular transcriptional response to these molecules is relatively unknown. C2C12 myoblasts, a model muscle cell, were subjected to short-term Poloxamer 188 (P188) and PEO181 (8,000 g/mol) treatment in culture. RNA was extracted and sequenced to quantify transcriptomic impact. The addition of moderate concentrations (14 µM) of either polymer to unstressed cells caused substantial differential gene expression, including at least twofold modulation of 357 and 588 genes, respectively. In addition, evaluation of the transcriptome response to osmotic stress without polymer treatment revealed dramatic change in RNA expression. Interestingly, the addition of polymer to stressed cells-at concentrations that provide physiological protection-did not yield a significant difference in expression of any gene relative to stress alone. Genome-scale expression analysis was corroborated by single-gene quantitative real-time PCR. Changes in protein expression were measured via western blot, which revealed partial alignment with the RNA results. Collectively, the significant changes to expression of multiple genes and resultant protein translation demonstrates an unexpectedly broad biochemical response to these polymers in healthy myoblasts in vitro. Meanwhile, the lack of substantial transcriptional response to polymer treatment in stressed cells highlights the physical nature of that protective mechanism.

Comparative transcriptome analysis provides insights into the TDG supersaturation stress response of Schizothorax davidi

In the dam discharge season, the supersaturation of total dissolved gas (TDG) in the downstream channel can seriously affect the survival of aquatic organisms. However, few studies have revealed the mechanism by which TDG supersaturation affects the physiology of fish thus far. The present study was conducted to study the mechanism of the effect of TDG supersaturation on Schizothorax davidi, a species that is very sensitive to gas bubble disease. S. davidi was exposed to 116 % TDG supersaturation stress for 24 h. Serum biochemical tests showed that the aspartate aminotransferase and alanine aminotransferase levels after TDG supersaturation exposure were significantly decreased compared to those in the control group, while superoxide dismutase activity was significantly increased. RNA-Seq of gill tissues identified 1890 differentially expressed genes (DEGs), which consisted of 862 upregulated genes and 1028 downregulated genes, in the TDG supersaturation group vs. the control group. Pathway enrichment analysis revealed that the cell cycle, apoptosis and immune signaling pathways were affected by TDG stress. The results of this study may contribute to our understanding of the underlying molecular mechanism of environmental stress in fish.

Repurposing Verapamil to Enhance Killing of T-ALL Cells by the mTOR Inhibitor Everolimus

New therapies are needed for patients with T-cell lymphoblastic leukemia (T-ALL) who do not respond to standard chemotherapy. Our previous studies showed that the mTORC1 inhibitor everolimus increases reactive oxygen species (ROS) levels, decreases the levels of NADPH and glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway (PPP), and induces apoptosis in T-ALL cells. Studies in T-ALL-xenografted NOD/SCID mice demonstrated that everolimus improved their response to the glucocorticoid (GC) dexamethasone. Here we show that verapamil, a calcium antagonist used in the treatment of supraventricular tachyarrhythmias, enhanced the effects of everolimus on ROS and cell death in T-ALL cell lines. The death-enhancing effect was synergistic and was confirmed in assays on a panel of therapy-resistant patient-derived xenografts (PDX) and primary samples from T-ALL patients. The verapamil-everolimus combination produced a dramatic reduction in the levels of G6PD and induction of p38 MAPK phosphorylation. Studies of NOD/SCID mice inoculated with refractory T-ALL PDX cells demonstrated that the addition of verapamil to everolimus plus dexamethasone significantly reduced tumor growth in vivo. Taken together, our results provide a rationale for repurposing verapamil in association with mTORC inhibitors and GC to treat refractory T-ALL.

Discovery of β-cyclocitral-derived mono-carbonyl curcumin analogs as anti-hepatocellular carcinoma agents via suppression of MAPK signaling pathway

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors with a high recurrence and mortality rate. In this study, a series of β-cyclocitral-derived mono-carbonyl curcumin analogs were synthesized and their anticancer properties were evaluated. Among the series, A19 exhibited the strongest cytotoxic activity by inhibiting cell viability and colony formation, inducing cell cycle G2/M phase arrest and cell apoptosis of HCC HepG2 and Huh-7 cells, while having almost no cytotoxicity on normal liver MIHA cells. Mechanistically, our results demonstrated that A19 triggered intense DNA damage via suppression of the ERK/JNK/p38 MAPK signaling pathway. Additionally, a combination of A19 with sorafenib significantly induced synergistic cytotoxicity in HCC cells. Overall, our results indicate the potential of A19 as a novel chemotherapeutic drug administered either separately or in combined therapy for HCC treatment.

Signaling pathways in rheumatoid arthritis: implications for targeted therapy

Rheumatoid arthritis (RA) is an incurable systemic autoimmune disease. Disease progression leads to joint deformity and associated loss of function, which significantly impacts the quality of life for sufferers and adds to losses in the labor force. In the past few decades, RA has attracted increased attention from researchers, the abnormal signaling pathways in RA are a very important research field in the diagnosis and treatment of RA, which provides important evidence for understanding this complex disease and developing novel RA-linked intervention targets. The current review intends to provide a comprehensive overview of RA, including a general introduction to the disease, historical events, epidemiology, risk factors, and pathological process, highlight the primary research progress of the disease and various signaling pathways and molecular mechanisms, including genetic factors, epigenetic factors, summarize the most recent developments in identifying novel signaling pathways in RA and new inhibitors for treating RA. therapeutic interventions including approved drugs, clinical drugs, pre-clinical drugs, and cutting-edge therapeutic technologies. These developments will hopefully drive progress in new strategically targeted therapies and hope to provide novel ideas for RA treatment options in the future.

P38 MAPK and Radiotherapy: Foes or Friends?

Over the last 30 years, the study of the cellular response to ionizing radiation (IR) has increased exponentially. Among the various signaling pathways affected by IR, p38 MAPK has been shown to be activated both in vitro and in vivo, with involvement in key processes triggered by IR-mediated genotoxic insult, such as the cell cycle, apoptosis or senescence. However, we do not yet have a definitive clue about the role of p38 MAPK in terms of radioresistance/sensitivity and its potential use to improve current radiotherapy. In this review, we summarize the current knowledge on this family of MAPKs in response to IR as well as in different aspects related to radiotherapy, such as their role in the control of REDOX, fibrosis, and in the radiosensitizing effect of several compounds.

Psymberin, a marine-derived natural product, induces cancer cell growth arrest and protein translation inhibition

Colorectal cancer (CRC) is the third most prevalent form of cancer in the United States and results in over 50,000 deaths per year. Treatments for metastatic CRC are limited, and therefore there is an unmet clinical need for more effective therapies. In our prior work, we coupled high-throughput chemical screens with patient-derived models of cancer to identify new potential therapeutic targets for CRC. However, this pipeline is limited by (1) the use of cell lines that do not appropriately recapitulate the tumor microenvironment, and (2) the use of patient-derived xenografts (PDXs), which are time-consuming and costly for validation of drug efficacy. To overcome these limitations, we have turned to patient-derived organoids. Organoids are increasingly being accepted as a "standard" preclinical model that recapitulates tumor microenvironment cross-talk in a rapid, cost-effective platform. In the present work, we employed a library of natural products, intermediates, and drug-like compounds for which full synthesis has been demonstrated. Using this compound library, we performed a high-throughput screen on multiple low-passage cancer cell lines to identify potential treatments. The top candidate, psymberin, was further validated, with a focus on CRC cell lines and organoids. Mechanistic and genomics analyses pinpointed protein translation inhibition as a mechanism of action of psymberin. These findings suggest the potential of psymberin as a novel therapy for the treatment of CRC.

Mycobacterium tuberculosis PE_PGRS19 Induces Pyroptosis through a Non-Classical Caspase-11/GSDMD Pathway in Macrophages

The PE/PPE protein family commonly exists in pathogenic species, such as Mycobacterium tuberculosis, suggesting a role in virulence and its maintenance. However, the exact role of most PE/PPE proteins in host-pathogen interactions remains unknown. Here, we constructed a recombinant Mycobacterium smegmatis expressing M. tuberculosis PE_PGRS19 (Ms_PE_PGRS19) and found that PE_PGRS19 overexpression resulted in accelerated bacterial growth in vitro, increased bacterial survival in macrophages, and enhanced cell damage capacity. Ms_PE_PGRS19 also induced the expression of pro-inflammatory cytokines, such as IL-6, TNF-α, IL-1β, and IL-18. Furthermore, we demonstrated that Ms_PE_PGRS19 induced cell pyroptosis by cleaving caspase-11 via a non-classical pathway rather than caspase-1 activation and further inducing the cleavage of gasdermin D, which led to the release of IL-1β and IL-18. To the best of our current knowledge, this is the first report of a PE/PPE family protein activating cell pyroptosis via a non-classical pathway, which expands the knowledge on PE/PPE protein functions, and these pathogenic factors involved in bacterial survival and spread could be potential drug targets for anti-tuberculosis therapy.

Periostin: an emerging activator of multiple signaling pathways

Matricellular proteins are responsible for regulating the microenvironment, the behaviors of surrounding cells, and the homeostasis of tissues. Periostin (POSTN), a non-structural matricellular protein, can bind to many extracellular matrix proteins through its different domains. POSTN usually presents at low levels in most adult tissues but is highly expressed in pathological sites such as in tumors and inflamed organs. POSTN can bind to diverse integrins to interact with multiple signaling pathways within cells, which is one of its core biological functions. Increasing evidence shows that POSTN can activate the TGF-β, the PI3K/Akt, the Wnt, the RhoA/ROCK, the NF-κB, the MAPK and the JAK pathways to promote the occurrence and development of many diseases, especially cancer and inflammatory diseases. Furthermore, POSTN can interact with some pathways in an upstream and downstream relationship, forming complicated crosstalk. This article focuses on the interactions between POSTN and different signaling pathways in diverse diseases, attempting to explain the mechanisms of interaction and provide novel guidelines for the development of targeted therapies.

Stress signaler p38 mitogen-activated kinase activation: a cause for concern?

Oxidative stress (OS) induced activation of p38 mitogen-activated kinase (MAPK) and cell fate from p38 signaling was tested using the human fetal membrane's amnion epithelial cells (AEC). We created p38 KO AEC using the CRISPR/Cas9 approach and tested cell fate in response to OS on an AEC-free fetal membrane extracellular matrix (ECM). Screening using image CyTOF indicated OS causing epithelial-mesenchymal transition (EMT). Further testing revealed p38 deficiency prevented AEC senescence, EMT, cell migration, and inflammation. To functionally validate in vitro findings, fetal membrane-specific conditional KO (cKO) mice were developed by injecting Cre-recombinase encoded exosomes intra-amniotically into p38αloxP/loxP mice. Amnion membranes from p38 cKO mice had reduced senescence, EMT, and increased anti-inflammatory IL-10 compared with WT animals. Our study suggested that overwhelming activation of p38 in response to OS inducing risk exposures can have an adverse impact on cells, cause cell invasion, inflammation, and ECM degradation detrimental to tissue homeostasis.

The effects of epithelial-mesenchymal transitions in COPD induced by cigarette smoke: an update

Cigarette smoke is a complex aerosol containing a large number of compounds with a variety of toxicity and carcinogenicity. Long-term exposure to cigarette smoke significantly increases the risk of a variety of diseases, including chronic obstructive pulmonary disease (COPD) and lung cancer. Epithelial–mesenchymal transition (EMT) is a unique biological process, that refers to epithelial cells losing their polarity and transforming into mobile mesenchymal cells, playing a crucial role in organ development, fibrosis, and cancer progression. Numerous recent studies have shown that EMT is an important pathophysiological process involved in airway fibrosis, airway remodeling, and malignant transformation of COPD. In this review, we summarized the effects of cigarette smoke on the development and progression of COPD and focus on the specific changes and underlying mechanisms of EMT in COPD induced by cigarette smoke. We spotlighted the signaling pathways involved in EMT induced by cigarette smoke and summarize the current research and treatment approaches for EMT in COPD, aiming to provide ideas for potential new treatment and research directions.

ErbB2/Her2-dependent downregulation of a cell death-promoting protein BLNK in breast cancer cells is required for 3D breast tumor growth

A significant proportion of breast cancers are driven by ErbB2/Her2 oncoprotein that they overexpress. These malignancies are typically treated with various ErbB2-targeted drugs, but many such cancers develop resistance to these agents and become incurable. Conceivably, treatment of ErbB2-positive cancers could be facilitated by use of agents blocking oncogenic signaling mechanisms downstream of ErbB2. However, current understanding of these mechanisms is limited. The ability of solid tumor cells to resist anoikis, cell death triggered by cell detachment from the extracellular matrix (ECM), is thought to be critical for 3D tumor growth. In an effort to understand the mechanisms of ErbB2-driven breast cancer cell anoikis resistance we found that detachment of non-malignant breast epithelial cells from the ECM upregulates a cell death-promoting tumor suppressor adapter protein BLNK and that ErbB2 blocks this upregulation by reducing tumor cell levels of transcription factor IRF6. We further observed that trastuzumab, a therapeutic anti-ErbB2 antibody, upregulates BLNK in human trastuzumab-sensitive but not trastuzumab-resistant ErbB2-positive breast cancer cells. Moreover, we established that BLNK promotes anoikis by activating p38 MAP kinase and that ErbB2-dependent BLNK downregulation blocks breast cancer cell anoikis. In search for pharmacological approaches allowing to upregulate BLNK in tumor cells we found that clinically approved proteasome inhibitor bortezomib upregulates IRF6 and BLNK in human breast cancer cells and inhibits their 3D growth in a BLNK-dependent manner. In addition, we found that BLNK upregulation in human ErbB2-positive breast cancer cells blocks their ability to form tumors in mice. Furthermore, we used publicly available data on mRNA levels in multiple breast cancers to demonstrate that increased BLNK mRNA levels correlate with increased relapse-free survival in a cohort of approximately 400 patients with ErbB2-positive breast cancer. In summary, we discovered a novel mechanism of ErbB2-driven 3D breast tumor growth mediated by ErbB2-dependent BLNK downregulation.

Identification and validation of four photodynamic therapy related genes inhibiting MAPK and inducing cell cycle alteration in squamous cell carcinoma

Introduction

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, and photodynamic therapy (PDT) is a promising modality against cSCC. This study investigated the impact of PDT on the MAPK pathway and cell cycle alternation of cSCC as well as the related molecular mechanisms.

Method

Expressing mRNA profile data sets GSE98767, GSE45216, and GSE84758 were acquired from the GEO database. The functions of differently expressed genes (DEGs) were enriched by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Least absolute shrinkage and selection operator (Lasso) analysis were used to establish a diagnosis model based on GSE98767. A correlation analysis and a protein–protein interaction (PPI) network were used to evaluate the relationship between cSCC-PDT-related genes and the MAPK pathway. Single-sample gene set enrichment analysis (ssGSEA) was performed on GSE98767 to estimate MAPK activation and cell cycle activity. Finally, the effect of MAPK activation on the cell cycle was explored in vitro.

Result

Four cSCC-PDT-related genes, DUSP6, EFNB2, DNAJB1, and CCNL1, were identified as diagnostic markers of cSCC, which were upregulated in cSCC or LC50 PDT-protocol treatment and negatively correlated with the MAPK promoter. Despite having a smaller MAPK activation score, cSCC showed higher cell cycle activity. The PDT treatment suppressed the G1 to G2/M phase in JNK overexpressed A431 cells.

Conclusion

CCNL1, DNAJB1, DUSP6, and EFNB2 were identified as potential PDT target genes in cSCC treatment, whose potential therapeutic mechanism was inhibiting the MAPK pathway and inducing cell cycle alternation.

Novel p38 Mitogen-Activated Protein Kinase Inhibitor Reverses Hypoxia-Induced Pulmonary Arterial Hypertension in Rats

Mitogen-activated protein kinase (MAPK) signaling is strongly implicated in cardiovascular remodeling in pulmonary hypertension (PH) and right ventricle (RV) failure. The effects of a newly designed p38 inhibitor, LASSBio-1824, were investigated in experimentally induced PH. Male Wistar rats were exposed to hypoxia and SU5416 (SuHx), and normoxic rats were used as controls. Oral treatment was performed for 14 days with either vehicle or LASSBio-1824 (50 mg/kg). Pulmonary vascular resistance and RV structure and function were assessed by echocardiography and catheterization. Histological, immunohistochemical and Western blot analysis of lung and RV were performed to investigate cardiovascular remodeling and inflammation. Treatment with LASSBio-1824 normalized vascular resistance by attenuating vessel muscularization and endothelial dysfunction. In the heart, treatment decreased RV systolic pressure, hypertrophy and collagen content, improving cardiac function. Protein content of TNF-α, iNOS, phosphorylated p38 and caspase-3 were reduced both in lung vessels and RV tissues after treatment and a reduced activation of transcription factor c-fos was found in cardiomyocytes of treated SuHx rats. Therefore, LASSBio-1824 represents a potential candidate for remodeling-targeted treatment of PH.

Cip1 tunes cell cycle arrest duration upon calcineurin activation

SignificanceTo ensure their survival, cells arrest the cell division cycle when they are exposed to environmental stress. The duration of this arrest is dependent upon the time it takes a cell to adapt to a particular environment. How cells adjust the amount of time they remain arrested is not known. This study investigates the role of the phosphatase calcineurin in controlling cell cycle arrest duration in yeast. We show that calcineurin lengthens arrest by prolonging Hog1-dependent activation of the poorly characterized cyclin-dependent kinase inhibitor Cip1. Cip1 only impacts cell cycle arrest in response to stressors that robustly activate calcineurin, suggesting that Cip1 is a context-specific regulator that differentially adjusts the length of arrest depending on the particular stressor.