Control of CD4+ T cells to restrain inflammatory diseases via eukaryotic elongation factor 2 kinase

Causal relationship between immunophenotypes and rheumatoid arthritis: A 2-sample Mendelian randomization study

As previous studies have demonstrated an association between immune inflammation and rheumatoid arthritis (RA), our study aimed to lend novel insight by exploring the potential causal association between RA and different immunophenotypes. Data were obtained from the genome-wide association study (GWAS) from Finn Gen. The dataset of GWAS contains a cohort of 6236 RA cases and 147,221 controls in European population. Data on immune cell traits are publicly available from the GWAS catalog. A total of 731 immunophenotypes were included in this study including absolute cell counts (ACs), median fluorescence intensity, morphological parameters, and relative cell counts. Mendelian randomization analysis was performed by several methods, and sensitivity analysis and visualization of the results were also carried out. After being adjusted by false discovery rate (FDR), 6 immune phenotypes were significantly and causally associated with the development of RA: CD16 on CD14+ CD16+ monocytes (adjusted odds ratio [OR]: 0.950, 95% confidence interval [CI]: 0.924-0.977, P = 4.04 × 10-4), CD62L-CD86+ myeloid DC %DC (adjusted OR: 1.048, 95% CI: 1.021-1.076, P = 4.29 × 10-4), CD62L-CD86+ myeloid DC AC (adjusted OR: 1.050, 95% CI: 1.024-1.076, P = 1.11 × 10-4), CD62L- myeloid DC AC (adjusted OR: 1.067, 95% CI: 1.033-1.101, P = 8.35 × 10-5), DC AC (adjusted OR: 1.105, 95% CI: 1.062-1.149, P = 7.73 × 10-7), myeloid DC AC (adjusted OR: 1.060, 95% CI: 1.029-1.091, P = 9.96 × 10-5). In addition, we found that CD62L- Dendritic cell % increases with the onset of RA (OR: 1.136, 95% CI: 1.064-1.213, P = 1.36 × 10-4, PFDR = 0.099). This study explored the association between different immunophenotypes and RA, which may lend some novel insights into RA pathogenesis and facilitate the development of new treatments.

Decoy-PROTAC for specific degradation of "Undruggable" STAT3 transcription factor

Signal transducer and activator of transcription 3 (STAT3) is widely recognized as an attractive target for cancer therapy due to its significant role in the initiation and progression of tumorigenesis. However, existing STAT3 inhibitors have suffered from drawbacks including poor efficacy, limited specificity, and undesirable off-target effects, due to the challenging nature of identifying active sites or allosteric regulatory pockets on STAT3 amenable to small-molecule inhibition. In response to these obstacles, we utilize the innovative proteolysis targeting chimera (PROTAC) technology to create a highly specific decoy-targeted protein degradation system for STAT3 protein, termed D-PROTAC. This system fuses DNA decoy that targets STAT3 with an E3 ligase ligand, utilizing a click chemistry approach. Experimental results demonstrate that D-PROTAC efficiently mediates the degradation of the STAT3 protein across various cancer cell types, leading to the downregulation of crucial downstream STAT3 targets, inhibiting tumor cell growth, triggering cell cycle arrest and apoptosis, and suppressing tumor immune evasion. Furthermore, D-PROTAC is capable of achieving significant tumor suppression in xenograft models. Overall, our research validates that D-PROTAC can successfully target and eliminate the "undruggable" STAT3, showcasing specificity and potent antitumor effects. This strategy will suggest a promising avenue for the development of targeted therapies against the critical functions of STAT3 in human cancers and potentially other diseases.

An initial investigation of transcutaneous delivery of plasmid DNA encoding interleukin-10 for the treatment of psoriatic skin conditions

Psoriasis is a chronic immune-mediated skin disorder characterized by intense local inflammation, epidermal hyperplasia, and leukocyte infiltration. Current treatment approaches for psoriasis aim to alleviate symptoms and prevent disease progression, including systemically administered drugs with whole body side effects. Despite some advances in psoriasis treatment, success has been quite limited. To begin to address this challenge, we undertook an initial investigation of whether transcutaneous delivery of an endogenous anti-inflammatory cytokine could provide an effective, local treatment of psoriatic-like skin conditions. To do this, we utilized a previously documented rodent model of psoriasis, induced via a single topical application of Imiquimod (IMQ) to the shaved back of rats. The therapeutic approach used for this initial investigation was delivery of plasmid DNA encoding rat interleukin-10 (pDNA-rIL10), a non-viral gene therapy approach previously shown to be effective in suppressing neuroinflammatory disorders after localized delivery either intracerebrally or intrathecally. Translation of this CNS therapeutic for use in psoriatic-like skin disorders required reformulation to enable transcutaneous delivery. Toward that end, pDNA-rIL10 was topically applied in Lipoderm HMW, a base explicitly designed to deliver higher molecular weight compounds into skin. Here we show that a single topical application of pDNA-rIL10 in Lipoderm HMW was effective in decreasing mRNA levels of pro-inflammatory cytokines as well as reducing the recruitment of T-cells to IMQ-treated skin. Furthermore, this transcutaneous IL-10 gene therapy decreased signs of skin inflammation, reflected by reduced erythema. Moreover, the results provide an initial indication that IL10 may stimulate hair regrowth in psoriatic-like skin.

eEF-2K Deficiency Boosts the Virus-Specific Effector CD8+ T Cell Responses During Viral Infection

In this study, we revealed a critical role of eukaryotic elongation factor-2 kinase (eEF-2K), a negative regulator of protein synthesis, in regulating T cells during vaccinia virus (VACV) infection. We found that eEF-2K-deficient (eEF-2K⁻/⁻) mice exhibited a significantly higher proportion of VACV-specific effector CD8+ T cells without compromising the development of VACV-specific memory CD8+ T cells. RNA sequencing demonstrated that eEF-2K⁻/⁻ VACV-specific effector CD8+ T cells had enhanced functionality, which improves their capacity to combat viral infection during the effector phase. Moreover, we identified tumor necrosis factor receptor-associated factor 3 (TRAF3) as a critical mediator of the stronger antiviral response observed in eEF-2K⁻/⁻ effector CD8+ T cells. These findings suggest that targeting eEF-2K may provide a novel strategy to augmenting effector CD8+ T cell responses against viral infections.

eEF2K alleviates doxorubicin-induced cardiotoxicity by inhibiting GSK3β and improving autophagy dysfunction

Doxorubicin-induced cardiotoxicity (DIC) poses a threat to the health and prognosis of cancer patients. It is important to find a safe and effective method for the prevention and treatment of DIC. eEF2K, which is a highly conserved α-kinase, is thought to be a therapeutic target for several human diseases. Nonetheless, it is still uncertain if eEF2K contributes to the cardiotoxic effects caused by doxorubicin (DOX). Our research revealed that eEF2K expression decreased in the DIC. eEF2K was overexpressed through adeno-associated virus in vivo and adenovirus in vitro, which presented alleviative cardiomyocyte death and cell atrophy induced by DOX. Autophagy dysfunction is one of important mechanisms in DIC. As a result, autophagic function was evaluated using Transmission electron microscopy in vivo, as well as LysoSensor and mRFPGFP-LC3 puncta in vitro. eEF2K overexpression improves DOX-induced autophagy blockade. In addition, eEF2K knockdown aggravated autophagy blockade and cardiomyocyte injury in DIC model. eEF2K also phosphorylated and inhibited GSK3β in DIC model. AR-A014418 (ARi), known for selectively inhibiting GSK3β, countered the effects of eEF2K knockdown, which aggravated autophagy blockade in the DIC. In conclusion, this study proposes that eEF2K alleviates DIC by inhibiting GSK3β and improving autophagy dysfunction. eEF2K is a promising therapeutic target against DIC.

RSK1 and RSK2 as therapeutic targets: an up-to-date snapshot of emerging data

INTRODUCTION

The four members of the p90 ribosomal S6 kinase (RSK) family are serine/threonine protein kinases, which are phosphorylated and activated by ERK1/2. RSK1/2/3 are further phosphorylated by PDK1. Receiving inputs from two major signaling pathways places RSK as a key signaling node in numerous pathologies. A plethora of RSK1/2 substrates have been identified, and in the majority of cases the causative roles these RSK substrates play in the pathology are unknown.

AREAS COVERED

The majority of studies have focused on RSK1/2 and their functions in a diverse group of cancers. However, RSK1/2 are known to have important functions in cardiovascular disease and neurobiological disorders. Based on the literature, we identified substrates that are common in these pathologies with the goal of identifying fundamental physiological responses to RSK1/2.

EXPERT OPINION

The core group of targets in pathologies driven by RSK1/2 are associated with the immune response. However, there is a paucity of the literature addressing RSK function in inflammation, which is critical to know as the pan RSK inhibitor, PMD-026, is entering phase II clinical trials for metastatic breast cancer. A RSK inhibitor has the potential to be used in numerous diverse diseases and disorders.

The Roles of T cells in Immune Checkpoint Inhibitor-Induced Arthritis

Immune checkpoint inhibitor (ICI) therapy, a novel anti-tumor strategy, can specifically eliminate tumors by activating the immune system and inhibiting tumor immune escape. However, ICI therapy can lead to notable negative outcomes known as immune-related adverse events (irAEs). ICI-induced arthritis, also known as ICI arthritis, stands as the prevailing form of irAEs. The purpose of this review is to highlight the crucial functions of T cells in the progression of ICI arthritis. Under the influence of different signaling molecules, T cells could gather in large numbers within the synovial membrane of joints, releasing inflammatory substances and enzymes that harm healthy tissues, ultimately causing ICI arthritis. Moreover, considering the functions of T cells in triggering ICI arthritis, this review suggests several treatments to prevent ICI arthritis, including inhibiting the overstimulation of T cells at the synovial sac of joints, enhancing the precision of ICI medications, and directing ICI drugs specifically towards tumor tissues instead of joints. Collectively, T lymphocytes play a vital role in the onset of ICI arthritis, offering a hopeful perspective on treating ICI arthritis through the specific targeting of T cells within the affected joints.

Role of STAT3 in cancer cell epithelial‑mesenchymal transition (Review)

Since its discovery, the role of the transcription factor, signal transducer and activator of transcription 3 (STAT3), in both normal physiology and the pathology of numerous diseases, including cancer, has been extensively studied. STAT3 is aberrantly activated in different types of cancer, fulfilling a critical role in cancer progression. The biological process, epithelial‑mesenchymal transition (EMT), is indispensable for embryonic morphogenesis. During the development of cancer, EMT is hijacked to confer motility, tumor cell stemness, drug resistance and adaptation to changes in the microenvironment. The aim of the present review was to outline recent advances in knowledge of the role of STAT3 in EMT, which may contribute to the understanding of the function of STAT3 in EMT in various types of cancer. Delineating the underlying mechanisms associated with the STAT3‑EMT signaling axis may generate novel diagnostic and therapeutic options for cancer treatment.

Glutaminolysis of CD4+ T Cells: A Potential Therapeutic Target in Viral Diseases

CD4+ T cells play a critical role in the pathogenesis of viral diseases, which are activated by the internal metabolic pathways encountering with viral antigens. Glutaminolysis converts glutamine into tricarboxylic acid (TCA) circulating metabolites by α-ketoglutaric acid, which is essential for the proliferation and differentiation of CD4+ T cells and plays a central role in providing the energy and structural components needed for viral replication after the virus hijacks the host cell. Changes in glutaminolysis in CD4+ T cells are accompanied by changes in the viral status of the host cell due to competition for glutamine between immune cells and host cells. More recently, attempts have been made to treat tumours, autoimmune diseases, and viral diseases by altering the breakdown of glutamine in T cells. In this review, we will discuss the current knowledge of glutaminolysis in the CD4+ T cell subsets from viral diseases, not only increasing our understanding of immunometabolism but also providing a new perspective for therapeutic target in viral diseases.