MAPK-Activated Protein Kinases: Servant or Partner?

Particulate matter in poultry house on poultry respiratory disease: a systematic review

Particulate matter (PM) is one of the essential environmental stressors for the poultry industry in the world. Given its large specific surface area, PM can adsorb and carry a variety of pollutants, including heavy metal ions, ammonia, and persistent organic pollutants such as pathogenic microorganisms. High concentrations of PM induce poultry respiratory inflammation and trigger various diseases. However, the pathogenic mechanism of PM in poultry houses on respiratory diseases has not been clarified due to its complexity and lack of accurate assays. In terms of pathogenesis, there are 3 ways to explain this phenomenon: Inhaled PM irritates the respiratory tract, decreases immune resistance, and causes a respiratory disease; respiratory tract irritation by compounds presents in PM; infections with pathogenic and non-pathogenic microorganisms attached to PM. The latter 2 modes of influence are more harmful. Specifically, PM can induce the respiratory disease through several toxic mechanisms, including ammonia ingestion and bioaccumulation, lung flora dysbiosis, oxidative stress, and metabolic disorders. Therefore, this review summarizes the characteristics of PM in the poultry house and the impact of poultry PM on respiratory disease and proposes potential pathogenic mechanisms.

Research progress of p38 as a new therapeutic target against morphine tolerance and the current status of therapy of morphine tolerance

With the development of the medical industry, new painkillers continue to appear in people's field of vision, but so far no painkiller can replace morphine. While morphine has a strong analgesic effect, it is also easy to produce pain sensitivity and tolerance. Due to the great inter-individual differences in patient responses, there are few clear instructions on how to optimise morphine administration regimens, which complicates clinicians' treatment strategies and limits the effectiveness of morphine in long-term pain therapy. P38MAPK is a key member of the MAPK family. Across recent years, it has been discovered that p38MAPK rises dramatically in a wide range of morphine tolerance animal models. Morphine tolerance can be reduced or reversed by inhibiting p38MAPK. However, the role and specific mechanism of p38MAPK are not clear. In this review, we synthesise the relevant findings, highlight the function and potential mechanism of p38MAPK in morphine tolerance, as well as the present status and efficacy of morphine tolerance therapy, and underline the future promise of p38MAPK targeted morphine tolerance treatment.

Targeting NK-1R attenuates renal fibrosis via modulating inflammatory responses and cell fate in chronic kidney disease

Background

Renal fibrosis is the final common pathway of chronic kidney disease (CKD), which is clinically irreversible and without effective therapy. Renal tubules are vulnerable to various insults, and tubular injury is involving in the initiation and evolution of renal inflammation and fibrosis. Neurokinin-1 receptor (NK-1R) functions by interacting with proinflammatory neuropeptide substance P (SP), exerting crucial roles in various neurological and non-neurological diseases. However, its roles in renal inflammation and fibrosis are still unknown.

Methods

We collected renal biopsy specimens and serum samples of individuals with or without CKD. Additionally, knockout mice lacking NK-1R expression, SP addition and NK-1R pharmacological antagonist treatment in the unilateral ureteral obstruction (UUO) model, and NK-1R-overexpressed HK-2 cells were employed.

Results

Renal SP/NK-1R and serum SP were increased in patients with CKD and mice experiencing UUO and correlated with renal fibrosis and function. SP addition enhanced UUO-induced progressive inflammatory responses and renal fibrosis, whereas genetically or pharmacologically targeting NK-1R attenuated these effects. Mechanistically, TFAP4 promoted NK-1R transcription by binding to its promoter, which was abolished by mutation of the binding site between TFAP4 and NK-1R promoter. Furthermore, SP acted through the NK-1R to activate the JNK/p38 pathways to modulate cell fate of tubular epithelial cells including growth arrest, apoptosis, and expression of profibrogenic genes.

Conclusion

Our data reveals that SP/NK-1R signaling promotes renal inflammatory responses and fibrosis, suggesting NK-1R could be a potential therapeutic target for the patients with CKD.

The Role of Macrophage Autophagy in Asthma: A Novel Therapeutic Strategy

Asthma is a chronic respiratory disease frequently associated with airway inflammation and remodeling. The development of asthma involves various inflammatory phenotypes that impact therapeutic effects, and macrophages are master innate immune cells in the airway that exert diverse functions including phagocytosis, antigen presentation, and pathogen clearance, playing an important role in the pathogeneses of asthma. Recent studies have indicated that autophagy of macrophages affects polarization of phenotype and regulation of inflammation, which implies that regulating autophagy of macrophages may be a potential strategy for the treatment of asthma. Thus, this review summarizes the signaling pathways and effects of macrophage autophagy in asthma, which will provide a tactic for the development of novel targets for the treatment of this disease.

On the Therapeutic Potential of ERK4 in Triple-Negative Breast Cancer

ERK3 and ERK4 define a distinct and understudied subfamily of mitogen-activated protein kinases (MAPKs). Little is known about the physiological roles of these atypical MAPKs and their association with human diseases. Interestingly, accumulating evidence points towards a role for ERK3 and ERK4 signaling in the initiation and progression of various types of cancer. Notably, a recent study reported that ERK4 is expressed in a subset of triple-negative breast cancer (TNBC) cell lines and that this expression is critical for AKT activation and for sustaining TNBC cell proliferation in vitro and tumor growth in mice. The authors also showed that depletion of ERK4 sensitizes TNBC cells to phosphatidylinositol-3-kinase (PI3K) inhibitors. They concluded that ERK4 is a promising therapeutic target for TNBC and has potential for combination therapy with PI3K inhibitors. Here, we raise concerns about the cellular models and experimental approaches used in this study, which compromise the conclusions on the oncogenic role of ERK4 in TNBC.

Small molecule inhibitors targeting the cancers

Compared with traditional therapies, targeted therapy has merits in selectivity, efficacy, and tolerability. Small molecule inhibitors are one of the primary targeted therapies for cancer. Due to their advantages in a wide range of targets, convenient medication, and the ability to penetrate into the central nervous system, many efforts have been devoted to developing more small molecule inhibitors. To date, 88 small molecule inhibitors have been approved by the United States Food and Drug Administration to treat cancers. Despite remarkable progress, small molecule inhibitors in cancer treatment still face many obstacles, such as low response rate, short duration of response, toxicity, biomarkers, and resistance. To better promote the development of small molecule inhibitors targeting cancers, we comprehensively reviewed small molecule inhibitors involved in all the approved agents and pivotal drug candidates in clinical trials arranged by the signaling pathways and the classification of small molecule inhibitors. We discussed lessons learned from the development of these agents, the proper strategies to overcome resistance arising from different mechanisms, and combination therapies concerned with small molecule inhibitors. Through our review, we hoped to provide insights and perspectives for the research and development of small molecule inhibitors in cancer treatment.

A β-Cyclodextrin-Based Nanoparticle with Very High Transfection Efficiency Unveils siRNA-Activated TLR3 Responses in Human Prostate Cancer Cells

Synthetic double-stranded small interfering RNAs (siRNAs) mimic interference RNAs (RNAi) and can bind target mRNAs with a high degree of specificity, leading to selective knockdown of the proteins they encode. However, siRNAs are very labile and must be both protected and transported by nanoparticles to be efficiently delivered into cells. In this work, we used a Janus-type polycationic amphiphilic β-cyclodextrin derivative to efficiently transfect siRNAs targeting mRNAs encoding mitogen-activated protein kinase (p42-MAPK) or Ras homolog enriched in brain (Rheb) into different cancer cell lines as well as astrocytes. We took advantage of this high transfection efficiency to simultaneously knock down p42-MAPK and Rheb to boost docetaxel (DTX)-mediated toxicity in two human prostate cancer cell lines (LNCaP and PC3). We found that double knockdown of p42-MAPK and Rheb increased DTX-toxicity in LNCaP but not in PC3 cells. However, we also observed the same effect when scramble siRNA was used, therefore pointing to an off-target effect. Indeed, we found that the siRNA we used in this work induced toll-like receptor 3 activation, leading to β-interferon production and caspase activation. We believe that this mechanism could be very useful as a general strategy to elicit an immune response against prostate cancer cells.

ERK1/2-RSK2 Signaling in Regulation of ERα-Mediated Responses

Signaling via extracellular regulated kinase 1/2 (ERK1/2) and p90 ribosomal S6 kinase (RSK), a downstream effector, mediates numerous processes. For example, ERK1/2-RSK signaling is essential for estrogen homeostasis in the mammary gland and uterus to maintain physiological responsiveness. This review will focus on the coordination of ERK1/2-RSK2 and estrogen signaling through estrogen receptor alpha (ERα). The interrelationship and the feedback mechanisms between these pathways occurs at the level of transcription, translation, and posttranslational modification. Identifying how ERK1/2-RSK2 and estrogen signaling cooperate in homeostasis and disease may lead to novel therapeutic approaches in estrogen-dependent disorders.

Downregulation of growth plate genes involved with the onset of femoral head separation in young broilers

Femoral head separation (FHS) is characterized by the detachment of growth plate (GP) and articular cartilage, occurring in tibia and femur. However, the molecular mechanisms involved with this condition are not completely understood. Therefore, genes and biological processes (BP) involved with FHS were identified in 21-day-old broilers through RNA sequencing of the femoral GP. 13,487 genes were expressed in the chicken femoral head transcriptome of normal and FHS-affected broilers. From those, 34 were differentially expressed (DE; FDR ≤0.05) between groups, where all of them were downregulated in FHS-affected broilers. The main BP were enriched in receptor signaling pathways, ossification, bone mineralization and formation, skeletal morphogenesis, and vascularization. RNA-Seq datasets comparison of normal and FHS-affected broilers with 21, 35 and 42 days of age has shown three shared DE genes (FBN2, C1QTNF8, and XYLT1) in GP among ages. Twelve genes were exclusively DE at 21 days, where 10 have already been characterized (SHISA3, FNDC1, ANGPTL7, LEPR, ENSGALG00000049529, OXTR, ENSGALG00000045154, COL16A1, RASD2, BOC, GDF10, and THSD7B). Twelve SNPs were associated with FHS (p < 0.0001). Out of those, 5 were novel and 7 were existing variants located in 7 genes (RARS, TFPI2, TTI1, MAP4K3, LINK54, and AREL1). We have shown that genes related to chondrogenesis and bone differentiation were downregulated in the GP of FHS-affected young broilers. Therefore, these findings evince that candidate genes pointed out in our study are probably related to the onset of FHS in broilers.

Reducing White Adipose Tissue Browning Using p38α MAPK Inhibitors Ameliorates Cancer-Associated Cachexia as Assessed by Magnetic Resonance Imaging

Background: Up to 80% of pancreatic cancer patients suffer from cachexia. White adipose tissue (WAT) browning caused by the tumorigenicity and progression aggravates the cancer-associated cachexia (CAC). Cancer-initiated changes in the protein-38 mitogen-activated protein kinases (p38 MAPK) pathway are likely involved in the development of CAC. Methods: p38 MAPK inhibitors, VCP979 or SB203580, were used in the in vitro and in vivo models of pancreatic cancer cachexia. Expression of uncoupling protein 1 (UCP1) in the p38 MARK pathway and the properties and level of white adipocytes were analyzed and correlated to browning, followed by immunohistochemistry and Western blotting validations. Changes in the volume and fat fraction of WAT in animals were monitored by magnetic resonance imaging (MRI). Results: The size of white adipocytes was increased after being treated with the p38 MAPK inhibitors, along with increase in the MRI-measured volume and fat fraction of WAT. Comparing two p38 MAPK inhibitors, the p38α subunit-specific inhibitor VCP979 had a better therapeutic effect than SB203580, which targets both p38α and β subunits. Conclusions: Blockade of p38 MAPK reduced the WAT browning that contributes to CAC. Thus, p38 MARK inhibitors can potentially be used as a therapy for treating CAC. Non-invasive MRI can also be applied to assess the progression and treatment responses of CAC.

Osteoprotective effects of flavonoids: Evidence from in vivo and in vitro studies (Review)

Osteoporosis is a systemic bone disease characterized by decreased bone mass and quality and bone micro‑architecture degradation. Its primary cause is disorder of bone metabolism: Over‑formation of osteoclasts, resulting in increased bone resorption and insufficient osteogenesis. Traditional herbal flavonoids can be used as alternative drugs to prevent and treat osteoporosis due to their wide range of sources, structural diversity and less adverse effects. The present paper reviewed six flavonoids, including quercetin, icariin, hesperitin, naringin, chrysin and pueraria, that promote bone formation and have been widely studied in the literature over the past five years, with the aim of providing novel ideas for the development of drugs for bone‑associated disease.