IL4/IL4R signaling promotes the osteolysis in metastatic bone of CRC through regulating the proliferation of osteoclast precursors

Sex-specific transcriptomic profiling reveals key players in bone loss associated with Alzheimer's disease

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is frequently associated with musculoskeletal complications, including sarcopenia and osteoporosis, which substantially impair patient quality of life. Despite these clinical observations, the molecular mechanisms linking AD to bone loss remain insufficiently explored. In this study, we examined the femoral bone microarchitecture and transcriptomic profiles of APP/PS1 transgenic mouse models of AD to elucidate the disease's impact on bone pathology and identify potential gene candidates associated with bone deterioration. We performed micro-computed tomography (microCT) and RNA transcriptome analysis on the femoral bone of these mice. We observed a significant reduction in bone microstructure in both male and female APP/PS1 mice compared to their wild-type counterparts. Transcriptomic analysis of femoral bone tissue revealed substantial differential gene expression between AD mice and controls. Specifically, APP/PS1 mice exhibited differential expression in 289 protein-coding genes across both sexes. Notably, in female APP/PS1 mice, 664 genes were differentially expressed, with key genes such as Shh, Efemp1, Arg1, EphA2, Irx1, and PORCN potentially implicated in bone loss. In male APP/PS1 mice, 787 genes were differentially expressed, with Sel1l, Ffar4, Hspa1a, AMH, WFS1, and CLIC1 emerging as notable candidates in the context of bone deterioration. Gene Ontology (GO) enrichment analysis further revealed distinct sex-specific gene pathways between male and female APP/PS1 mice, underscoring the differential molecular underpinnings of bone pathology in AD. This study identifies novel sex-specific genes in the APP/PS1 mouse model and proposes potential therapeutic targets to mitigate bone loss in AD patients.

The complexity of immune evasion mechanisms throughout the metastatic cascade

Metastasis, the spread of cancer from a primary site to distant organs, is an important challenge in oncology. This Review explores the complexities of immune escape mechanisms used throughout the metastatic cascade to promote tumor cell dissemination and affect organotropism. Specifically, we focus on adaptive plasticity of disseminated epithelial tumor cells to understand how they undergo phenotypic transitions to survive microenvironmental conditions encountered during metastasis. The interaction of tumor cells and their microenvironment is analyzed, highlighting the local and systemic effects that innate and adaptive immune systems have in shaping an immunosuppressive milieu to foster aggressive metastatic tumors. Effectively managing metastatic disease demands a multipronged approach to target the parallel and sequential mechanisms that suppress anti-tumor immunity. This management necessitates a deep understanding of the complex interplay between tumor cells, their microenvironment and immune responses that we provide with this Review.

MDSCs in bone metastasis: Mechanisms and therapeutic potential

Bone metastasis (BM) is a frequent complication associated with advanced cancer that significantly increases patient mortality. Myeloid-derived suppressor cells (MDSCs) play a pivotal role in BM progression by promoting angiogenesis, inhibiting immune responses, and inducing osteoclastogenesis. MDSCs induce immunosuppression through diverse mechanisms, including the generation of reactive oxygen species, nitric oxide, and immunosuppressive cytokines. Within the bone metastasis niche (BMN), MDSCs engage in intricate interactions with tumor, stromal, and bone cells, thereby establishing a complex regulatory network. The biological activities and functions of MDSCs are regulated by the microenvironment within BMN. Conversely, MDSCs actively contribute to microenvironmental regulation, thereby promoting BM development. A comprehensive understanding of the indispensable role played by MDSCs in BM is imperative for the development of novel therapeutic strategies. This review highlights the involvement of MDSCs in BM development, their regulatory mechanisms, and their potential as viable therapeutic targets.

Effects of circulating inflammatory proteins on osteoporosis and fractures: evidence from genetic correlation and Mendelian randomization study

Objective

There is a controversy in studies of circulating inflammatory proteins (CIPs) in association with osteoporosis (OP) and fractures, and it is unclear if these two conditions are causally related. This study used MR analyses to investigate the causal associations between 91 CIPs and OP and 9 types of fractures.

Methods

Genetic variants data for CIPs, OP, and fractures were obtained from the publicly available genome-wide association studies (GWAS) database. We used inverse variance weighted (IVW) as the primary analysis, pleiotropy, and heterogeneity tests to analyze the validity and robustness of causality and reverse MR analysis to test for reverse causality.

Results

The IVW results with Bonferroni correction indicated that CXCL11 (OR = 1.2049; 95% CI: 1.0308-1.4083; P = 0.0192) can increase the risk of OP; IL-4 (OR = 1.2877; 95% CI: 1.1003-1.5070; P = 0.0016), IL-7 (OR = 1.2572; 95% CI: 1.0401-1.5196; P = 0.0180), IL-15RA (OR = 1.1346; 95% CI: 1.0163-1.2668; P = 0.0246), IL-17C (OR = 1.1353; 95% CI: 1.0272-1.2547; P = 0.0129), CXCL10 (OR = 1.2479; 95% CI: 1.0832-1.4377; P = 0.0022), eotaxin/CCL11 (OR = 1.1552; 95% CI: 1.0525-1.2678; P = 0.0024), and FGF23 (OR = 1.9437; 95% CI: 1.1875-3.1816; P = 0.0082) can increase the risk of fractures; whereas IL-10RB (OR = 0.9006; 95% CI: 0.8335-0.9730; P = 0.0080), CCL4 (OR = 0.9101; 95% CI: 0.8385-0.9878; P = 0.0242), MCP-3/CCL7 (OR = 0.8579; 95% CI: 0.7506-0.9806; P = 0.0246), IFN-γ [shoulder and upper arm (OR = 0.7832; 95% CI: 0.6605-0.9287; P = 0.0049); rib(s), sternum and thoracic spine (OR = 0.7228; 95% CI: 0.5681-0.9197; P = 0.0083)], β-NGF (OR = 0.8384; 95% CI: 0.7473-0.9407; P = 0.0027), and SIRT2 (OR = 0.5167; 95% CI: 0.3296-0.8100; P = 0.0040) can decrease fractures risk.

Conclusion

Mendelian randomization (MR) analyses indicated the causal associations between multiple genetically predicted CIPs and the risk of OP and fractures.

Comparative developmental toxicities of zebrafish towards structurally diverse per- and polyfluoroalkyl substances

Structurally diverse per- and polyfluoroalkyl substances (PFASs) are increasingly detected in ecosystems and humans. Therefore, the clarification of their ecological and health risks is urgently required. In the present study, the toxicity of a series of PFASs, including PFOS, PFBS, Nafion BP1, Nafion BP2, F53B, OBS, PFOA, PFUnDA, PFO5DoDA, HFPO-TA was investigated. Similarities and differences in the developmental toxicity potentials were revealed. Our results demonstrated that PFUnDA exhibited the highest toxicity with the lowest EC50 value of 4.36 mg/L (for morphological abnormality); this was followed by F53B (5.58 mg/L), PFOS (6.15 mg/L), and OBS (10.65 mg/L). Positive correlations with volatility/solubility and chemotypes related to specific biological activity, including the bioconcentration factor (LogBCF), and negative correlations with lipid solubility and carbon chain component-related chemotypes, including the number of carbon and fluorine atoms, provided a reasonable explanation in the view of molecular structures. Furthermore, comparative transcriptome analysis provided molecular evidence for the relationship between PFASs exposure and malformations. Common differentially expressed genes (DEGs) involved in spine curve development, pericardial edema, and cell/organism growth-related pathways presented common targets, leading to toxic effects. Therefore, the present results provide novel insights into the potential environmental risks of structurally diverse PFASs and contribute to the selection of safer PFAS replacements.

Melittin acupoint injection in attenuating bone erosion in collagen-induced arthritis mice via inhibition of the RANKL/NF-κB signaling pathway

Background

Rheumatoid arthritis (RA) is an autoimmune disease leading to chronic joint inflammation. Bone erosion is the most serious pathological condition of RA and the main cause of joint deformities and disability. Melittin acupoint injection (MAI) is an effective traditional Chinese medicine (TCM) method for RA treatment. This study aimed to investigate the effect of MAI on RA bone erosion and to elucidate the underlying mechanism.

Methods

A collagen-induced arthritis (CIA) mouse model was established as the experimental subject. MAI was administrated once every other day for 28 days to mice with CIA. The effects of MAI on joint diseases were assessed by body weight, arthritis index (AI) score, swollen joint count (SJC) score, and hind paw thickness. Ankle radiological changes were captured by micro-computed tomography (micro-CT) and histological changes were observed by pathological staining. Organ histological changes, spleen index, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine (Crea) levels of serum were tested to evaluate the toxicity of MAI. Cytokine expression levels were confirmed by enzyme-linked immunosorbent assay (ELISA) to evaluate the immunity of CIA mice.

Results

MAI administration markedly improved the clinical signs of CIA in mice, including hind paw thickness, AI, and the number of swollen paw joints (most of them P<0.05 or even <0.01). According to histopathological analysis, MAI ameliorated inflammatory cell infiltration, synovial hyperplasia, pannus formation, and bone erosion (all P<0.01). Micro-CT and tartrate-resistant acid phosphatase (TRAP) staining (P<0.01) also revealed that MAI could relieve bone erosion via reducing the formation of osteoclasts. Not only could MAI relieve the immunological boost [P<0.05 for the high-dose MAI (HM) group], but also it had no liver or kidney side effects (P>0.05). In addition, it decreased the serum levels of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) and increased the serum levels of IL-4 and IL-10 (the majority of P<0.05 or even <0.01). Transcriptome sequencing results indicated that MAI affected the expression of osteoclast differentiation pathway genes, which was connected with the receptor activator of the nuclear factor κB ligand/nuclear factor kappa B (RANKL/NF-κB) pathway.

Conclusions

Based on our findings, MAI could suppress joint inflammation and inhibit RANKL/NF-κB-mediated osteoclast differentiation to rescue bone erosion in CIA mice, suggesting that MAI can be a potentially therapeutic substance for RA.

Role of protein phosphorylation in cell signaling, disease, and the intervention therapy

Protein phosphorylation is an important post-transcriptional modification involving an extremely wide range of intracellular signaling transduction pathways, making it an important therapeutic target for disease intervention. At present, numerous drugs targeting protein phosphorylation have been developed for the treatment of various diseases including malignant tumors, neurological diseases, infectious diseases, and immune diseases. In this review article, we analyzed 303 small-molecule protein phosphorylation kinase inhibitors (PKIs) registered and participated in clinical research obtained in a database named Protein Kinase Inhibitor Database (PKIDB), including 68 drugs approved by the Food and Drug Administration of the United States. Based on previous classifications of kinases, we divided these human protein phosphorylation kinases into eight groups and nearly 50 families, and delineated their main regulatory pathways, upstream and downstream targets. These groups include: protein kinase A, G, and C (AGC) and receptor guanylate cyclase (RGC) group, calmodulin-dependent protein kinase (CaMK) group, CMGC [Cyclin-dependent kinases (CDKs), Mitogen-activated protein kinases (MAPKs), Glycogen synthase kinases (GSKs), and Cdc2-like kinases (CLKs)] group, sterile (STE)-MAPKs group, tyrosine kinases (TK) group, tyrosine kinase-like (TKL) group, atypical group, and other groups. Different groups and families of inhibitors stimulate or inhibit others, forming an intricate molecular signaling regulatory network. This review takes newly developed new PKIs as breakthrough point, aiming to clarify the regulatory network and relationship of each pathway, as well as their roles in disease intervention, and provide a direction for future drug development.

Muscle and Bone Defects in Metastatic Disease

PURPOSE OF REVIEW

The present review addresses most recently identified mechanisms implicated in metastasis-induced bone resorption and muscle-wasting syndrome, known as cachexia.

RECENT FINDINGS

Metastatic disease in bone and soft tissues is often associated with skeletal muscle defects. Recent studies have identified a number of secreted molecules and extracellular vesicles that contribute to cancer cell growth and metastasis leading to bone destruction and muscle atrophy. In addition, alterations in muscle microenvironment including dysfunctions in hepatic and mitochondrial metabolism have been implicated in cancer-induced regeneration defect and muscle loss. Moreover, we review novel in vitro and animal models including promising new drug candidates for bone metastases and cancer cachexia. Preservation of bone health could be highly beneficial for maintaining muscle mass and function. Therefore, a better understanding of molecular pathways implicated in bone and muscle crosstalk in metastatic disease may provide new insights and identify new strategies to improve current anticancer therapeutics.

A Review of Signaling Transduction Mechanisms in Osteoclastogenesis Regulation by Autophagy, Inflammation, and Immunity

Osteoclastogenesis is an ongoing rigorous course that includes osteoclast precursors fusion and bone resorption executed by degradative enzymes. Osteoclastogenesis is controlled by endogenous signaling and/or regulators or affected by exogenous conditions and can also be controlled both internally and externally. More evidence indicates that autophagy, inflammation, and immunity are closely related to osteoclastogenesis and involve multiple intracellular organelles (e.g., lysosomes and autophagosomes) and certain inflammatory or immunological factors. Based on the literature on osteoclastogenesis induced by different regulatory aspects, emerging basic cross-studies have reported the emerging disquisitive orientation for osteoclast differentiation and function. In this review, we summarize the partial potential therapeutic targets for osteoclast differentiation and function, including the signaling pathways and various cellular processes.

The Role of Inflammatory Cytokines in the Pathogenesis of Colorectal Carcinoma—Recent Findings and Review

The inflammatory process plays a significant role in the development of colon cancer (CRC). Intestinal cytokine networks are critical mediators of tissue homeostasis and inflammation but also impact carcinogenesis at all stages of the disease. Recent studies suggest that inflammation is of greater importance in the serrated pathway than in the adenoma-carcinoma pathway. Interleukins have gained the most attention due to their potential role in CRC pathogenesis and promising results of clinical trials. Malignant transformation is associated with the pro-tumorigenic and anti-tumorigenic cytokines. The harmony between proinflammatory and anti-inflammatory factors is crucial to maintaining homeostasis. Immune cells in the tumor microenvironment modulate immune sensitivity and facilitate cancer escape from immune surveillance. Therefore, clarifying the role of underlying cytokine pathways and the effects of their modulation may be an important step to improve the effectiveness of cancer immunotherapy.