CXCL12/CXCR4 signal transduction in diseases and its molecular approaches in targeted-therapy

A novel phthalein component ameliorates neuroinflammation and cognitive dysfunction by suppressing the CXCL12/CXCR4 axis in rats with vascular dementia

ETHNOPHARMACOLOGICAL RELEVANCE

Chuanxiong, a plant of the Umbelliferae family, is a genuine medicinal herb from Sichuan Province. Phthalides are one of its main active components and exhibit good protective effect against cerebrovascular diseases. However, the mechanism by which phthalides exert neuroprotective effects is still largely unclear.

AIM OF THE STUDY

In this study, we extracted a phthalein component (named as QBT) from Ligusticum Chuanxiong, and investigated its neuroprotective effects against vascular dementia (VaD) rats and the underlying mechanism, focusing on the chemokine 12 (CXCL12)/chemokine (C-X-C motif) receptor 4 (CXCR4) axis.

METHODS

A rat model of VaD was established, and treated with QBT. Cognitive dysfunction in VaD rats was assessed using the Y-maze, new object recognition, and Morris water maze tests. Neuronal damage and inflammatory response in VaD rats were examined through Nissl staining, immunofluorescence, enzyme-linked immunospecific assay, and western blotting analysis. Furthermore, the effects of QBT on CXCL12/CXCR4 axis and its downstream signaling pathways, Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3) and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/nuclear factor-κB (NF-κB), were investigated in VaD rats and BV2 microglial cells exposed to oxygen glucose deprivation.

RESULTS

QBT significantly alleviated cognitive dysfunction and neuronal damage in VaD rats, along with inhibition of VaD-induced over-activation of microglia and astrocytes and inflammatory response. Moreover, QBT exhibited anti-inflammatory effects by inhibiting the CXCL12/CXCR4 axis and its downstream JAK2/STAT3 and PI3K/AKT/NF-κB pathways, thereby attenuating the neuroinflammatory response both in vivo and in vitro.

CONCLUSION

QBT effectively mitigated neuronal damage and cognitive dysfunction in VaD rats, exerting neuroprotective effects by suppressing neuroinflammatory response through inhibition of the CXCL12/CXCR4 axis.

Causal relationships between modifiable risk factors and polycystic ovary syndrome: a comprehensive Mendelian randomization study

Background

Polycystic Ovary Syndrome (PCOS) is a heritable condition with an as yet unclear etiology. Various factors, such as genetics, lifestyle, environment, inflammation, insulin resistance, hyperandrogenism, iron metabolism, and gut microbiota, have been proposed as potential contributors to PCOS. Nevertheless, a systematic assessment of modifiable risk factors and their causal effects on PCOS is lacking. This study aims to establish a comprehensive profile of modifiable risk factors for PCOS by utilizing a two-sample Mendelian Randomization (MR) framework.

Methods

After identifying over 400 modifiable risk factors, we employed a two-sample MR approach, including the Inverse Variance Weighted (IVW) method, Weighted Median method, and MR-Egger, to investigate their causal associations with PCOS. The reliability of our estimates underwent rigorous examination through sensitivity analyses, encompassing Cochran's Q test, MR-Egger intercept analysis, leave-one-out analysis, and funnel plots.

Results

We discovered that factors such as smoking per day, smoking initiation, body mass index, basal metabolic rate, waist-to-hip ratio, whole body fat mass, trunk fat mass, overall health rating, docosahexaenoic acid (DHA) (22:6n-3) in blood, monounsaturated fatty acids, other polyunsaturated fatty acids apart from 18:2 in blood, omega-3 fatty acids, ratio of bisallylic groups to double bonds, omega-9 and saturated fatty acids, total lipids in medium VLDL, phospholipids in medium VLDL, phospholipids in very large HDL, triglycerides in very large HDL, the genus Oscillibacter, the genus Alistipes, the genus Ruminiclostridium 9, the class Mollicutes, and the phylum Tenericutes, showed a significant effect on heightening genetic susceptibility of PCOS. In contrast, factors including fasting insulin interaction with body mass index, sex hormone-binding globulin, iron, ferritin, SDF1a, college or university degree, years of schooling, household income, the genus Enterorhabdus, the family Bifidobacteriaceae, the order Bifidobacteriales, the class Actinobacteria, and the phylum Actinobacteria were determined to reduce risk of PCOS.

Conclusion

This study innovatively employs the MR method to assess causal relationships between 400 modifiable risk factors and the susceptibility of PCOS risk. It supports causal links between factors like smoking, BMI, and various blood lipid levels and PCOS. These findings offer novel insights into potential strategies for the management and treatment of PCOS.

CXCR4-mediated neutrophil dynamics in periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis is a common oral disease closely related to immune response and this study is aimed to identify the key immune-related pathogenic genes and analyze the infiltration and function of immune cells in the disease using bioinformatics methods.

METHODS

Transcriptome datasets and single-cell RNA sequencing (scRNA-seq) datasets were downloaded from the GEO database. We utilized weighted correlation network analysis and least absolute selection and shrinkage operator, protein-protein interaction network construction to screen out key pathogenic genes as well as conducted the cell-type identification by estimating relative subsets of RNA transcripts algorithm to analyze and characterize immune cell types in periodontal tissues. In addition to bioinformatics validations, clinical and cell samples were collected and mouse periodontitis models were constructed to validate the important role of key genes in periodontitis.

RESULTS

Bioinformatics analysis pointed out the positive correlation between CXCR4 expression and periodontitis, and revealed the increased infiltration of neutrophils in periodontal inflammatory. Similar results were obtained from clinical samples and animal models. In addition, the clustering and functional enrichment results based on CXCR4 expression levels included activation of immune response and cell migration, implying the possible function of CXCR4 on regulating neutrophil dynamics, which might contribute to periodontitis. Subsequent validation experiments confirmed that the increased expression of CXCR4 in neutrophils under periodontitis, where cell migration-related pathways also were activated.

CONCLUSION

CXCR4 could be the key pathogenic gene of periodontitis and CXCR4/CXCL12 signal axial might contribute to the development of periodontitis by mediating neutrophil dynamics, suggesting that CXCR4 could be a potential target to help identify novel strategies for the clinical diagnosis and treatment of periodontitis.

Overexpression of HSP27 accelerates stress-induced gastric ulcer healing via the CXCL12/CXCR4 axis

Chronic stress often triggers gastrointestinal complications, including gastric injury and ulcers. Understanding the role of heat shock protein 27 (HSP27) in stress-induced gastric ulcers could unveil novel therapeutic targets. Here, we established a stress-induced gastric ulcer rat model using water immersion restraint stress and administered adenovirus-packaged HSP27 overexpression vector. Gastric ulcer severity was scored, and mucosal changes were assessed. Gastric epithelial and endothelial cells were treated with lipopolysaccharide and transfected with HSP27 overexpression vectors to evaluate cell viability, migration and angiogenesis. Expression levels of HSP27, C-X-C motif chemokine ligand 12 (CXCL12) and C-X-C motif chemokine receptor 4 (CXCR4) were measured in tissues and cells. HSP27 expression was initially low during stress-induced gastric ulceration but increased during ulcer healing. HSP27 overexpression accelerated ulcer healing in rats, promoting gastric epithelial cell proliferation and migration and gastric endothelial cell angiogenesis through the CXCL12/CXCR4 axis. Inhibitor IT1t reversed the effects of HSP27 overexpression on cell proliferation, migration and angiogenesis. In summary, HSP27 overexpression facilitated ulcer healing, which was partially mediated by the CXCL12/CXCR4 axis.

Chemokine systems in oncology: From microenvironment modulation to nanocarrier innovations

Over the past few decades, significant strides have been made in understanding the pivotal roles that chemokine networks play in tumor biology. These networks, comprising chemokines and their receptors, wield substantial influence over cancer immune regulation and therapeutic outcomes. As a result, targeting these chemokine systems has emerged as a promising avenue for cancer immunotherapy. However, therapies targeting chemokines face significant challenges in solid tumor treatment, due to the complex and fragile of the chemokine networks. A nuanced comprehension of the complicacy and functions of chemokine networks, and their impact on the tumor microenvironment, is essential for optimizing their therapeutic utility in oncology. This review elucidates the ways in which chemokine networks interact with cancer immunity and tumorigenesis. We particularly elaborate on recent innovations in manipulating these networks for cancer treatment. The review also highlights future challenges and explores potential biomaterial strategies for clinical applications.

A promising strategy of surface-modified nanoparticles targeting CXCR4 for precision cancer therapy

Nanoparticle (NP) functionalization with specific ligands enhances targeted cancer therapy and imaging by promoting receptor recognition and improving cellular uptake. This review focuses on recent research exploring the interaction between cancer cell-expressed chemokine receptor 4 (CXCR4) and ligand-conjugated NPs, utilising small molecules, peptides, and antibodies. Active NP targeting has shown improved tumour targeting and reduced toxicity, enabling precision therapy and diagnosis. However, challenges persist in the clinical translation of targeted NPs due to issues with biological response, tumour accumulation, and maintaining NP quality at an industrial scale. Biological and intratumoral barriers further hinder efficient NP accumulation in tumours, hampering translatability. To address these challenges, the academic community is refocusing efforts on understanding NP biological fate and establishing robust preclinical models. Future studies should investigate NP-body interactions, develop computational models, and identify optimal preclinical models. Establishing central NP research databases and fostering collaboration across disciplines is crucial to expediting clinical translation. Overcoming these hurdles will unlock the transformative potential of CXCR4-ligand-NP conjugates in revolutionising cancer treatment.

Revolutionizing Neurocare: Biomimetic Nanodelivery Via Cell Membranes

Brain disorders represent a significant challenge in medical science due to the formidable blood-brain barrier (BBB), which severely limits the penetration of conventional therapeutics, hindering effective treatment strategies. This review delves into the innovative realm of biomimetic nanodelivery systems, including stem cell-derived nanoghosts, tumor cell membrane-coated nanoparticles, and erythrocyte membrane-based carriers, highlighting their potential to circumvent the BBB's restrictions. By mimicking native cell properties, these nanocarriers emerge as a promising solution for enhancing drug delivery to the brain, offering a strategic advantage in overcoming the barrier's selective permeability. The unique benefits of leveraging cell membranes from various sources is evaluated and advanced technologies for fabricating cell membrane-encapsulated nanoparticles capable of masquerading as endogenous cells are examined. This enables the targeted delivery of a broad spectrum of therapeutic agents, ranging from small molecule drugs to proteins, thereby providing an innovative approach to neurocare. Further, the review contrasts the capabilities and limitations of these biomimetic nanocarriers with traditional delivery methods, underlining their potential to enable targeted, sustained, and minimally invasive treatment modalities. This review is concluded with a perspective on the clinical translation of these biomimetic systems, underscoring their transformative impact on the therapeutic landscape for intractable brain diseases.

Pathological progression of osteoarthritis: a perspective on subchondral bone

Osteoarthritis (OA) is a degenerative bone disease associated with aging. The rising global aging population has led to a surge in OA cases, thereby imposing a significant socioeconomic burden. Researchers have been keenly investigating the mechanisms underlying OA. Previous studies have suggested that the disease starts with synovial inflammation and hyperplasia, advancing toward cartilage degradation. Ultimately, subchondral-bone collapse, sclerosis, and osteophyte formation occur. This progression is deemed as "top to bottom." However, recent research is challenging this perspective by indicating that initial changes occur in subchondral bone, precipitating cartilage breakdown. In this review, we elucidate the epidemiology of OA and present an in-depth overview of the subchondral bone's physiological state, functions, and the varied pathological shifts during OA progression. We also introduce the role of multifunctional signal pathways (including osteoprotegerin (OPG)/receptor activator of nuclear factor-kappa B ligand (RANKL)/receptor activator of nuclear factor-kappa B (RANK), and chemokine (CXC motif) ligand 12 (CXCL12)/CXC motif chemokine receptor 4 (CXCR4)) in the pathology of subchondral bone and their role in the "bottom-up" progression of OA. Using vivid pattern maps and clinical images, this review highlights the crucial role of subchondral bone in driving OA progression, illuminating its interplay with the condition.

Berberine chloride suppresses pancreatic adenocarcinoma proliferation and growth by targeting inflammation-related genes: an in silico analysis with in vitro and vivo validation

PURPOSE

Targeting inflammatory crosstalk between tumors and their microenvironment has emerged as a crucial method for suppressing pancreatic adenocarcinoma (PAAD) progression. Berberine (BBR) is a natural pentacyclic isoquinoline alkaloid known for its anti-inflammatory and antitumor pharmacological effects; however, the mechanism underlying PAAD suppression remains unclear. We aim to investigate the effects of BBR on PAAD progression and their underlying mechanisms.

METHODS

The prognostic value of inflammation-related genes in PAAD was assessed using bioinformatics analyses, then the pharmacological effects and potential mechanisms of BBR on PAAD will be investigated in silico, in vitro, and in vivo.

RESULTS

Fifty-eight prognostic inflammation-related genes were identified in PAAD, which were shown to have good sensitivity and specificity using a novel inflammation-related gene risk-prognosis prediction model. Among these, four candidate genes (CAPS3, PTGS2, ICAM1, and CXCR4) were predicted as targets of BBR in PAAD in silico. Molecular docking simulations showed that the four key targets docked well with BBR. Further BBR treatment suppressed cell proliferation, colony formation, and induced cell cycle arrest in vitro. Moreover, BBR exhibited a significant tumor-suppressive effect in murine subcutaneous xenografts without macroscopic hepatic and renal toxicities. In addition, BBR downregulated CAPS3, PTGS2, ICAM1, and CXCR4 protein expression.

CONCLUSION

This study not only elucidated the prognostic value of inflammation-related genes in PAAD but also demonstrated the potential of BBR to inhibit PAAD by targeting these genes.

SPI1-mediated CXCL12 expression in bladder cancer affects the recruitment of tumor-associated macrophages

Bladder cancer (BC) originates principally from the epithelial compartment of the bladder. The immune system and its diverse players, chemokines, in particular, have been related to the responses against BC. The goal of the study here was to examine if C-X-C motif chemokine 12 (CXCL12) in BC cells could manipulate protumorigenic properties of tumor-associated macrophages (TAMs) which affects anticancer immunity supporting tumor development in the tumor microenvironment. CXCL12 was found to be overexpressed in BC and predicted poor survival. CXCL12 in BC was associated with multiple immune cell infiltrations, with TAM infiltration playing a key role. CXCL12 elevated chemotaxis of TAMs. CXCL12 downregulation inhibited cellular activity and TAM and suppressed the ability of TAMs to secrete inflammatory factors and MMP9. Furthermore, chromatin immunoprecipitation analysis revealed that SPI1 was localized to the CXCL12 promoter in BC cells, suggesting that CXCL12 serves a direct target of SPI1, which was consistent with the fact that SPI1 reversed the repressive effects of si-CXCL12 on BC cell activity and TAM recruitment in vitro and in vivo. Collectively, these findings suggest that SPI1 is involved in modulating TAM recruitment, representing a new mechanism through which it may influence tumor growth. This may be partly mediated by regulating CXCL12 expression.

VNS improves VSMC metabolism and arteriogenesis in infarcted hearts through m/n-AChR-Akt-SDF-1α in adult male rats

Vagal nerve stimulation (VNS) provides a novel therapeutic strategy for injured hearts by activating cholinergic anti-inflammatory pathways. However, little information is available on the metabolic pattern and arteriogenesis of VSMCs after MI. VNS has been shown to stimulate the expression of CPT1α, CPT1β, Glut1, Glut4 and SDF-1α in coronary VSMCs, decreasing the number of CD68-positive macrophages while increasing CD206-positive macrophages in the infarcted hearts, leading to a decrease in TNF-α and IL-1β accompanied by a reduced ratio of CD68- and CD206-positive cells, which were dramatically abolished by atropine and mecamylamine in vivo. Knockdown of SDF-1α substantially abrogated the effect of VNS on macrophagecell alteration and inflammatory factors in infarcted hearts. Mechanistically, ACh induced SDF-1α expression in VSMCs in a dose-dependent manner. Conversely, atropine, mecamylamine, and a PI3K/Akt inhibitor completely eliminated the effect of ACh on SDF-1α expression. Functionally, VNS promoted arteriogenesis and improved left ventricular performance, which could be abolished by Ad-shSDF-1α. Thus, VNS altered the VSMC metabolism pattern and arteriogenesis to repair the infarcted heart by inducing SDF-1α expression, which was associated with the m/nAChR-Akt signaling pathway.

Monomeric CXCL12-Engineered Adipose-Derived Stem Cells Transplantation for the Treatment of Ischemic Stroke

Adipose-derived stem cells (ASCs) possess therapeutic potential for ischemic brain injury, and the chemokine CXCL12 has been shown to enhance their functional properties. However, the cumulative effects of ASCs when combined with various structures of CXCL12 on ischemic stroke and its underlying molecular mechanisms remain unclear. In this study, we genetically engineered mouse adipose-derived ASCs with CXCL12 variants and transplanted them to the infarct region in a mice transient middle cerebral artery occlusion (tMCAO) model of stroke. We subsequently compared the post-ischemic stroke efficacy of ASC-mCXCL12 with ASC-dCXCL12, ASC-wtCXCL12, and unmodified ASCs. Neurobehavior recovery was assessed using modified neurological severity scores, the hanging wire test, and the elevated body swing test. Changes at the tissue level were evaluated through cresyl violet and immunofluorescent staining, while molecular level alterations were examined via Western blot and real-time PCR. The results of the modified neurological severity score and cresyl violet staining indicated that both ASC-mCXCL12 and ASC-dCXCL12 treatment enhanced neurobehavioral recovery and mitigated brain atrophy at the third and fifth weeks post-tMCAO. Additionally, we observed that ASC-mCXCL12 and ASC-dCXCL12 promoted angiogenesis and neurogenesis, accompanied by an increased expression of bFGF and VEGF in the peri-infarct area of the brain. Notably, in the third week after tMCAO, the ASC-mCXCL12 exhibited superior outcomes compared to ASC-dCXCL12. However, when treated with the CXCR4 antagonist AMD3100, the beneficial effects of ASC-mCXCL12 were reversed. The AMD3100-treated group demonstrated worsened neurological function, aggravated edema volume, and brain atrophy. This outcome is likely attributed to the interaction of monomeric CXCL12 with CXCR4, which regulates the recruitment of bFGF and VEGF. This study introduces an innovative approach to enhance the therapeutic potential of ASCs in treating ischemic stroke by genetically engineering them with the monomeric structure of CXCL12.

The functional roles of chemokines and chemokine receptors in colorectal cancer progression

Colorectal cancer is a common malignancy with significant rates of morbidity and mortality. A number of factors, including the tumor microenvironment, chemokines, the inflammatory response, have an impact on the development of colorectal cancer. A critical component of the tumor microenvironment is chemokines. Various cell subsets are attracted to the tumor microenvironment through interactions with chemokine receptors. These cells have varying effects on the development of the tumor and the effectiveness of treatment. Additionally, chemokines can participate in inflammatory processes and have effects that are either pro- or anti-tumor. Chemokines can be exploited as targets for medication resistance and treatment in colorectal cancer. In this review, we discuss the expression of chemokines and chemokine receptors, and their relationship with immune cells in the tumor microenvironment. At the same time, we also collect and discuss the significance of chemokines and chemokine receptors in colorectal cancer progression, and their potential as molecular targets for CRC treatment.

Esketamine inhibits the c-Jun N-terminal kinase pathway in the spinal dorsal horn to relieve bone cancer pain in rats

Cancer-induced bone pain (CIBP) is one of the most common and feared symptoms in patients with advanced tumors. The X-C motif chemokine ligand 12 (CXCL12) and the CXCR4 receptor have been associated with glial cell activation in bone cancer pain. Moreover, mitogen-activated protein kinases (MAPKs), as downstream CXCL12/CXCR4 signals, and c-Jun, as activator protein AP-1 components, contribute to the development of various types of pain. However, the specific CIBP mechanisms remain unknown. Esketamine is a non-selective N-methyl-d-aspartic acid receptor (NMDA) inhibitor commonly used as an analgesic in the clinic, but its analgesic mechanism in bone cancer pain remains unclear. We used a tumor cell implantation (TCI) model and explored that CXCL12/CXCR4, p-MAPKs, and p-c-Jun were stably up-regulated in the spinal cord. Immunofluorescence images showed activated microglia in the spinal cord on day 14 after TCI and co-expression of CXCL12/CXCR4, p-MAPKs (p-JNK, p-ERK, p-p38 MAPK), and p-c-Jun in microglia. Intrathecal injection of the CXCR4 inhibitor AMD3100 reduced JNK and c-Jun phosphorylations, and intrathecal injection of the JNK inhibitor SP600125 and esketamine also alleviated TCI-induced pain and reduced the expression of p-JNK and p-c-Jun in microglia. Overall, our data suggest that the CXCL12/CXCR4-JNK-c-Jun signaling pathway of microglia in the spinal cord mediates neuronal sensitization and pain hypersensitivity in cancer-induced bone pain and that esketamine exerts its analgesic effect by inhibiting the JNK-c-Jun pathway.

Single-cell Transcriptomics Reveals Activation of Macrophages in All-trans Retinoic Acid (atRA)-induced Cleft Palate

Cleft palate is among the most common birth defects with an impact on swallowing and speaking and is difficult to diagnose with ultrasound during pregnancy. In this study, we systematically capture the cellular composition of all-trans retinoic acid (atRA)-exposed and normal embryonic gestation 16.5 days mouse palate by the single-cell RNA sequencing technique. The authors identified 14 major cell types with the largest proportion of fibroblasts. The proportion of myeloid cells in atRA-exposed palate was markedly higher than those in the normal palate tissue, especially M1-like macrophages and monocytes. The upregulated genes of the different expression genes between atRA-exposed palate and normal palate tissue were linked to the biological processes of leukocyte chemotaxis and migration. Protein TLR2, CXCR4, THBS1, MRC1, transcription factor encoding genes Cebpb, Fos, Jun, Rela, and signaling pathway IL-17 and phagosome were found to be significantly involved in these processes. Subsequently, cellular communication network analysis suggested that myeloid-centered cell interactions SELL, SELPLG, MIF, CXCL, ANNEXIN, THBS, and NECTIN were significantly more activated in atRA-exposed palate. Overall, we delineate the single-cell landscape of atRA-induced cleft palate, revealing the effects of overexposure to atRA during palate tissue development and providing insights for the diagnosis of cleft palate.

Vagus nerve stimulation-induced stromal cell-derived factor-l alpha participates in angiogenesis and repair of infarcted hearts

AIMS

We aim to explore the role and mechanism of vagus nerve stimulation (VNS) in coronary endothelial cells and angiogenesis in infarcted hearts.

METHODS AND RESULTS

Seven days after rat myocardial infarction (MI) was prepared by ligation of the left anterior descending coronary artery, the left cervical vagus nerve was treated with electrical stimulation 1 h after intraperitoneal administration of the α7-nicotinic acetylcholine inhibitor mecamylamine or the mAChR inhibitor atropine or 3 days after local injection of Ad-shSDF-1α into the infarcted heart. Cardiac tissue acetylcholine (ACh) and serum ACh, tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6) levels were detected by ELISA to determine whether VNS was successful. An inflammatory injury model in human coronary artery endothelial cells (HCAECs) was established by lipopolysaccharide and identified by evaluating TNF-α, IL-1β and IL-6 levels and tube formation. Immunohistochemistry staining was performed to evaluate CD31-positive vessel density and stromal cell-derived factor-l alpha (SDF-1α) expression in the MI heart in vivo and the expression and distribution of SDF-1α, C-X-C motif chemokine receptor 4 and CXCR7 in HCAECs in vitro. Western blotting was used to detect the levels of SDF-1α, V-akt murine thymoma viral oncogene homolog (AKT), phosphorylated AKT (pAKT), specificity protein 1 (Sp1) and phosphorylation of Sp1 in HCAECs. Left ventricular performance, including left ventricular systolic pressure, left ventricular end-diastolic pressure and rate of the rise and fall of ventricular pressure, should be evaluated 28 days after VNS treatment. VNS was successfully established for MI therapy with decreases in serum TNF-α, IL-1β and IL-6 levels and increases in cardiac tissue and serum ACh levels, leading to increased SDF-1α expression in coronary endothelial cells of MI hearts, triggering angiogenesis of MI hearts with increased CD31-positive vessel density, which was abolished by the m/nAChR inhibitors mecamylamine and atropine or knockdown of SDF-1α by shRNA. ACh promoted SDF-1α expression and its distribution along with the branch of the formed tube in HCAECs, resulting in an increase in the number of tubes formed in HCAECs. ACh increased the levels of pAKT and phosphorylation of Sp1 in HCAECs, resulting in inducing SDF-1α expression, and the specific effects could be abolished by mecamylamine, atropine, the PI3K/AKT blocker wortmannin or the Sp1 blocker mithramycin. Functionally, VNS improved left ventricular performance, which could be abolished by Ad-shSDF-1α.

CONCLUSIONS

VNS promoted angiogenesis to repair the infarcted heart by inducing SDF-1α expression and redistribution along new branches during angiogenesis, which was associated with the m/nAChR-AKT-Sp1 signalling pathway.

Endothelial progenitor cells in pregnancy-related diseases

Placental neovascularization plays a crucial role in fetomaternal circulation throughout pregnancy and is dysregulated in several pregnancy-related diseases, including preeclampsia, gestational diabetes mellitus, and fetal growth restriction. Endothelial progenitor cells (EPCs) are a heterogeneous population of cells that differentiate into mature endothelial cells, which influence vascular homeostasis, neovascularization, and endothelial repair. Since their discovery in 1997 by Asahara et al., the role of EPCs in vascular biology has garnered a lot of interest. However, although pregnancy-related conditions are associated with changes in the number and function of EPCs, the reported findings are conflicting. This review discusses the discovery, isolation, and classification of EPCs and highlights discrepancies between current studies. Overviews of how various diseases affect the numbers and functions of EPCs, the role of EPCs as biomarkers of pregnancy disorders, and the potential therapeutic applications involving EPCs are also provided.

Flavokawain A ameliorates pulmonary fibrosis by inhibiting the TGF-β signaling pathway and CXCL12/CXCR4 axis

Idiopathic pulmonary fibrosis is a progressive fibrotic lung disease characterized by myofibroblast proliferation and extracellular matrix deposition that has a high mortality rate and limited therapeutic options. Flavokawain A(FKA) is the major component of chalcone in kava extract. FKA has been reported to inhibit TGF-β1-induced cardiomyocyte fibrosis by suppressing ROS production in A7r5 cells, but the role and mechanism of FKA in pulmonary fibrosis are unknown. In this study, we evaluated the effect of FKA on pulmonary fibrosis using an animal model of bleomycin-induced pulmonary fibrosis and showed that FKA alleviated the development of pulmonary fibrosis in a dose-dependent manner and improved lung function as well as collagen deposition and extracellular matrix accumulation in mice. In vitro studies showed that FKA inhibited myofibroblast activation and lung fibrosis progression by inhibiting TGF-β1/Smad signaling in a dose-dependent manner. In addition, we identified CXCL12 as a potential target of FKA through target prediction. Molecular docking, CETSA(cellular thermal displacement assay) and silver staining assays further demonstrated that FKA could interact with CXCL12 and that FKA could inhibit CXCL12 dimerization in vitro. Further analysis revealed that FKA could inhibit fibroblast activation and reduce extracellular matrix (ECM) production and collagen deposition by blocking CXCL12/CXCR4 signaling, and knocking down CXCR4 expression could weaken the inhibitory effect of FKA on CXCL12/CXCR4 signal transduction. In conclusion, our study showed that FKA inhibited CXCL12/CXCR4 signaling by inhibiting CXCL12 dimerization, blocked the CXCL12/CXCR4 signaling pathway and inhibited the TGF-β1-mediated signaling pathway to ameliorate pulmonary fibrosis, and FKA is a promising therapeutic agent for pulmonary fibrosis.

The interplay of FLT3 and CXCR4 in acute myeloid leukemia: an ongoing debate

FLT3 mutations are very frequent in AML and utilization of FLT3 inhibitors as approved treatment options are very common. Despite the initial success of inhibitor treatment, the development of resistances against this treatment is a major challenge in AML therapy. One of the mechanisms causing resistance is the homing of the leukemic cells in the protective niche of the bone marrow microenvironment (BMM). A pathway mediating homing to the BMM and leukemic cell survival is the CXCL12/CXCR4 axis. The analysis of patient samples in several independent studies indicated that FLT3-ITD expression led to higher CXCR4 surface expression. However, several in vitro studies reported contradictory findings, suggesting that FLT3-ITD signaling negatively influenced CXCR4 expression. In this commentary, we provide an overview summarizing the studies dealing with the relationship of FLT3 and CXCR4. Taken together, the current research status is not sufficient to answer the question whether FLT3 and CXCR4 act together or independently in leukemia progression. Systematic analyses in model cell systems are needed to understand the interplay between FLT3 and CXCR4, since this knowledge could lead to the development of more effective treatment strategies for AML patients.

ABCF1/CXCL12/CXCR4 Enhances Glioblastoma Cell Proliferation, Migration, and Invasion by Activating the PI3K/AKT Signal Pathway

Glioblastoma (GBM) is the most prevalent and fatal form of brain tumor, which is associated with a poor prognosis. ATP-binding cassette subfamily F member 1 (ABCF1) is an E2 ubiquitin-conjugating enzyme, which is implicated in regulating immune responses and tumorigenesis. Aberrant E3 ubiquitylation has been evidenced in GBM. However, the role of ABCF1 in GBM needs to be further explored. The expression of ABCF1, CXC chemokine ligand 12 (CXCL12), and CXC chemokine receptor 4 (CXCR4) in GBM tissues was examined by the GEPIA tool, real-time PCR and Western blotting. HMC3, U251MG, and LN-229 cells were cultured and transfected with shRNA targeting ABCF1 and ABCF1 plasmids. The proliferative, migrative, and invasive ability of cells was detected. Western blotting was used to detect the levels of phosphorylated phosphatidylinositol 3-kinase (PI3K) and phosphorylated protein kinase B (AKT). We observed that GBM tissues had higher ABCF1, CXCL12, and CXCR4 expression levels. The expression levels of CXCL12 and CXCR4 were enhanced by ABCF1 overexpression, which were significantly reversed by silence of ABCF1 in GBM cells. Silencing ABCF1 or CXCR4 inhibition weakened the capacity of GBM cell growth, migration, and invasion, while ectopic ABCF1 expression or CXCL12 treatment enhanced the cellular function of GBM cells. Furthermore, p-PI3K and p-AKT protein levels were downregulated by ABCF1 knockdown or CXCR4 blockade, which were prompted by ABCF1 overexpression or CXCL12 supplement. The ABCF1-CXCL12-CXCR4 axis was identified as a key player in GBM cell survival and metastasis by activating the PI3K/AKT signaling pathway in GBM cells.

New insight into the role of fibroblasts in the epithelial immune microenvironment in the single-cell era

The skin is exposed to environmental challenges and contains heterogeneous cell populations such as epithelial cells, stromal cells, and skin-resident immune cells. As the most abundant type of stromal cells, fibroblasts have been historically considered silent observers in the immune responses of the cutaneous epithelial immune microenvironment (EIME), with little research conducted on their heterogeneity and immune-related functions. Single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) have overcome the limitations of bulk RNA sequencing and help recognize the functional and spatial heterogeneity of fibroblasts, as well as their crosstalk with other types of cells in the cutaneous EIME. Recently, emerging single-cell sequencing data have demonstrated that fibroblasts notably participate in the immune responses of the EIME and impact the initiation and progression of inflammatory skin diseases. Here, we summarize the latest advances in the role of fibroblasts in the cutaneous EIME of inflammatory skin diseases and discuss the distinct functions and molecular mechanisms of activated fibroblasts in fibrotic skin diseases and non-fibrotic inflammatory skin diseases. This review help unveil the multiple roles of fibroblasts in the cutaneous EIME and offer new promising therapeutic strategies for the management of inflammatory skin diseases by targeting fibroblasts or the fibroblast-centered EIME.

The importance of CXCR4 expression in tumor stroma as a potential biomarker in pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the main causes of cancer mortality in the world. A characteristic feature of this cancer is that a large part of the tumor volume is composed of a stroma with different cells and factors. Among these, we can highlight the cytokines, which perform their function through binding to their receptors. Given the impact of the CXCR4 receptor in the interactions between tumor cells and their microenvironment and its involvement in important signaling pathways in cancer, it is proposed as a very promising prognostic biomarker and as a goal for new targeted therapies. Numerous studies analyze the expression of CXCR4 but we suggest focusing on the expression of CXCR4 in the stroma.

METHODS

Expression of CXCR4 in specimens from 33 patients with PDAC was evaluated by immunohistochemistry techniques and matched with clinicopathological parameters, overall and disease-free survival rates.

RESULTS

The percentage of stroma was lower in non-tumor tissue (32.4 ± 5.2) than in tumor pancreatic tissue (67.4 ± 4.8), P-value = 0.001. The level of CXCR4 expression in stromal cells was diminished in non-tumor tissue (8.7 ± 4.6) and higher in tumor pancreatic tissue (23.5 ± 6.1), P-value = 0.022. No significant differences were identified in total cell count and inflammatory cells between non-tumor tissue and pancreatic tumor tissue. No association was observed between CXCR4 expression and any of the clinical or pathological data, overall and disease-free survival rates. Analyzing exclusively the stroma of tumor samples, the CXCR4 expression was associated with tumor differentiation, P-value = 0.05.

CONCLUSIONS

In this study, we reflect the importance of CXCR4 expression in the stroma of patients diagnosed with PDAC. Our results revealed a high CXCR4 expression in the tumor stroma, which is related to a poor tumor differentiation. On the contrary, we could not find an association between CXCR4 expression and survival and the rest of the clinicopathological variables. Focusing the study on the CXCR4 expression in the tumor stroma could generate more robust results. Therefore, we consider it key to develop more studies to enlighten the role of this receptor in PDAC and its implication as a possible biomarker.

First reported case of splenic diffuse red pulp small B-cell lymphoma with novel mutations in CXCR4 and TRAF3 genes

Splenic diffuse red pulp small B-cell lymphoma (SDRPL) is a rare B-cell tumor whose genetic characteristics are poorly understood. Here, we introduce the case of a 62-year-old patient with SDRPL who showed progressive elevation of lymphocytes and progressive spleen enlargement. Immunohistochemistry showed that CD20 and CD79a were positive, and the Ki-67 labelling index was approximately 5%, consistent with the pathological features of splenic B-cell lymphoma. Spleen tissue and peripheral blood samples from the patient were sequenced using a next-generation sequencing platform, and mutations possibly were detected in the CXCR4 and TRAF3 genes that may be related to the pathogenesis of the disease. This finding may provide insights into the molecular pathogenesis of SDRPL and assist in molecular diagnosis and targeted therapy for SDRPL.

High Targeting Specificity toward Pulmonary Inflammation Using Mesenchymal Stem Cell-Hybrid Nanovehicle for an Efficient Inflammation Intervention

Pulmonary inflammation is one of the most reported tissue inflammations in clinic. Successful suppression of inflammation is vital to prevent further inevitably fatal lung degeneration. Glucocorticoid hormone, such as methylprednisolone (MP), is the most applied strategy to control the inflammatory progression yet faces the challenge of systemic side effects caused by the requirement of large-dosage and frequent administration. Highly efficient delivery of MP specifically targeted to inflammatory lung sites may overcome this challenge. Therefore, the present study develops an inflammation-targeted biomimetic nanovehicle, which hybridizes the cell membrane of mesenchymal stem cell with liposome, named as MSCsome. This hybrid nanovehicle shows the ability of high targeting specificity toward inflamed lung cells, due to both the good lung endothelium penetration and the high uptake by inflamed lung cells. Consequently, a single-dose administration of this MP-loaded hybrid nanovehicle achieves a prominent treatment of lipopolysaccharide-induced lung inflammation, and negligible treatment-induced side effects are observed. The present study provides a powerful inflammation-targeted nanovehicle using biomimetic strategy to solve the current challenges of targeted inflammation intervention.

TET2-mediated mRNA demethylation regulates leukemia stem cell homing and self-renewal

TET2 is recurrently mutated in acute myeloid leukemia (AML) and its deficiency promotes leukemogenesis (driven by aggressive oncogenic mutations) and enhances leukemia stem cell (LSC) self-renewal. However, the underlying cellular/molecular mechanisms have yet to be fully understood. Here, we show that Tet2 deficiency significantly facilitates leukemogenesis in various AML models (mediated by aggressive or less aggressive mutations) through promoting homing of LSCs into bone marrow (BM) niche to increase their self-renewal/proliferation. TET2 deficiency in AML blast cells increases expression of Tetraspanin 13 (TSPAN13) and thereby activates the CXCR4/CXCL12 signaling, leading to increased homing/migration of LSCs into BM niche. Mechanistically, TET2 deficiency results in the accumulation of methyl-5-cytosine (m5C) modification in TSPAN13 mRNA; YBX1 specifically recognizes the m5C modification and increases the stability and expression of TSPAN13 transcripts. Collectively, our studies reveal the functional importance of TET2 in leukemogenesis, leukemic blast cell migration/homing, and LSC self-renewal as an mRNA m5C demethylase.

Cathepsin S deficiency improves muscle mass loss and dysfunction via the modulation of protein metabolism in mice under pathological stress conditions

Cathepsin S (CTSS) is a widely expressed cysteinyl protease that has garnered attention because of its enzymatic and non-enzymatic functions under inflammatory and metabolic pathological conditions. Here, we examined whether CTSS participates in stress-related skeletal muscle mass loss and dysfunction, focusing on protein metabolic imbalance. Eight-week-old male wildtype (CTSS^+/+ ) and CTSS-knockout (CTSS^-/- ) mice were randomly assigned to non-stress and variable-stress groups for 2 weeks, and then processed for morphological and biochemical studies. Compared with non-stressed mice, stressed CTSS^+/+ mice showed significant losses of muscle mass, muscle function, and muscle fiber area. In this setting, the stress-induced harmful changes in the levels of oxidative stress-related (gp91^phox and p22^phox ,), inflammation-related (SDF-1, CXCR4, IL-1β, TNF-α, MCP-1, ICAM-1, and VCAM-1), mitochondrial biogenesis-related (PPAR-γ and PGC-1α) genes and/or proteins and protein metabolism-related (p-PI3K, p-Akt, p-FoxO3α, MuRF-1, and MAFbx1) proteins; and these alterations were rectified by CTSS deletion. Metabolomic analysis revealed that stressed CTSS^-/- mice exhibited a significant improvement in the levels of glutamine metabolism pathway products. Thus, these findings indicated that CTSS can control chronic stress-related skeletal muscle atrophy and dysfunction by modulating protein metabolic imbalance, and thus CTSS was suggested to be a promising new therapeutic target for chronic stress-related muscular diseases.

CXC chemokine receptor 4 (CXCR4) blockade in cancer treatment

CXC chemokine receptor type 4 (CXCR4) is a member of the G protein-coupled receptors (GPCRs) superfamily and is specific for CXC chemokine ligand 12 (CXCL12, also known as SDF-1), which makes CXCL12/CXCR4 axis. CXCR4 interacts with its ligand, triggering downstream signaling pathways that influence cell proliferation chemotaxis, migration, and gene expression. The interaction also regulates physiological processes, including hematopoiesis, organogenesis, and tissue repair. Multiple evidence revealed that CXCL12/CXCR4 axis is implicated in several pathways involved in carcinogenesis and plays a key role in tumor growth, survival, angiogenesis, metastasis, and therapeutic resistance. Several CXCR4-targeting compounds have been discovered and used for preclinical and clinical cancer therapy, most of which have shown promising anti-tumor activity. In this review, we summarized the physiological signaling of the CXCL12/CXCR4 axis and described the role of this axis in tumor progression, and focused on the potential therapeutic options and strategies to block CXCR4.

Single cell transcriptomics clarifies the basophil differentiation trajectory and identifies pre-basophils upstream of mature basophils

Basophils are the rarest granulocytes and are recognized as critical cells for type 2 immune responses. However, their differentiation pathway remains to be fully elucidated. Here, we assess the ontogenetic trajectory of basophils by single-cell RNA sequence analysis. Combined with flow cytometric and functional analyses, we identify c-Kit^-CLEC12A^hi pre-basophils located downstream of pre-basophil and mast cell progenitors (pre-BMPs) and upstream of CLEC12A^lo mature basophils. The transcriptomic analysis predicts that the pre-basophil population includes previously-defined basophil progenitor (BaP)-like cells in terms of gene expression profile. Pre-basophils are highly proliferative and respond better to non-IgE stimuli but less to antigen plus IgE stimulation than do mature basophils. Although pre-basophils usually remain in the bone marrow, they emerge in helminth-infected tissues, probably through IL-3-mediated inhibition of their retention in the bone marrow. Thus, the present study identifies pre-basophils that bridge the gap between pre-BMPs and mature basophils during basophil ontogeny.

SDF-1α promotes subchondral bone sclerosis and aggravates osteoarthritis by regulating the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells

BACKGROUND

Subchondral bone sclerosis is a major feature of osteoarthritis (OA), and bone marrow mesenchymal stem cells (BMSCs) are presumed to play an important role in subchondral bone sclerosis. Accumulating evidence has shown that stromal cell-derived factor-1α (SDF-1α) plays a key role in bone metabolism-related diseases, but its role in OA pathogenesis remains largely unknown. The purpose of this study was to explore the role of SDF-1α expressed on BMSCs in subchondral bone sclerosis in an OA model.

METHODS

In the present study, C57BL/6J mice were divided into the following three groups: the sham control, destabilization of the medial meniscus (DMM), and AMD3100-treated DMM (DMM + AMD3100) groups. The mice were sacrificed after 2 or 8 weeks, and samples were collected for histological and immunohistochemical analyses. OA severity was assessed by performing hematoxylin and eosin (HE) and safranin O-fast green staining. SDF-1α expression in the OA model was measured using an enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (q-PCR), and immunohistochemistry. Micro-CT was used to observe changes in subchondral bone in the OA model. CD44, CD90, RUNX2, and OCN expression in subchondral bone were measured using q-PCR and immunohistochemistry. In vitro, BMSCs were transfected with a recombinant lentivirus expressing SDF-1α, an empty vector (EV), or siRNA-SDF-1α. Western blot analysis, q-PCR, and immunofluorescence staining were used to confirm the successful transfection of BMSCs. The effect of SDF-1α on BMSC proliferation was evaluated by performing a CCK-8 assay and cell cycle analysis. The effect of SDF-1α on the osteogenic differentiation of BMSCs was assessed by performing alkaline phosphatase (ALP) and alizarin red S (ARS) staining. Cyclin D1, RUNX2 and OCN expression were measured using Western blot analysis, q-PCR, and immunofluorescence staining.

RESULTS

SDF-1α expression in the DMM-induced OA model increased. In the DMM + AMD3100 group, subchondral bone sclerosis was alleviated, OA was effectively relieved, and CD44, CD90, RUNX2, and OCN expression in subchondral bone was decreased. In vitro, high levels of SDF-1α promoted BMSC proliferation and increased osteogenic differentiation. Cyclin D1, RUNX2, and OCN expression increased.

CONCLUSION

The results of this study reveal a new molecular mechanism underlying the pathogenesis of OA. The targeted regulation of SDF-1α may be clinically effective in suppressing OA progression.

Automated synthesis and quality control of [68Ga]Ga-PentixaFor using the Gaia/Luna Elysia-Raytest module for CXCR4 PET imaging

BACKGROUND

[⁶⁸Ga]Ga-PentixaFor is a promising radiotracer for positron emission tomography imaging of several human tumors overexpressing the chemokine receptor-4 (CXCR4). CXCR4 overexpression has been demonstrated in patients with hematologic malignancies, solid cancers, as well as cardiovascular pathologies of inflammatory origins. However, its radio synthesis is not yet fully developed in France, and existing methods do not use our type of synthesis module. Therefore, we aimed at developing a [⁶⁸Ga]Ga-PentixaFor synthesis with Gaia/Luna Elysia-Raytest module to use it in clinical purpose.

RESULTS

12 syntheses were carried out by varying the temperature conditions and radiolabeling times, and led to choose specific labelling conditions with the Gaia/Luna Elysia-Raytest module: 97 °C, 4 min. The mean synthesis time of the 3 validation runs under good manufacturing practice (GMP) was 24 min 27 s (± 8 s), and the mean radiochemical yield was 87.0% [standard deviation (SD) 6.67%]. Different quality control parameters were also evaluated in accordance with European Pharmacopeia: radiochemical and radionuclidic purity, pH, sterility, stability and endotoxins levels. The average radiochemical purity was 99.1% (SD 0.25%) assessed by instant thin layer chromatography and 99.8% (SD 0.092%) assessed by high pressure liquid chromatography. average [⁶⁸Ge] breakthrough was 1.48 × 10^-5%, under the recommended level of 0.001%. We assessed the stability of the radiotracer up to 4 h at room temperature (no augmentation of the [⁶⁸Ga] chloride in the final product, i.e. radiochemical purity (RCP) > 98.5%). The endotoxins levels were < 5 EU/mL, and the pH was 6.5 (same for the three syntheses).

CONCLUSION

The [⁶⁸Ga]Ga-PentixaFor synthesis process developed on the Gaia/Luna Elysia-Raytest module has fulfilled all acceptance criteria for injectable radiopharmaceutical products regarding the European Pharmacopeia. The radiochemical purity, stability, efficacy, as well as the microbiological quality of the three GMP batches were found to be good. The robustness of the synthesis process may be suitable for multi-dose application in clinical settings.

Effect of tocopherol conjugation on polycation-mediated siRNA delivery to orthotopic pancreatic tumors

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive form of cancer with a five-year survival rate of around 10 %. CXCR4 and STAT3 display crucial effects on proliferation, metastasis, angiogenesis, and formation of immunosuppressive microenvironment in pancreatic tumors. Here, we have tested the hypothesis that conjugation of α-tocopherol (TOC) to a polycation (PAMD), synthesized from CXCR4-antagonist AMD3100, will improve delivery of therapeutic siRNA to silence STAT3 in PDAC tumors. PAMD-TOC/siSTAT3 nanoparticles showed superior anti-cancer and anti-migration performance compared to the parent PAMD/siSTAT3 nanoparticles in both murine and human PDAC cell lines. The biodistribution of the nanoparticles in orthotropic mouse KPC8060 and human PANC-1 models, indicated that tumor accumulation of PAMD-TOC/siRNA nanoparticles was improved greatly as compared to PAMD/siRNA nanoparticles. This improved cellular uptake, penetration, and tumor accumulation of PAMD-TOC/siSTAT3 nanoparticles, also contributed to the suppression of tumor growth, metastasis and improved survival. Overall, this study presents a prospective treatment strategy for PDAC.

In Vitro and Ex Vivo Methodologies for T-Cell Trafficking Through Blood-Brain Barrier After TLR Activation

This chapter describes ex vivo isolation of human T cells and of naïve splenocytes respectively collected from multiple sclerosis patients and healthy controls and experimental autoimmune encephalomyelitis-affected mice. After the magnetic sorting of naïve and activated T helper lymphocytes, we provide details about the cell cultures to measure the interaction with extracellular matrix proteins using standard cell invasion or hand-made in vitro assays, upon different stimuli, through Toll-like receptor(s) ligands, T-cell activators, and cell adhesion molecules modulators. Finally, we describe the methods to harvest and recover T cells to evaluate the properties associated with their trafficking ability.

CXCL12/CXCR4: An amazing challenge and opportunity in the fight against fibrosis

Fibrosis is a pathological process caused by abnormal wound healing response, which often leads to excessive deposition of extracellular matrix, distortion of organ architecture, and loss of organ function. Aging is an important risk factor for the development of organ fibrosis. C-X-C receptor 4 (CXCR4) is the predominant chemokine receptor on fibrocytes, C-X-C motif ligand 12 (CXCL12) is the only ligand of CXCR4. Accumulated evidence have confirmed that CXCL12/CXCR4 can be involved in multiple pathological mechanisms in fibrosis, such as inflammation, immunity, epithelial-mesenchymal transition, and angiogenesis. In addition, CXCL12/CXCR4 have also been shown to improve fibrosis levels in many organs including the heart, liver, lung and kidney; thus, they are promising targets for anti-fibrotic therapy. Notably, inhibitors of CXCL12 or CXCR4 also play an important role in various fibrosis-related diseases. In summary, this review systematically summarizes the role of CXCL12/CXCR4 in fibrosis, and this information is of great significance for understanding CXCL12/CXCR4. This will also contribute to the design of further studies related to CXCL12/CXCR4 and fibrosis, and shed light on potential therapies for fibrosis.

Interactions of the chemokines CXCL11 and CXCL12 in human tumor cells

BACKGROUND

The chemokines, CXCL12 and CXCL11, are upregulated in tumors from many organs and control their progression. CXCL12 and CXCL11 affect tumor cell functions by either binding their prime receptors, CXCR4 and CXCR3, respectively, and/or CXCR7 as a common second chemokine receptor. In humans, CXCR3 exists in the functional splice variants, CXCR3A and CXCR3B, which either have pro- or anti-tumor activity, respectively. Despite the intimate crosstalk between the CXCL12- and CXCL11-system, the impact of a combination of CXCL12 and CXCL11 on tumor progression remains vague.

METHODS

In the present work, we have analyzed CXCL12 and CXCL11 for combined effects on migration, invasion, proliferation, and cytostatic-induced apoptosis of the human tumor cells, A549, A767, A772, DLD-1, and MDA-MB-231.

RESULTS

We demonstrate that the mode of interaction differs with respect to cell type and function and allows for either potentiation, attenuation or no changes of cellular responses. The divergent responses are not the result of the distinct use of different CXCL12- and CXCL11-receptors by the respective tumor cells, but in case of cell migration seem to be associated with the activation of p38 signaling pathways.

CONCLUSIONS

Our findings point to therapeutic limitations of ongoing efforts to selectively target CXCR3, CXCR4, or CXCR7 in cancer patients, and rather favor individualized targeting strategies.

Dynamic immune ecosystem of dengue infection revealed by single-cell sequencing

Dengue is the most common human arboviral disease worldwide, which can result in severe complications. A dysfunctional immune response in dengue infective patients is a recurrent theme impacting symptoms and mortality, but the heterogeneity and dynamics of immune infiltrates during dengue infection remain poorly characterized. Here, we identified the immune cell types in scRNA-seq data from 13127 cells of 10 dengue infective patients and discovered the dynamic immune ecosystems of dengue infection. Notably, genes that exhibited higher expression in specific cell types play important roles in response to virus infection in a module manner. Transcription factors (TFs) are the major regulators (i.e., PAX5, IRF7, KLF4, and IRF8) that can potentially regulate infection-related genes. We demonstrated that the dynamic rewired regulatory network during dengue infection. Moreover, our data revealed the complex cell-cell communications from control to fever and severe dengue patients and prevalent cell-cell communication rewiring was observed. We further identified the IFN-II and CXCL signaling pathways that medicated the communications and play important roles in dengue infection. Together, our comprehensive analysis of dynamic immune ecosystem of dengue infection provided novel insights for understanding the pathogenesis of and developing effective therapeutic strategies for dengue infection.

Biologic Functions of Hydroxychloroquine in Disease: From COVID-19 to Cancer

Chloroquine (CQ) and Hydroxychloroquine (HCQ), initially utilized in the treatment of malaria, have now developed a long list of applications. Despite their clinical relevance, their mechanisms of action are not clearly defined. Major pathways by which these agents are proposed to function include alkalinization of lysosomes and endosomes, downregulation of C-X-C chemokine receptor type 4 (CXCR4) expression, high-mobility group box 1 protein (HMGB1) inhibition, alteration of intracellular calcium, and prevention of thrombus formation. However, there is conflicting data present in the literature. This is likely the result of the complex overlapping pathways between these mechanisms of action that have not previously been highlighted. In fact, prior research has focused on very specific portions of particular pathways without describing these in the context of the extensive CQ/HCQ literature. This review summarizes the detailed data regarding CQ/HCQ's mechanisms of action while also providing insight into the overarching themes. Furthermore, this review provides clinical context to the application of these diverse drugs including their role in malaria, autoimmune disorders, cardiovascular disease, thrombus formation, malignancies, and viral infections.

Implications of cancer stem cells in diabetes and pancreatic cancer

This review provides a detailed study of pancreatic cancer (PC) and the implication of different types of cancers concerning diabetes. The combination of anti-diabetic drugs with other anti-cancer drugs and phytochemicals can help prevent and treat this disease. PC cancer stem cells (CSCs) and how they migrate and develop into malignant tumors are discussed. A detailed explanation of the different mechanisms of diabetes development, which can enhance the pancreatic CSCs' proliferation by increasing the IGF factor levels, epigenetic modifications, DNA damage, and the influence of lifestyle factors like obesity, and inflammation, has been discussed. It also explains how cancer due to diabetes is associated with high mortality rates. One of the well-known diabetic drugs, metformin, can be combined with other anti-cancer drugs and prevent the development of PC and has been taken as one of the prime focus in this review. Overall, this paper provides insight into the relationship between diabetes and PC and the methods that can be employed to diagnose this disease at an earlier stage successfully.

Role of endothelial CXCR4 in the development of aortic valve stenosis

Background

CXCL12/CXCR4 signaling is essential in cardiac development and repair, however, its contribution to aortic valve stenosis (AVS) remains unclear. In this study, we tested the role of endothelial CXCR4 on the development of AVS.

Materials and methods

We generated CXCR4 endothelial cell-specific knockout mice (EC CXCR4 KO) by crossing CXCR4^fl/fl mice with Tie2-Cre mice to study the role of endothelial cell CXCR4 in AVS. CXCR4^fl/fl mice were used as controls. Echocardiography was used to assess the aortic valve and cardiac function. Heart samples containing the aortic valve were stained using Alizarin Red for detection of calcification. Masson’s trichrome staining was used for the detection of fibrosis. The apex of the heart samples was stained with wheat germ agglutinin (WGA) to visualize ventricular hypertrophy.

Results

Compared with the control group, the deletion of CXCR4 in endothelial cells led to significantly increased aortic valve peak velocity and aortic valve peak pressure gradient, with decreased aortic valve area and ejection fraction. EC CXCR4 KO mice also developed cardiac hypertrophy as evidenced by increased diastolic and systolic left ventricle posterior wall thickness (LVPW), cardiac myocyte size, and heart weight (HW) to body weight (BW) ratio. Our data also confirmed increased microcalcifications, interstitial fibrosis, and thickened valvular leaflets of the EC CXCR4 KO mice.

Conclusion

The data collected throughout this study suggest the deletion of CXCR4 in endothelial cells is linked to the development of aortic valve stenosis and left ventricular hypertrophy. The statistically significant parameters measured indicate that endothelial cell CXCR4 plays an important role in aortic valve development and function. We have compiled compelling evidence that EC CXCR4 KO mice can be used as a novel model for AVS.

Advances in mesenchymal stromal cell therapy for acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) develops rapidly and has high mortality. ALI/ARDS is mainly manifested as acute or progressive hypoxic respiratory failure. At present, there is no effective clinical intervention for the treatment of ALI/ARDS. Mesenchymal stromal cells (MSCs) show promise for ALI/ARDS treatment due to their biological characteristics, easy cultivation, low immunogenicity, and abundant sources. The therapeutic mechanisms of MSCs in diseases are related to their homing capability, multidirectional differentiation, anti-inflammatory effect, paracrine signaling, macrophage polarization, the polarization of the MSCs themselves, and MSCs-derived exosomes. In this review, we discuss the pathogenesis of ALI/ARDS along with the biological characteristics and mechanisms of MSCs in the treatment of ALI/ARDS.

Combination of chemically modified SDF-1α mRNA and small skin improves wound healing in diabetic rats with full-thickness skin defects

OBJECTIVES

Diabetes mellitus is associated with refractory wound healing, yet current therapies are insufficient to accelerate the process of healing. Recent studies have indicated chemically modified mRNA (modRNA) as a promising therapeutic intervention. The present study aimed to explore the efficacy of small skin engineered to express modified mRNAs encoding the stromal cell-derived factor-1α (SDF-1α) facilitating wound healing in a full-thickness skin defect rat model. This study, devised therapeutic strategies for diabetic wounds by pre-treating small skin with SDF-1α modRNA.

MATERIALS AND METHODS

The in vitro transfection efficiency was evaluated using fluorescence microscopy and the content of SDF-1α in the medium was determined using ELISA after the transfection of SDF-1α into the small skin. To evaluate the effect of SDF-1α modRNA and transplantation of the small skin cells on wound healing, an in vivo full-thickness skin defect rat model was assessed.

RESULTS

The results revealed that a modRNA carrying SDF-1α provided potent wound healing in the small skin lesions reducing reduced scar thickness and greater angiogenesis (CD31) in the subcutaneous layer. The SDF-1α cytokines were significantly secreted by the small skin after transfection in vitro.

CONCLUSIONS

This study demonstrated the benefits of employing small skin combined with SDF-1α modRNA in enhancing wound healing in diabetic rats having full-thickness skin defects.

Enhanced migration and immunoregulatory capacity of BMSCs mediated by overexpression of CXCR4 and IL-35

Bone marrow-derived mesenchymal stem cells (BMSCs) have been widely studied for their applications in immunoregulation and tissue repair. However, the therapeutic effects of BMSCs in the body are limited, partly due to the low homing efficiency of BMSCs to affected parts. The stromal cell-derived factor 1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR4) axis is well known to play an essential role in the homing of BMSCs. Interleukin 35 (IL-35) is a newly discovered cytokine confirmed to inhibit overactivated immune function and have a good therapeutic effect on autoimmune diseases. In this study, we innovatively developed dual gene modification of BMSCs by transducing CXCR4 and IL-35 and found that the migration and immunomodulatory activity of genetically engineered BMSCs were significantly enhanced compared to their natural counterparts. These results suggest that BMSCs modified by dual overexpression of CXCR4 and IL-35 may provide a potential treatment strategy for autoimmune diseases.

Recent Advances in CXCL12/CXCR4 Antagonists and Nano-Based Drug Delivery Systems for Cancer Therapy

Chemokines can induce chemotactic cell migration by interacting with G protein-coupled receptors to play a significant regulatory role in the development of cancer. CXC chemokine-12 (CXCL12) can specifically bind to CXC chemokine receptor 4 (CXCR4) and is closely associated with the progression of cancer via multiple signaling pathways. Over recent years, many CXCR4 antagonists have been tested in clinical trials; however, Plerixafor (AMD3100) is the only drug that has been approved for marketing thus far. In this review, we first summarize the mechanisms that mediate the physiological effects of the CXCL12/CXCR4 axis. Then, we describe the use of CXCL12/CXCR4 antagonists. Finally, we discuss the use of nano-based drug delivery systems that exert action on the CXCL12/CXCR4 biological axis.

The involvement of a chemokine receptor antagonist CTCE-9908 and kynurenine metabolites in cancer development

Cancer is the second leading cause of mortality worldwide. Skin cancer is the most common cancer in South Africa with nearly 20,000 reported cases every year and 700 deaths. If diagnosed early, the 5-year survival rate is about 90%, however, when diagnosed late, the 5-year survival rate decreases to about 20%. Melanoma is a type of skin cancer with an estimated 5-year survival rate of approximately 90%. Neuroblastoma is a paediatric cancer with a low survival rate. Sixty percent of patients with metastatic disease do not survive 5 years after diagnosis. Despite recent advances in targeted therapies, there is a crucial need to identify reliable prognostic biomarkers which will be able to contribute to the development of more precision-based chemotherapeutic strategies to prevent tumour migration and metastasis. The compound, CTCE-9908 inhibits the binding of CXC chemokine ligand 12 (CXCL12) to the CXC chemokine receptor 4 (CXCR4) receptor leading to reduced metastasis. Kynurenine metabolites are derived tryptophan, which is an essential amino acid. Kynurenine metabolites inhibit T-cell proliferation resulting in cell growth arrest. For this reason, chemokines receptors represent potential targets for the treatment of cancer growth and metastasis. In this review paper, the role of the CXCL12/CXCR4 signalling pathway in the development of cancer is highlighted together with the current available treatments involving the CTCE-9908 compound in combination with microtubule inhibitors like paclitaxel and docetaxel.

Metformin counteracts stimulatory effects induced by insulin in primary breast cancer cells

Background

Metabolic disorders are associated with increased incidence, aggressive phenotype and poor outcome of breast cancer (BC) patients. For instance, hyperinsulinemia is an independent risk factor for BC and the insulin/insulin receptor (IR) axis is involved in BC growth and metastasis. Of note, the anti-diabetic metformin may be considered in comprehensive therapeutic approaches in BC on the basis of its antiproliferative effects obtained in diverse pre-clinical and clinical studies.

Methods

Bioinformatics analysis were performed using the information provided by The Invasive Breast Cancer Cohort of The Cancer Genome Atlas (TCGA) project. The naturally immortalized BC cell line, named BCAHC-1, as well as cancer-associated fibroblasts (CAFs) derived from BC patients were used as model systems. In order to identify further mechanisms that characterize the anticancer action of metformin in BC, we performed gene expression and promoter studies as well as western blotting experiments. Moreover, cell cycle analysis, colony and spheroid formation, actin cytoskeleton reorganization, cell migration and matrigel drops evasion assays were carried out to provide novel insights on the anticancer properties of metformin.

Results

We first assessed that elevated expression and activation of IR correlate with a worse prognostic outcome in estrogen receptor (ER)-positive BC. Thereafter, we established that metformin inhibits the insulin/IR-mediated activation of transduction pathways, gene changes and proliferative responses in BCAHC-1 cells. Then, we found that metformin interferes with the insulin-induced expression of the metastatic gene CXC chemokine receptor 4 (CXCR4), which we found to be associated with poor disease-free survival in BC patients exhibiting high levels of IR. Next, we ascertained that metformin prevents a motile phenotype of BCAHC-1 cells triggered by the paracrine liaison between tumor cells and CAFs upon insulin activated CXCL12/CXCR4 axis.

Conclusions

Our findings provide novel mechanistic insights regarding the anti-proliferative and anti-migratory effects of metformin in both BC cells and important components of the tumor microenvironment like CAFs. Further investigations are warranted to corroborate the anticancer action of metformin on the tumor mass toward the assessment of more comprehensive strategies halting BC progression, in particular in patients exhibiting metabolic disorders and altered insulin/IR functions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03463-y.

Drug Delivery Systems in the Development of Novel Strategies for Glioblastoma Treatment

Glioblastoma multiforme (GBM) is a grade IV glioma considered the most fatal cancer of the central nervous system (CNS), with less than a 5% survival rate after five years. The tumor heterogeneity, the high infiltrative behavior of its cells, and the blood-brain barrier (BBB) that limits the access of therapeutic drugs to the brain are the main reasons hampering the current standard treatment efficiency. Following the tumor resection, the infiltrative remaining GBM cells, which are resistant to chemotherapy and radiotherapy, can further invade the surrounding brain parenchyma. Consequently, the development of new strategies to treat parenchyma-infiltrating GBM cells, such as vaccines, nanotherapies, and tumor cells traps including drug delivery systems, is required. For example, the chemoattractant CXCL12, by binding to its CXCR4 receptor, activates signaling pathways that play a critical role in tumor progression and invasion, making it an interesting therapeutic target to properly control the direction of GBM cell migration for treatment proposes. Moreover, the interstitial fluid flow (IFF) is also implicated in increasing the GBM cell migration through the activation of the CXCL12-CXCR4 signaling pathway. However, due to its complex and variable nature, the influence of the IFF on the efficiency of drug delivery systems is not well understood yet. Therefore, this review discusses novel drug delivery strategies to overcome the GBM treatment limitations, focusing on chemokines such as CXCL12 as an innovative approach to reverse the migration of infiltrated GBM. Furthermore, recent developments regarding in vitro 3D culture systems aiming to mimic the dynamic peritumoral environment for the optimization of new drug delivery technologies are highlighted.

Bone Marrow Mesenchymal Stem Cells (BMSCs)-Originated miR-1298 Impedes the Aggressiveness of Non-Small Cell Lung Cancer by Hindering the Chemokine Receptor 4 (CXCR4)-Induced Epithelial-Mesenchymal Transition (EMT) Process

Exosomes are a subclass of extracellular vesicles, which are produced and secreted by various cells including bone marrow mesenchymal stem cells (BMSCs). BMSCs-originated exosomes can provide a beneficial microenvironment and manipulate tumor growth. However, whether BMSCs-derived miR-1298 exerts roles in NSCLC remains unclear. miR-1298 level was quantified in NSCLC tumor tissues and para-cancerous tissues and NSCLC cell lines. Cells were transfected with miR-136 mimics/miR-136 inhibitors or treatment with BMSCs-originated exosomes to measure cell biological behaviors. Our results found a diminished miR-1298 expression in NSCLC tumor specimens and cell lines. Meanwhile, miR-1298 overexpression or miR-1298 derived from BMSC-originated exosomes can restrain the proliferating feature of NSCLC cells, and impedes cell aggressiveness via hindering EMT process. Additionally, CXCR4 was a target of miR-1298. In conclusion, miR-1298 is served as a tumor suppressor gene in NSCLC and can retard the proliferating and invading behaviors of NSCLC cells by targeting CXCR4 expression, indicating that it might be a novel therapeutic target for treating NSCLC.

Role of chemokine systems in cancer and inflammatory diseases

Chemokines are a large family of small secreted proteins that have fundamental roles in organ development, normal physiology, and immune responses upon binding to their corresponding receptors. The primary functions of chemokines are to coordinate and recruit immune cells to and from tissues and to participate in regulating interactions between immune cells. In addition to the generally recognized antimicrobial immunity, the chemokine/chemokine receptor axis also exerts a tumorigenic function in many different cancer models and is involved in the formation of immunosuppressive and protective tumor microenvironment (TME), making them potential prognostic markers for various hematologic and solid tumors. In fact, apart from its vital role in tumors, almost all inflammatory diseases involve chemokines and their receptors in one way or another. Modulating the expression of chemokines and/or their corresponding receptors on tumor cells or immune cells provides the basis for the exploitation of new drugs for clinical evaluation in the treatment of related diseases. Here, we summarize recent advances of chemokine systems in protumor and antitumor immune responses and discuss the prevailing understanding of how the chemokine system operates in inflammatory diseases. In this review, we also emphatically highlight the complexity of the chemokine system and explore its potential to guide the treatment of cancer and inflammatory diseases.

MSX-122: Is an effective small molecule CXCR4 antagonist in cancer therapy?

Chemokines, a subgroup of cytokines along with their receptors, are involved in various biologic processes and regulation of a wide range of immune responses in different physiologic and pathologic states such as tissue repair, infection, and inflammation. C-X-C motif chemokine receptor 4 (CXCR4), a G-protein-coupled receptor (GPCR), has one identified natural ligand termed stromal-derived factor-1(SDF-1 or CXCL12). Evidence demonstrated that the ligation of SDF-1 to CXCR4 initiates several intracellular signaling pathways, regulating cell proliferation, survival, chemotaxis, migration, angiogenesis, adhesion, as well as bone marrow (BM)-resident cells homing and mobilization. Additionally, CXCR4 is expressed by tumor cells in blood malignancies and solid tumors. Therefore, CXCR4 is considered a potential therapeutic target in cancer therapy, and CXCR4 antagonists, including AMD3100, MSX-122, BPRCX807, WZ811, Motixafortide, TN14003, AMD3465, and AMD1170, have been employed in experimental and clinical studies to enhance cancer therapy. MSX-122 is a specific small-molecule antagonist of CXCR4/CXCL12 and the only orally available non-peptide CXCR4 antagonist with promising anti-cancer properties. Studies have shown that MSX-122 is particularly important in treating metastatic cancers and has great therapeutic potential. Accordingly, this review summarized the characteristics of MSX-122 and its effects on the CXCL12/CXCR4 axis as well as cancer therapy.