Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer.

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

The role of oral microbiota in cancer.

Cancer remains a significant global challenge, with an estimated 47% increase in cancer patients from 2020 to 2040. Increasing research has identified microorganism as a risk factor for cancer development. The oral cavity, second only to the colon, harbors more than 700 bacterial species and serves as a crucial microbial habitat. Although numerous epidemiological studies have reported associations between oral microorganisms and major systemic tumors, the relationship between oral microorganisms and cancers remains largely unclear. Current research primarily focuses on respiratory and digestive system tumors due to their anatomical proximity to the oral cavity. The relevant mechanism research mainly involves 47% dominant oral microbial population that can be cultured in vitro. However, further exploration is necessary to elucidate the mechanisms underlying the association between oral microbiota and tumors. This review systematically summarizes the reported correlations between oral microbiota and common cancers while also outlining potential mechanisms that may guide biological tumor treatment.

Molecular Characterization of Two Wamide Neuropeptide Signaling Systems in Mollusk Aplysia.

Neuropeptides with the C-terminal Wamide (Trp-NH2) are one of the last common ancestors of peptide families of eumetazoans and play various physiological roles. In this study, we sought to characterize the ancient Wamide peptides signaling systems in the marine mollusk Aplysia californica, i.e., APGWamide (APGWa) and myoinhibitory peptide (MIP)/Allatostatin B (AST-B) signaling systems. A common feature of protostome APGWa and MIP/AST-B peptides is the presence of a conserved Wamide motif in the C-terminus. Although orthologs of the APGWa and MIP signaling systems have been studied to various extents in annelids or other protostomes, no complete signaling systems have yet been characterized in mollusks. Here, through bioinformatics, molecular and cellular biology, we identified three receptors for APGWa, namely, APGWa-R1, APGWa-R2, and APGWa-R3. The EC50 values for APGWa-R1, APGWa-R2, and APGWa-R3 are 45, 2100, and 2600 nM, respectively. For the MIP signaling system, we predicted 13 forms of peptides, i.e., MIP1-13 that could be generated from the precursor identified in our study, with MIP5 (WKQMAVWa) having the largest number of copies (4 copies). Then, a complete MIP receptor (MIPR) was identified and the MIP1-13 peptides activated the MIPR in a dose-dependent manner, with EC50 values ranging from 40 to 3000 nM. Peptide analogs with alanine substitution experiments demonstrated that the Wamide motif at the C-terminus is necessary for receptor activity in both the APGWa and MIP systems. Moreover, cross-activity between the two signaling systems showed that MIP1, 4, 7, and 8 ligands could activate APGWa-R1 with a low potency (EC50 values: 2800-22,000 nM), which further supported that the APGWa and MIP signaling systems are somewhat related. In summary, our successful characterization of Aplysia APGWa and MIP signaling systems represents the first example in mollusks and provides an important basis for further functional studies in this and other protostome species. Moreover, this study may be useful for elucidating and clarifying the evolutionary relationship between the two Wamide signaling systems (i.e., APGWa and MIP systems) and their other extended neuropeptide signaling systems.

Identification of three elevenin receptors and roles of elevenin disulfide bond and residues in receptor activation in Aplysia californica.

Neuropeptides are ubiquitous intercellular signaling molecules in the CNS and play diverse roles in modulating physiological functions by acting on specific G-protein coupled receptors (GPCRs). Among them, the elevenin signaling system is now believed to be present primarily in protostomes. Although elevenin was first identified from the L11 neuron of the abdominal ganglion in mollusc Aplysia californica, no receptors have been described in Aplysia, nor in any other molluscs. Here, using two elevenin receptors in annelid Platynereis dumerilii, we found three putative elevenin GPCRs in Aplysia. We cloned the three receptors and tentatively named them apElevR1, apElevR2, and apElevR3. Using an inositol monophosphate (IP1) accumulation assay, we demonstrated that Aplysia elevenin with the disulfide bond activated the three putative receptors with low EC50 values (ranging from 1.2 to 25 nM), supporting that they are true receptors for elevenin. In contrast, elevenin without the disulfide bond could not activate the receptors, indicating that the disulfide bond is required for receptor activity. Using alanine substitution of individual conserved residues other than the two cysteines, we showed that these residues appear to be critical to receptor activity, and the three different receptors had different sensitivities to the single residue substitution. Finally, we examined the roles of those residues outside the disulfide bond ring by removing these residues and found that they also appeared to be important to receptor activity. Thus, our study provides an important basis for further study of the functions of elevenin and its receptors in Aplysia and other molluscs.

Characterization of an Aplysia vasotocin signaling system and actions of posttranslational modifications and individual residues of the ligand on receptor activity.

The vasopressin/oxytocin signaling system is present in both protostomes and deuterostomes and plays various physiological roles. Although there were reports for both vasopressin-like peptides and receptors in mollusc Lymnaea and Octopus, no precursor or receptors have been described in mollusc Aplysia. Here, through bioinformatics, molecular and cellular biology, we identified both the precursor and two receptors for Aplysia vasopressin-like peptide, which we named Aplysia vasotocin (apVT). The precursor provides evidence for the exact sequence of apVT, which is identical to conopressin G from cone snail venom, and contains 9 amino acids, with two cysteines at position 1 and 6, similar to nearly all vasopressin-like peptides. Through inositol monophosphate (IP1) accumulation assay, we demonstrated that two of the three putative receptors we cloned from Aplysia cDNA are true receptors for apVT. We named the two receptors as apVTR1 and apVTR2. We then determined the roles of post-translational modifications (PTMs) of apVT, i.e., the disulfide bond between two cysteines and the C-terminal amidation on receptor activity. Both the disulfide bond and amidation were critical for the activation of the two receptors. Cross-activity with conopressin S, annetocin from an annelid, and vertebrate oxytocin showed that although all three ligands can activate both receptors, the potency of these peptides differed depending on their residue variations from apVT. We, therefore, tested the roles of each residue through alanine substitution and found that each substitution could reduce the potency of the peptide analog, and substitution of the residues within the disulfide bond tended to have a larger impact on receptor activity than the substitution of those outside the bond. Moreover, the two receptors had different sensitivities to the PTMs and single residue substitutions. Thus, we have characterized the Aplysia vasotocin signaling system and showed how the PTMs and individual residues in the ligand contributed to receptor activity.

[Effect of low-energy microwave irradiation on orthodontic tooth movement and periodontal tissue remodeling in rats].

PURPOSE: To investigate the effect of low-energy microwave irradiation on the movement of orthodontic teeth and periodontal tissue reconstruction in rats. METHODS: SD rats were randomly divided into control group and experimental group. Helical spring force method was used to construct a rat orthodontic model through a nickel-titanium tension spring device. Rats in the experimental group were irradiated with a microwave treatment apparatus once a day to move the first molars for 30 minutes, while rats in the control group were not given any intervention. The rats were sacrificed on the day of modeling, 7 d, 14 d, and 21 d thereafter. The movement distance of the rat's first molars was measured. Tartrate-resistant acid phosphatase (TRAP) staining was used to detect osteoclast counts in rat periodontal tissues, immunohistochemistry was used to detect the expression of cell differentiation factor (osteoclast differentiation factor, ODF) in rat periodontal tissues; real-time fluorescence quantitative PCR(RT-PCR) was used to detect the mRNA expression of interleukin 6(IL-6) and tumor necrosis factor-α (TNF-α). SPSS 20.0 software package was used to analyze the experimental data. RESULTS: At 7, 14, 21 d, compared with the control group, the distance of the first molar movement, the count of osteoclasts in the periodontal tissue, and the expression of ODF in the experimental group were significantly increased (P＜0.05), while the mRNA expression of IL-6 and TNF-α in periodontal tissues was significantly decreased (P＜0.05). CONCLUSIONS: Low-energy microwave irradiation can significantly accelerate the movement of orthodontic teeth, inhibit the expression of inflammatory genes, and promote the reconstruction of periodontal tissue.

Identification of an allatostatin C signaling system in mollusc Aplysia.

Neuropeptides, as pervasive intercellular signaling molecules in the CNS, modulate a variety of behavioral systems in both protostomes and deuterostomes. Allatostatins are neuropeptides in arthropods that inhibit the biosynthesis of juvenile hormones. Based on amino acid sequences, they are divided into three different types in arthropods: allatostatin A, allatostatin B, allatostatin C. Allatostatin C (AstC) was first isolated from Manduca sexta, and it has an important conserved feature of a disulfide bridge formed by two cysteine residues. Moreover, AstC appears to be the ortholog of mammalian somatostatin, and it has functions in common with somatostatin, such as modulating feeding behaviors. The AstC signaling system has been widely studied in arthropods, but minimally studied in molluscs. In this study, we seek to identify the AstC signaling system in the marine mollusc Aplysia californica. We cloned the AstC precursor from the cDNA of Aplysia. We predicted a 15-amino acid peptide with a disulfide bridge, i.e., AstC, using NeuroPred. We then cloned two putative allatostatin C-like receptors and through NCBI Conserved Domain Search we found that they belonged to the G protein-coupled receptor (GPCR) family. In addition, using an inositol monophosphate 1 (IP1) accumulation assay, we showed that Aplysia AstC could activate one of the putative receptors, i.e., the AstC-R, at the lowest EC50, and AstC without the disulfide bridge (AstC') activated AstC-R with the highest EC50. Moreover, four molluscan AstCs with variations of sequences from Aplysia AstC but with the disulfide bridge activated AstC-R at intermediate EC50. In summary, our successful identification of the Aplysia AstC precursor and its receptor (AstC-R) represents the first example in molluscs, and provides an important basis for further studies of the AstC signaling system in Aplysia and other molluscs.

Evolution of the mir-155 family and possible targets in cancers and the immune system.

The mir-155 family is not only involved in a diversity of cancers, but also as a regulator of the immune system. However, the evolutionary history of this family is still unclear. The present study indicates that mir-155 evolved independently with lineage-specific gain of miRNAs. In addition, arm switching has occurred in the mir-155 family, and alternative splicing could produce two different lengths of ancestral sequences, implying the alternative splicing can also drive evolution for intragenic miRNAs. Here we screened validated target genes and immunity- related proteins, followed by analyzation of the mir-155 family function by high-throughput methods like the gene ontology (GO) and Kyoto Eneyclopedin of Genes and Genemes (KEGG) pathway enrichment analysis. The high-throughput analysis showed that the CCND1 and EGFR genes were outstanding in being significantly enriched, and the target genes cebpb and VCAM1 and the protein SMAD2 were also vital in mir-155-related immune reponse activities. Therefore, we conclude that the mir-155 family is highly conserved in evolution, and CCND1 and EGFR genes might be potential targets of mir-155 with regard to progress of cancers, while the cebpb and VCAM1 genes and the protein SMAD2 might be key factors in the mir-155 regulated immune activities.

Environmental tobacco smoke exposure and Chinese schoolchildren's respiratory health: a prospective cohort study.

BACKGROUND: Although China is the most coveted cigarette market worldwide, few studies have examined the longitudinal effects of environmental tobacco smoke (ETS) on health. PURPOSE: To examine the relationship between exposure to ETS and respiratory health in Chinese schoolchildren. METHODS: The study subjects included 1718 children, who were never-smokers, aged 10.05±0.86 years and asthma-free at baseline. The children performed spirometric tests in 2006 and 18 months later. Parents reported the children's respiratory symptoms and illnesses, ETS exposure, and other related information by self-administered survey at both assessment points. The data were analyzed in 2010. RESULTS: Significant exposure-response relationships were found between ETS exposure and coughing at night (p for trend<0.001); sneezing (p for trend=0.031); and sneezing with itchy, watery eyes (p for trend=0.006) in the first survey, and coughing at night (p for trend=0.019); phlegm without a cold (p for trend<0.001); and sneezing (p for trend=0.036) in the second survey. Compared with those who reported no ETS exposure in either survey, children who had a high ETS exposure level (>5 cigarettes/day) in either survey had lower growth rates in forced expiratory flow between 25% and 75% of forced vital capacity (FEF(25-75); ß= -0.104, p=0.020) and forced expiratory flow at 25% of forced vital capacity (FEF(25); ß= -0.077, p=0.027). A monotonic exposure-response effect was observed between ETS exposure and the deficits in the growth rate of FEF(25) and FEF(25-75.) CONCLUSIONS: Exposure to ETS increased the risks of respiratory symptoms in Chinese school-aged children and was associated with impaired lung function growth. A dose-response relationship was observed for the latter effect.

Infliximab protects against pulmonary emphysema in smoking rats.

BACKGROUND: It is widely accepted that tumor necrosis factor-α (TNF-α) plays an important role in the pathogenesis of emphysema. This study aimed at investigating the protective effects of anti-TNF-α antibody, infliximab, in the development of emphysema induced by passive smoking in rats. METHODS: Thirty-nine rats were randomly divided into a normal control group (group 1), an emphysema group (group 2), and an infliximab-intervention group (group 3). Rat models of emphysema were established by exposure to cigarette smoking daily for 74 days. After 1 month, the infliximab intervention group was treated with infliximab via subcutaneous injection. The levels of TNF-α, IL-8 and vascular endothelial growth factor (VEGF) in bronchoalveolar lavage fluid (BALF) were measured with enzyme linked immunosorbent assay (ELISA). The number and classification of cells in the BALF were measured. Lung tissue sections stained by hematoxylin and eosin (HE) were observed, and mean linear intercept (MLI) and mean alveolar numbers (MAN) were measured. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) methods were used to examine the percentage of positive cells and distribution of apoptotic cells. RESULTS: The levels of TNF-α and IL-8 in BALF were higher in group 2 than in group 1 and group 3. The MLI was greater in group 2 than that in group 1 and group 3 while MAN was decreased. The concentration of VEGF in BALF of group 2 was significantly decreased as compared with group 1. The total cells and neutrophils number was significantly increased in group 2 as compared with group 1 and group 3, so was the percentage of neutrophils. The number of TUNEL positive cells in the alveolar septa was significantly increased in group 2 as compared with group 1 and group 3. CONCLUSION: Infliximab protects against cigarette smoking-induced emphysema by reducing airway inflammation, attenuating alveolar septa cell apoptosis and improving pathological changes.

Effects of ambient air pollution on lung function growth in Chinese schoolchildren.

OBJECTIVE: To evaluate the adverse effect of exposure to air pollution on lung function growth in school-aged children. METHODS: A cohort of 1983 children from three districts in Guangzhou, China was followed-up for 6 months. The children performed pulmonary function tests twice, and their parents reported the child's respiratory symptoms by self-administered questionnaires in both surveys. RESULTS: The annual mean concentrations of air pollutants for the past 5 years for particulate matter less than 10 microns in diameter (PM(10)), nitrogen (NO(2)), and sulfur dioxide (SO(2)) were respectively: 96.1 microg/m(3), 76.0 microg/m(3), and 65.7 microg/m(3) in the highly-polluted district (HPD), 80.3 microg/m(3), 67.6 mug/m(3), and 54.5 microg/m(3) in the moderately-polluted district (MPD), and 80.0 microg/m(3), 48.1 microg/m(3), and 52.2 microg/m(3) in the least-polluted district (LPD). After adjustment for potential confounders, significant deficits were found in the annual growth rates of forced expiratory flows at 25% (FEF(25)), and between 25% and 75% (FEF(25-75)) in boys and FEF(25) in girls (In boys, for FEF(25), -0.136 l/s, p = 0.008 in MPD and -0.153 l/s, p = 0.004 in HPD, respectively; for FEF(25-75), -0.176 l/s, p = 0.013 in MPD and -0.167 l/s, p = 0.021 in HPD, respectively. In girls, for FEF(25), -0.123 l/s, p = 0.043 in HPD), using LPD as the reference. Deficits in the annual growth rate of forced expiratory volume in 1 s (FEV(1)) were also negatively associated with air pollution in boys (-0.063 L, p = 0.032 in HPD). CONCLUSIONS: The study adds more evidence that exposure to air pollution has adverse effects on lung function growth in schoolchildren.

Rosiglitazone, a peroxisome proliferator-activated receptor-gamma agonist, attenuates acrolein-induced airway mucus hypersecretion in rats.

BACKGROUND: Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a member of the ligand-activated nuclear receptor superfamily, has been shown to be implicated in anti-inflammatory and immunomodulatory responses, but its role in airway mucus hypersecretion remains not clear. OBJECTIVE: To investigate the role of PPAR-gamma in airway mucus hypersecretion, we used an acrolein-exposed rat model treated with rosiglitazone, a peroxisome proliferator-activated receptor-gamma agonist. METHODS: Rats were exposed to acrolein (3.0 ppm, 6h/day, 7 days/week) and orally administered with rosiglitazone (2, 4, 8 mg/kg) once daily for up to 2 weeks. The expressions of Muc5ac protein and mRNA, and infiltration of inflammatory cells and levels of inflammatory cytokines (interleukin (IL)-1beta, IL-8 and tumor necrosis factor (TNF)-alpha) in bronchoalveolar lavage fluid (BALF) were detected with real-time PCR, Western blot, cell counting and ELISA. In addition, the role of nuclear factor (NF)-kappaB pathway in this process was also explored. RESULTS: Acrolein exposure significantly induced goblet cell hyperplasia in bronchial epithelium and Muc5ac mRNA and protein expressions in rat lungs, as well as the associated airway inflammation evidenced by the increased numbers of inflammatory cells and levels of inflammatory cytokines in BALF, which were attenuated with rosiglitazone treatment in a dose-dependent manner (P<0.05). Simultaneously, the increased expression of NF-kappaB and decreased expression of cytoplasmic IkappaB in acrolein-exposed lungs were reversed by rosiglitazone treatment. CONCLUSIONS: These findings suggest that PPAR-gamma activation by its ligands can attenuate acrolein-induced airway mucus hypersecretion in rats, which may be involved in inhibition of NF-kappaB pathway.