Puerariae lobatae Radix ameliorates chronic kidney disease by reshaping gut microbiota and downregulating Wnt/ß­catenin signaling.

Gut microbiota dysfunction is a key factor affecting chronic kidney disease (CKD) susceptibility. Puerariae lobatae Radix (PLR), a traditional Chinese medicine and food homologous herb, is known to promote the gut microbiota homeostasis; however, its role in renoprotection remains unknown. The present study aimed to investigate the efficacy and potential mechanism of PLR to alleviate CKD. An 8­week 2% NaCl­feeding murine model was applied to induce CKD and evaluate the therapeutic effect of PLR supplementary. After gavage for 8 weeks, The medium and high doses of PLR significantly alleviated CKD­associated creatinine, urine protein increasement and nephritic histopathological injury. Moreover, PLR protected kidney from fibrosis by reducing inflammatory response and downregulating the canonical Wnt/ß­catenin pathway. Furthermore, PLR rescued the gut microbiota dysbiosis and protected against high salt­induced gut barrier dysfunction. Enrichment of Akkermansia and Bifidobacterium was found after PLR intervention, the relative abundances of which were in positive correlation with normal maintenance of renal histology and function. Next, fecal microbiota transplantation experiment verified that the positive effect of PLR on CKD was, at least partially, exerted through gut microbiota reestablishment and downregulation of the Wnt/ß­catenin pathway. The present study provided evidence for a new function of PLR on kidney protection and put forward a potential therapeutic strategy target for CKD.

The effects of Nardosinone on levodopa intervention in the treatment of Parkinson's disease.

BACKGROUND: The roots and rhizomes of Nardostachys jatamansi DC. are reported to be useful for the treatment of Parkinson's disease (PD). Previous research has also shown that Nardosinone, the main active component isolated from Nardostachys jatamansi DC., exhibits the potential to treat PD. AIM OF THE STUDY: To investigate how the effects of Nardosinone could assist levodopa in the treatment of PD, how this process changes the intestinal flora, and to explore the effective forms of Nardosinone in the intestinal flora. MATERIAL AND METHODS: We used behavioral experiments, and hematoxylin-eosin staining and immunohistochemical staining, to investigate the effects of a combination of Nardosinone and levodopa on rotenone-induced PD rats. In addition, we used LC/MS-MS to determine the levels of levodopa, 5-hydroxytryptamine, dopamine and its metabolite 3, 4-dihydroxyphenylacetic acid, and homovanillic acid, to investigate the effect of the intestinal flora on co-administration in the treatment of PD. LC/MS-MS was also used to detect the metabolites of Nardosinone on the gastrointestinal tract and intestinal flora. RESULTS: The behavioral disorders and neuronal damage associated with PD were significantly improved following the co-administration. Analysis also revealed that the co-administration increased the levels of five neurotransmitters in the striatum, plasma and feces. In vitro experiments further demonstrated that the levels of dopamine and levodopa were increased in the intestinal flora. In total, five metabolites of Nardosinone were identified. CONCLUSION: Our findings indicate that Nardosinone and its metabolites might act as a potential adjutant to enhance the efficacy of levodopa via the intestinal flora, thus expanding the therapeutic potential of the combination of Chinese and Western medicine as a treatment method for PD.

Therapeutic stapled peptides: Efficacy and molecular targets.

Peptide stapling, by employing a stable, preformed alpha-helical conformation, results in the production of peptides with improved membrane permeability and enhanced proteolytic stability, compared to the original peptides, and provides an effective solution to accelerate the rapid development of peptide drugs. Various reviews present peptide stapling chemistries, anchoring residues and one- or two-component cyclization, however, therapeutic stapled peptides have not been systematically summarized, especially focusing on various disease-related targets. This review highlights the latest advances in therapeutic peptide drug development facilitated by the application of stapling technology, including different stapling techniques, synthetic accessibility, applicability to biological targets, potential for solving biological problems, as well as the current status of development. Stapled peptides as therapeutic drug candidates have been classified and analysed mainly by receptor- and ligand-based stapled peptide design against various diseases, including cancer, infectious diseases, inflammation, and diabetes. This review is expected to provide a comprehensive reference for the rational design of stapled peptides for different diseases and targets to facilitate the development of therapeutic peptides with enhanced pharmacokinetic and biological properties.

Exploring the influence of microstructure and phospholipid type of liposomes on their interaction with lung.

Liposome is a promising carrier for pulmonary drug delivery and the nano-sized liposomes have been widely investigated in the treatment of lung diseases. However, there still lack the knowledge of micron-sized liposomes for lung delivery, which have more advantages in terms of drug loading and sustained drug release capacity. The micron-sized liposomes can be classified into multilamellar liposome (MLL) and multivesicular liposome (MVL) according to their microstructure, thus, this study focused on exploring how the micron-sized liposomes with different microstructure and phospholipid composition influence their interaction with the lung. The MLL and MVL were prepared from different types of phospholipids (including soya phosphatidylcholine (SPC), egg yolk phosphatidylcholine (EPC), and dipalmitoyl phosphatidylcholine (DPPC)) with geometric diameter around 5 µm, and their in vitro pulmonary cell uptake, in vivo lung retention and organ distribution were investigated. The results showed that the microstructure of liposomes didn't affect pulmonary cellular uptake, in vivo lung retention and organ distribution. MLL and MVL prepared with the same phospholipid had similar cellular uptake in both NR8383 cells and A549 cells, and both of them possessed prolonged lung retention and limited distribution in other organs during 72 h. Notably, the phospholipid type presented remarkable influence on liposomes' interaction with the lung. SPC-based liposomes exhibited higher cellular uptake than the DPPC-based ones in both NR8383 cells and A549 cells, also possessed a better lung retention behavior. In conclusion, this study might provide theoretical knowledge for designing micron-sized liposomes intended for lung delivery.

Tunable rigidity of PLGA shell-lipid core nanoparticles for enhanced pulmonary siRNA delivery in 2D and 3D lung cancer cell models.

Faced with the threat of lung cancer-related deaths worldwide, small interfering RNA (siRNA) can silence tumor related messenger RNA (mRNA) to tackle the issue of drug resistance with enhanced anti-tumor effects. However, how to increase lung tumor targeting and penetration with enhanced gene silencing are the issues to be addressed. Thus, the objective of this study is to explore the feasibility of designing non-viral siRNA vectors for enhanced lung tumor therapy via inhalation. Here, shell-core based polymer-lipid hybrid nanoparticles (HNPs) were prepared via microfluidics by coating PLGA on siRNA-loaded cationic liposomes (Lipoplexes). Transmission electron microscopy and energy dispersive spectroscopy study demonstrated that HNP consists of a PLGA shell and a lipid core. Atomic force microscopy study indicated that the rigidity of HNPs could be well tuned by changing thickness of the PLGA shell. The designed HNPs were muco-inert with increased stability in mucus and BALF, good safety, enhanced mucus penetration and cellular uptake. Crucially, HNP1 with the thinnest PLGA shell exhibited superior transfection efficiency (84.83%) in A549 cells, which was comparable to that of lipoplexes and Lipofectamine 2000, and its tumor permeability was 1.88 times that of lipoplexes in A549-3T3 tumor spheroids. After internalization of the HNPs, not only endosomal escape but also lysosomal exocytosis was observed. The transfection efficiency of HNP1 (39.33%) was 2.26 times that of lipoplexes in A549-3T3 tumor spheroids. Moreover, HNPs exhibited excellent stability during nebulization via soft mist inhaler. In conclusion, our study reveals the great potential of HNP1 in siRNA delivery for lung cancer therapy via inhalation.

All-hydrocarbon stapling enables improvement of antimicrobial activity and proteolytic stability of peptide Figainin 2.

Figainin 2 is a cationic, hydrophobic, α-helical host-defense peptide with 28 residues, which was isolated from the skin secretions of the Chaco tree frog. It shows potent inhibitory activity against both Gram-negative and Gram-positive pathogens and has garnered considerable interest in developing novel classes of natural antibacterial agents. However, as a linear peptide, conformational flexibility and poor proteolytic stability hindered its development as antibacterial agent. To alleviate its susceptibility to proteolytic degradation and improve its antibacterial activity, a series of hydrocarbon-stable analogs of Figainin 2 were synthesized and evaluated for their secondary structure, protease stability, antimicrobial, and hemolytic activities. Among them, F2-12 showed significant improvement in protease resistance and antimicrobial activity compared to that of the template peptide. This study provides a promising strategy for the development of antimicrobial drugs.

UTX inhibition suppresses proliferation and promotes apoptosis in patient-derived glioblastoma stem cells by modulating periostin expression.

Glioblastoma stem cells (GSCs) exert a crucial influence on glioblastoma (GBM) development, progression, resistance to therapy, and recurrence, making them an attractive target for drug discovery. UTX, a histone H3K27 demethylase, participates in regulating multiple cancer types. However, its functional role in GSCs remains insufficiently explored. This study aims to investigate the role and regulatory mechanism of UTX on GSCs. Analysis of TCGA data revealed heightened UTX expression in glioma, inversely correlating with overall survival. Inhibiting UTX suppressed GBM cell growth and induced apoptosis. Subsequently, we cultured primary GSCs from three patients, observing that UTX inhibition suppressed cell proliferation and induced apoptosis. RNA-seq was performed to analyze the gene expression changes after silencing UTX in GSCs. The results indicated that UTX-mediated genes were strongly correlated with GBM progression and regulatory tumor microenvironment. The transwell co-cultured experiment showed that silencing UTX in the transwell chamber GSCs inhibited the well plate cell proliferation. Protein-protein interaction analysis revealed that periostin (POSTN) played a role in the UTX-mediated transcriptional regulatory network. Replenishing POSTN reversed the effects of UTX inhibition on GSC proliferation and apoptosis. Our study demonstrated that UTX inhibition hindered POSTN expression by enhancing the H3K27me2/3 level, eventually resulting in inhibiting proliferation and promoting apoptosis of patient-derived GSCs. Our findings may provide a novel and effective strategy for the treatment of GBM.

Screening and verification of hemostatic effective components group of Panax Notoginseng based on spectrum-effect relationships.

ETHNOPHARMACOLOGICAL RELEVANCE: Panax Notoginseng (PN) can disperse blood stasis, hemostasis, and detumescence analgesic, which can be used for hemoptysis, hematemesis and another traumatic bleeding, and it is known as "A miracle hemostatic medicine". Studies show that the chemical composition of PN is relatively comprehensive, however, its hemostatic active ingredients have not been fully clarified. AIM OF STUDY: This study aimed to clarify the hemostatic effective components group (HECG) of PN, provide a foundation for the assessment of PN's quality and its comprehensive development, and for further studies on the pharmacodynamic material basis of other Traditional Chinese Medicines (TCMs). MATERIALS AND METHODS: UPLC-MS was used to establish the fingerprint and identify the common peaks in 44 batches of PN extracts (PNE). In addition, the plasma recalcification time and in vitro coagulation time were measured. For spectrum-effect analysis, bivariate correlation analysis (BCA) and partial least squares regression analysis (PLSR) were used to screen the hemostasis candidate active monomers of PN. The monomers were prepared by combining several preparative chromatography techniques. The efficacy was verified by plasma recalcification time, in vitro coagulation time, and a rat model of gastric hemorrhage. RESULTS: A total of 30 common peaks and hemostatic efficacy indexes of 44 batches of PNE were obtained. A total of 18 components were positively correlated with the comprehensive coagulation index by two statistical methods. Six and eleven monomers were obtained respectively by chromatographic preparation and procurement, and one monomer was eliminated due to preparation difficulty and other reasons. Seven active monomers with direct hemostatic effect and one active monomer with synergistic hemostatic effect were screened through plasma recalcification time, and their combinations were used as candidate HECG for hemostatic effect verification. The results of in vitro experiments showed that plasma recalcification time and in vitro coagulation time were significantly reduced (P < 0.05) in the HECG group, compared to the PNE group. The results of in vivo experiment also indicated that the hemostatic effect of HECG was comparable to that of PNE and PN powder. CONCLUSION: The composition and efficacy of the HECG of PN were screened and verified using the spectral correlation method and in vivo and in vitro efficacy verification; the HECG included Dencichine, Ginsenoside Rg1, Ginsenoside Rd, Ginsenoside Rh1, Ginsenoside F1, Notoginsenoside R1, Notoginsenoside Ft1 and Notoginsenoside Fe. These results laid a foundation for the quality evaluation of PN and provided a reference for the basic research of pharmacodynamic material basis of other TCMs.

METTL3/YTHDF2 m6A axis mediates the progression of diabetic nephropathy through epigenetically suppressing PINK1 and mitophagy.

AIMS: This research aimed to investigate the specific mechanism of methyltransferase like 3 (METTL3) in the progression of diabetic kidney disease (DKD). MATERIALS AND METHODS: The model of diabetic kidney disease was established with HK-2 cells and mice in vitro and in vivo. The N6 methyladenosine (m6A) contents in the cells and tissues were detected with a commercial kit and the m6A levels of PTEN induced putative kinase 1 (PINK2) were detected with a MeRIP kit. The mRNA and protein levels were determined with RT-qPCR and western blot. The ROS, TNF-α, and IL-6 levels were assessed with ELISA. The cell proliferative ability was measured by a CCK-8 assay and cell apoptosis was determined with TUNEL staining. The HE and Masson staining was performed to observe the renal morphology. The RIP assay was conducted to detect the interaction between METTL3/YTHDF2 and PINK1. RESULTS: The m6A content and METTL3 levels were prominently elevated in diabetic kidney disease. METTL3 silencing promoted the cell growth and the expression of LC3 II, PINK1, and Parkin, while inhibiting the cell apoptosis and the expression of LC3 I and p62 in the high glucose (HG) stimulated HK-2 cells. METTL3 silencing also decreased the ROS, TNF-α, and IL-6 levels in diabetic kidney disease. PINK1 silencing neutralized the function of sh-METTL3 in the HG stimulated HK-2 cells. The HE and Masson staining showed that METTL3 silencing alleviated the kidney injury induced by DKD. METTL3 silencing decreased the m6A levels of PINK1, while increased the mRNA levels of PINK1 which depended on YTHDF2. CONCLUSIONS: METTL3 silencing could inhibit the progression of diabetic nephropathy in vivo and in vitro by regulating the m6A modification of PINK1, which depends on YTHDF2. Our research lays the theoretical foundation for the precise treatment of diabetic kidney disease and the development of targeted drugs in the future.

miR-155 facilitates the synergistic replication between avian leukosis virus subgroup J and reticuloendotheliosis virus by targeting a dual pathway.

IMPORTANCE: The synergy of two oncogenic retroviruses is an essential phenomenon in nature. The synergistic replication of ALV-J and REV in poultry flocks increases immunosuppression and pathogenicity, extends the tumor spectrum, and accelerates viral evolution, causing substantial economic losses to the poultry industry. However, the mechanism of synergistic replication between ALV-J and REV is still incompletely elusive. We observed that microRNA-155 targets a dual pathway, PRKCI-MAPK8 and TIMP3-MMP2, interacting with the U3 region of ALV-J and REV, enabling synergistic replication. This work gives us new targets to modulate ALV-J and REV's synergistic replication, guiding future research on the mechanism.

A 3D Digital Model for the Diagnosis and Treatment of Pulmonary Nodules.

The three-dimensional (3D) reconstruction of pulmonary nodules using medical images has introduced new technical approaches for diagnosing and treating pulmonary nodules, and these approaches are progressively being acknowledged and adopted by physicians and patients. Nonetheless, constructing a relatively universal 3D digital model of pulmonary nodules for diagnosis and treatment is challenging due to device differences, shooting times, and nodule types. The objective of this study is to propose a new 3D digital model of pulmonary nodules that serves as a bridge between physicians and patients and is also a cutting-edge tool for pre-diagnosis and prognostic evaluation. Many AI-driven pulmonary nodule detection and recognition methods employ deep learning techniques to capture the radiological features of pulmonary nodules, and these methods can achieve a good area under-the-curve (AUC) performance. However, false positives and false negatives remain a challenge for radiologists and clinicians. The interpretation and expression of features from the perspective of pulmonary nodule classification and examination are still unsatisfactory. In this study, a method of continuous 3D reconstruction of the whole lung in horizontal and coronal positions is proposed by combining existing medical image processing technologies. Compared with other applicable methods, this method allows users to rapidly locate pulmonary nodules and identify their fundamental properties while also observing pulmonary nodules from multiple perspectives, thereby providing a more effective clinical tool for diagnosing and treating pulmonary nodules.

Identification and Quantification of Organic Contaminants and Evaluation of Their Effects on Amine Foaming in the Natural Gas Sweetening Industry.

Contamination is a leading cause of corrosion, foaming, and amine-absorption capacity limitation, predominantly foaming. There is currently an urgent need to identify the sources of amine foaming and eliminate them or reduce their impacts. Gas chromatography-mass spectrometry (GC-MS) and a sample pretreatment method were developed to identify and quantify the organic contaminants. Linear hydrocarbons (C12-C22), long-chain carboxylic acids and esters, alcohol ethoxylates, and benzene derivatives were detected, characterized, and quantified in amine solutions. Furthermore, the effects of the contaminant concentrations on foaming behavior were also investigated by adding those contaminants. The results reveal that the main issue of foaming is due to the presence of unsaturated fatty acids and alcohol ethoxylates, even with a small amount of 10 ppm, whereas benzene derivatives like methylpyridine, quinoline, methyl naphthalene, benzyl alcohol, octahydroacridine, and linear hydrocarbons have little effect on amine foaming, even with an amount up to 2000 ppm. Therefore, it is necessary to monitor the existence and content of these surface-active contaminants.

Unraveling the impact of Lactobacillus spp. and other urinary microorganisms on the efficacy of mirabegron in female patients with overactive bladder.

Objective: Overactive bladder (OAB) is a disease that seriously affects patients' quality of life and mental health. To address this issue, more and more researchers are examining the relationship between OAB treatment and urinary microecology. In this study, we sought to determine whether differences in treatment efficacy were related to microbiome diversity and composition as well as the abundance of specific genera. Machine learning algorithms were used to construct predictive models for urine microbiota-based treatment of OAB. Methods: Urine samples were obtained from 64 adult female OAB patients for 16S rRNA gene sequencing. Patients' overactive bladder symptom scores (OABSS) were collected before and after mirabegron treatment and patients were divided into effective and ineffective groups. The relationship between the relative abundance of certain genera and OABSS were analyzed. Three machine learning algorithms, including random forest (RF), supporting vector machine (SVM) and eXtreme gradient boosting (XGBoost) were utilized to predict the therapeutic effect of mirabegron based on the relative abundance of certain genera in OAB patients' urine microbiome. Results: The species composition of the two groups differed. For one, the relative abundance of Lactobacillus was significantly higher in the effective group than in the ineffective group. In addition, the relative abundance of Gardnerella and Prevotella in the effective group was significantly lower than in the ineffective group. Alpha-diversity and beta-diversity differed significantly between the two groups. LEfSe analysis revealed that Lactobacillus abundance increased while Prevotella and Gardnerella abundance decreased in the effective group. The Lactobacillus abundance ROC curve had high predictive accuracy. The OABSS after treatment was negatively correlated with the abundance of Lactobacillus, whereas the relationship between OABSS and Prevotella and Gardnerella showed the opposite trend. In addition, RF, SVM and XGBoost models demonstrated high predictive ability to assess the effect of mirabegron in OAB patients in the test cohort. Conclusions: The results of this study indicate that urinary microbiota might influence the efficacy of mirabegron, and that Lactobacillus might be a potential marker for evaluating the therapeutic efficacy of mirabegron in OAB patients.

Efficient Pathogen Capture and Sensing Promoted by Dynamic Deformable Nanointerfaces.

The M13 bacteriophage (M13 phage) has emerged as an attractive bionanomaterial due to its chemistry/gene modifiable feature and unique structures. Herein, a dynamic deformable nanointerface is fabricated taking advantage of the unique feature of the M13 phage for ultrasensitive detection of pathogens. PIII proteins at the tip of the M13 phage are genetically modified to display 6His peptide for site-specific anchoring onto Ni-NTA microbeads, whereas pVIII proteins along the side of the M13 phage are orderly arranged with thousands of aptamers and their complementary strands (c-apt). The flexible M13 nanofibers with rich recognition sites act as octopus tentacles, resulting in a 19-fold improvement in the capture affinity toward the target. The competitive binding of the target pathogen releases c-apts and initiates rolling circle amplification (RCA). The sway motion of M13 nanofibers accelerates the diffusion of c-apts, thus promoting RCA efficiency. Benefiting from the strengthened capture ability toward the target and the accelerated RCA process, three-orders of magnitude improvement in the sensitivity is achieved, with a detection limit of 8 cfu mL-1 for Staphylococcus aureus. The promoted capture ability and assay performance highlights the essential role of the deformable feature of the engineered interface. This may provide inspiration for the construction of more efficient reaction interfaces.

Musashi-1 and miR-147 Precursor Interaction Mediates Synergistic Oncogenicity Induced by Co-Infection of Two Avian Retroviruses.

Synergism between avian leukosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV) has been reported frequently in co-infected chicken flocks. Although significant progress has been made in understanding the tumorigenesis mechanisms of ALV and REV, how these two simple oncogenic retroviruses induce synergistic oncogenicity remains unclear. In this study, we found that ALV-J and REV synergistically promoted mutual replication, suppressed cellular senescence, and activated epithelial-mesenchymal transition (EMT) in vitro. Mechanistically, structural proteins from ALV-J and REV synergistically activated the expression of Musashi-1(MSI1), which directly targeted pri-miR-147 through its RNA binding site. This inhibited the maturation of miR-147, which relieved the inhibition of NF-κB/KIAA1199/EGFR signaling, thereby suppressing cellular senescence and activating EMT. We revealed a synergistic oncogenicity mechanism induced by ALV-J and REV in vitro. The elucidation of the synergistic oncogenicity of these two simple retroviruses could help in understanding the mechanism of tumorigenesis in ALV-J and REV co-infection and help identify promising molecular targets and key obstacles for the joint control of ALV-J and REV and the development of clinical technologies.

Hybrid Ag nanoparticles/polyoxometalate-polydopamine nano-flowers loaded chitosan/gelatin hydrogel scaffolds with synergistic photothermal/chemodynamic/Ag+ anti-bacterial action for accelerated wound healing.

Bacterial infections significantly slow the wound healing process, thus severely threatening human health. Furthermore, traditional antibiotics may promote the development of multidrug-resistant bacteria. Therefore, developing novel bactericides and therapeutic strategies for bacterial infections is important to enhance wound healing. Herein, a three-in-one bactericidal flower-like nanocomposite was assembled using Ag nanoparticles/phosphotungstic acid-polydopamine nano-flowers (AgNPs/POM-PDA). The nanocomposite exhibited photothermal therapy (PTT) when exposed to NIR light via photothermal conversion by PDA. The resultant photothermal effect accelerated and controlled the Ag+ released from AgNPs. The chemodynamic therapy (CDT) was obtained via POM catalytic Fenton-like reaction. The combined PTT/CDT/Ag+ treatment achieved excellent synergistic anti-bacterial activity against both gram-negative E. coli and gram-positive S. aureus. A multifunctional wound dressing was then obtained by embedding the AgNPs/POM-PDA flower-like nanocomposite into the chitosan (CS)/gelatin (GE) biocomposite hydrogel. The synergy of AgNPs/POM-PDA nanocomposites and CS/GE hydrogel remarkably accelerated wound healing in vivo due to the excellent biocompatibility, hydroabsorptivity, and breathability of the hydrogel. In this study, a multifunctional agent was developed to synergistically combat bacterial infections and accelerate wound healing.

RIOK3-Mediated Akt phosphorylation facilitates synergistic replication of Marek's disease and reticuloendotheliosis viruses.

Co-infection of Marek's disease virus (MDV) and reticuloendotheliosis virus (REV) synergistically drives disease progression, yet little is known about the mechanism of the synergism. Here, we found that co-infection of REV and MDV increased their replication via the RIOK3-Akt pathway. Initially, we noticed that the viral titres of MDV and REV significantly increased in REV and MDV co-infected cells compared with single-infected cells. Furthermore, tandem mass tag peptide labelling coupled with LC/MS analysis showed that Akt was upregulated in REV and MDV co-infected cells. Overexpression of Akt promoted synergistic replication of MDV and REV. Conversely, inhibition of Akt suppressed synergistic replication of MDV and REV. However, PI3K inhibition did not affect synergistic replication of MDV and REV, suggesting that the PI3K/Akt pathway is not involved in the synergism of MDV and REV. In addition, we revealed that RIOK3 was recruited to regulate Akt in REV and MDV co-infected cells. Moreover, wild-type RIOK3, but not kinase-dead RIOK3, mediated Akt phosphorylation and promoted synergistic replication of MDV and REV. Our results illustrate that MDV and REV activated a novel RIOK3-Akt signalling pathway to facilitate their synergistic replication.

Differential MC5R loss in whales and manatees reveals convergent evolution to the marine environment.

Melanocortin 5 receptor (MC5R), which is expressed in the terminally differentiated sebaceous gland, is a G protein-coupled receptor (GPCR). MC5R exists mostly in mammals but is completely lost in whales; only the relic of MC5R can be detected in manatees, and phenotypically, they have lost sebaceous glands. Interestingly, whales and manatees are both aquatic mammals but have no immediate common ancestors. The loss of MC5R and sebaceous glands in whales and manatees is likely to be a result of convergent evolution. Here, we find that MC5R in whales and manatees are lost by two different mechanisms. Homologous recombination of MC5R in manatees and the insertion of reverse transcriptase in whales lead to the gene loss, respectively. On one hand, in manatees, there are two "TTATC" sequences flanking MC5R, and homologous recombination of the segments between the two "TTATC" sequences resulted in the partial loss of the sequence of MC5R. On the other hand, in whales, reverse transcriptase inserts between MC2R and RNMT on the chromosome led to the loss of MC5R. Based on these two different mechanisms for gene loss in whales and manatees, we finally concluded that MC5R loss might be the result of convergent evolution to the marine environment, and we explored the impact on biological function that is significant to environmental adaptation.

The influence of a biomimetic pulmonary surfactant modification on the in vivo fate of nanoparticles in the lung.

Direct biomimetic modification of nanoparticles (NPs) with endogenous surfactants is helpful to improve the biocompatibility of NPs and avoid damage to the physiological function of the lung. Therefore, the objective of this study is to investigate the influence of biomimetic endogenous pulmonary surfactant phospholipid modification on the in vivo fate of NPs after lung delivery. Here, two neutral phospholipids (dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylamine (DPPE)) and two negatively charged phospholipids (dipalmitoylphosphatidylglycerol (DPPG), dipalmitoylphosphatidylserine (DPPS)) were selected to modify paclitaxel (PTX)-loaded PLGA NPs with different molar ratio. DPPC, DPPE, and DPPG improved mucoadhesion, in contrast, DPPS improved the mucus permeability of the NPs. Neutral DPPC and DPPE reduced, but negatively charged DPPS and DPPG increased the uptake by alveolar macrophages, all types of phospholipid increased the uptake by lung epithelial cells and increased PTX retention in the whole lung. Whereas, DPPC, DPPE, and DPPG promoted PTX retention in bronchoalveolar lavage fluid (BALF), while DPPS promoted PTX absorption in the lung tissue. Only DPPS-PLGA (1:1) NPs remarkably increased PTX systemic exposure. A good correlation between PTX percentage in the supernatant of BALF and PTX concentration in plasma was established, implying PTX entered the system circulation mainly in molecular form. Phospholipid modification had no effect on extrapulmonary organ distribution of PTX. Taken together, our study disclosed that different phospholipid modification can endow the NPs mucoadhesive or mucus penetration and cellular uptake properties, with tunable retention in BALF and absorption in the lung tissue, providing the scientific background for translational nanocarrier design for inhalation as required. STATEMENT OF SIGNIFICANCE: Inhaled nanomedicines will inevitably interact with pulmonary surfactant and form "surfactant corona". However, the contribution of individual pulmonary surfactant phospholipid on the in vivo fate of nanomedicines is still unclear. In this regard, the most abundant pulmonary surfactant phospholipid dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylamine, and dipalmitoylphosphatidylglycerol and dipalmitoylphosphatidylserine were selected to modify the paclitaxel loaded PLGA nanoparticles and the effect of these pulmonary surfactant phospholipids on their in vivo fate was investigated. It was demonstrated that different phospholipid modification can endow the nanoparticles mucoadhesive or mucus penetration properties, with tunable retention in bronchoalveolar lavage fluid, alveolar macrophages uptake and absorption in the lung tissue. The present study provided a comprehensive understanding for the role of pulmonary surfactant phospholipid on inhaled nanomedicines.