Rosacea is a common chronic inflammatory skin disease that predominantly affects the central face. It can impair appearance and cause various discomforts, thus negatively impacting patients' physical and mental well-being as well as their quality of life. Its pathophysiological mechanisms involve multiple factors. Studies have confirmed that ultraviolet radiation plays a significant role in the pathogenesis of rosacea, affecting skin tissues, cells, DNA, and proteins, and inducing oxidative damage. Ultraviolet can lead to the occurrence and development of rosacea by up-regulating the expression of LL-37, matrix metalloproteinase, vascular endothelial growth factor, and reactive oxygen species, and influence their interactions, thereby triggering inflammatory responses, altering the dermal matrix, and promoting capillary dilation and neovascularization, which contribute to the onset and progression of rosacea. Exploring the role of ultraviolet in the pathogenesis of rosacea can provide new strategies for protection and treatment, and enhance awareness of ultraviolet protection among patients with rosacea.
Humans ; Rosacea/metabolism* ; Ultraviolet Rays/adverse effects* ; Cathelicidins ; Reactive Oxygen Species/metabolism* ; Antimicrobial Cationic Peptides/metabolism* ; Matrix Metalloproteinases/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Skin/metabolism*

Porcine reproductive and respiratory syndrome (PRRS), caused by the porcine reproductive and respiratory syndrome virus (PRRSV), is one of the major diseases threatening the swine industry. This study aims to rationally design and optimize natural antimicrobial peptides to identify antiviral candidates with potent inhibitory activity against PRRSV, thereby establishing a foundation for the development of novel preventive and therapeutic agents targeting PRRS. In this study, with cecropin D (CD) as the parent peptide, three derivatives (CD-2, CD-3, and CD-4) were designed through amino acid substitutions. CD and derived peptides were obtained by solid-phase peptide synthesis. MS and reversed-phase (RP)-HPLC were employed for sequence identification, purification, and purity analysis. The secondary structures of the peptides were investigated by circular dichroism spectroscopy. CellTiter 96^® AQueous one solution cell proliferation assay was used to evaluate the cytotoxicity of the peptides. The inhibitory activities and mechanisms of the peptides against PRRSV were studied by Western blotting, RT-qPCR, and indirect immunofluorescence assay. The MS and RP-HPLC results showed that CD and derived peptides were successfully synthesized, with the purity reaching up to 95%. Circular dichroism analysis revealed that the CD derivatives exhibited more stable and abundant α-helices in a cell membrane-mimicking environment. The MTS assay indicated that all tested peptides at 100 μg/mL had negligible cytotoxicity. The experimental results of the action phase of the peptide against PRRSV demonstrated that the derived peptides significantly enhanced antiviral activities at the viral entry stage compared with the parent peptide. This enhancement was attributed to the introduction of lysine, tryptophan, and phenylalanine, which increased the hydrophobicity and positive charge of the peptides. These findings provide a theoretical basis for the application and structural optimization of antiviral peptides and may offer a new strategy for preventing and controlling PRRSV.
Porcine respiratory and reproductive syndrome virus/physiology* ; Animals ; Swine ; Antiviral Agents/chemistry* ; Porcine Reproductive and Respiratory Syndrome/virology* ; Virus Internalization/drug effects* ; Antimicrobial Peptides/chemistry*

Bacillus is a class of spore-producing Gram-positive bacteria that produce a variety of antimicrobial substances with different structures and functions. The application of the antimicrobial substances produced by Bacillus can effectively inhibit the activity of harmful bacteria and fungi and promote the sustainable development of green agriculture. The antimicrobial substances produced by Bacillus mainly include proteins, lipopeptides, polyketones, and polypeptides. This paper reviews the synthesis gene clusters, synthesis pathways, structures, and mechanisms of various antimicrobial substances produced by Bacillus and discusses the challenges in the industrial application of these antimicrobial substances. Furthermore, this paper clarifies the future research and development focuses and prospects the application prospects, and provides comprehensive theoretical support for the in-depth research and wide application of the antimicrobial substances produced by Bacillus.
Bacillus/genetics* ; Anti-Infective Agents/metabolism* ; Bacterial Proteins/genetics* ; Antimicrobial Peptides/biosynthesis* ; Lipopeptides/biosynthesis*

OBJECTIVES: To investigate the expression levels of ghrelin and liver-expressed antimicrobial peptide-2 (LEAP-2) in children with idiopathic short stature (ISS) to provide reference for further understanding the etiology of short stature. METHODS: A prospective study was conducted from December 2021 to October 2023, involving 46 children diagnosed with ISS (ISS group) and 46 healthy children with normal height (control group) at the First Affiliated Hospital of Shihezi University. General data and serum levels of ghrelin and LEAP-2 were compared between the two groups. The predictive value of these two indicators for ISS was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: The serum level of ghrelin in the ISS group was higher than that in the control group, while the level of LEAP-2 was lower (P<0.05). The ratio of LEAP-2 to ghrelin was lower in the ISS group compared to the control group (P<0.05). Multivariate logistic regression analysis showed that HtSDS, IGF-1, ghrelin, LEAP-2, and the ratio of LEAP-2/ghrelin were independently associated with the occurrence of ISS (P<0.05). ROC curve analysis indicated that the AUCs for ghrelin, LEAP-2, the ratio of ghrelin to LEAP-2, and their combination in predicting ISS were all >0.8. The optimal cutoff values for ghrelin, LEAP-2, and the LEAP-2/ghrelin ratio were 5 607 pg/mL, 1 155 pg/mL, and 0.212, respectively. In children with ISS, ghrelin showed a negative correlation with chronological age, LEAP-2, and the LEAP-2/ghrelin ratio (P<0.05), while it was positively correlated with growth rate and peak growth hormone levels (P<0.05). LEAP-2 was negatively correlated with growth rate, peak growth hormone levels, and ghrelin (P<0.05), but positively correlated with chronological age and the LEAP-2/ghrelin ratio (P<0.05). CONCLUSIONS Ghrelin and LEAP-2 are correlated with the occurrence of ISS, which may provide references for the diagnosis and etiological analysis of children with ISS.
Humans ; Ghrelin/blood* ; Male ; Child ; Female ; Prospective Studies ; Child, Preschool ; Growth Disorders/etiology* ; Antimicrobial Cationic Peptides/blood* ; Body Height ; Adolescent ; Insulin-Like Growth Factor I/analysis* ; Blood Proteins

OBJECTIVE: To evaluate the predictive value of plasma heparin-binding protein (HBP) combined with albumin (Alb) for predicting 28-day mortality in patients with sepsis. METHODS: The clinical data of patients with sepsis admitted to the emergency intensive care unit (EICU) of the People's Hospital of Shenzhen Baoan District from March 2020 to March 2024 were retrospectively analyzed. The study began at the time of the first diagnosis of sepsis upon EICU admission and ended upon patient death or at 28 days. The gender, age, length of stay in EICU, underlying diseases, and infection sites were recorded. Within 24 hours of sepsis diagnosis, blood culture results, white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT), blood lactate acid (Lac), HBP, Alb, sequential organ failure assessment (SOFA), acute physiology and chronic health evaluation II (APACHE II), mortality in emergency department sepsis score (MEDS), modified early warning score (MEWS), number of organ failures, use of vasopressors, application of mechanical ventilation, renal replacement therapy, and 28-day prognosis were recorded, the differences in these indicators between two groups were compared. Univariate and multivariate Logistic regression analyses were used to analyze the risk factors of 28-day mortality in patients with sepsis. Receiver operator characteristic curve (ROC curve) was drawn, and the area under the ROC curve (AUC) was calculated to evaluate the early predictive value of various risk factors for 28-day mortality in patients with sepsis. RESULTS: A total of 300 patients with sepsis were included, with 16 excluded, resulting in 284 patients being analyzed. Among them, 191 survived and 93 died within 28 days. There were no statistically significant differences between the two groups in terms of gender, age, underlying diseases, infection sites, blood culture positivity rate, number of organ failures, and length of stay in EICU. Univariate analysis showed that the rate of vasopressor use, the rate of mechanical ventilation, HBP, PCT, CRP, Lac, SOFA score, APACHE II score, MEDS score, and MEWS score were significantly higher in the death group than those in the survival group, while Alb was significantly lower in the death group than that in the survival group. Multivariate Logistic regression analysis showed that HBP and Alb were independent risk factors for predicting 28-day mortality in patients with sepsis [odds ratio (OR) and 95% confidence interval (95%CI) were 1.093 (0.989-1.128) and 1.174 (1.095-1.259), both P < 0.05]. ROC curve analysis showed that both HBP and Alb had certain predictive value for 28-day mortality in patients with sepsis [AUC and 95%CI were 0.820 (0.717-0.923) and 0.786 (0.682-0.890), both P < 0.05]. When the critical value of HBP was 117.50 μg/L, the sensitivity was 85.90%, and the specificity was 70.50%. When the critical value of Alb was 28.30 g/L, the sensitivity was 69.30%, and the specificity was 81.20%. When the two indexes were combined for diagnosis, the AUC was 0.881 (95%CI was 0.817-0.945, P < 0.001), the sensitivity was 92.70%, and the specificity was 76.80%. CONCLUSIONS HBP and Alb are independent risk factors for predicting 28-day mortality in patients with sepsis. The combined prediction efficiency of HBP and Alb for 28-day mortality in patients with sepsis is superior to a single indicator.
Humans ; Sepsis/diagnosis* ; Retrospective Studies ; Predictive Value of Tests ; Intensive Care Units ; Blood Proteins/analysis* ; Prognosis ; Antimicrobial Cationic Peptides/blood* ; APACHE ; Male ; Female ; Organ Dysfunction Scores ; ROC Curve ; Middle Aged ; C-Reactive Protein/analysis* ; Emergency Service, Hospital ; Aged ; Hospital Mortality ; Serum Albumin/analysis*

Antimicrobial peptides (AMPs) are small molecular peptides widely existing in the innate immunity of organisms, serving as the first line of defense. Natural AMPs possess various biological activities and are difficult to develop drug resistance. However, they are easily broken down by digestive enzymes in the body. In recent years, increasing methods have been reported to enhance the stability of AMPs, including incorporation of unnatural amino acids, chemical modifications, strategic avoidance of enzyme cleavage sites, cyclization, and nano peptide design. This review summarizes the methods for improving the stability of AMPs against protease degradation, aiming to provide references for further research in this field.
Antimicrobial Peptides/pharmacology* ; Humans ; Peptide Hydrolases/metabolism* ; Protein Stability ; Antimicrobial Cationic Peptides/chemistry* ; Anti-Infective Agents/chemistry*

Antimicrobial peptides (AMPs) are small molecule peptides that are widely found in living organisms with broad-spectrum antibacterial activity and immunomodulatory effect. Due to slower emergence of resistance, excellent clinical potential and wide range of application, AMP is a strong alternative to conventional antibiotics. AMP recognition is a significant direction in the field of AMP research. The high cost, low efficiency and long period shortcomings of the wet experiment methods prevent it from meeting the need for the large-scale AMP recognition. Therefore, computer-aided identification methods are important supplements to AMP recognition approaches, and one of the key issues is how to improve the accuracy. Protein sequences could be approximated as a language composed of amino acids. Consequently, rich features may be extracted using natural language processing (NLP) techniques. In this paper, we combine the pre-trained model BERT and the fine-tuned structure Text-CNN in the field of NLP to model protein languages, develop an open-source available antimicrobial peptide recognition tool and conduct a comparison with other five published tools. The experimental results show that the optimization of the two-phase training approach brings an overall improvement in accuracy, sensitivity, specificity, and Matthew correlation coefficient, offering a novel approach for further research on AMP recognition.
Anti-Bacterial Agents/chemistry* ; Amino Acid Sequence ; Antimicrobial Cationic Peptides/chemistry* ; Antimicrobial Peptides ; Natural Language Processing

This study constructed a nano-drug delivery system, A3@GMH, by co-delivering the stapled anoplin peptide(Ano-3, A3) with the light-harvesting material graphene oxide(GO), and evaluated its oncolytic immunotherapy effect on triple-negative breast cancer(TNBC). A3@GMH was prepared using an emulsion template method and its physicochemical properties were characterized. The in vivo and in vitro photothermal conversion abilities of A3@GMH were investigated using an infrared thermal imager. The oncoly-tic activity of A3@GMH against TNBC 4T1 cells was evaluated through cell counting kit-8(CCK-8), lactate dehydrogenase(LDH) release, live/dead cell staining, and super-resolution microscopy. The targeting properties of A3@GMH on 4T1 cells were assessed using a high-content imaging system and flow cytometry. In vitro and in vivo studies were conducted to investigate the antitumor mechanism of A3@GMH in combination with photothermal therapy(PTT) through inducing immunogenic cell death(ICD) in 4T1 cells. The results showed that the prepared A3@GMH exhibited distinct mesoporous and coated structures with an average particle size of(308.9±7.5) nm and a surface potential of(-6.79±0.58) mV. The encapsulation efficiency and drug loading of A3 were 23.9%±0.6% and 20.5%±0.5%, respectively. A3@GMH demonstrated excellent photothermal conversion ability and biological safety. A3@GMH actively mediated oncolytic features such as 4T1 cell lysis and LDH release, as well as ICD effects, and showed enhanced in vitro antitumor activity when combined with PTT. In vivo, A3@GMH efficiently induced ICD effects with two rounds of PTT, activated the host's antitumor immune response, and effectively suppressed tumor growth in 4T1 tumor-bearing mice, achieving an 88.9% tumor inhibition rate with no apparent toxic side effects. This study suggests that the combination of stapled anoplin peptide and PTT significantly enhances the oncolytic immunotherapy for TNBC and provides a basis for the innovative application of anti-tumor peptides derived from TCM in TNBC treatment.
Humans ; Animals ; Mice ; Photothermal Therapy ; Triple Negative Breast Neoplasms/pathology* ; Antimicrobial Cationic Peptides ; Immunotherapy/methods* ; Cell Line, Tumor ; Phototherapy/methods* ; Nanoparticles/chemistry*

Candida albicans is one of the major causes of invasive fungal infections and a serious opportunistic pathogen in immunocompromised individuals. The antimicrobial peptide AMP-17 has prominent anti-Candida activity, and proteomic analysis revealed significant differences in the expression of cell wall (XOG1) and oxidative stress (SRR1) genes upon the action of AMP-17 on C. albicans, suggesting that AMP-17 may exert anti-C. albicans effects by affecting the expression of XOG1 and SRR1 genes. To further investigate whether XOG1 and SRR1 genes were the targets of AMP-17, C. albicans xog1Δ/Δ and srr1Δ/Δ mutants were constructed using the clustered regulatory interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9) system. Phenotypic observations revealed that deletion of two genes had no significant effect on C. albicans growth and biofilm formation, whereas XOG1 gene deletion affected in vitro stress response and mycelium formation of C. albicans. Drug sensitivity assay showed that the MIC₈₀ values of AMP-17 against xog1Δ/Δ and srr1Δ/Δ mutants increased from 8 μg/mL (for the wild type C. albicans SC5314) to 16 μg/mL, while the MIC₈₀ values against srr1Δ/Δ: : srr1 revertants decreased to the level of the wild type SC5314. In addition, the ability of AMP-17 to inhibit biofilm formation of both deletion strains was significantly reduced compared to that of wild type SC5314, indicating that the susceptibility of the deletion mutants to AMP-17 was reduced in both the yeast state and during biofilm formation. These results suggest that XOG1 and SRR1 genes are likely two of the potential targets for AMP-17 to exert anti-C. albicans effects, which may facilitate further exploration of the antibacterial mechanism of novel peptide antifungal drugs.
Humans ; Candida albicans ; Antimicrobial Peptides ; Proteomics ; Peptides/pharmacology* ; Transcription Factors/metabolism* ; Antifungal Agents/pharmacology*

Objective: To fabricate TiO₂ nanotube material functionalized by antimicrobial peptide LL-37, and to explore its effects on biological behaviors such as adhesion and migration of human keratinocytes (HaCaT) and its antibacterial properties. Methods: The TiO₂ nanotube array (NT) was constructed on the surface of polished titanium (PT) by anodization, and the antimicrobial peptide LL-37 was loaded on the surface of TiO₂ nanotube (LL-37/NT) by physical adsorption. Three samples were selected by simple random sampling in each group. Surface morphology, roughness, hydrophilicity and release characteristics of LL-37 of the samples were analyzed with a field emission scanning electron microscope, an atomic force microscope, a contact angle measuring device and a microplate absorbance reader. HaCaT cells were respectively cultured on the surface of three groups of titanium samples. Each group had 3 replicates. The morphology of cell was observed by field emission scanning electron microscope. The number of cell adhesion was observed by cellular immunofluorescence staining. Cell counting kit-8 (CCK-8) assay was used to detect cell proliferation. Wound scratch assay was used to observe the migration of HaCaT. The above experiments were used to evaluate the effect of each group on the biological behavior of HaCaT cells. To evaluate their antibacterial effects, Porphyromonas gingivalis (Pg) was respectively inoculated on the surface of three groups of titanium samples. Each group had 3 replicates. The morphology of bacteria was observed by field emission scanning electron microscope. Bacterial viability was determined by live/dead bacterial staining. Results: A uniform array of nanotubes could be seen on the surface of titanium samples in LL-37/NT group, and the top of the tube was covered with granular LL-37. Compared with PT group [the roughness was (2.30±0.18) nm, the contact angle was 71.8°±1.7°], the roughness [(20.40±3.10) and (19.10±4.11) nm] and hydrophilicity (the contact angles were 22.4°±3.1° and 25.3°±2.2°, respectively) of titanium samples increased in NT and LL-37/NT group (P<0.001). The results of in vitro release test showed that the release of antimicrobial peptide LL-37 was characterized by early sudden release (1-4 h) and long-term (1-7 d) slow release. With the immunofluorescence, more cell attachment was found on NT and LL-37/NT than that on PT at the first 0.5 and 2.0 h of culture (P<0.05). The results of CCK-8 showed that there was no significant difference in the proliferation of cells among groups at 1, 3 and 5 days after culture. Wound scratch assay showed that compared with PT and NT group, the cell moved fastest on the surface of titanium samples in LL-37/NT group at 24 h of culture [(96.4±4.9)%] (F=35.55, P<0.001). A monolayer cells could be formed and filled with the scratch in 24 h at LL-37/NT group. The results of bacterial test in vitro showed that compared with the PT group, the bacterial morphology in the NT and LL-37/NT groups was significantly wrinkled, and obvious bacterial rupture could be seen on the surface of titanium samples in LL-37/NT group. The results of bacteria staining showed that the green fluorescence intensity of titanium samples in LL-37/NT group was the lowest in all groups (F=66.54,P<0.001). Conclusions: LL-37/NT is beneficial to the adhesion and migration of HaCaT cells and has excellent antibacterial properties, this provides a new strategy for the optimal design of implant neck materials.
Humans ; Titanium/chemistry* ; Antimicrobial Peptides ; Cathelicidins ; Sincalide ; Anti-Bacterial Agents/pharmacology* ; Nanotubes/chemistry* ; Dental Materials ; Bacteria ; Keratinocytes ; Surface Properties