Our previous research found that the poor stability of the antimicrobial peptide Feleucin-K3 (FK3) had limited its transition into clinical application. Herein, we developed a series of FK3 derivatives stapled by all-hydrocarbon and thioether to enhance the stability and then implemented an amino acid substitution strategy to reduce the hemolytic toxicity. Consequently, after replacing the first phenylalanine of FK3 with alanine and conducting (i, i + 4) all-hydrocarbon stapling with (S)-2-(4-pentenyl) alanine at the 5,9-position, analog S1-1A displayed the highest therapeutic index, high stability, and potent antimicrobial effects against multidrug-resistant (MDR) bacteria as well as antibiofilm properties. A striking finding was that S1-1A exhibited 8-fold greater antimicrobial activity against resistant strains of Staphylococcus aureus than vancomycin. The efficacy of S1-1A in vivo was as effective as vancomycin in the skin wound infection model. Overall, stapled peptide S1-1A showed promising potential for being developed into a novel drug for combating MDR bacterial infections.

Pulmonary fibrosis is a common pathological outcome of various lung diseases, and therapeutic options limited. In view of the anti-inflammatory activity of antimicrobial peptides and the role of inflammation in pulmonary fibrosis, herein, we investigated the therapeutic potential of the antimicrobial peptide YD against pulmonary fibrosis for the first time. To improve its druggability, the structure of YD was optimized. Based on alanine scanning and cleavage site mapping, YD was truncated and modified with unnatural amino acids, thereby significantly enhancing its stability. Cyclization further improved its pharmacokinetic profile and in vivo efficacy. The optimized cyclic peptide CYP9 potently inhibited myofibroblast activation, epithelial-mesenchymal transition, and extracellular matrix synthesis at nanomolar concentrations. It exhibited an extended half-life and the ultralow effective dose of 0.02 mg/kg. Mechanistic studies revealed CYP9 effectively inhibits the TGF-β/Smad and MAPK signaling pathway. This study identifies the peptide CYP9 as a promising candidate for treating pulmonary fibrosis.

Biofilm-related infections pose a growing global health threat and demand novel therapeutic agents. Although Daptomycin is effective against Gram-positive bacteria and biofilms, the emergence of resistant strains necessitates next-generation derivatives. Herein, a library of aryl-Daptomycin was successfully constructed by postmodification of Daptomycin at the tryptophan residue. The lead compound 1i exhibited improved antibacterial activity, antibiofilm efficacy, and stability compared with Daptomycin, and also showed rapid killing of both planktonic and persister cells. In vivo studies, 1i significantly reduced drug-resistant bacterial counts and biofilm burdens in mouse models of skin wound infection and catheter-related biofilm infection. Mechanistic studies revealed that it exerts antibacterial activity by inducing membrane depolarization and disruption, while it inhibits biofilm formation by downregulating the ica gene and blocking the agr system. Moreover, molecular dynamics simulations confirmed the higher tetrameric stability of 1i compared with Daptomycin. Collectively, 1i represents a promising candidate for clinical treatment of bacterial infections.

The emergence of multidrug-resistant bacteria poses a significant threat to modern medical practices and human health, creating an urgent demand for novel antibacterial agents. Inspired by host-defense peptides (HDPs), herein we employed fatty acid acylation to fine-tune the amphiphilic balance of cysteine-based amphiphilic compounds, synthesizing a series of antimicrobial peptidomimetics and evaluating their antimicrobial activity. Among them, 10c stood out due to its broad-spectrum antimicrobial activity against both Gram-positive and Gram-negative bacteria, as well as its low hemolytic activity. Like HDPs, it rapidly killed bacteria primarily via a membrane-disruptive action mode, with a low propensity to induce bacterial resistance. Additionally, its ease of synthesis, serum stability, and ability to address some of the challenges HDPs face in different physiological conditions may enhance its clinical applications. Importantly, 10c demonstrated significant therapeutic potential in mouse models of MRSA-induced pneumonia and keratitis. Overall, the present study provides new therapeutic strategies and identifies a potential lead compound for addressing antibiotic-resistant bacteria, offering novel insights for the development of next-generation antibacterial agents.

Renal fibrosis, resulting from myofibroblast-mediated excessive extracellular matrix (ECM) deposition, lacks effective treatments. Novel peptide DR3penA developed by our group showed therapeutic potential for fibrotic diseases; however, its application was hindered by poor stability and bioavailability. To address this unmet need, we implemented stepwise optimization of DR3penA. The conformationally restricted analogs designed via structural predictions enhanced both activity and stability. Through structure-activity relationship analysis and cleavage site mapping, introducing unnatural amino acids improved stability. Fatty acid modifications conferred fibroblast-selective cytotoxicity and improved pharmacokinetics. After several rounds of progressive modification, peptide 27 exhibited remarkable stability, with a 5.68-fold extended half-life compared to DR3penA. Following profibrotic stimuli, peptide 27 effectively inhibited myofibroblast activation, epithelial-mesenchymal transition, and ECM synthesis. It also attenuated renal fibrosis in a unilateral ureteral obstruction model. Our study leverages multiple modifications that integrate cell and animal models to identify peptide 27 as a promising candidate for renal fibrosis therapy.

De novo design of antimicrobial peptides (AMPs) offers a promising strategy to overcome the limitations of natural AMPs through rational design, providing potential solutions to address the growing risk of traditional antibiotic resistance. In this study, a series of new AMPs are generated using the α-helical template (XXFY)n and its β-sheet counterpart (KFKY)n (X = Lys, Dab, Orn, or Arg; F = Phe; Y = Leu, Ile, Phe, or Trp; K = Lys; n = 2, 3, 4, or 5), enabling a systematic investigation of their structure-activity relationships (SAR). The optimal peptide 27, designated as (OOFI)4 (O = Orn, I = Ile), demonstrates potent broad-spectrum antimicrobial activity against both standard and multidrug-resistant bacterial strains, along with low hemolytic toxicity. Furthermore, 27 exhibits a low propensity for inducing resistance, rapid bactericidal effects, robust membrane-disrupting activity, and immunomodulatory activity. Notably, peptide 27 also shows remarkable efficacy in treating multidrug-resistant P. aeruginosa 124-induced lung infections and MRSA-induced skin infections in murine models. In conclusion, the SAR analysis in this study offers novel insights into template-based AMP design, and the newly developed peptide 27 emerges as a promising candidate for treating clinically relevant drug-resistant bacterial infections.

Despite the great advances in target therapy, lung cancer remains the top cause of cancer-related death worldwide. G protein-coupled receptor neurokinin-1 (NK1R) is shown to play multiple roles in various cancers; however, the pathological roles and clinical implication in lung cancer are unclarified. Here we identified NK1R as a significantly upregulated GPCR in the transcriptome and tissue array of human lung cancer samples, associated with advanced clinical stages and poor prognosis. Notably, NK1R is co-expressed with epidermal growth factor receptor (EGFR) in NSCLC patients’ tissues and co-localized in the tumor cells. NK1R can crosstalk with EGFR by interacting with EGFR, transactivating EGFR phosphorylation and regulating the intracellular signaling of ERK1/2 and Akt. Activation of NK1R promotes the proliferation, colony formation, EMT, MMP2/14 expression, and migration of lung cancer cells. The inhibition of NK1R by selective antagonist aprepitant repressed cell proliferation and migration in vitro. Knockdown of NK1R significantly slowed down the tumor growth in nude mice. The sensitivity of lung cancer cells to gefitinib/osimertinib is highly increased in the presence of the selective NK1R antagonist aprepitant. Our data suggest that NK1R plays an important role in lung cancer development through EGFR signaling and the crosstalk between NK1R and EGFR may provide a potential therapeutic target for lung cancer treatment.

The peptide CPF-7, developed by our group previously, is a modified analog of the natural antimicrobial peptide CPF-C1, which demonstrated increased antibacterial activity. However, its perfect α-helical structure contributes to high hemolysis, thereby limiting its applications. Herein, to improve the druggability of CPF-7, we first introduced isopeptide bonds to modulate helicity, generating analogs with a favorable therapeutic index. But these modifications resulted in poor serum stability. Based on the cleavage sites analysis, a second round of modification was performed by substituting amino acids. The lead peptide IP2-D4 was screened and identified potent antibacterial activity against multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii (MIC = 4-8 μg/mL), reduced hemolysis (MHC20 = 256 μg/mL), and high stability (t1/2 = 2.932 h). It also showed a low tendency to induce resistance and potent eradication of persisters and biofilms. Importantly, IP2-D4 demonstrated significant antimicrobial efficacy in vivo, effectively treating skin wound infections and catheter-associated biofilm infections. RNA sequencing revealed that it up-regulated the expression of membrane genes in bacteria, and we further confirmed its antibacterial mechanism of membrane destruction.

Peptide stapling is recognized as an effective strategy for improving the proteolytic stability and cell permeability of peptides. In this study, we present a novel approach for the site-selective unsymmetric perfluoroaryl stapling of Ser and Cys residues in unprotected peptides. The stapling reaction proceeds smoothly under very mild conditions, exhibiting a remarkably rapid reaction rate. It can furnish stapled products in both liquid and solid phases, and the presence of nucleophilic groups other than Cys thiol within the peptide does not impede the reaction, resulting in uniformly high yields. Importantly, the chemoselective activation of Ser beta-C(sp(3))-H enables the unreacted -OH to serve as a reactive handle for subsequent divergent modification of the staple moiety with various therapeutic functionalities, including a clickable azido group, a polar moiety, a lipid tag, and a fluorescent dye. In our study, we have also developed a visible-light-induced chemoselective C(sp(3))-H polyfluoroarylation of the Ser beta-position. This reaction avoids interference with the competitive reaction of Ser -OH, enabling the precise late-stage polyfluoroarylative modification of Ser residues in various unprotected peptides containing other highly reactive amino acid residues. The biological assay suggested that our peptide stapling strategy would potentially enhance the proteolytic stability and cellular permeability of peptides.

Interstitial lung diseases (ILDs) are a group of restrictive lung diseases characterized by interstitial inflammation and pulmonary fibrosis. The incidence of ILDs associated with exposure to multiple hazards such as inhaled particles, fibers, and ingested soluble chemicals is increasing yearly, and there are no ideal drugs currently available. Our previous research showed that the novel and low-toxicity peptide DHa-(4-pentenyl)-ANPQIR-NH2 a-(4-pentenyl)-ANPQIR-NH 2 (DR3penA) had a strong antifibrotic effect on a bleomycin-induced murine model. Based on the druggability of DR3penA, we sought to investigate its effects on respirable particulate silicon dioxide (SiO2)- 2 )- and soluble chemical paraquat (PQ)-induced pulmonary fibrosis in this study by using western blot, quantitative reverse-transcription polymerase chain reaction (RT-qPCR), immunofluorescence, H&E and Masson staining, immunohistochemistry, and serum biochemical assays. The results showed that DR3penA alleviated the extent of fibrosis by inhibiting the expression of fibronectin and collagen I and suppressed oxidative stress and epithelial-mesenchymal transition (EMT) in vitro and in vivo. Further study revealed that DR3penA may mitigate pulmonary fibrosis by negatively regulating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway and mitogen-activated protein kinase (MAPK) pathway. Unexpectedly, through the conversion of drug bioavailability under different routes of administration, DR3penA exerted antifibrotic effects equivalent to those of the positive control drug pirfenidone (PFD) at lower doses. In summary, DR3penA may be a promising lead compound for various fibrotic ILDs. SIGNIFICANCE STATEMENT Our study verified that DHa-(4-pentenyl)-ANPQIR-NH2 a-(4-pentenyl)-ANPQIR-NH 2 (DR3penA) exhibited positive antifibrotic activity in pulmonary fibrosis induced by silicon dioxide (SiO2) 2 ) particles and soluble chemical paraquat (PQ) and demonstrated a low-dose advantage compared to the small-molecule drug pirfenidone (PFD). The peptide DR3penA can be further developed for the treatment of multiple fibrotic lung diseases.

Renal fibrosis is a complex pathological process that contributes to the development of chronic kidney disease due to various risk factors. Conservative treatment to curb progression without dialysis or renal transplantation is widely applicable, but its effectiveness is limited. Here, the inhibitory effect of the novel peptide DR3penA (DHα-(4-pentenyl)-AlaNPQIR-NH2), which was developed by our group, on renal fibrosis was assessed in cells and mice with established fibrosis and fibrosis triggered by transforming growth factor-β1 (TGF-β1), unilateral ureteral obstruction, and repeated low-dose cisplatin. DR3penA preserved renal function and ameliorated renal fibrosis at a dose approximately 100 times lower than that of captopril, which is currently used in the clinic. DR3penA also significantly reduced existing fibrosis and showed similar efficacy after subcutaneous or intraperitoneal injection. Mechanistically, DR3penA repressed TGF-β1 signaling via miR-212-5p targeting of low-density lipoprotein receptor class a domain containing 4, which interacts with Smad2/3. In addition to having good pharmacological effects, DR3penA could preferentially target injured kidneys and exhibited low toxicity in acute and chronic toxicity experiments. These results unveil the advantages of DR3penA regarding efficacy and toxicity, making it a potential candidate compound for renal fibrosis therapy.

Late-stage peptide modification showcases a huge potential for the construction of peptide libraries, and the investigation of structure-activity relation-ships. Herein we report a dimethyl sulfoxide/visible light comediated chemoselective modification of tryptophan residue by forging the C-S structure using thiophenols irradiated with blue light-emitting diodes at room temperature. This method shows excellent chemoselectivity toward the C-2 position of the tryptophan residue and good compatibility with diverse thiophenol derivatives bearing various functional groups. Both protected oligopeptides and unmasked bioactive peptides smoothly underwent site-selective modification, furnishing the corresponding products. Above all, this study provides a new competent toolkit for late-stage peptide modification, labelling, and peptide-drug conjugation and provides a clue for protein bioconjugation.

The emergence and increasing prevalence of multidrug-resistant (MDR) bacteria have posed an urgent demand for novel antibacterial drugs. Currently, antimicrobial peptides (AMPs), potential novel antimicrobial agents with rare antimicrobial resistance, represent an available strategy to combat MDR bacterial infections but suffer the limitation of protease degradation. In this study, we developed a highly effective method for optimizing the stability of AMPs by introducing fluorinated sulfono-γ-AApeptides, and successfully synthesized novel Feleucin-K3-analogs. The results demonstrated that the incorporation of fluorinated sulfono-γ-AA into Feleucin-K3 effectively improved stability and afforded optimal peptides, such as CF3–K11, which exhibited 8–9 times longer half-lives than Feleucin-K3. Moreover, CF3–K11 displayed potent antimicrobial activity against clinically isolated Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), excellent biosafety, low resistance propensity, and possessed powerful antimicrobial efficacy for both local skin infection and pneumonia infection. The optimal CF3–K11 exhibited strong therapeutic potential and offered a superior approach for treating MDR bacterial infections.

Interstitial lung diseases (ILDs) are a group of restrictive lung diseases characterized by interstitial inflammation and pulmonary fibrosis. The incidence of ILDs associated with exposure to multiple hazards such as inhaled particles, fibers, and ingested soluble chemicals is increasing yearly, and there are no ideal drugs currently available. Our previous research showed that the novel and low-toxicity peptide DH α-(4-pentenyl)-ANPQIR-NH2 (DR3penA) had a strong antifibrotic effect on a bleomycin-induced murine model. Based on the druggability of DR3penA, we sought to investigate its effects on respirable particulate silicon dioxide (SiO2)- and soluble chemical paraquat (PQ)-induced pulmonary fibrosis in this study by using western blot, quantitative reverse-transcription polymerase chain reaction (RT-qPCR), immunofluorescence, H&E and Masson staining, immunohistochemistry, and serum biochemical assays. The results showed that DR3penA alleviated the extent of fibrosis by inhibiting the expression of fibronectin and collagen I and suppressed oxidative stress and epithelial-mesenchymal transition (EMT) in vitro and in vivo. Further study revealed that DR3penA may mitigate pulmonary fibrosis by negatively regulating the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway and mitogen-activated protein kinase (MAPK) pathway. Unexpectedly, through the conversion of drug bioavailability under different routes of administration, DR3penA exerted antifibrotic effects equivalent to those of the positive control drug pirfenidone (PFD) at lower doses. In summary, DR3penA may be a promising lead compound for various fibrotic ILDs. SIGNIFICANCE STATEMENT Our study verified that DH α-(4-pentenyl)-ANPQIR-NH2 (DR3penA) exhibited positive antifibrotic activity in pulmonary fibrosis induced by silicon dioxide (SiO2) particles and soluble chemical paraquat (PQ) and demonstrated a low-dose advantage compared to the small-molecule drug pirfenidone (PFD). The peptide DR3penA can be further developed for the treatment of multiple fibrotic lung diseases.

Pulmonary fibrosis (PF), which is caused by continuous alveolar epithelial cell injury and abnormal repair, is referred to as a difficult disease of the lung system by the World Health Organization due to its rapid progression, poor prognosis, and high mortality rate. However, there is still a lack of ideal therapeutic strategies. The peptide DR8 (DHNNPQIR-NH2 ), which is derived from rapeseed, exerted antifibrotic activity in the lung, liver, and kidney in our previous studies. By studying the structure-activity relationship and rational design, we introduced an unnatural hydrophobic amino acid (α-(4-pentenyl)-Ala) into DR8 and screened the novel peptide DR4penA (DHNα-(4-pentenyl)-APQIR-NH2 ), which had higher anti-PF activity, higher antioxidant activity and a longer half-life than DR8. Notably, DR4penA attenuated bleomycin- and paraquat-induced PF, and the anti-PF activity of DR4penA was equivalent to that of pirfenidone. Additionally, DR4penA suppressed the TGF-β/Smad pathway in TGF-β1-induced A549 cells and paraquat-induced rats. This study demonstrates that the novel peptide DR4penA is a potential candidate compound for PF therapy, and its antifibrotic activity in different preclinical models of PF provides a theoretical basis for further study.

Interstitial lung diseases (ILDs) are a group of restrictive lung diseases characterized by interstitial inflammation and pulmonary fibrosis. The incidence of ILDs associated with exposure to multiple hazards such as inhaled particles, fibers, and ingested soluble chemicals is increasing yearly, and there are no ideal drugs currently available. Our previous research showed that the novel and low-toxicity peptide DH

显微图像分析在基础医学研究中发挥着重要作用,兰州大学基础医学院实验教学中心在医学形态学实验课程中设置了相关内容.基于课时和授课对象的先修知基础等情况,该课题设计了有针对性的教学方案.方案总体着重于对基本原理的宏观和直观介绍,并通过案例实践熟悉基本操作方法从而更进一步体会、理解基本原理.这种教学设计,使学生在较短时间内掌握显微图像分析的基本原理和操作方法,满足医学生创新科研的现实需求,同时也为今后更深层次的图像分析学习奠定基础.

The prevalence of multidrug-resistant bacterial infections has led to dramatically increased morbidity and mortality. Antimicrobial peptides (AMPs) have great potential as new therapeutic agents to reverse this dangerous trend. Herein, a series of novel AMP Feleucin-K3 analogues modified with unnatural peptidomimetic sulfono-γ-AA building blocks were designed and synthesized. The structure-activity, structure-toxicity, and structure-stability relationships were investigated to discover the optimal antimicrobial candidates. Among them, K122 exhibited potent and broad-spectrum antimicrobial activity and high selectivity. K122 had a rapid bactericidal effect and a low tendency to induce resistance. Surprisingly, K122 showed excellent effectiveness against bacterial pneumonia. For biofilm and local skin infections, K122 significantly decreased the bacterial load and improved tissue injury at a dose of only 0.25 mg/kg, which was 160 times lower than the concentration deemed to be safe for local dermal applications. In summary, K122 is an outstanding candidate for the treatment of multidrug-resistant bacteria and biofilm infections.

The widespread application of antiandrogen therapies has aroused a significant increase in the incidence of NEPC, a lethal form of the disease lacking efficient clinical treatments. Here we identified a cell surface receptor neurokinin-1 (NK1R) as a clinically relevant driver of treatment-related NEPC (tNEPC). NK1R expression increased in prostate cancer patients, particularly higher in metastatic prostate cancer and treatment-related NEPC, implying a relation with the progression from primary luminal adenocarcinoma toward NEPC. High NK1R level was clinically correlated with accelerated tumor recurrence and poor survival. Mechanical studies identified a regulatory element in the NK1R gene transcription ending region that was recognized by AR. AR inhibition enhanced the expression of NK1R, which mediated the PKCα-AURKA/N-Myc pathway in prostate cancer cells. Functional assays demonstrated that activation of NK1R promoted the NE transdifferentiation, cell proliferation, invasion, and enzalutamide resistance in prostate cancer cells. Targeting NK1R abrogated the NE transdifferentiation process and tumorigenicity in vitro and in vivo. These findings collectively characterized the role of NK1R in tNEPC progression and suggested NK1R as a potential therapeutic target.

在"健康中国"的战略背景下,全国高校推行"课程思政"改革是时代发展的必然要求,也面临着一些现实挑战.以病理生理学实验教学为例,探讨有效推进病理生理学实验"课程思政"的实施路径,紧抓课程建设"主战场",课堂教学"主渠道",教师队伍"主力军",促进专业教育和思政教育同向同行,培养符合新时代要求的具备综合素质的医学生.