scholarly journals Exploration of the Structure–Function Relationships of a Novel Frog Skin Secretion-Derived Bioactive Peptide, t-DPH1, through Use of Rational Design, Cationicity Enhancement and In Vitro Studies

Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1529
Author(s):  
Haixin Qin ◽  
Hantian Fang ◽  
Xiaoling Chen ◽  
Lei Wang ◽  
Chengbang Ma ◽  
...  

Amphibian skin-derived antimicrobial peptides (AMPs) have attracted increasing attention from scientists because of their excellent bioactivity and low drug resistance. In addition to being the alternative choice of antibiotics or anticancer agents, natural AMPs can also be modified as templates to optimise their bioactivities further. Here, a novel dermaseptin peptide, t-DPH1, with extensive antimicrobial activity and antiproliferative activity, was isolated from the skin secretion of Phyllomedusa hypochondrialis through ‘shotgun’ cloning. A series of cationicity-enhanced analogues of t-DPH1 were designed to further improve its bioactivities and explore the charge threshold of enhancing the bioactivity of t-DPH1. The present data suggest that improving the net charge can enhance the bioactivities to some extent. However, when the charge exceeds a specific limit, the bioactivities decrease or remain the same. When the net charge achieves the limit, improving the hydrophobicity makes no sense to enhance bioactivity. For t-DPH1, the upper limit of the net charge was +7. All the designed cationicity-enhanced analogues produced no drug resistance in the Gram-negative bacterium, Escherichia coli. These findings provide creative insights into the role of natural drug discovery in providing templates for structural modification for activity enhancement.

2021 ◽  
Author(s):  
xingang wang ◽  
YAN ZHENG ◽  
YU WANG

Abstract Background and AimsPseudopodium-enriched atypical kinase 1 (PEAK1) has reported to be upregulated in human malignancies and related with poor prognosis. Enhanced PEAK1 expression facilitates tumor cell survival, invasion, metastasis and chemoresistance. However, the role of PEAK1 in breast cancer is not clear. Here, we investigated the PEAK1 expression in breast cancer and analyzed its relation with clinicopathological status and chemotherapy resistance to the neoadjuvant chemotherapy (NAC). We also investigated the role of PEAK1 on breast cancer cells in vitro and in vivo. MethodsImmunohistochemistry (IHC) was performed in 112 surgical resected breast cancer tissues. The associations between clinicopathological status, multi-drug resistance and PEAK1 expression were determined. Effect of PEAK1 overexpression or down-expression on proliferation, colony formation, invasion, migration, metastasis and Doxorubicin sensitivity in the MCF-7 cells in vitro and in vivo was detected. ResultsPEAK1 was overexpressed in breast cancer tissues and NAC -resistant breast cancer tissues. High PEAK1 expression was related with tumor size, high tumor grade, T stage, LN metastasis, recurrence, Ki-67 expression, Her-2 expression and multi-drug resistance. Targeting PEAK1 inhibited cell growth, invasion, metastasis and reversed chemoresistance to Doxorubicin in breast cancer cells in vitro and in vivo. ConclusionHigh PEAK1 expression was associated with invasion, metastasis and chemoresistance of breast cancers. Furthermore, targeting PEAK1 could inhibit cell growth and metastasis, and reverse chemoresistance in breast cancer cells, which provides an effective treatment strategies for breast cancer.


2019 ◽  
Vol 20 (23) ◽  
pp. 6017 ◽  
Author(s):  
Prospero Civita ◽  
Diana M. Leite ◽  
Geoffrey Pilkington

The role of astrocytes in the glioblastoma (GBM) microenvironment is poorly understood; particularly with regard to cell invasion and drug resistance. To assess this role of astrocytes in GBMs we established an all human 2D co-culture model and a 3D hyaluronic acid-gelatin based hydrogel model (HyStem™-HP) with different ratios of GBM cells to astrocytes. A contact co-culture of fluorescently labelled GBM cells and astrocytes showed that the latter promotes tumour growth and migration of GBM cells. Notably, the presence of non-neoplastic astrocytes in direct contact, even in low amounts in co-culture, elicited drug resistance in GBM. Recent studies showed that non-neoplastic cells can transfer mitochondria along tunneling nanotubes (TNT) and rescue damaged target cancer cells. In these studies, we explored TNT formation and mitochondrial transfer using 2D and 3D in vitro co-culture models of GBM and astrocytes. TNT formation occurs in glial fibrillary acidic protein (GFAP) positive “reactive” astrocytes after 48 h co-culture and the increase of TNT formations was greater in 3D hyaluronic acid-gelatin based hydrogel models. This study shows that human astrocytes in the tumour microenvironment, both in 2D and 3D in vitro co-culture models, could form TNT connections with GBM cells. We postulate that the association on TNT delivery non-neoplastic mitochondria via a TNT connection may be related to GBM drug response as well as proliferation and migration.


2020 ◽  
Vol 21 (17) ◽  
pp. 5951
Author(s):  
Laura Patras ◽  
Marcel H. A. M. Fens ◽  
Pieter Vader ◽  
Arjan Barendrecht ◽  
Alina Sesarman ◽  
...  

Extracellular vesicles (EV) secreted in the tumour microenvironment (TME) are emerging as major antagonists of anticancer therapies by orchestrating the therapeutic outcome through altering the behaviour of recipient cells. Recent evidence suggested that chemotherapeutic drugs could be responsible for the EV-mediated tumour–stroma crosstalk associated with cancer cell drug resistance. Here, we investigated the capacity of tumour EV (TEV) secreted by normoxic and hypoxic (1% oxygen) C26 cancer cells after doxorubicin (DOX) treatment to alter the response of naïve C26 cells and RAW 264.7 macrophages to DOX. We observed that C26 cells were less responsive to DOX treatment under normoxia compared to hypoxia, and a minimally cytotoxic DOX concentration that mounted distinct effects on cell viability was selected for TEV harvesting. Homotypic and heterotypic pretreatment of naïve hypoxic cancer and macrophage-like cells with normoxic DOX-elicited TEV rendered these cells slightly less responsive to DOX treatment. The observed effects were associated with strong hypoxia-inducible factor 1-alpha (HIF-1α) induction and B-cell lymphoma–extra-large anti-apoptotic protein (Bcl-xL)-mediated anti-apoptotic response in normoxic DOX-treated TEV donor cells, being also tightly connected to the DOX-TEV-mediated HIF-1α induction, as well as Bcl-xL levels increasing in recipient cells. Altogether, our results could open new perspectives for investigating the role of chemotherapy-elicited TEV in the colorectal cancer TME and their modulatory actions on promoting drug resistance.


2020 ◽  
Vol 11 ◽  
Author(s):  
Manuel Soto ◽  
Laura Ramírez ◽  
José Carlos Solana ◽  
Emma C. L. Cook ◽  
Elena Hernández-García ◽  
...  

Unveiling the protective immune response to visceral leishmaniasis is critical for a rational design of vaccines aimed at reducing the impact caused by this fatal, if left untreated, vector-borne disease. In this study we sought to determine the role of the basic leucine zipper transcription factor ATF-like 3 (Batf3) in the evolution of infection with Leishmania infantum, the causative agent of human visceral leishmaniasis in the Mediterranean Basin and Latin America. For that, Batf3-deficient mice in C57BL/6 background were infected with an L. infantum strain expressing the luciferase gene. Bioluminescent imaging, as well as in vitro parasite titration, demonstrated that Batf3-deficient mice were unable to control hepatic parasitosis as opposed to wild-type C57BL/6 mice. The impaired microbicide capacities of L. infantum-infected macrophages from Batf3-deficient mice mainly correlated with a reduction of parasite-specific IFN-γ production. Our results reinforce the implication of Batf3 in the generation of type 1 immunity against infectious diseases.


2019 ◽  
Vol 12 (4) ◽  
pp. 146 ◽  
Author(s):  
Claudia Riccardi ◽  
Domenica Musumeci ◽  
Marco Trifuoggi ◽  
Carlo Irace ◽  
Luigi Paduano ◽  
...  

The great advances in the studies on metal complexes for the treatment of different cancer forms, starting from the pioneering works on platinum derivatives, have fostered an increasingly growing interest in their properties and biomedical applications. Among the various metal-containing drugs investigated thus far, ruthenium(III) complexes have emerged for their selective cytotoxic activity in vitro and promising anticancer properties in vivo, also leading to a few candidates in advanced clinical trials. Aiming at addressing the solubility, stability and cellular uptake issues of low molecular weight Ru(III)-based compounds, some research groups have proposed the development of suitable drug delivery systems (e.g., taking advantage of nanoparticles, liposomes, etc.) able to enhance their activity compared to the naked drugs. This review highlights the unique role of Ru(III) complexes in the current panorama of anticancer agents, with particular emphasis on Ru-containing nanoformulations based on the incorporation of the Ru(III) complexes into suitable nanocarriers in order to enhance their bioavailability and pharmacokinetic properties. Preclinical evaluation of these nanoaggregates is discussed with a special focus on the investigation of their mechanism of action at a molecular level, highlighting their pharmacological potential in tumour disease models and value for biomedical applications.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 46-46
Author(s):  
Loic Ysebaert ◽  
Mary Poupot ◽  
Yovan Sanchez-Ruiz ◽  
Camille Laurent ◽  
Guy Laurent ◽  
...  

Abstract Abstract 46 Introduction: CLL cells interact with many accessory cells in an environment mimicking that of normal mature B cells. Role of antigen, cytokines, adhesion pathways are critical for many aspects in the disease course (proliferation/survival, migration or homing, drug resistance, and presumably relapse). Nurse-like cells (NLC) belong to a monocytic-derived, bystander population among CLL lymph node and spleen stromal cells. Aim: To investigate the nature, functions, and location of NLC within CLL microenvironment. Methods: Gene expression profiles (GEP) from in vitro expanded NLC from patients (n=10) were produced and compared to those from normal CD14+ monocytes, M1-polarized macrophages, M2-polarized macrophages and tumor-associated macrophages (produced in the lab or downloaded from GEO datasets). Principal Component Analysis was used to categorize these five populations of cells and in-house-built GSEA software was used for functional interpretation of their relevant gene lists. Protein expression patterns were validated with multi-analyte ELISArray kits, proteome profiler arrays, flow cytometry (FC) or immunohistochemistry (IHC). Results: New insights into the physiopathological role of NLC in CLL are suggested from five lines of evidence: 1/a Òmonocytic gene signatureÓ (i.e. a set of 549 genes) is shared by the NLC and the monocyte subtypes. The genes over-represented in NLC vs normal monocytes pinpointed positive modulation of apoptotic cell clearance (scavenger, mannose and complement receptors, LXRalpha), lipid metabolism (Apolipoprotein E, PPAR signaling), extracellular matrix-receptor interactions (integrins, SPARC, Matrix MetalloProteinases) and actin cytoskeleton remodeling. 2/unsupervised clustering show that NLC represent an M2-skewed, TAM-like cell population. They down-regulate mRNA and proteins for classic M1 inflammatory markers (e.g. IL-1, IL-6, IL-12, COX2) while increase secretion of TGFbeta, IL-10, CCL17 and CCL22 soluble factors. 3/these and previously published observations suggest that B-CLL-to-NLC interactions may orchestrate immunosuppression in this disease. PBMCs from Òwatch and waitÓ CLL patients (all stage A/Rai 0, mutated IgVH, low risk cytogenetics profile) or healthy donors were stimulated with anti-CD3/CD28 beads + IL-2, either in standard RPMI+10% FCS or in conditioned medium (CM, after 14d CLL-NLC co-culture in vitro) and their proliferation/phenotype were compared after 2 weeks. Significant expansion of T cells with Treg (CD4+CD25+FoxP3+) phenotype was observed only from CLL PBMCs grown in conditioned medium (mean % Treg: 2.85 vs 3.05 in CM for normal PBMCs, and 1.54 vs 15.9 in CM for CLL PBMCs, P< 0.05). 4/although NLC make immune synapses with live B-CLL, they do not phagocytose them. Over-expression of CD47 (ÒdonÕt eat meÓ signal) by B-CLL cells (mfi= 3490 vs 2581 on normal cells, P< 0.05, n=18) may provide them with a protective signal against NLC. 5/from our GEP, flow cytometric and IHC analyses, we propose CD163 (classic M2 marker) as a reliable tool to identify NLC in vivo. Although in vitro, CLL cells can pervert healthy donor monocytes into NLC, only CLL-derived NLC are truly CD14+ CD163+. In vivo, CD163 staining reveals putative NLC in CLL lymph nodes(LN)/spleen sections but not in bone marrow. In LN from all patients, NLC reside in the subcapsular areas and line vessel structures, suggesting a role in CLL cells trafficking. Most interestingly, NLC infiltrate pseudofollicles structures only in a subset of cases. We will present updated IHC and clinical presentation correlation studies. Conclusions: Our results suggest that the role of NLC in CLL might be broader than initially thought. Beside of nursing and conferring drug resistance, NLC may also be crucial in the setting of immunosuppression, of CLL cells recruitment, and should thus be considered as therapeutic targets. Disclosures: Off Label Use: GA101 is not currently approved for CLL treatment.


2021 ◽  
Author(s):  
Simranjit X. Singh ◽  
Rui Yang ◽  
Kristen Roso ◽  
Landon J. Hansen ◽  
Changzheng Du ◽  
...  

Glioblastoma (GBM) is a lethal brain cancer exhibiting high levels of drug resistance, a feature partially imparted by tumor cell stemness. Recent work shows that homozygous MTAP deletion, a genetic alteration occurring in about half of all GBMs, promotes stemness in GBM cells. Exploiting MTAP loss-conferred deficiency in adenine salvage, we demonstrate that transient adenine blockade via treatment with L-Alanosine (ALA), an inhibitor of de novo adenine synthesis, attenuates stemness of MTAP-deficient GBM cells. This ALA-induced reduction in stemness is accompanied by compromised mitochondrial function, highlighted by diminished spare respiratory capacity. Direct pharmacological inhibition of mitochondrial respiration recapitulates the effect of ALA on GBM cell stemness, suggesting ALA targets stemness partially via affecting mitochondrial function. Finally, in agreement with diminished stemness and compromised mitochondrial function, we show that ALA sensitizes GBM cells to temozolomide (TMZ) in vitro and in an orthotopic GBM model. Collectively, these results identify critical roles of adenine supply in maintaining mitochondrial function and stemness of GBM cells, highlight a critical role of mitochondrial function in sustaining GBM stemness, and implicate adenine synthesis inhibition as a complementary approach for treating MTAP-deleted GBMs.


2021 ◽  
Vol 5 (18) ◽  
pp. 3656-3667
Author(s):  
Xin Li ◽  
Jingjing Wang ◽  
Shuai Zhu ◽  
Jinxin Zheng ◽  
Ying Xie ◽  
...  

Abstract Proteasome inhibitors, such as bortezomib (BTZ), represent the key elements in chemotherapy regimens for multiple myeloma (MM), whereas acquired chemoresistance and ultimately relapse remain a major obstacle. In the current study, we screened differently expressed cytokines in bortezomib-resistant MM cells and found that Dickkopf-1 (DKK1) level was remarkably augmented, whereas CD138 level was significantly suppressed. DKK1 in vitro specifically enhanced the resistance of myeloma cells to bortezomib treatment, and excessive DKK1 drove CD138 downregulation via inhibition of canonical Wnt signaling. Notably, DKK1 mainly induced drug resistance in MM cells via the receptor of CKAP4. Mechanistically, CKAP4 transduced DKK1 signal and evoked NF-κB pathway through recruiting and preventing cullin associated and neddylation dissociated 1 from hampering the assembly of E3 ligase-mediated ubiquitination of IκBα. In addition, we found that interleukin-6 (IL-6) stimulated CKAP4 expression to generate drug resistance, and disturbance of DKK1-CKAP4 axis improved sensitivity to BTZ treatment of MM and attenuated bone destruction in a mouse model. Collectively, our study revealed the previously unidentified role of DKK1 in myeloma drug resistance via Wnt signaling dependent and independent manners, and clarified the importance of antagonism of DKK1-IL-6 loop in bone marrow microenvironment.


Biomolecules ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 280 ◽  
Author(s):  
Yuxi Miao ◽  
Guanzhu Chen ◽  
Xinping Xi ◽  
Chengbang Ma ◽  
Lei Wang ◽  
...  

Anuran amphibian skin secretions are a rich source of peptides, many of which represent novel protease inhibitors and can potentially act as a source for protease inhibitor drug discovery. In this study, a novel bioactive Bowman-Birk type inhibitory hexadecapeptide of the Ranacyclin family from the defensive skin secretion of the Fukien gold-striped pond frog, Pelophlax plancyi fukienesis, was successfully isolated and identified, named PPF-BBI. The primary structure of the biosynthetic precursor was deduced from a cDNA sequence cloned from a skin-derived cDNA library, which contains a consensus motif representative of the Bowman-Birk type inhibitor. The peptide was chemically synthesized and displayed a potent inhibitory activity against trypsin (Ki of 0.17 µM), as well as an inhibitory activity against tryptase (Ki of 30.73 µM). A number of analogues of this peptide were produced by rational design. An analogue, which substituted the lysine (K) at the predicted P1 position with phenylalanine (F), exhibited a potent chymotrypsin inhibitory activity (Ki of 0.851 µM). Alternatively, a more potent protease inhibitory activity, as well as antimicrobial activity, was observed when P16 was replaced by lysine, forming K16-PPF-BBI. The addition of the cell-penetrating peptide Tat with a trypsin inhibitory loop resulted in a peptide with a selective inhibitory activity toward trypsin, as well as a strong antifungal activity. This peptide also inhibited the growth of two lung cancer cells, H460 and H157, demonstrating that the targeted modifications of this peptide could effectively and efficiently alter its bioactivity.


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