Purified recombinant human Chromogranin A N46 peptide with remarkable anticancer effect on human colon cancer cells

Interdisciplinary gene manipulation, molecular cloning, and recombinant expression of modified human growth hormone isoform-1 in E. coli system

BACKGROUND

Growth hormone (GH) is a hormone that promotes growth, cell reproduction, and cell restoration in humans and animals.

OBJECTIVES

Production of recombinant human growth hormone (rhGH) in Escherichia coli (E. coli) and assessment of its characteristics and proliferation stimulatory activity.

METHODS

The hGH gene was cloned into a pET 3a expression vector and transformed into a competent E. coli cell. The refolded hGH was purified, Western blot and batch fermentation were performed. Cell cytotoxicity was tested on Vero cells, and MALDI-TOF and Nano-LC-ESI MS/MS were used for protein and target peptide analysis.

RESULTS

Induced rhGH was purified with a concentration of 511.9 mg/ml. Western blot confirmed the molecular identity of rhGH, showing a single 22 kDa band. The bacterial growth at OD600 after 24 h in batch fermentation was 9.78 ± 0.26, and wet cell weight (WCWg/L) was 15.2 ± 0.32. Purified rhGH activity on Vero cells was 0.535 IU/mg. LC-MS/MS analysis revealed a score of 70.51 % and coverage of 60.37 %.

CONCLUSION

Biologically active native rhGH protein was successfully expressed in the Prokaryotic system. Our goal is to increase its production on a pilot level in the native form at a high activity effect identical to isoform 1.

Fundamental Uses of Peptides as a New Model in Both Treatment and Diagnosis

An amino acid short chain is known as a peptide. Peptide bonds are the connections that hold the amino acids of a peptide together in a particular order. Characteristically, the shorter length of peptides helps to identify them from proteins. Different ways are used to classify peptides, including chain length, source of peptides, or their biological functions. The fact that peptides serve several purposes suggests that there is a foundation for improvement in peptide production and structure to enhance action. In addition, many patents on peptides for therapeutic and diagnostic approaches have been obtained. This review aims to give an overview of peptides used recently in treatment and diagnosis.

A multimodality therapeutic application on Toxoplasma gondii encephalitis utilizing Spiramycin and 'de novo' Ferula asafetida in immunodeficient mice

This study investigated a 'de Novo' medicinal herb, Ferula asafetida (FA), against toxoplasma encephalitis either alone or combined with spiramycin (SP). Female Swiss-Webster mice (n = 72) were divided into three batches. Batch-I received no DMS to serve as an immunocompetent control, batch-II was immune-suppressed with the DMS (0.25 mg/g/day) for 14 days pre-infection, whilst batch-III was immune-suppressed with the DMS on the same day of infection. All experimental mice were inoculated with Toxoplasma gondii ME49 cysts (n = 75). Each batch was split into four subgroups: Mono-SP, mono-FA, combined drug (SP + FA), or neither. Therapies were administered on day zero of infection in batches (I and II) and 35 days post-infection in batch (III). Treatments lasted for 14 days, and mice were sacrificed 60 days post-infection. Histopathological changes, cysts load, and CD4 and CD8 T-cells were counted in brain tissues. The cyst-load count in mice receiving SP + FA was significantly (p < .0001) the least compared to the mono treatments in all protocols. Interestingly, the combined therapy demolished the T-cell subsets to zero in immunocompetent and immunocompromised infected mice. In conclusion, F. asafetida might be a powerfully natural, safe vehicle of SP in the digestive system and/or across the brain-blood barrier to control toxoplasmosis even through immunodeficient conditions.

A novel antibacterial approach of Cecropin-B peptide loaded on chitosan nanoparticles against MDR Klebsiella pneumoniae isolates

Egypt has witnessed the emergence of multidrug-resistant (MDR) Klebsiella pneumoniae, which has posed a serious healthcare challenge. The proper treatment choice for MDR-KP infections is not well determined which renders the problem more complicated, thus making the control of such infections a serious challenge for healthcare professionals. This study aims to encapsulate the cationic antimicrobial peptide; Cecropin-B (Cec-B), to increase its lifetime, drug targeting, and efficacy and study the antimicrobial effect of free and encapsulated recombinant rCec-B peptide on multidrug-resistant K. pneumoniae (MDR-KP) isolates. Fifty isolates were collected from different clinical departments at Theodore Bilharz Research Institute. Minimal inhibitory concentrations (MICs) of rCec-B against MDR-KP isolates were determined by the broth microdilution test. In addition, encapsulation of rCec-B peptide into chitosan nanoparticles and studying its bactericidal effect against MDR-KP isolates were also performed. The relative expression of efflux pump and porin coding genes (ArcrB, TolC, mtdK, and Ompk35) was detected by quantitative PCR in treated MDR-KP bacterial isolates compared to untreated isolates. Out of 60 clinical MDR isolates, 50 were MDR-KP. 60% of the isolates were XDR while 40% were MDR. rCec-B were bactericidal on 21 isolates, then these isolates were subjected to treatment using free nanocapsule in addition to the encapsulated peptide. Free capsules showed a mild cytotoxic effect on MDR-KP at the highest concentration. MIC of encapsulated rCec-B was higher than the free peptide. The expression level of genes encoding efflux and porin (ArcrB, TolC, mtdK, and Ompk35) was downregulated after treatment with encapsulated rCec-B. These findings indicate that encapsulated rCec-B is a promising candidate with potent antibacterial activities against drug-resistant K. pneumoniae.

Application Value of Antimicrobial Peptides in Gastrointestinal Tumors

Gastrointestinal cancer is a common clinical malignant tumor disease that seriously endangers human health and lacks effective treatment methods. As part of the innate immune defense of many organisms, antimicrobial peptides not only have broad-spectrum antibacterial activity but also can specifically kill tumor cells. The positive charge of antimicrobial peptides under neutral conditions determines their high selectivity to tumor cells. In addition, antimicrobial peptides also have unique anticancer mechanisms, such as inducing apoptosis, autophagy, cell cycle arrest, membrane destruction, and inhibition of metastasis, which highlights the low drug resistance and high specificity of antimicrobial peptides. In this review, we summarize the related studies on antimicrobial peptides in the treatment of digestive tract tumors, mainly oral cancer, esophageal cancer, gastric cancer, liver cancer, pancreatic cancer, and colorectal cancer. This paper describes the therapeutic advantages of antimicrobial peptides due to their unique anticancer mechanisms. The length, net charge, and secondary structure of antimicrobial peptides can be modified by design or modification to further enhance their anticancer effects. In summary, as an emerging cancer treatment drug, antimicrobial peptides need to be further studied to realize their application in gastrointestinal cancer diseases.

Antimicrobial Peptides with Anti-Candida Activity

Mycoses are accountable for millions of infections yearly worldwide. Invasive candidiasis is the most usual, presenting a high morbidity and mortality. Candida albicans remains the prevalent etiologic agent, but the incidence of other species such as Candida parapsilosis, Candida glabrata and Candida auris keeps increasing. These pathogens frequently show a reduced susceptibility to commonly used antifungal drugs, including polyenes, triazoles and echinocandins, and the incidence of emerging multi-drug-resistant strains of these species continues to increase. Therefore, the need to search for new molecules that target these pathogenic species in a different manner is now more urgent than ever. Nature is an almost endless source of interesting new molecules that could meet this need. Among these molecules, antimicrobial peptides, present in different sources in nature, possess some advantages over conventional antifungal agents, even with their own drawbacks, and are considered as a promising pharmacological option against a wide range of microbial infections. In this review, we describe 20 antimicrobial peptides from different origins that possess an activity against Candida.

Lab-scale Preparation of Recombinant Human Insulin-like Growth Factor-1 in Escherichia coli and its Potential Safety on Normal Human Lung Cell Line

BACKGROUND

Insulin-like growth factor-1 (IGF-1) is structurally similar to insulin and acts as an endocrine hormone secreted by the liver.

OBJECTIVE

Production of recombinant human IGF-1 (rhIGF-1) in Escherichia coli (E.coli) and evaluation of its proliferation stimulatory activity.

METHODS

hIGF-1 gene cloned into pBSK (+) simple vector was transformed into TOP 10 chemically competent cells of E. coli. Polymerase chain reaction (PCR) was achieved using specific hIGF-1 gene primers to confirm the successful transformation. To express the rhIGF-1 in E. coli (Rosetta (DE3) pLysS); the hIGF-1 gene was cloned into the pET-15b expression vector and then the recombinant pET-15b/IGF-1 vector was transformed into a chemically prepared competent expression bacterial cells; Rosetta (DE3) pLysS. The rhIGF-1 was expressed as insoluble aggregates called inclusion bodies (IBs) using a 2 mM Isopropyl β-D-1-thiogalactopyranoside (IPTG) inducer. IBs were solubilized in a denatured form using 6 M guanidinium hydrochloride (GdmCl), followed by in vitro protein refolding using the rapid dilution method. The refolded hIGF-1 was purified using the HiTrap- ANX anion exchange column. Western blot and ELISA using rabbit polyvalent anti-hIGF- 1 were performed to confirm the protein antigenic identity. Cell proliferation activity of rhIGF-1 was testified on normal human lung cell line (WI-38).

RESULTS

rhIGF-1 was purified from the HiTrap-ANX column at a concentration of 300 μg/ml. Western blot showed a single 7.6 kDa band obtained in the induced Rosetta (DE3) pLYsS. ELISA confirmed the molecular identity of the rhIGF-1 epitope, the concentration of purified rhIGF-1 obtained from the ELISA standard curve using rhIGF-1 reference protein as a standard was 300 μg/ml, and activity on WI-38 cells was 2604.17I U/mg.

CONCLUSION

Biologically active native rhIGF-1 protein was successfully expressed. Patents related to the preparation of IGF-1 were mentioned along the text.