Bacteria can produce recombinant proteins quickly and cost effectively. However, their physiological properties limit their use for the production of proteins in their native form, especially polypeptides that are subjected to major post-translational modifications. Proteins that rely on disulfide bridges for their stability are difficult to produce in Escherichia coli. The bacterium offers the least costly, simplest, and fastest method for protein production. However, it is difficult to produce proteins with a very large size. Saccharomyces cerevisiae and Pichia pastoris are the most commonly used yeast species for protein production. At a low expense, yeasts can offer high protein yields, generate proteins with a molecular weight greater than 50 kDa, extract signal sequences, and glycosylate proteins. Both eukaryotic and prokaryotic species maintain reducing conditions in the cytoplasm. Hence, the formation of disulfide bonds is inhibited. These bonds are formed in eukaryotic cells during the export cycle, under the oxidizing conditions of the endoplasmic reticulum. Bacteria do not have an advanced subcellular space, but in the oxidizing periplasm, they exhibit both export systems and enzymatic activities directed at the formation and quality of disulfide bonds. Here, we discuss current techniques used to target eukaryotic and prokaryotic species for the generation of correctly folded proteins with disulfide bonds.

Multidrug-resistant (MDR) bacteria are becoming more and more common, which presents a serious threat to world health and could eventually render many of the antibiotics we currently use useless. The research and development of innovative antimicrobial tactics that can defeat these hardy infections are imperative in light of this predicament. Antimicrobial peptides (AMPs), which have attracted a lot of attention due to their distinct modes of action and capacity to elude conventional resistance mechanisms, are among the most promising of these tactics. As a promising substitute for conventional antibiotics, AMPs are a varied class of naturally occurring compounds that target bacteria membranes and disrupt cellular activities to demonstrate broad-spectrum antimicrobial activity. The objective of this study is to present a thorough summary of the current knowledge regarding AMP mechanisms against MDR bacteria, including immunological modulation, interactions with microbial membranes, and possible synergy with currently used antimicrobial drugs. In addition, we define the review’s scope to include the most recent developments in AMP research, emphasizing the innovations’ development, optimization, and therapeutic promise. We hope to emphasize the crucial role that AMPs will play in the future of antimicrobial therapy by bringing together recent research and highlighting current issues. We also hope to advocate for AMPs’ continued research and development as part of a comprehensive strategy to counteract the growing threat of antibiotic resistance.

This article reviews the mechanisms by which marine natural products regulate ferroptosis and their potential applications in tumor therapy. Ferroptosis is a form of programmed cell death driven by iron-dependent lipid peroxidation, characterized primarily by the accumulation of lipid peroxides and the failure of antioxidant defense systems. Due to their unique chemical structural diversity, marine natural products demonstrate significant advantages in regulating the ferroptosis pathway. Studies showed that marine compounds target key molecules such as glutathione peroxidase 4 (GPX4) and long-chain acyl-CoA synthetase 4 (ACSL4(a)) ACSL4(1) to modulate lipid peroxidation and iron metabolism, inducing ferroptosis in tumor cells and reshaping the tumor microenvironment (TME). In addition, marine compounds can enhance anti-tumor effects by activating immune responses. Although marine compounds hold great potential in regulating ferroptosis, their clinical translation faces challenges such as low bioavailability and tumor type dependency. Future research needs to integrate multi-omics techniques to further analyze the mechanisms of marine compounds and develop precision therapeutic strategies based on marine compounds to overcome the bottlenecks in ferroptosis therapy.

Antimicrobial peptides (AMPs) have broad-spectrum antimicrobial activity, enabling them to rapidly detect and eliminate targets. In addition, many AMPs are natural peptides, making them promising candidates for therapeutic drugs. This review discusses the basic properties and mechanisms of action of AMPs, highlighting their ability to disrupt microbial membranes and modulate host immune responses. It also reviews the current state of research into using AMPs against various viral infections, focusing on their therapeutic potential against viruses that contribute to the global health crisis. Despite promising developments, therapies based on AMPs still face challenges such as stability, toxicity, and production costs. In this text, we will discuss these challenges and the latest technological advances aimed at overcoming them. The combination of nanotechnology and bioengineering approaches offers new ways to enhance the delivery, efficacy, and safety of AMPs. We emphasize the importance of further research to fully exploit the potential of AMPs in antiviral therapy, advocating a multifaceted approach that includes optimizing clinical use and exploring synergies with existing antiviral drugs.

Reactive nitrogen species (RNS) play a pivotal role in tumorigenesis through complex regulatory networks within the tumor microenvironment (TME). This review summarizes recent advances in understanding RNS-mediated mechanisms, focusing on core components and their concentration-dependent bidirectional effects on tumor cell proliferation, apoptosis, invasion, and metabolism. It explores RNS sources in the TME, including autonomous synthesis by tumor cells and secretion by immune cells (e.g., TAMs, TANs), and their modulation of key signaling pathways (e.g., PI3 K/Akt, NF-κB, HIF-1α). Additionally, the review discusses RNS-mediated regulation of immune responses and angiogenesis, highlighting their dual roles in promoting tumor progression and enabling immune evasion. Finally, it outlines potential clinical applications, such as RNS-targeted diagnostic probes and therapeutic strategies (e.g., iNOS inhibitors, NO donors), providing a foundation for precision oncology.

Hepcidin, an antimicrobial peptide produced by the liver, also controls the iron balance and regeneration in vertebrates. Two types of hepcidin (Hamp1 and Hamp2) have been found in the bodies of black rockfish (Sebastes schlegelii). The full-length cDNA of hepcidin was cloned to enable a study of the antibacterial roles of these two hepcidins (Hamp) in black rockfish. The antimicrobial function of recombinant hepcidins was tested both in vitro and in vivo by the synthesis in Escherichia coli of recombinant hepcidin (approximately 11 kDa) from black rockfish. The recombinant hepcidins inhibited the growth of two bacterial species, Streptococcus iniae FP5228 and Pseudomonas aeruginosa, at various concentrations, in vitro after 6 h post-incubation, respectively. During infection, the production of ferroportin was reduced, suggesting the preservation of iron to prevent microbial proliferation. In vivo administration of Hamp1, but not Hamp2, synthetic peptides induced a substantial reduction in the expression of ferroportin, suggesting that in black rockfish with two forms of hepcidin, ferroportin production is regulated by the iron-regulator Hamp1, and not by the dedicated antimicrobial Hamp2. The findings of this study suggest the various antimicrobial roles of these two types of hepcidin.