Biotechnology Journal最新文献

Retinol, the major active form of vitamin A, plays a crucial role in vision, immune function, and skin health. The industrial model yeast Saccharomyces cerevisiae (S. cerevisiae) inherently possesses the mevalonate pathway, which supplies precursors for retinol biosynthesis. However, the imbalanced distribution of metabolic flux between the retinol synthesis pathway and other competing pathways limits the retinol titer. To improve the efficiency of the retinol synthesis pathway, we first identified two key bottleneck enzymes, geranylgeranyl diphosphate synthase (CrtE) and β-carotene 15,15′-dioxygenase (Blh), and optimized their gene copy numbers, resulting in a 72.0% increase in retinol titer. Subsequently, to reduce the diversion of the metabolic flux toward squalene production, we employed a multidimensional manipulation strategy to regulate the expression of squalene synthase (ERG9). By replacing the native ERG9 promoter with P_SPI1 and using a decompartmentalization strategy, the retinol titer was further increased to 1.41 g/L. After auxotrophic marker gene complementation, the resulting retinol titer in a 5-L bioreactor was 7.19 g/L, which was the highest reported value in S. cerevisiae. This work establishes an effective engineering strategy for high-yield retinol production in S. cerevisiae, which can facilitate subsequent process development and scale-up.

Cis,cis-muconic acid (ccMA) is a promising platform chemical for the production of polymers and fine chemicals. However, conventional synthesis suffers from poor selectivity and environmental concerns, while plasmid-dependent biosynthesis requires expensive antibiotics and inducers for large-scale fermentation. Here, we constructed a plasmid-free and inducer-free Escherichia coli strain for the efficient production of from glucose. The biosynthetic pathway was established via the endogenous shikimate pathway, through 3-dehydroshikimate, which is sequentially converted to protocatechuate by a 3-dehydroshikimate dehydratase (ApAroZ^R363A), to catechol by a protocatechuate decarboxylase (KpAroY), and finally to ccMA by a catechol 1,2-dioxygenase (PpCatA). To increase the supply of ccMA, the competitive pathway genes (aroE, pykF, and ptsG) were disrupted, and the essential pathway genes (galP, glK, tktA, talB, aroG, aroB, and aroD) were overexpressed. To address the carbon flux imbalance caused by aroE and pykF knockouts, their expression was dynamically regulated using P_fliA-ATG-aroE and P_flgB-TTG-pykF designs. To eliminate the plasmid burden and the need for antibiotics or inducers, the ccMA pathway genes were chromosomally integrated, and the final engineered strain WMA101 produced 9.54 g/L of ccMA with a yield of 40.3% (mol/mol) from glucose in shake flasks. These studies demonstrate a sustainable, scalable platform for ccMA biomanufacturing.

Hepatocellular carcinoma (HCC), a highly lethal disease often developing in the context of chronic liver disease, is marked by high relapse rates and low 5-year survival. To investigate the multicellular ecosystem and molecular features of hepatocarcinogenesis and progression, a comprehensive analysis integrating single-cell and spatial transcriptomics was conducted. Significant alterations were observed in various cell types, notably an increase in liver parenchymal and endothelial cells, which play critical roles in tissue repair and angiogenesis. Scissor⁺ cells, predominantly hepatocytes, were identified as potentially evolving into malignant cells with poor prognosis and enhanced immune evasion capabilities. Key genes associated with Scissor⁺ cells exhibited potential as cancer prognostic markers. Additionally, the disruption of cellular communication networks during malignant progression revealed the evolution of hepatocytes into cancerous phenotypes. The enhanced signaling pathways, such as MDK-SDC4 and COL4A-SDC, were identified as pivotal in driving the malignant transformation of hepatocytes. This transformative process, wherein Scissor⁺ cells acquire malignant features, highlights novel mechanisms of cancer progression. These findings provide deeper insights into hepatocarcinogenesis and offer potential avenues for targeted and personalized therapeutic strategies.

Hyaluronic acid (HA) is an important homopolysaccharide also known as a natural anionic mucopolysaccharide or glycosaminoglycan formed by the alternate connection of glucuronic acid and N-acetylglucosamine as disaccharide units. For this review, the literature was searched in PubMed, Scopus, and Web of Science, using a few specific keywords including hyaluronic acid, biopolymer, glucuronic acid, N-acetylglucosamine, cosmetic, pharmaceutical, anti-aging and wound. Among the searched publications, further screening was done to select reports on the use of HA in healthcare and pharmaceutical products. Information relevant to the topic of this review has been presented in the article using 100 selected references, in eight tables and five figures. HA is a commercially valuable biocompatible polymer, which has been traditionally derived from rooster combs and animal tissues. However, it is currently produced through microbial fermentation by group C Streptococci. This biopolymer occurs naturally in several human tissues, including the skin and eyes. HA is a vital ingredient used in numerous products by global industries due to its unique characteristics, like inherent biocompatibility, tissue regenerative capacity, and anti-inflammatory properties. There has been a significant interest in recent years, enhanced across the pharmaceutical and cosmetic industries. Equally, the increased consumer interest from the aging population is compelling the demand for anti-aging products. Therefore, the global market for products formulated with HA marketed with defined benefits is experiencing significant growth. In this review, we have summarized current commercial applications of HA in many industries and consequently the increasing market size in specific application sectors in the next five years by 2030 in the international market.

The musculoskeletal system consists of bones, joint cartilage, tendons, ligaments, muscles, and their associated nerves and blood vessels. These components work together to maintain human movement and mechanical stability, serving as the critical foundation for sustaining life activities. In recent years, with the acceleration of population aging, the incidence of musculoskeletal-related diseases such as sarcopenia, muscle atrophy, osteoporosis (OP), osteoarthritis (OA), and tendon injuries has continued to rise, significantly impacting patients’ quality of life and imposing a heavy social health burden. Mesenchymal stem cells (MSCs) have garnered widespread attention in tissue repair and regenerative medicine due to their excellent self-renewal capacity, multipotent differentiation potential, and low immunogenicity. Numerous studies have shown that the therapeutic effects of MSCs primarily depend on their paracrine actions, particularly the extracellular vesicles (EVs) they secrete, which play a crucial role in regulating tissue homeostasis and repairing damage. MSC-derived EVs possess biological functions similar to those of their parent cells and lack immunogenicity and tumorigenic risks. As effective carriers of intercellular signaling, they can transport various bioactive substances (such as miRNAs, mRNAs, proteins, and lipids), demonstrating significant advantages in regulating cellular functions within the musculoskeletal system, promoting tissue regeneration, and alleviating inflammation. This paper provides a systematic review of the research progress of MSC-derived EVs in musculoskeletal system diseases, focusing on their mechanisms of action and application potential in sarcopenia, osteoporosis, degenerative joint cartilage diseases, and tendon repair, aiming to provide theoretical basis and new research directions for related basic research and clinical translation.

Myocardial infarction remains a leading cause of mortality worldwide, primarily due to the limited regenerative capacity of adult cardiac tissue. Recent advances in regenerative medicine aim to address this limitation through stem cell therapies supported by bioengineered scaffolds and targeted delivery systems. This review highlights current progress in scaffold-guided cardiac regeneration, focusing on the therapeutic potential of embryonic, mesenchymal, induced pluripotent, and cardiac-resident stem cells. The integration of natural and synthetic biomaterials, including hydrogels, decellularized extracellular matrices, and smart polymers, is discussed in relation to cell survival, engraftment, and paracrine signaling. Moreover, we examine innovative delivery strategies, such as temperature-responsive cell sheets, injectable hydrogel systems, and 3D-printed constructs. Key challenges, including poor cell retention, immune rejection, and variability in scaffold performance, are addressed along with emerging solutions like bioresponsive materials and multimodal imaging for in vivo cell tracking. Finally, we propose translational perspectives to accelerate the clinical application of scaffold-assisted stem cell therapies for heart repair. Overall, this review synthesizes current advances and emerging technologies to provide a comprehensive roadmap for optimizing scaffold-based stem cell strategies in cardiac regeneration.