Recombinant Lactococcus lactis Expressing Ling Zhi 8 Protein Ameliorates Nonalcoholic Fatty Liver and Early Atherogenesis in Cholesterol-Fed Rabbits

The Anti-Inflammatory Effect of Lactococcus lactis-Ling-Zhi 8 on Ameliorating Atherosclerosis and Nonalcoholic Fatty Liver in High-Fat Diet Rabbits

Inflammation plays a crucial role in atherosclerosis and nonalcoholic fatty liver disease (NAFLD). We previously engineered a recombinant Lactococcus lactis strain expressing the Ling-Zhi immunomodulatory protein (L. lactis-LZ8). This study investigated the anti-atherosclerotic effects of L. lactis-LZ8 in rabbits fed a high-fat diet (HFD). Changes in body weight, serum lipid profiles, and liver function were monitored. The aorta and liver tissues were analyzed for gross pathology and histopathology. Eight-week administration of L. lactis-LZ8 with HFD ameliorated atherosclerosis by downregulating protein and gene expression associated with lipid metabolism and inflammation in the aortas. The rabbits receiving L. lactis-LZ8 exhibited a significant dose-dependent reduction in hepatic fat accumulation. RNA sequencing of the livers revealed that inflammatory genes in the L. lactis-LZ8 groups were downregulated compared to the HFD group. Disease ontology enrichment analysis indicated that these genes were involved in atherosclerosis. Gene set enrichment analysis plots revealed significant enrichment in the gene sets related to cholesterol homeostasis. CIBERSORT immune cell fraction analysis indicated significant infiltration by regulatory T cells, CD8+ T cells, activated dendritic cells, and natural killer cells in the L. lactis-LZ8 group. Our studies underscore LZ8's role in precision nutrition, providing a potential solution to the current challenges in modifying atherosclerosis and NAFLD.

Cardiovascular disease therapeutics via engineered oral microbiota: Applications and perspective

Engineering bacteria are considered as a potential treatment for cardiovascular diseases and related risk factors. Oral bacteria are closely related to the occurrence and development of cardiovascular diseases, and their engineering has broad prospects and potential in the treatment of cardiovascular diseases. Oral pathogenic bacteria undergo protein and genetic engineering, including the incorporation of exogenous plasmids to yield therapeutic effects; genetically engineered oral probiotics can be harnessed to secrete cytokines and reactive oxygen species, offering novel therapeutic avenues for cardiovascular diseases.

Nisin lantibiotic prevents NAFLD liver steatosis and mitochondrial oxidative stress following periodontal disease by abrogating oral, gut and liver dysbiosis

Oral microbiome dysbiosis mediates chronic periodontal disease, gut microbial dysbiosis, and mucosal barrier disfunction that leads to steatohepatitis via the enterohepatic circulation. Improving this dysbiosis towards health may improve liver disease. Treatment with antibiotics and probiotics have been used to modulate the microbial, immunological, and clinical landscape of periodontal disease with some success. The aim of the present investigation was to evaluate the potential for nisin, an antimicrobial peptide produced by Lactococcus lactis, to counteract the periodontitis-associated gut dysbiosis and to modulate the glycolipid-metabolism and inflammation in the liver. Periodontal pathogens, namely Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Fusobacterium nucleatum, were administrated topically onto the oral cavity to establish polymicrobial periodontal disease in mice. In the context of disease, nisin treatment significantly shifted the microbiome towards a new composition, commensurate with health while preventing the harmful inflammation in the small intestine concomitant with decreased villi structural integrity, and heightened hepatic exposure to bacteria and lipid and malondialdehyde accumulation in the liver. Validation with RNA Seq analyses, confirmed the significant infection-related alteration of several genes involved in mitochondrial dysregulation, oxidative phosphorylation, and metal/iron binding and their restitution following nisin treatment. In support of these in vivo findings indicating that periodontopathogens induce gastrointestinal and liver distant organ lesions, human autopsy specimens demonstrated a correlation between tooth loss and severity of liver disease. Nisin's ability to shift the gut and liver microbiome towards a new state commensurate with health while mitigating enteritis, represents a novel approach to treating NAFLD-steatohepatitis-associated periodontal disease.

Engineered probiotics introduced to improve intestinal microecology for the treatment of chronic diseases: present state and perspectives

Purpose

Correcting intestinal microecological imbalance has become one of the core strategies to treat chronic diseases. Some traditional microecology-based therapies targeting intestine, such as prebiotic therapy, probiotic therapy and fecal microbiota transplantation therapy, have been used in the prevention and treatment of clinical chronic diseases, which still facing low safety and poor controllability problems. The development of synthetic biology technology has promoted the development of intestinal microecology-based therapeutics for chronic diseases, which exhibiting higher robustness and controllability, and become an important part of the next generation of microecological therapy. The purpose of this review is to summarize the application of synthetic biology in intestinal microecology-based therapeutics for chronic diseases.

Methods

The available literatures were searched to find out experimental studies and relevant review articles on the application of synthetic biology in intestinal microecology-based therapeutics for chronic diseases from year 1990 to 2023.

Results

Evidence proposed that synthetic biology has been applied in the intestinal microecology-based therapeutics for chronic diseases, covering metabolic diseases (e.g. diabetes, obesity, nonalcoholic fatty liver disease and phenylketonuria), digestive diseases (e.g. inflammatory bowel disease and colorectal cancer), and neurodegenerative diseases (e.g. Alzheimer's disease and Parkinson's disease).

Conclusion

This review summarizes the application of synthetic biology in intestinal microecology-based therapeutics for major chronic diseases and discusses the opportunities and challenges in the above process, providing clinical possibilities of synthetic biology technology applied in microecological therapies.

Ameliorating effect of probiotic on nonalcoholic fatty liver disease and lipolytic gene expression in rabbits

Nonalcoholic fatty liver disease (NAFLD) is a condition that affects about 24% of people worldwide. Increased liver fat, inflammation, and, in the most severe cases, cell death are all characteristics of NAFLD. However, NAFLD pathogenesis and therapy are still not clear enough. Thus, this study aimed to determine the effect of a high-cholesterol diet (HCD) inducing NAFLD on lipolytic gene expression, liver function, lipid profile, and antioxidant enzymes in rabbits and the modulatory effects of probiotic Lactobacillus acidophilus (L. acidophilus) on it. A total of 45 male New Zealand white rabbits, eight weeks old, were randomly divided into three groups of three replicates (5 rabbits/replicate). Rabbits in group I were given a basal diet; rabbits in group II were given a high-cholesterol diet that caused NAFLD; and rabbits in group III were given a high-cholesterol diet as well as probiotics in water for 8 weeks. The results showed that a high-cholesterol diet caused hepatic vacuolation and upregulated the genes for lipoprotein lipase (LPL), hepatic lipase (HL), and cholesteryl ester transfer protein (CETP). Downregulated low-density lipoprotein receptor (LDLr) gene, increased liver enzymes [alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH)], cholesterol, triglycerides (TG), low-density lipoprotein (LDL), glucose, and total bilirubin. On the other hand, it decreased high-density lipoprotein (HDL), total protein, albumin, and liver antioxidants [glutathione peroxidase (GPx), catalase (CAT), reduced glutathione (GSH), and superoxide dismutase (SOD)]. Supplementing with probiotics helped to return all parameters to normal levels. In conclusion, probiotic supplementation, especially L. acidophilus, protected against NAFLD, and restored lipolytic gene expression, liver functions, and antioxidants to normal levels.

Periodontal treatment and microbiome-targeted therapy in management of periodontitis-related nonalcoholic fatty liver disease with oral and gut dysbiosis

A growing body of evidence from multiple areas proposes that periodontal disease, accompanied by oral inflammation and pathological changes in the microbiome, induces gut dysbiosis and is involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). A subgroup of NAFLD patients have a severely progressive form, namely nonalcoholic steatohepatitis (NASH), which is characterized by histological findings that include inflammatory cell infiltration and fibrosis. NASH has a high risk of further progression to cirrhosis and hepatocellular carcinoma. The oral microbiota may serve as an endogenous reservoir for gut microbiota, and transport of oral bacteria through the gastro-intestinal tract can set up a gut microbiome dysbiosis. Gut dysbiosis increases the production of potential hepatotoxins, including lipopolysaccharide, ethanol, and other volatile organic compounds such as acetone, phenol and cyclopentane. Moreover, gut dysbiosis increases intestinal permeability by disrupting tight junctions in the intestinal wall, leading to enhanced translocation of these hepatotoxins and enteric bacteria into the liver through the portal circulation. In particular, many animal studies support that oral administration of Porphyromonas gingivalis, a typical periodontopathic bacterium, induces disturbances in glycolipid metabolism and inflammation in the liver with gut dysbiosis. NAFLD, also known as the hepatic phenotype of metabolic syndrome, is strongly associated with metabolic complications, such as obesity and diabetes. Periodontal disease also has a bidirectional relationship with metabolic syndrome, and both diseases may induce oral and gut microbiome dysbiosis with insulin resistance and systemic chronic inflammation cooperatively. In this review, we will describe the link between periodontal disease and NAFLD with a focus on basic, epidemiological, and clinical studies, and discuss potential mechanisms linking the two diseases and possible therapeutic approaches focused on the microbiome. In conclusion, it is presumed that the pathogenesis of NAFLD involves a complex crosstalk between periodontal disease, gut microbiota, and metabolic syndrome. Thus, the conventional periodontal treatment and novel microbiome-targeted therapies that include probiotics, prebiotics and bacteriocins would hold great promise for preventing the onset and progression of NAFLD and subsequent complications in patients with periodontal disease.

Encouraging Tactics with Genetically Modified Probiotics to Improve Immunity for the Prevention of Immune-Related Diseases including Cardio-Metabolic Disorders

The PI3K/AKT/mTOR signaling pathway may play crucial roles in the pathogenesis of obesity and diabetes mellitus, as well as metabolic syndromes, which could also be risk factors for cardio-metabolic disorders. Consistently, it has been shown that beneficial effects may be convoyed by the modulation of the PI3K/AKT/mTOR pathway against the development of these diseases. Importantly, the PI3K/AKT/mTOR signaling pathway can be modulated by probiotics. Probiotics have a variety of beneficial properties, with the potential of treating specific diseases such as immune-related diseases, which are valuable to human health. In addition, an increasing body of work in the literature emphasized the contribution of genetically modified probiotics. There now seems to be a turning point in the research of probiotics. A better understanding of the interactions between microbiota, lifestyle, and host factors such as genetics and/or epigenetics might lead to a novel therapeutic approach with probiotics for these diseases. This study might provide a theoretical reference for the development of genetically modified probiotics in health products and/or in functional foods for the treatment of cardio-metabolic disorders.

New insights into the interaction between duodenal toxicity and microbiota disorder under copper exposure in chicken: Involving in endoplasmic reticulum stress and mitochondrial toxicity

Copper (Cu) has been widely used in industrial agricultural production, but excess use can lead to toxic effect on host physiology, which poses a threaten to public hygiene. However, the relationship between gut microbiota and Cu-induced intestinal toxicity is unclear. Here, we identified that intestinal flora disturbance was related to duodenal toxicity under Cu exposure. We found that excess Cu disturbed gut microbiota homeostasis, resulting in Cu accumulation and intestinal damage. In addition, Cu considerably increased intestinal permeability by reducing expression of tight junction proteins (Claudlin-1, Occludin, and ZO-1). Meanwhile, Cu could induce endoplasmic reticulum stress, mitophagy, and mitochondria-mediated apoptosis in the duodenum, with the evidence by the elevated levels of GRP78, GRP94, LC3Ⅱ/LC3Ⅰ and Caspase-3 protein expression. Correlation analysis showed that Melainabacteria was closely related to tight junction proteins and endoplasmic reticulum stress of duodenum, indicating that disturbance of intestinal flora may aggravate the toxic effect of Cu. Therefore, our results suggest that the destruction of intestinal flora induced by excessive Cu may further lead to intestinal barrier damage, ultimately leading to endoplasmic reticulum stress, mitophagy and apoptosis. This research provides a new insight into interpretation of the interrelationship between microbiota disorder and duodenal toxicity under Cu exposure.

Ganoderma immunomodulatory proteins: mushrooming functional FIPs

Fungal immunomodulatory protein (FIP) is a novel functional protein family with specific immunomodulatory activity identified from several macro-fungi. A variety of biological activities of FIPs have been reported, such as anti-allergy, anti-tumor, mitogenic activity, and immunomodulation. Among all known FIPs, the firstly discovered FIP was isolated from Ganoderma lucidum, and most FIP members were from Ganoderma genus. Compared with other FIPs, Ganoderma FIPs possess some advantageous bioactivities, like stronger anti-tumor activity. Therein, gene sequences, protein structural features, biofunctions, and recombinant expression of Ganoderma FIPs were summarized and addressed, focusing on elucidating their anti-tumor activity and molecular mechanisms. Combined with current advances, development potential and application of Ganoderma FIPs were also prospected. KEY POINTS: • More than a dozen of reported FIPs are identified from Ganoderma species. • Ganoderma immunomodulatory proteins have superior anti-tumor activity with promising prospects and application. • Current review comprehensively addresses characterization, biofunctions, and anti-tumor mechanisms of Ganoderma FIPs.

The cold - resistance mechanism of a mutagenic Volvariella volvacea strain VH3 with outstanding traits revealed by transcriptome profiling

Background

The straw mushroom (Volvariella volvacea) is one of the important vegetables that is popular for its delicious taste. However, the straw mushroom is sensitive to low temperature, resulting in economic loss during transportation and storage. We obtained a novel straw mushroom strain, named VH3, via ultraviolet mutagenesis.

Results

Our study revealed that VH3 exhibited high cold resistance compared to an ordinary straw mushroom cultivar, V23. We found that the electrolyte leakages of VH3 were always significantly lower than that of V23 treated with 4 °C for 0 h, 2 h,4 h, 8 h, 16 h, and 24 h. Before cold treatment (0 h), there were no difference of MDA contents, SOD activities, and CAT activities between VH3 and V23. At the late stage (8 h, 26 h, and 24 h) of cold treatment, the MDA contents of VH3 were lower while both the SOD and CAT activities were higher than those of V23. To investigate the potential mechanisms of VH3 cold resistance, we performed transcriptome sequencing to detect the transcriptome profiling of VH3 and V23 after 0 h and 4 h cold treatment. Transcriptome sequencing revealed that 111 differentially expressed genes (DEG) between V23 (0 h) and VH3 (0 h) (V23–0_vs_VH3–0), consisting 50 up-regulated and 61 down-regulated DEGs. A total of 117 DEGs were obtained between V23 (4 h) and VH3(4 h) (V23–4_vs_VH3–4), containing 94 up-regulated and 23 down-regulated DEGs. Among these DEGs, VVO_00021 and VVO_00017 were up-regulated while VVO_00003, VVO_00004, VVO_00010, and VVO_00030 were down-regulated in V23–0_vs_VH3–0 and VH3–4_vs_V23–4. KEGG and GO analysis revealed that the 6 DEGs were annotated to pathways related to cold stress. Besides, the GA3 content was also decreased in VH3.

Conclusions

Collectively, our study first revealed that the increased cold resistance of VH3 might be caused by the expression change of VVO_00003, VVO_00004, VVO_00017, VVO_00021, and VVO_00030, and decreased GA₃.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02396-8.

Zearalenone exposure mediated hepatotoxicity via mitochondrial apoptotic and autophagy pathways: Associated with gut microbiome and metabolites

Zearalenone (ZEN), a mycotoxin is frequently detected in different food products and has been widely studied for its toxicity. However, the underlying mechanisms of hepatotoxic effects, relationship between gut microbiome and liver metabolite mediated hepatotoxicity mechanisms induced by ZEN are still not clear. Here, we reported that the different microscopic changes like swelling of hepatocyte, disorganization of hepatocytes and extensive vacuolar degeneration were observed, and the mitochondrial functions decreased in exposed mice. Results exhibited up-regulation in expression of signals of apoptosis and autophagy in liver of treated mice via mitochondrial apoptotic and autophagy pathway (Beclin1/p62). The diversity of gut microbiome decreased and the values of various microbiome altered in treated mice, including 5 phyla (Chloroflexi, Sva0485, Methylomirabilota, MBNT15 and Kryptonia) and genera (Frankia, Lactococcus, Anaerolinea, Halomonas and Sh765B-TzT-35) significantly changed. Liver metabolism showed that the concentrations of 91 metabolite including lipids and lipid like molecules were significantly changed. The values of phosphatidylcholine, 2-Lysophosphatidylcholine and phosphatidate concentrations suggestive of abnormal glycerophosphate metabolism pathway were significantly increased in mice due to exposure to ZEN. In conclusion, the findings suggest that the disorders in gut microbiome and liver metabolites due to exposure to ZEN in mice may affect the liver.

The Enhancing Effect of Fungal Immunomodulatory Protein-Volvariella Volvacea (FIP-vvo) on Maturation and Function of Mouse Dendritic Cells

Volvariella volvacea, also known as straw mushroom, is a common edible mushroom in Chinese cuisine. It contains many nutrients for human health. A fungal immunomodulatory protein (FIP) has been isolated from V. volvacea and named FIP-vvo. Although the regulatory effects of many FIPs on immunity have been identified, the impact of FIP-vvo in modulating dendritic cells (DCs), which play a key role to connect the innate and the adaptive immunity, is not known. In this study, we aim to study the effect of FIP-vvo on the DC maturation and function. We found that FIP-vvo slightly increased the generation of CD11c⁺ bone marrow-derived DC (BMDC). In addition, the surface expression of MHCII was promoted in BMDCs after the treatment of FIP-vvo, suggesting that FIP-vvo induces DC maturation. Furthermore, FIP-vvo enhanced the ability of BMDCs to activate antigen-specific T cell responses in vitro. In the in vivo study, the FIP-vvo treatment facilitated T cell response in lymph nodes. Therefore, for the first time, our data demonstrated that FIP-vvo promoted DC maturation and function and suggested that FIP-vvo could have benefits for human health by enhancing immunity.

Plasmid Replicons for the Production of Pharmaceutical-Grade pDNA, Proteins and Antigens by Lactococcus lactis Cell Factories

The Lactococcus lactis bacterium found in different natural environments is traditionally associated with the fermented food industry. But recently, its applications have been spreading to the pharmaceutical industry, which has exploited its probiotic characteristics and is moving towards its use as cell factories for the production of added-value recombinant proteins and plasmid DNA (pDNA) for DNA vaccination, as a safer and industrially profitable alternative to the traditional Escherichia coli host. Additionally, due to its food-grade and generally recognized safe status, there have been an increasing number of studies about its use in live mucosal vaccination. In this review, we critically systematize the plasmid replicons available for the production of pharmaceutical-grade pDNA and recombinant proteins by L. lactis. A plasmid vector is an easily customized component when the goal is to engineer bacteria in order to produce a heterologous compound in industrially significant amounts, as an alternative to genomic DNA modifications. The additional burden to the cell depends on plasmid copy number and on the expression level, targeting location and type of protein expressed. For live mucosal vaccination applications, besides the presence of the necessary regulatory sequences, it is imperative that cells produce the antigen of interest in sufficient yields. The cell wall anchored antigens had shown more promising results in live mucosal vaccination studies, when compared with intracellular or secreted antigens. On the other side, engineering L. lactis to express membrane proteins, especially if they have a eukaryotic background, increases the overall cellular burden. The different alternative replicons for live mucosal vaccination, using L. lactis as the DNA vaccine carrier or the antigen producer, are critically reviewed, as a starting platform to choose or engineer the best vector for each application.

Oral Immunotherapy Using Probiotic Ice Cream Containing Recombinant Food-Grade Lactococcus lactis Which Inhibited Allergic Responses in a BALB/c Mouse Model

This study was conducted to evaluate the effects of recombinant probiotic bacteria as a candidate for oral vaccine with the potential of treating allergy to Amaranthus retroflexus pollens. The main gene of this allergen, Ama r 2, was cloned into the food grade plasmid pNZ7025 and then was electrotransformed into the food grade Lactococcus lactis NZ1330. No expression was observed in the primary structure due to the distance between the ribosome binding site and the start codon. Therefore, the vector structure was corrected using the site-directed mutagenesis (SDM) technique. The cell extract of this strain was used for assessing the expression of the recombinant allergen in western blot analysis, and the existence of this protein with a molecular weight of 14.2 kDa was confirmed. To evaluate the efficacy of this strain in the treatment of allergies as an oral vaccine, probiotic ice cream was prepared. After the sensitization of mice, the treatment was performed by oral immunotherapy for 4 weeks, 4 to 5 times per week. 20 μl of functional ice cream with 10¹² CFU/ml of r-L. lactis NZ1330 significantly reduced the serum IgE level. The levels of IFN-γ and TGF-β cytokines increased in the 20 μl ice cream treatment group as well as 40 μg/ml pure allergen compared with the PBS-treated group, and IL-4 cytokine levels decreased compared with the PBS-treated group. Overall, 20 μl ice cream with 10¹² CFU/ml of the recombinant bacteria resulted in the best performance in terms of improving allergies to Th1 and Treg responses.

Current Understanding of the Structure and Function of Fungal Immunomodulatory Proteins

Fungal immunomodulatory proteins (FIPs) are a group of proteins found in fungi, which are extensively studied for their immunomodulatory activity. Currently, more than 38 types of FIPs have been described. Based on their conserved structure and protein identity, FIPs can be classified into five subgroups: Fve-type FIPs (Pfam PF09259), Cerato-type FIPs (Pfam PF07249), PCP-like FIPs, TFP-like FIPs, and unclassified FIPs. Among the five subgroups, Fve-type FIPs are the most studied for their hemagglutinating, immunomodulating, and anti-cancer properties. In general, these small proteins consist of 110–125 amino acids, with a molecular weight of ~13 kDa. The other four subgroups are relatively less studied, but also show a noticeable influence on immune cells. In this review, we summarized the protein modifications, 3-dimensional structures and bioactivities of all types of FIPs. Moreover, structure-function relationship of FIPs has been discussed, including relationship between carbohydrate binding module and hemagglutination, correlation of oligomerization and cytokine induction, relevance of glycosylation and lymphocyte activation. This summary and discussion may help gain comprehensive understanding of FIPs' working mechanisms and scope future studies.