Current trends and possibilities of typical microbial protein production approaches: a review.

Global population growth and demographic restructuring are driving the food and agriculture sectors to provide greater quantities and varieties of food, of which protein resources are particularly important. Traditional animal-source proteins are becoming increasingly difficult to meet the demand of the current consumer market, and the search for alternative protein sources is urgent. Microbial proteins are biomass obtained from nonpathogenic single-celled organisms, such as bacteria, fungi, and microalgae. They contain large amounts of proteins and essential amino acids as well as a variety of other nutritive substances, which are considered to be promising sustainable alternatives to traditional proteins. In this review, typical approaches to microbial protein synthesis processes were highlighted and the characteristics and applications of different types of microbial proteins were described. Bacteria, fungi, and microalgae can be individually or co-cultured to obtain protein-rich biomass using starch-based raw materials, organic wastes, and one-carbon compounds as fermentation substrates. Microbial proteins have been gradually used in practical applications as foods, nutritional supplements, flavor modifiers, and animal feeds. However, further development and application of microbial proteins require more advanced biotechnological support, screening of good strains, and safety considerations. This review contributes to accelerating the practical application of microbial proteins as a promising alternative protein resource and provides a sustainable solution to the food crisis facing the world.

Randomized, Single-Blind, Comparative Study of Remimazolam Besylate vs Propofol for Facial Plastic Surgery.

BACKGROUND: Use of local anesthesia and conscious sedation with a combination of a sedative and anesthetic drug during a surgical procedure is an approach designed to avoid intubation, which produces fewer adverse events compared to general anesthesia. In the present study, a comparison was made between the efficacy and safety of remimazolam besylate and propofol for facial plastic surgery. OBJECTIVES: The objective was to evaluate the clinical efficacy, comfort, and incidence of adverse events of remimazolam compared with propofol combined with alfentanil in outpatient facial plastic surgery. METHODS: In this randomized, single-blind, single-center, comparative study, facial plastic surgery patients were randomly divided into remimazolam-alfentanil (n = 50) and propofol-alfentanil (n = 50) groups for sedation and analgesia. The primary endpoint was the incidence of hypoxemia, while secondary endpoints included efficacy and safety evaluations. RESULTS: There were no significant differences regarding the surgical procedure, sedation and induction times, pain and comfort scores, muscle strength recovery, heart rate, respiratory rate, and blood pressure, but the dosage of alfentanil administered to the remimazolam group (387.5 µg) was lower than that for the propofol group (600 µg). The incidence of hypoxemia (P = .046) and towing of the mandibular (P = .028), as well as wake-up (P = .027) and injection pain (P = .008), were significantly higher in the propofol group than the remimazolam group. CONCLUSIONS: Remimazolam and propofol had similar efficacies for sedation and analgesia during facial plastic surgery, but especially the incidence of respiratory depression was significantly lower in patients given remimazolam.

Enhancing solubility and bioavailability of octacosanol: Development of a green O/W nanoemulsion synthesis process.

Octacosanol, a naturally occurring higher fatty alcohol, possessed numerous biological effects. However, octacosanol limited solubility in water due to its lipophilic nature and large structure, resulting in poor absorption and low bioavailability. To overcome this challenge, we developed a simple, environmentally friendly, and energy-efficient O/W nanoemulsion synthesis process. The nanoemulsion achieved an average droplet size of approximately 30 nm, exhibited excellent dispersibility and stability at room temperature for 60 days, and showcased robust storage properties insensitive to ambient temperature, pH, NaCl, and sucrose. Remarkably, the preparation process of the nanoemulsion maintained the biological activity of octacosanol while demonstrating significantly enhancing antioxidant activity compared to octacosanol suspension. Additionally, the nanoemulsion displayed negligible cytotoxic effects on Caco-2 cells. Significantly, the octacosanol nanoemulsion exhibited a 5.4-fold enhancement in transmembrane transport efficiency when compared to the suspension in Caco-2 cell monolayers. Additionally, in an in vivo experiment, there was a notable 2.9-fold increase in rat intestinal absorption. These findings could provide valuable insights into the development of octacosanol nanoemulsion, supporting its future applications and paving the way for the design of stable nanoemulsion systems for other lipophilic and sparingly soluble substances.

Key enzyme in charge of ketone reabsorption of renal tubular SMCT1 may be a new target in diabetic kidney disease.

OBJECTIVE: A ketogenic diet or mildly increased ketone body levels are beneficial for diabetic kidney disease (DKD) patients. Our previous study has found that sodium-coupled monocarboxylate transporter 1 (SMCT1), a key enzyme in charge of ketone reabsorption, possesses beneficial effects on the function of renal tubular epithelial cells (TECs) in energy crisis. Our present study is to investigate whether SMCT1 is important in maintaining the physiological function of renal tubular and plays a role in DKD. METHODS: We tested the expression of SMCT1 in kidney tissues from DKD patients receiving kidney biopsy as well as diabetes mice. We compared the difference of ß-hydroxybutyrate (ß-HB) levels in serum, urine and kidney tissues between diabetic mice and control. Using recombinant adeno-associated viral vector containing SMCT1 (encoded by Slc5a8 gene), we tested the effect of SMCT1 upregulation on microalbuminuria as well as its effects on mitochondrial energy metabolism in diabetic mice. Then we investigated the role of SMCT1 and its ß-HB reabsorption function in maintaining the physiological function of renal tubular using renal tubule-specific Slc5a8 gene knockout mice. Transcriptomes and proteomics analysis were used to explore the underlying mechanism. RESULTS: SMCT1 downregulation was found in DKD patients as well as in diabetic mice. Moreover, diabetic mice had a decreased renal ß-HB level compared with control, and SMCT1 upregulation could improve microalbuminuria and mitochondrial energy metabolism. In renal tubule-specific Slc5a8 gene knockout mice, microalbuminuria occurred early at 24 weeks of age, accompanied by ATP shortage and metabolic reprogramming in the kidney; however, supplementation with ß-HB precursor substance 1,3-butanediol in food alleviated kidney damage as well as energy metabolic reprogramming. CONCLUSIONS: Decreased SMCT1 expression and its ketone reabsorption function play an important role in the occurrence of DKD. SMCT1 may be a new promising target in treating DKD.

Raspberry polyphenols alleviate neurodegenerative diseases: through gut microbiota and ROS signals.

Neurodegenerative diseases are neurological disorders that become more prevalent with age, usually caused by damage or loss of neurons or their myelin sheaths, such as Alzheimer's disease and epilepsy. Reactive oxygen species (ROS) are important triggers for neurodegenerative disease development, and mitigation of oxidative stress caused by ROS imbalance in the human body is important for the treatment of these diseases. As a widespread delicious fruit, the raspberry is widely used in the field of food and medicine because of its abundant polyphenols and other bioactive substances. Polyphenols from a wide variety of raspberry sources could alleviate neurodegenerative diseases. This review aims to summarize the current roles of these polyphenols in maintaining neurological stability by regulating the composition and metabolism of the intestinal flora and the gut-brain axis signal transmission. Especially, we discuss the therapeutic effects on neurodegenerative diseases of raspberry polyphenols through intestinal microorganisms and ROS signals, by means of summary and analysis. Finally, methods of improving the digestibility and utilization of raspberry polyphenols are proposed, which will provide a potential way for raspberry polyphenols to guarantee the health of the human nervous system.

Hyperinsulinemia impairs the metabolic switch to ketone body utilization in proximal renal tubular epithelial cells under energy crisis via the inhibition of the SIRT3/SMCT1 pathway.

Objective: To investigate the effects and mechanism of hyperinsulinemia on the metabolic switch to ß-hydroxybutyrate (BHB) absorption and utilization under a starvation or hypoxic environment in proximal tubular epithelial cells. Methods: A high-fat diet-induced hyperinsulinemia model in ZDF rats was used to test the expression of key enzymes/proteins of ketone body metabolism in the kidney. Notably, 12-week-old renal tubule SMCT1 specific knockout mice (SMCT1 flox/floxCre+) and control mice (SMCT1 flox/floxCre-) were used to confirm the roles of SMCT1 in kidney protection under starvation. The changes of key enzymes/proteins of energy metabolism, mitochondrial function, and albumin endocytosis in HK2 cells under low glucose/hypoxic environments with or without 50 ng/mL insulin were studied. Silent information regulation 2 homolog 3 (SIRT3) was overexpressed to evaluate the effect of hyperinsulinemia on the metabolic switch to BHB absorption and utilization through the SIRT3/SMCT1 pathway in HK2 cells. Results: In ZDF rats, the expression of HMGCS2 increased, the SMCT1 expression decreased, while SCOT remained unchanged. In renal tubule SMCT1 gene-specific knockout mice, starvation for 48 h induced an increase in the levels of urine retinol-binding protein, N-acetyl-ß-glucosaminidase, and transferrin, which reflected tubular damages. In HK2 cells under an environment of starvation and hypoxia, the levels of key enzymes related to fatty acid oxidation and ketone body metabolism were increased, whereas glucose glycolysis did not change. The addition of 2 mmol/l BHB improved ATP production, mitochondrial biosynthesis, and endocytic albumin function, while cell apoptosis was reduced in HK2 cells. The addition of 50 ng/ml insulin resulted in the decreased expression of SMCT1 along with an impaired mitochondrial function, decreased ATP production, and increased apoptosis. The overexpression of SIRT3 or SMCT1 reversed these alterations induced by a high level of insulin both in low-glucose and hypoxic environments. Conclusions: The increased absorption and utilization of BHB is part of the metabolic flexibility of renal tubular epithelial cells under starvation and hypoxic environments, which exhibits a protective effect on renal tubular epithelial cells by improving the mitochondrial function and cell survival. Moreover, hyperinsulinemia inhibits the absorption of BHB through the inhibition of the SIRT3/SMCT1 pathway.

Retinal Neuropathy in IGT Stage of OLETF Rats: Another Characteristic Change of Diabetic Retinopathy.

AIMS: We investigated the changes of retinal structure in normal glucose tolerance (NGT), impaired glucose tolerance (IGT), diabetes mellitus (DM), and diabetic kidney disease (DKD) stages in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. METHODS: We assigned OLETF rats to four groups based on their OGTT results and 24 h urinary microalbumin (24 h UMA) levels: NGT, IGT, DM, and DKD groups. We observed the structural and the corresponding pathological changes and quantified the expression of HIF-1α, iNOS, NF-κB, VEGF, ICAM-1, and occludin in the retina. RESULTS: Significant damage to the retinal structure, especially in retinal ganglion cells (RGCs), was observed in the IGT stage. The expression of HIF-1α, iNOS, NF-κB, VEGF, and ICAM-1 was significantly upregulated, while that of occludin was downregulated. CONCLUSION: Significant retinal neuropathy occurs in the IGT stage. Inflammation and hypoxia may damage the blood retina barrier (BRB), leading to diabetic retinopathy.

[Expression of herpes simplex virus type 2 latency associated transcript ORF1 and its anti-apoptotic function].

To study the expression of herpes simplex virus type 2 latency-associated transcript (LAT) open reading frame 1 (ORF1) and its anti-apoptosis function induced by actinomycin D in Vero cells. The recombinant plasmid pEGFP-ORF1 was constructed and transfected into Vero cells, and the expression of ORF1 was identified by RT-PCR. The changes of Vero cells morphology induced by actinomycin D were observed by fluorescence microscopy, Hochest33258 fluorescence staining. Cells viability was evaluated by MTT assay and cells apoptosis rate was detected by flow cytometry. Double digestion and sequencing confirmed the pEGFP-ORF1 was constructed successfully, RT-PCR showed that the target gene was highly expressed in Vero cells. Hochest33258 staining reaveals that Vero cells transfected with pEGFP-ORF1 and induced apoptosis by actinomycin D had no changes in morphology. MTT assay showed that the viabilities of Vero cells transfected with recombinant plasmid pEGFP-ORF1 and induced apoptosis by actinomycin D has no statistically significant difference compared with the untreated normal control group (P > 0.05), but remarkable higher than Vero cells transfected with empty plasmid pEGFP-C2 and induced apoptosis by actinomycin D, the difference was statistically significant (P < 0.05). Flow cytometry assay shows that the cells apoptosis rate had no significant difference between pEGFP-ORF1 group and the normal group, but the cells apoptosis rate ofpEGFP-ORF1 was lower than the pEGFP-C2 group. HSV-2 LAT ORF1 gene can be expressed in Vero cells and can protect Vero cells from apoptosis induced by actinomycin D.