Katanin regulatory subunit B1 (KATNB1) regulates BTB dynamics through changes in cytoskeletal organization.

In this study, we have explored the role of the KATNB1 gene, a microtubule-severing protein, in the seminiferous epithelium of the rat testis. Our data have shown that KATNB1 expressed in rat brain, testes, and Sertoli cells. KATNB1 was found to co-localize with α-tubulin showing a unique stage-specific distribution across the seminiferous epithelium. Knockdown of KATNB1 by RNAi led to significant disruption of the tight junction (TJ) permeability barrier function in primary Sertoli cells cultured in vitro with an established functional TJ-barrier, as well as perturbations in the microtubule and actin cytoskeleton organization. The disruption in these cytoskeletal structures, in turn, led to improper distribution of TJ and basal ES proteins essential for maintaining the Sertoli TJ function. More importantly, overexpression of KATNB1 in the testis in vivo was found to block cadmium-induced blood-testis barrier (BTB) disruption and testis injury. KATNB1 exerted its promoting effects on BTB and spermatogenesis through corrective spatiotemporal expression of actin- and microtubule-based regulatory proteins by maintaining the proper organization of cytoskeletons in the testis, illustrating its plausible therapeutic implication. In summary, Katanin regulatory subunit B1 (KATNB1) plays a crucial role in BTB and spermatogenesis through its effects on the actin- and microtubule-based cytoskeletons in Sertoli cells and testis, providing important insights into male reproductive biology.

Clinical characteristics and outcomes of acute liver failure in neonates: a retrospective cohort in China.

Neonatal acute liver failure (NALF), as a rare disease with high mortality, has limited relevant literature reports in China. We attempted to analyze a NALF cohort to improve the prognosis of this disease. We included all patients diagnosed with NALF at our institution between 2016 and 2021 and retrospectively reviewed their electronic records. NALF was defined as an INR ≥ 2.0 due to liver disease 28 days after birth. Comparisons were made according to etiology and outcome. The Kaplan-Meier method was used to estimate survival. Fifty-eight patients were included in this study. Etiologies included hypoxic/ischemic injury (29.3%), infection (27.6%), gestational alloimmune liver disease with neonatal hemochromatosis (GALD-NH) (10.3%), inherited metabolic diseases (5.2%), hemophagocytic lymphohistiocytosis (1.7%), other etiologies (12.1%), and unidentified causes (13.8%). Enteroviruses constituted 87.5% of the viral infections, whereas herpes simplex virus accounted for no infections. The median INR was significantly lower in the infection group than in the GALD-NH group (P < 0.05 for multiple comparisons). At the last follow-up, none of the patients had undergone liver transplantation, and the overall mortality rate was 50%. Liver function completely recovered in 31% of the patients, all of whom survived. The overall median survival time was 48 days; 26 days for hypoxic/ischemic injury and 43 days for GALD-NH. The incidence of cholestasis was significantly greater among surviving patients (P = 0.018).   Conclusion: Hypoxic/ischemic injury and infection are the predominant etiologies of NALF in China. The overall prognosis of NALF is poor, but its short-term prognosis is determined by the etiology. What is Known: • Neonatal acute liver failure (NALF) is a rare disorder with limited cohort studies, especially in China. • Gestational alloimmune liver disease, viral infections (especially herpes simplex virus), metabolic diseases and ischemic insults are common etiologies of NALF, which are significantly different from other populations. • There are no reliable biochemical markers to predict the outcome of NALF. What is New: • In this first report on a Chinese NALF cohort, we demonstrate that hypoxic/ischemic injury and infection (excluding herpes simplex virus) are the predominant etiologies of NALF. • The overall prognosis of NALF is poor, and its etiology determines the short-term outcome.

Structure and biological activities of glycoproteins and their metabolites in maintaining intestinal health.

Glycoproteins formed by covalent links between oligosaccharide and polypeptides are abundant in various food sources. They are less sensitivity to gastrointestinal enzymes, and hence many of them undergo fermentation in the colon by microorganisms. Therefore, the confer various health benefits on the intestinal ecosystem. However, the current understanding of the effect of glycoproteins on intestinal microorganisms and gut health is limited. This is probably due to their heterogeneous structures and complex metabolic programming patterns. The structure and biological activities of glycoproteins and their microbial metabolites were summarized in this review. The metabolic pathways activated by intestinal bacteria were then discussed in relation to their potential benefits on gut health. Food-derived glycoproteins and their metabolites improve gut health by regulating the intestinal bacteria and improving intestinal barrier function, thereby amplifying immune response. The data reviewed here show that food-derived glycoproteins are promising candidates for preventing various gastrointestinal diseases. Further studies should explore the interaction mechanisms between intestinal microorganisms and host metabolites.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1987857 .

Circ_ATAD3B inhibits cell proliferation of breast cancer via mediating the miR-570-3p/MX2 axis.

It has been discovered that some circular RNAs can serve as excellent therapeutic targets for breast cancer (BC). However, the biological role that circ ATAD3B plays in BC is not yet completely understood. As a result, the purpose of this work was to evaluate the function of circ_ATAD3B in the development of BC. Three different GEO datasets were used to compile the expression profiles of circRNAs related to BC (GSE101124, GSE165884, and GSE182471). CCK-8 and the production of clones, in addition to RT-PCR and western blot assays, were utilized in this study to evaluate the regulation of these three biological molecules in the process of BC carcinogenesis.circ_ATAD3B was the only potential BC-related circRNA that was significantly reduced in BC tumor tissues, and it functioned as a miR-570-3p sponge to suppress cell survival and proliferation, as stated by the aforementioned two algorithms. The expression of MX2 was boosted when circ_ATAD3B was used to sponge miR-570-3p. The inhibitory effect that circ_ATAD3B has on the malignant phenotype of BC cells was overcome by the expression of miR-570-3p through up-regulation and MX2 through down-regulation. The tumor suppressor circ_ATAD3B prevents cancer progression by regulating the miR-570-3p/MX2 pathway. Circ_ATAD3B may be a candidate for targeted therapy of breast cancer.

RAMP2-AS1 stabilized RAPM2 mRNA through TIA1 to inhibit the progression of non-small cell lung cancer.

As the most common subtype of lung cancer, non-small cell lung cancer (NSCLC)is responsible for a large proportion of global cancer-caused deaths. The implication of long non-coding RNAs (lncRNAs) as tumor-suppressor or carcinogenic genes in NSCLC has been widely documented. Our study sought to investigate the performance of lncRNA RAMP2 antisense RNA1 (RAMP2-AS1) in NSCLC. GEPIA bioinformatics tool and RT-qPCR were applied for assessing the expression of RAMP2-AS1 and its neighboring gene receptor activity-modifying protein 2 (RAMP2) in NSCLC. Functional assays including CCK-8 assay, colony formation assay as well as caspase-3 activity analysis and Transwell invasion assays were applied for detecting the biological phenotypes of NSCLC cells. Interaction among RAMP2-AS1, RAMP2 and T-cell intracellular antigen 1cytotoxic granule associated RNA binding protein (TIA1) was evaluated by RNA immunoprecipitation and pulldown assays. We found that RAMP2-AS1 and RAMP2 were downregulated in NSCLC. Overexpression of RAMP2-AS1 hampered proliferation and invasion, whereas induced apoptosis of NSCLC cells. Mechanistically, RAMP2-AS1 interacted with TIA1 to stabilize the mRNA of RAMP2. In conclusion, we first uncovered that RAMP2-AS1 stabilized RAPM2 mRNA through TIA1 to inhibit the progression of NSCLC, providing new insight to improve the treatment efficacy of NSCLC.

A bifunctional agent for efficient imaging of PD-L1 and antimelanoma activity.

Immune checkpoint inhibitors targeting PD-L1 lead to challenging patterns of efficacy and toxicity. Herein, by focusing on tracing the molecular biomarker of response to efficacy, we formulated a central hypothesis for the construction of theranostic functional monoclonal antibody incorporation with tracing ability based on fluorescence turn-on and controllable release strategies. Functional atezolizumab was constructed by in situ assembly of both biorthogonal group and controllable release group. The theranostic monoclonal antibodies achieved quantitative monitoring of PD-L1 on cells with different expression levels through biorthogonal light-up fluorescence, followed by the release of atezolizumab in combination with high tumor reduction conditions to promote immune activation. The combination of bio-orthogonal reaction-driven fluorescence turn-on and tumor microenvironment-responsive controllable release afforded theranostic bifunctional monoclonal antibodies for the detection of PD-L1 and combination therapy. Remarkably, these novel theranostics might be used as probes for fluorescent imaging and simultaneously achieving potent antitumor efficacy.

Identification of potential targets against SARS-CoV-2 of antiviral drugs based on photoaffinity probes.

Facing the sudden outbreak of coronavirus disease 2019 (COVID-19), it is extremely urgent to develop effective antiviral drugs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Drug repurposing is a promising strategy for the treatment of COVID-19. To identify the precise target protein of marketed medicines, we initiate a chemical biological program to identify precise target of potential antivirus drugs. In this study, two types of recombinant human coronavirus SARS-CoV-2 RdRp protein capturing probes with various photoaffinity labeling units were designed and synthesized based on the structure of FDA-approved drugs stavudine, remdesivir, acyclovir, and aladenosine. Fortunately, it was found that one novel photoaffinity probe, RD-1, could diaplayed good affinity with SARS-CoV-2 RdRp around the residue ARG_553. In addition, RD-1 probe also exhibited potent inhibitory activity against 3CLpro protease. Taken together, our findings will elucidate the structural basis for the efficacy of marketed drugs, and explore a rapid and efficient strategy of drug repurposing based on the identification of new targets. Moreover, these results could also provide a scientific basis for the clinical application of marketed drugs.

Structure and in vitro digestion characteristics of skim goat milk protein during processing: effects of fat separation.

BACKGROUND: Although nonfat milk has been used worldwide in the industrial dairy process, little is known about the effects of fat separation during the manufacturing process on skim milk's structural and digestive properties. This study investigated the effects of the manufacturing process on the structure and in vitro digestion properties of skim goat milk, particularly emphasizing fat separation. RESULTS: Changes in the surface charge and hydrophobicity of milk proteins caused by fat separation resulted in oxidation and aggregation in the subsequent homogenization, heat and spray-drying processing, which affected its digestibility. Compared with separation by dish separator (DS), skim milk after tubular centrifugal separation (CS) showed a higher initial and final digestibility. The CS samples also had a lower surface hydrophobicity level and higher free sulfhydryl content, ζ-potential, and average particle size (P < 0.05). Goat milk protein after CS was more readily oxidized and aggregated during the subsequent homogenization and heat treatment, as evidenced by the higher carbonyl content and particle size. Centrifugal separation also converted more ß-sheets to α-helices, thus promoting the aggregation of oxidized skim milk protein. CONCLUSION: The skim milk after CS and DS demonstrated different structural and digestive properties. Skim goat milk products after CS were more susceptible to oxidant-induced protein structural changes, resulting in higher protein digestibility. These findings provide insights into the mechanism involved in the control of gastric digestion of skim milk during manufacturing process. © 2023 Society of Chemical Industry.

Lactobacillus coryniformis MXJ32 administration ameliorates azoxymethane/dextran sulfate sodium-induced colitis-associated colorectal cancer via reshaping intestinal microenvironment and alleviating inflammatory response.

PURPOSE: Gut microbiota has been reported to contribute to either prevent or promote colorectal cancer (CRC), and treatment with probiotics might be a promising intervention method. The present study aimed to evaluate the potential anti-CRC effects of Lactobacillus coryniformis MXJ32 on a colitis-associated (CA)-CRC mouse model. METHODS: The CA-CRC mouse model was induced by a single intraperitoneal injection of 10 mg/kg azoxymethane and followed by three 7-day cycles of 2% dextran sulfate sodium in drinking water with a 14-day recovery period. Mice were supplemented with L. coryniformis MXJ32 by oral gavage (1 × 109 CFU/day/mouse). The CA-CRC attenuating effects of this probiotic were assessed via intestinal barrier integrity, inflammation, and gut microenvironment. RESULTS: Treatment with L. coryniformis MXJ32 could significantly inhibit the total number of tumors and the average tumor diameter. This probiotic administration prevented the damage of intestinal barrier function by enhancing the expression of tight junction proteins (Occludin, Claudin-1, and ZO-1) and recovering the loss of goblet cells. Moreover, L. coryniformis MXJ32 alleviated intestinal inflammation via down-regulating the expression of inflammatory cytokines (TNF-α, IL-1ß, IL-6, IL-γ, and IL-17a) and chemokines (Cxcl1, Cxcl2, Cxcl3, Cxcl5, and Ccl7). In addition, L. coryniformis MXJ32 supplementation increased the abundance of some beneficial bacteria (such as SCFAs-producing bacteria, Lactobacillus, Bifidobacterium, Akkermansia, and Faecalibaculum) and decreased the abundance of some harmful bacteria (such as pro-inflammatory bacteria, Desulfovibrio and Helicobacter), which in turn attenuated the overexpression of inflammation. CONCLUSION: Lactobacillus coryniformis MXJ32 could effectively ameliorate CA-CRC via regulating intestinal microenvironment, alleviating inflammation, and intestinal barrier damage, which further suggested that L. coryniformis MXJ32 could be considered as a functional food ingredient for the alleviation of CA-CRC.

Full components conversion of lignocellulose via a closed-circuit biorefinery process on a pilot scale.

This study developed a closed-circuit biorefinery process for full conversion of lignocellulose into ethanol, biogas and organic fertilizer with zero waste on a pilot scale. In the process, subcritical water pretreatment could effectively break the structure of wheat straw (WS), and ethanol was obtained from pretreated wheat straw (PWS) using two batches of simultaneous saccharification and fermentation (SSF). The pretreatment and ethanol fermentation wastes were reused for biogas and organic fertilizer production by anaerobic digestion (AD), whereas the pretreatment and ethanol conversion efficiency were reduced when supernatant after AD was recovered for next batch pretreatment. The yields of ethanol (0.08-0.09 g/g), biogas (0.05-0.10 L/g) and organic fertilizer (0.55-0.79 g/g) were demonstrated through mass balance. Furthermore, the hidden problems were exposed on pilot-scale conversion process, and several strategies were provided for optimizing the biorefinery process in the future.

Bleeding in neonates with severe thrombocytopenia: a retrospective cohort study.

BACKGROUND: Severe neonatal thrombocytopenia is a rare disease with multiple etiologies. Severe thrombocytopenia with bleeding is life-threatening and has attracted significant attention from clinicians. However, only a few studies have focused on the association between severe thrombocytopenia and bleeding. Thus, this study aimed to describe the neonates' postnatal age at which severe thrombocytopenia was first recognized, clinical characteristics, bleeding patterns, and outcomes and to evaluate the association between minimum platelet count and bleeding. METHODS: A single-center retrospective cohort study for neonates with severe thrombocytopenia (platelet count ≤ 50 × 109/L) was conducted. Neonates who were admitted to our neonatal intensive care unit between October 2016 and February 2021 and developed severe thrombocytopenia were analyzed. Data were collected retrospectively until the patients were referred to other hospitals, discharged, or deceased. RESULTS: Among the 5819 neonatal inpatients, 170 with severe thrombocytopenia were included in this study. More than 30% of the patients had severe thrombocytopenia in the first 3 days of life. Among the 118 neonates with bleeding, 47 had more than one type of pathological bleeding. Neonates with very severe thrombocytopenia (point estimate: 53.7%, 95% confidence interval [CI]: 44.2%-63.1%) had a higher incidence rate of cutaneous bleeding than those with severe thrombocytopenia (point estimate: 23.4%, 95% CI: 12.3%-34.4%). The gestational age (median: 36.2 [interquartile range [IQR]: 31.4-39.0] weeks) and birth weight (median: 2310 [IQR: 1213-3210] g) of the major bleeding group were the lowest among no bleeding, minor bleeding, and major bleeding groups. Regression analysis controlled for confounders and confirmed that a lower platelet count (odds ratio [OR]: 2.504 [95% CI: 1.180-5.314], P = 0.017) was associated with a significant increase in the rate of bleeding. Very severe thrombocytopenia (point estimate: 49.1%, 95% CI: 39.6%-58.6%) had a higher rate of platelet transfusion than severe thrombocytopenia (point estimate: 5.7%, 95% CI: 0.7%-10.7%). The mortality rate was higher in neonates with bleeding than in those without bleeding (point estimates with 95% CI: 33.1% [24.4%-41.7%] vs. 7.7% [0.2%-15.2%]). CONCLUSIONS: These findings describe the incidence of severe thrombocytopenia and demonstrate that a lower platelet count is associated with an increased bleeding rate in patients with severe thrombocytopenia.

Design, synthesis, and biological evaluation of novel Bcr-AblT315I inhibitors incorporating amino acids as flexible linker.

Despite the success of imatinib in CML therapy through Bcr-Abl inhibition, acquired drug resistance occurs over time in patients. In particular, the resistance caused by T315I mutation remains a challenge in clinic. Herein, we embarked on a structural optimization campaign aiming at discovery of novel Bcr-Abl inhibitors toward T315I mutant based on previously reported dibenzoylpiperazin derivatives. We proposed that incorporation of flexible linker could achieve potent inhibition of Bcr-AblT315I by avoiding steric clash with bulky sidechain of Ile315. A library of 28 compounds with amino acids as linker has been developed and evaluated. Among them, compound AA2 displayed the most potent activity against Bcr-AblWT and Bcr-AblT315I, as well as toward Bcr-Abl driven K562 and K562R cells. Further investigations indicated that AA2 could induce apoptosis of K562 cells and down regulate phosphorylation of Bcr-Abl. In summary, the compounds with amino acid as novel flexible linker exhibited certain antitumor activities, providing valuable hints for the discovery of novel Bcr-Abl inhibitors to overcome T315I mutant resistance, and AA2 could be considered as a candidate for further optimization.

Exploring the potential intracellular targets of vascular normalization based on active candidates.

We previously developed two candidates with potency of inducing vascular normalization, BD7 and B14. However, the definite intracellular molecular target(s) responsible for their activity remains unknown. Herein, we report the discovery and functional assessment of several multifunctional photoaffinity probes for determining the potential biological targets of active compounds. The probes bear a photoaffinity moiety and a bioorthogonal unit attached to B7 or B14 and maintained the bioactivity of the parent active molecules. Using in vitro biological assays, we preliminarily identified VEGFR-2 as a potential intracellular target for the active candidates. Our results demonstrate the utility of these multifunctional photoaffinity probes for analyzing the biological activity and subcellular localization of the intracellular target proteins of active candidates.

Purification, characterization, and mode of action of a novel bacteriocin BM173 from Lactobacillus crustorum MN047 and its effect on biofilm formation of Escherichia coli and Staphylococcus aureus.

There is an increasing demand for dairy products, but the presence of food-spoilage bacteria seriously affects the development of the dairy industry. Bacteriocins are considered to be a potential antibacterial or antibiofilm agent that can be applied as a preservative. In this study, bacteriocin BM173 was successfully expressed in the Escherichia coli expression system and purified by a 2-step method. Furthermore, it exhibited a broad-spectrum antibacterial activity, high thermal stability (121°C, 20 min), and broad pH stability (pH 3-11). Moreover, the minimum inhibitory concentration values of BM173 against E. coli ATCC 25922 and Staphylococcus aureus ATCC 25923 were 14.8 µg/mL and 29.6 µg/mL, respectively. Growth and time-kill curves showed that BM173 exhibited antibacterial and bactericidal activity. The results of scanning electron microscopy and transmission electron microscopy demonstrated that BM173 increased membrane permeability, facilitated pore formation, and even promoted cell lysis. The disruption of cell membrane integrity was further verified by propidium iodide uptake and lactic dehydrogenase release. In addition, BM173 exhibited high efficiency in inhibiting biofilm formation. Therefore, BM173 has promising potential as a preservative used in the dairy industry.

Mining, heterologous expression, purification, antibactericidal mechanism, and application of bacteriocins: A review.

Bacteriocins are generally considered as low-molecular-weight ribosomal peptides or proteins synthesized by G+ and G- bacteria that inhibit or kill other related or unrelated microorganisms. However, low yield is an important factor restricting the application of bacteriocins. This paper reviews mining methods, heterologous expression in different systems, the purification technologies applied to bacteriocins, and identification methods, as well as the antibacterial mechanism and applications in three different food systems. Bioinformatics improves the efficiency of bacteriocins mining. Bacteriocins can be heterologously expressed in different expression systems (e.g., Escherichia coli, Lactobacillus, and yeast). Ammonium sulfate precipitation, dialysis membrane, pH-mediated cell adsorption/desorption, solvent extraction, macroporous resin column, and chromatography are always used as purification methods for bacteriocins. The bacteriocins are identified through electrophoresis and mass spectrum. Cell envelope (e.g., cell permeabilization and pore formation) and inhibition of gene expression are common antibacterial mechanisms of bacteriocins. Bacteriocins can be added to protect meat products (e.g., beef and sausages), dairy products (e.g., cheese, milk, and yogurt), and vegetables and fruits (e.g., salad, apple juice, and soybean sprouts). The future research directions are also prospected.

Screening of cellulolytic bacteria from rotten wood of Qinling (China) for biomass degradation and cloning of cellulases from Bacillus methylotrophicus.

BACKGROUND: Cellulosic biomass degradation still needs to be paid more attentions as bioenergy is the most likely to replace fossil energy in the future, and more evaluable cellulolytic bacteria isolation will lay a foundation for this filed. Qinling Mountains have unique biodiversity, acting as promising source of cellulose-degrading bacteria exhibiting noteworthy properties. Therefore, the aim of this work was to find potential cellulolytic bacteria and verify the possibility of the cloning of cellulases from the selected powerful bacteria. RESULTS: In present study, 55 potential cellulolytic bacteria were screened and identified from the rotten wood of Qinling Mountains. Based on the investigation of cellulase activities and degradation effect on different cellulose substrates, Bacillus methylotrophicus 1EJ7, Bacillus subtilis 1AJ3 and Bacillus subtilis 3BJ4 were further applied to hydrolyze wheat straw, corn stover and switchgrass, and the results suggested that B. methylotrophicus 1EJ7 was the most preponderant bacterium, and which also indicated that Bacillus was the main cellulolytic bacteria in rotten wood. Furthermore, scanning electron microscopy (SEM) and X-ray diffraction analysis of micromorphology and crystallinity of wheat straw also verified the significant hydrolyzation. With ascertaining the target sequence of cellulase ß-glucosidase (243 aa) and endoglucanase (499 aa) were successfully heterogeneously cloned and expressed from B. methylotrophicus 1EJ7, and which performed a good effect on cellulose degradation with enzyme activity of 1670.15 ± 18.94 U/mL and 0.130 ± 0.002 U/mL, respectively. In addition, based on analysis of amino acid sequence, it found that ß-glucosidase were belonged to GH16 family, and endoglucanase was composed of GH5 family catalytic domain and a carbohydrate-binding module of CBM3 family. CONCLUSIONS: Based on the screening, identification and cellulose degradation effect evaluation of cellulolytic bacteria from rotten wood of Qinling Mountains, it found that Bacillus were the predominant species among the isolated strains, and B. methylotrophicus 1EJ7 performed best on cellulose degradation. Meanwhile, the ß-glucosidase and endoglucanase were successfully cloned and expressed from B. methylotrophicus for the first time, which provided new materials of both strain and the recombinant enzymes for the study of cellulose degradation and its application in industry.

Anti-obesity effect of Lactobacillus rhamnosus LS-8 and Lactobacillus crustorum MN047 on high-fat and high-fructose diet mice base on inflammatory response alleviation and gut microbiota regulation.

PURPOSE: The objective of the study was to evaluate the anti-obesity effect of Lactobacillus rhamnosus LS-8 and Lactobacillus crustorum MN047, and illustrate the potential functional mechanism about the alleviation of high fat and high fructose diet (HFFD) induced obesity and related metabolic abnormalities. METHODS: C57BL/6J mice were subjected to a standard or HFFD with or without supplementation of L. rhamnosus LS-8 and L. crustorum MN047 for 10 weeks. Obesity related metabolic indices including glucose tolerance, insulin resistance, serum lipid, liver function, hormones and inflammatory cytokines were assessed by standard protocols. For the monitoring of inflammatory response and lipid metabolism, transcriptional levels were profiled in liver and/or adipose tissues. Furthermore, gut microbiota composition analyses in the fecal samples were performed using 16S rRNA gene sequencing, and gut microbial metabolites, including lipopolysaccharide (LPS) and short-chain fatty acids (SCFAs), were also tested for the assessment of the relationship between gut microbiota variation and inflammatory response. RESULTS: Administration with L. rhamnosus LS-8 and L. crustorum MN047 significantly mitigated body weight gain and insulin resistance, and inflammatory response (TNF-α, IL-1ß and IL-6 levels in serum and corresponding mRNA levels in adipose tissues) was significantly inhibited in these two strains-treated mice. Moreover, L. rhamnosus LS-8 and L. crustorum MN047 could partially normalized mRNA expression levels involved in lipid metabolism including Pparγ, Srebp-1c, CD36, Fabp2 and FAS. In addition, these two strains manipulated gut microbiota by decreasing the abundance of Bacteroides and Desulfovibrio and increasing that of Lactobacillus and Bifidobacterium, which in turn raised the levels of feces SCFAs and lowered the levels of circulating LPS. CONCLUSION: These results indicated that L. rhamnosus LS-8 and L. crustorum MN047 supplementation possessed the anti-obesity effect on the HFFD fed mice by alleviating inflammatory response and regulating gut microbiota, which further suggested that these two probiotics can be considered as an alternative dietary supplement in combination with the preventive and therapeutic strategies against obesity and related complications.

Fermentation optimization and kinetic model for high cell density culture of a probiotic microorganism: Lactobacillus rhamnosus LS-8.

To develop a practical food-grade medium and optimal fermentation process for the cost-effective fermentation of Lactobacillus rhamnosus LS-8, both culture medium and conditions were optimized by combining single-factor experimental design, Plackett-Burman design and Box-Behnken design. The medium was simplified to five ingredients (g/L): whey powder (62.5), maltose syrup (50), corn steep liquor (55), NaCl (1) and lysine (0.05), and the optimal culture conditions were initial pH (6.28), constant fermentation pH (4.7), neutralizing agent (NaOH), aeration rate (0.2 v/v/min) and stirrer speed (200 rpm). After culturing in this optimized medium and conditions, the cell density of L. rhamnosus LS-8 was improved to 4.5 × 109 CFU/mL, which was elevated about 9 times higher than that obtained in MRS medium. Moreover, cell growth and substrate consumption kinetic constants were determined by the logistic equation and Luedeking-Piret model, and the R2 values from the model equation were 0.9900 and 0.9971, respectively, indicating that these models were able to simulate the growth and substrate consumption of L. rhamnosus LS-8 accurately. In addition, a high-efficient production process of L. rhamnosus LS-8 was developed by repeated-batch operation, which was verified by five cycles of fermentation with good stability and repeatability. In conclusion, the efficiency of L. rhamnosus LS-8 fermentation was greatly improved as well as the reduction of the cost using the medium and process developed in the present study.

Flurbiprofen Inhibits Androgen Productions in Rat Immature Leydig Cells.

Flurbiprofen is one of the nonsteroidal anti-inflammatory drugs. Whether flurbiprofen affects androgen biosynthesis in Leydig cells is still unknown. Immature Leydig cells (ILCs) isolated from 35-day-old male Sprague-Dawley rats were cultured with 0-100 µM flurbiprofen for 24 h and medium androgen levels and Leydig cell mRNA levels were measured. Immature Leydig cells were also incubated with 100 µM flurbiprofen for 3 h in combination with luteinizing hormone (LH), 8bromo-cAMP, 22R-OH-cholesterol, pregnenolone, progesterone, androstenedione, testosterone, and dihydrotestosterone, respectively, and medium androgen levels were measured. The ROS generation and apoptosis rate were also investigated. The direct effects of flurbiprofen on androgen biosynthetic and metabolizing enzyme activities were measured. Flurbiprofen significantly inhibited basal, LH, and 8bromo-cAMP stimulated androgen production at 10 and 100 µM. Further study demonstrated that flurbiprofen competitively inhibited rat and human testis 3ß-hydroxysteroid dehydrogenase (HSD3B) activity with the half maximal inhibitory concentration (IC50) values of 0.95 µM for rat enzyme and 6.31 µM for human enzyme. In addition, flurbiprofen down-regulated the expression of Srd5a1 and Akr1c14 at 1, 10, and 100 µM. Flurbiprofen also down-regulated Lhcgr expression at 100 µM. Flurbiprofen at 10 and 100 µM increased ROS production and apoptosis rate of rat Leydig cells. In conclusion, flurbiprofen directly inhibits HSD3B activity and the expression levels of Srd5a1 and Akr1c14 in rat Leydig cells, thus leading to the reduction of androgen secretion.

Isolation of nitrite-degrading strains from Douchi and their application to degrade high nitrite in Jiangshui.

BACKGROUND: Excessive nitrite in food is potentially harmful to human health because of carcinogenic effects caused by its nitroso-derivatives. Douchi, which widely distributed throughout the country, is a traditional solid fermented soybean food with low nitrite content. RESULTS: In this study, bacteria which can degrade nitrite were isolated from Douchi and identified from their 16S rDNA sequences. Acinetobacter guillouiae, Acinetobacter bereziniae, Bacillus subtilis, Bacillus tequilensis, Bacillus amyloliquefaciens, Bacillus licheniformis, Bacillus aryabhattai and Bacillus methylotrophicus were selected. It was shown that all strains were able to degrade nitrite to some extent, including Bacillus subtilis NDS1, which was able to degrade 99.41% of nitrite. The enzyme activities of these strains were determined at 24 and 48 h and were shown to correspond with their nitrite degradation rates. The strains were used to inoculate Jiangshui, a kind of traditional fermented vegetable from northwest China that often has a high nitrite content. Of the strains tested, Bacillus subtilis NDS1, Bacillus tequilensis NDS3, Acinetobacter bereziniae NDS4, Bacillus subtilis NDS6, and Bacillus subtilis NDS12 were able to degrade nitrite in Jiangshui more rapidly, with Acinetobacter bereziniae NDS4 degrading almost all nitrite in 48 h compared with 180 h of control. CONCLUSION: These results indicate that the selected strains have potential to be used as nitrite-degrading agents in food. © 2018 Society of Chemical Industry.