Effect of Limosilactobacillus fermentum 332 on physicochemical characteristics, volatile flavor components, and Quorum sensing in fermented sausage.

The effects of Limosilactobacillus fermentum 332 on quality characteristics in fermented sausage were explored in terms of physicochemical characteristics, volatile flavor components, and Quorum sensing (QS). The results showed that the pH of fermented sausage decreased from 5.20 to 4.54 within 24 h with the inoculation of L. fermentum 332. Lightness and redness were significantly improved, and hardness and chewiness were significantly increased after the addition of L. fermentum 332. With the inoculation of L. fermentum 332, the thiobarbituric acid reactive substance content decreased from 0.26 to 0.19 mg/100 g and total volatile basic nitrogen content decreased from 2.16 to 1.61 mg/100 g. In total, 95 and 104 types of volatile flavor components were detected in the control and fermented sausage inoculated with starter culture, respectively. The AI-2 activity of fermented sausage inoculated with L. fermentum 332 was significantly higher than that of the control and positively correlated with viable count and quality characteristics. These results provide support for further research on the effect of microorganisms on the quality of fermented food.

LBX2-AS1 as a Novel Diagnostic Biomarker and Therapeutic Target Facilitates Multiple Myeloma Progression by Enhancing mRNA Stability of LBX2.

Objective: Multiple myeloma (MM) represents a common age-associated malignancy globally. The function and underlying mechanism of antisense lncRNA LBX2-AS1 remain ambiguous in multiple myeloma (MM). Herein, we aimed to observe the biological implication of this lncRNA in MM. Methods: RT-qPCR was employed to examine circulating LBX2-AS1 and LBX2 in 60 paired MM and healthy subjects. Correlation between the two was analyzed by Pearson test. Under transfection with shLBX2-AS1, proliferation and apoptosis were evaluated in MM cells through CCK-8, colony formation and flow cytometry. LBX2 expression was examined in MM cells with shLBX2-AS1 or pcDNA3.1-LBX2 transfection. Following treatment with cycloheximide or actinomycin D, LBX2 expression was examined in pcDNA3.1-LBX2-transfected MM cells at different time points. Rescue assays were then presented. Finally, xenograft tumor models were established. Results: Circulating LBX2-AS1 was up-regulated in MM patients and positively correlated to LBX2 expression. Area under the curve (AUC) of LBX2-AS1 expression was 0.7525. Its up-regulation was also found in MM cells and primarily distributed in cytoplasm. LBX2-AS1 knockdown distinctly weakened proliferative ability and induced apoptosis in MM cells. Overexpressing LBX2-AS1 markedly strengthened LBX2 expression by increasing its mRNA stability. Rescue assays showed that silencing LBX2-AS1 distinctly weakened the pcDNA3.1-LBX2-induced increase in proliferation and decrease in apoptosis for MM cells. Silencing LBX2-AS1 markedly weakened tumor growth. Conclusion: Our data demonstrated that circulating LBX2-AS1 could be an underlying diagnostic marker in MM. Targeting LBX2-AS1 suppressed tumor progression by affecting mRNA stability of LBX2 in MM. Hence, LBX2-AS1 could be a novel therapeutic marker against MM.

FABP5, a Novel Immune-Related mRNA Prognostic Marker and a Target of Immunotherapy for Multiple Myeloma.

Objective: Multiple myeloma is an incurable hematological malignancy. It is imperative to identify immune markers for early diagnosis and therapy. Here, this study analyzed immune-related mRNAs and assessed their prognostic value and therapeutic potential. Methods: Abnormally expressed immune-related mRNAs were screened between multiple myeloma and normal bone marrow specimens in the GSE47552 and GSE6477 datasets. Their biological functions were then explored. Survival analysis was presented for assessing prognosis-related mRNAs. CIBERSORT was utilized for identifying 22 immune cell compositions of each bone marrow specimen. Correlation between FABP5 mRNA and immune cells was then analyzed in multiple myeloma. Results: Thirty-one immune-related mRNAs were abnormally expressed in multiple myeloma, which were primarily enriched in B cells-related biological processes and pathways. Following validation, FABP5 mRNA was a key risk factor of multiple myeloma. Patients with its up-regulation usually experienced unfavorable outcomes. There were distinct differences in the infiltration levels of B cells naïve, B cells memory, plasma cells, T cells CD4 naïve, resting memory CD4 T cells, activated memory CD4 T cells, Tregs, resting NK cells, M0 macrophages, M1 macrophages, M2 macrophages, and neutrophils between multiple myeloma and normal samples. FABP5 mRNA had correlations to B cells memory, B cells naïve, dendritic cells activated, macrophages M0, macrophages M1, macrophages M2, neutrophils, activated NK cells, resting memory CD4 T cells, CD8 T cells and Tregs. Conclusion: Collectively, our data showed that FABP5 mRNA was related to immune microenvironment, which could be a target of immunotherapy and prognostic marker for multiple myeloma.

AKT Degradation Selectively Inhibits the Growth of PI3K/PTEN Pathway-Mutant Cancers with Wild-Type KRAS and BRAF by Destabilizing Aurora Kinase B.

Using a panel of cancer cell lines, we characterized a novel degrader of AKT, MS21. In mutant PI3K-PTEN pathway cell lines, AKT degradation was superior to AKT kinase inhibition for reducing cell growth and sustaining lower signaling over many days. AKT degradation, but not kinase inhibition, profoundly lowered Aurora kinase B (AURKB) protein, which is known to be essential for cell division, and induced G2-M arrest and hyperploidy. PI3K activated AKT phosphorylation of AURKB on threonine 73, which protected it from proteasome degradation. A mutant of AURKB (T73E) that mimics phosphorylation and blocks degradation rescued cells from growth inhibition. Degrader-resistant lines were associated with low AKT phosphorylation, wild-type PI3K/PTEN status, and mutation of KRAS/BRAF. Pan-cancer analysis identified that 19% of cases have PI3K-PTEN pathway mutation without RAS pathway mutation, suggesting that these patients with cancer could benefit from AKT degrader therapy that leads to loss of AURKB. SIGNIFICANCE: MS21 depletes cells of phosphorylated AKT (pAKT) and a newly identified AKT substrate, AURKB, to inhibit tumor growth in mice. MS21 is superior to prior agents that target PI3K and AKT due to its ability to selectively target active, pAKT and sustain repression of signaling to deplete AURKB. This article is highlighted in the In This Issue feature, p. 2945.

KLF6 loss of function in human prostate cancer progression is implicated in resistance to androgen deprivation.

Inactivation of the transcription factor/tumor suppressor Krüppel-like factor 6 (KLF6) has been described in prostate cancer (PC). This study investigated the prevalence and significance of KLF6 exon 2 mutations and splice variants (SVs) in different stages of human PC progression. By using laser-capture microdissection and recombinant clone isolation of DNA sequences to enhance sensitivity, base changes were found in 20 (24.7%) of 81 PC tissues versus 1 (4%) of 25 normal prostate tissues (P = 0.02). Of 26 base changes, 54% produced nonsynonymous mutations. Only three mutations had driver characteristics (PCs, 4%; NPs, 0%). By using microdissection of fresh-frozen tissues and recombinant isolation of RNA sequences, SVs were found in 39 (75%) of 52 PCs and in 10 (45%) of 22 NPs (P = 0.01). Sixteen different SVs, including 13 unique SVs, were identified that used cryptic splicing sites and encoded nonfunctional KLF6 proteins. PCs that had survived hormone (androgen)-deprivation therapy (n = 21) had a significantly higher (P < 0.05) incidence, number, and expression level of nonfunctional SVs than either NPs (n = 22) or hormone-naïve PCs (n = 25). Forced expression of nonfunctional SVs conferred a survival advantage of androgen-dependent LNCaP cells under castration-simulated culture conditions. Together, these data suggest that decreased availability of functional KLF6 contributes to clinical PC progression. This decrease arises infrequently by somatic mutation and more commonly by the acquisition of SVs that provide a survival advantage under castrate conditions, enabling resistance to hormone therapy.

Nandrolone reduces activation of Notch signaling in denervated muscle associated with increased Numb expression.

Nandrolone, an anabolic steroid, slows denervation-atrophy in rat muscle. The molecular mechanisms responsible for this effect are not well understood. Androgens and anabolic steroids activate Notch signaling in animal models of aging and thereby mitigate sarcopenia. To explore the molecular mechanisms by which nandrolone prevents denervation-atrophy, we investigated the effects of nandrolone on Notch signaling in denervated rat gastrocnemius muscle. Denervation significantly increased Notch activity reflected by elevated levels of nuclear Notch intracellular domain (NICD) and expression of Hey1 (a Notch target gene). Activation was greatest at 7 and 35 days after denervation but remained present at 56 days after denervation. Activation of Notch in denervated muscle was prevented by nandrolone associated with upregulated expression of Numb mRNA and protein. These data demonstrate that denervation activates Notch signaling, and that nandrolone abrogates this response associated with increased expression of Numb, suggesting a potential mechanism by which nandrolone reduces denervation-atrophy.

Growth hormone receptor regulates ß cell hyperplasia and glucose-stimulated insulin secretion in obese mice.

Insulin, growth hormone (GH), and insulin-like growth factor-1 (IGF-1) play key roles in the regulation of ß cell growth and function. Although ß cells express the GH receptor, the direct effects of GH on ß cells remain largely unknown. Here we have employed a rat insulin II promoter-driven (RIP-driven) Cre recombinase to disrupt the GH receptor in ß cells (ßGHRKO). ßGHRKO mice fed a standard chow diet exhibited impaired glucose-stimulated insulin secretion but had no changes in ß cell mass. When challenged with a high-fat diet, ßGHRKO mice showed evidence of a ß cell secretory defect, with further deterioration of glucose homeostasis indicated by their altered glucose tolerance and blunted glucose-stimulated insulin secretion. Interestingly, ßGHRKO mice were impaired in ß cell hyperplasia in response to a high-fat diet, with decreased ß cell proliferation and overall reduced ß cell mass. Therefore, GH receptor plays critical roles in glucose-stimulated insulin secretion and ß cell compensation in response to a high-fat diet.

Cellular senescence and organismal ageing in the absence of p21(CIP1/WAF1) in ku80(-/-) mice.

Ku80 is important in the repair of DNA double-strand breaks by its essential function in non-homologous end-joining. The absence of Ku80 causes the accumulation of DNA damage and leads to premature ageing in mice. We showed that mouse embryonic fibroblasts (MEFs) from ku80(-/-) mice senesced rapidly with elevated levels of p53 and p21. Deletion of p21 delayed the early senescence phenotype in ku80(-/-) MEFs, despite an otherwise intact response of p53. In contrast to ku80(-/-)p53(-/-) mice, which die rapidly primarily from lymphomas, there was no significant increase in tumorigenesis in ku80(-/-)p21(-/-) mice. However, ku80(-/-)p21(-/-) mice showed no improvement with respect to rough fur coat or osteopaenia, and even showed a shortened lifespan compared with ku80(-/-) mice. These results show that the increased lifespan of ku80(-/-) MEFs owing to the loss of p21 is not associated with an improvement of the premature ageing phenotypes of ku80(-/-) mice observed at the organismal level.