TRIM25 upregulation by Mycobacterium tuberculosis infection promotes intracellular survival of M.tb in RAW264.7 cells

Activation of the lysosomal damage response and selective autophagy: the coordinated actions of galectins, TRIM proteins, and CGAS-STING1 in providing immunity against Mycobacterium tuberculosis

Autophagy is a crucial immune defense mechanism that controls the survival and pathogenesis of M. tb by maintaining cell physiology during stress and pathogen attack. The E3-Ub ligases (PRKN, SMURF1, and NEDD4) and autophagy receptors (SQSTM1, TAX1BP1, CALCOCO2, OPTN, and NBR1) play key roles in this process. Galectins (LGALSs), which bind to sugars and are involved in identifying damaged cell membranes caused by intracellular pathogens such as M. tb, are essential. These include LGALS3, LGALS8, and LGALS9, which respond to endomembrane damage and regulate endomembrane damage caused by toxic chemicals, protein aggregates, and intracellular pathogens, including M. tb. They also activate selective autophagy and de novo endolysosome biogenesis. LGALS3, LGALS9, and LGALS8 interact with various components to activate autophagy and repair damage, while CGAS-STING1 plays a critical role in providing immunity against M. tb by activating selective autophagy and producing type I IFNs with antimycobacterial functions. STING1 activates cGAMP-dependent autophagy which provides immunity against various pathogens. Additionally, cytoplasmic surveillance pathways activated by ds-DNA, such as inflammasomes mediated by NLRP3 and AIM2 complexes, control M. tb. Modulation of E3-Ub ligases with small regulatory molecules of LGALSs and TRIM proteins could be a novel host-based therapeutic approach for controlling TB.

The role of TRIM25 in the occurrence and development of cancers and inflammatory diseases

The tripartite motif (TRIM) family proteins are a group of proteins involved in different signaling pathways. The changes in the expression regulation, function, and signaling of this protein family are associated with the occurrence and progression of a wide range of disorders. Given the importance of these proteins in pathogenesis, they can be considered as potential therapeutic targets for many diseases. TRIM25, as an E3-ubiquitin ligase, is involved in the development of various diseases and cellular mechanisms, including antiviral innate immunity and cell proliferation. The clinical studies conducted on restricting the function of this protein have reached promising results that can be further evaluated in the future. Here, we review the regulation of TRIM25 and its function in different diseases and signaling pathways, especially the retinoic acid-inducible gene-I (RIG-I) signaling which prompts many kinds of cancers and inflammatory disorders.

Exploring the Transcriptome Dynamics of In Vivo Theileria annulata Infection in Crossbred Cattle

The molecular changes occurring in the host in response to in vivo Theileria annulata parasitic infection are not well understood. Therefore, the present study investigated the differential expression profiles of peripheral blood mononuclear cells (PBMCs) across Theileria annulata-infected and non-infected crossbred cows. The differential expression profiles from PBMCs of infected and non-infected crossbred cows were generated by RNA sequencing. A marked difference in the expression of genes associated with innate immunity (FTH1, ACTB, ISG15) was observed between the two groups. The over-represented pathways in Theileria annulata-infected cows were associated with the immune system and regulation of the mitotic cycle. Enriched genes and pathways in non-infected animals were associated with the maintenance of chromatin integrity and cell structure. The highly connected genes identified in this study form potential candidates for further investigation into host-parasite interactions in cattle. An improved understanding of the transcriptomic dynamics during theileriosis would lead to underpinning molecular level differences related to the health status of cattle.

The ubiquitin ligase TRIM32 promotes the autophagic response to Mycobacterium tuberculosis infection in macrophages

Mycobacterium tuberculosis (Mtb) is known to evade host immune responses and persist in macrophages for long periods. A mechanism that the host uses to combat Mtb is xenophagy, a selective form of autophagy that targets intracellular pathogens for degradation. Ubiquitination of Mtb or Mtb-containing compartments is a key event to recruit the autophagy machinery and mediate the bacterial delivery to the lysosome. This event relies on the coordinated and complementary activity of different ubiquitin ligases, including PARKIN, SMURF1, and TRIM16. Because each of these factors is responsible for the ubiquitination of a subset of the Mtb population, it is likely that additional ubiquitin ligases are employed by macrophages to trigger a full xenophagic response during Mtb infection. In this study, we investigated the role TRIM proteins whose expression is modulated in response to Mtb or BCG infection of primary macrophages. These TRIMs were ectopically expressed in THP1 macrophage cell line to assess their impact on Mtb replication. This screening identified TRIM32 as a novel player involved in the intracellular response to Mtb infection, which promotes autophagy-mediated Mtb degradation. The role of TRIM32 in xenophagy was further confirmed by silencing TRIM32 expression in THP1 cells, which causes increased intracellular growth of Mtb associated to impaired Mtb ubiquitination, reduced recruitment of the autophagy proteins NDP52/CALCOCO2 and BECLIN 1/BECN1 to Mtb and autophagosome formation. Overall, these findings suggest that TRIM32 plays an important role in the host response to Mtb infection through the induction of autophagy, representing a promising target for host-directed tuberculosis therapies.

Role of ISG15 post-translational modification in immunity against Mycobacterium tuberculosis infection

ISG15 encoded by a type I interferon (IFN) inducible gene mediates an important cellular process called ISGylation. ISGylation emerges as a powerful host tactic against intracellular pathogens like Mycobacterium tuberculosis (Mtb). However, the exact role of ISGylation in immunity remains elusive. To shed light on how ISGylation, which is both interesting and complex, participates in immunity against Mtb, this manuscript summarized the current knowledge about the structural characteristics and targets of ISG15 and how ISGylation cross-talks with other host post-translational modifications to exert its effect.

Effect of Yang He Decoction on Treatment of Bone Tuberculosis via Phosphoinositide 3-Kinases/Protein Kinase B and Mitogen-Activated Protein Kinase Signaling Pathways

Yang He Decoction (YHD), a classical Chinese medicine prescription, is used to treat bone and joint diseases. However, there are few mechanism studies for YHD on the use of YHD to treat bone tuberculosis (BT) and the corresponding mechanism of action of YHD. In the present study, the chemical ingredients of YHD and targets of the ingredients were revealed by a network pharmacology method, and an ingredient–target–disease network was visualized and analyzed. Then, gene ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were carried out. In addition, molecular docking was performed to clarify the binding of the key active ingredients of YHD to the key targets. Further, an in vitro model of Mycobacterium tuberculosis-induced BT was established, and a mechanism for the inhibitory effect of YHD on the differentiation of RAW 264.7 cells into osteoclasts was investigated. A total of 138 active ingredients in YHD and 50 targets between YHD ingredients and BT were identified. The phosphatidylinositol 3-kinase–protein kinase B (PI3K–Akt) and mitogen-activated protein kinase (MAPK) signaling pathways were the key pathways involved in the anti-BT effect of YHD. Moreover, the in vitro results showed that YHD inhibited the differentiation of RAW 264.7 cells into osteoclasts. YHD decreased the levels of tumor necrosis factor-α and interleukin-1β, increased the levels of superoxide dismutase and glutathione peroxide, and decreased the level of malondialdehyde. Further, YHD inhibited the protein and messenger RNA expression of PI3K/Akt, p38 MAPK, and c-Jun N-terminal kinase. These findings show that YHD is a promising anti-BT agent that suppresses the PI3K/Akt and MAPK signaling pathways to inhibit the differentiation of RAW 264.7 cells into osteoclasts and ameliorate inflammation and oxidative stress.

Expression profiling of TRIM gene family reveals potential diagnostic biomarkers for rifampicin-resistant tuberculosis

The epidemic of pulmonary tuberculosis (TB), especially rifampin-resistant tuberculosis (RR-TB) presents a major challenge for TB control today. However, there is a lack of reliable and specific biomarkers for the early diagnosis of RR-TB. We utilized reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to profile the transcript levels of 72 tripartite motif (TRIM) genes from a discovery cohort of 10 drug-sensitive tuberculosis (DS-TB) patients, 10 RR-TB patients, and 10 healthy controls (HCs). A total of 35 differentially expressed genes (DEGs) were screened out, all of which were down-regulated. The bio functions and pathways of these DEGs were enriched in protein ubiquitination, regulation of the viral process, Interferon signaling, and innate immune response, etc. A protein-protein interaction network (PPI) was constructed and analyzed using STRING and Cytoscape. Twelve TRIM genes were identified as hub genes, and seven (TRIM1, 9, 21, 32, 33, 56, 66) of them were verified by RT-qPCR in a validation cohort of 95 subjects. Moreover, we established the RR-TB decision tree models based on the 7 biomarkers. The receiver operating characteristic (ROC) analyses showed that the models exhibited the areas under the curve (AUC) values of 0.878 and 0.868 in discriminating RR-TB from HCs and DS-TB, respectively. Our study proposes potential biomarkers for RR-TB diagnosis, and also provides a new experimental basis to understand the pathogenesis of RR-TB.