Photobiomodulation promotes spinal cord injury repair by inhibiting macrophage polarization through lncRNA TUG1-miR-1192/TLR3 axis

Long non-coding RNA DANCR increases spinal cord neuron apoptosis and inflammation of spinal cord injury by mediating the microRNA-146a-5p/MAPK6 axis

OBJECTIVE

This research was to unravel the impact of the lncRNA differentiation antagonizing non-protein coding RNA (DANCR)/microRNA (miR)-146a-5p/mitogen-activated protein kinase 6 (MAPK6) axis on spinal cord injury (SCI).

METHODS

SCI mouse models were established and injected with si-DANCR or miR-146a-5p agomir. The recovery of motor function was assessed by Basso Mouse Scale. SCI was pathologically evaluated, and serum inflammatory factors were measured in SCI mice. Mouse spinal cord neurons were injured by H2O2 and transfected, followed by assessment of proliferation and apoptosis. DANCR, miR-146a-5p, and MAPK6 in tissues and cells were detected, as well as their relationship.

RESULTS

DANCR increased and miR-146a-5p decreased in SCI. Silencing DANCR or enhancing miR-146a-5p stimulated the proliferation of mouse spinal cord neurons and reduced apoptosis. DANCR was bound to miR-146a-5p to target MAPK6. DANCR affected the proliferation and apoptosis of spinal cord neurons by mediating the miR-146a-5p/MAPK6 axis. Downregulating DANCR or upregulating miR-146a-5p improved inflammation, the destruction of spinal cord tissue structure, and apoptosis in SCI mice.

CONCLUSION

DANCR affects spinal cord neuron apoptosis and inflammation of SCI by mediating the miR-146a-5p/MAPK6 axis.

Application of a physiotherapeutic protocol associated with photobiomodulation for the treatment of leprosy patients

Leprosy is a chronic infectious disease characterized by acute inflammatory episodes that affect the skin and peripheral nerves and can develop progressive and irreversible disabilities and deformities. In addition, drug therapy and physiotherapy offer resources and techniques capable of mitigating the consequences of neural lesions, but neural lesions can occur before, during, and even after drug treatment. Thus, new treatments are needed. Photobiomodulation (PBM) might be a promissor therapy since it aims to reduce the inflammatory process and restore motor and sensory functions in the affected area. This study aims to compare the evolution of neural status, pain, and functionality in patients with leprosy and neuritis after a physiotherapeutic protocol and PBM treatment. This was a randomized controlled clinical trial that analyzed a group of patients receiving a physiotherapeutic protocol (PPG) and another receiving physiotherapeutic protocol associated with PBM (PLG) (wavelength 904 nm, potency 70 mW, time per point 9 s). Our results showed when evaluating functional capacity limitations with the SALSA scale, the PLG patients improved from moderate to mild limitations. On the other hand, the PPG remained as moderate limitations. Also, the PLG showed a significant reduction in pain on the VAS scale. The neurological assessment showed that PLG improved palpation of the median, radial, and peroneal nerves. In the strength test, PLG patients improved in the 5th finger abduction and ankle dorsiflexion. Assessing sensitivity, it was identified an improvement in PLG for the ulnar nerve and tibial nerve. All those changes were statistically significant when compared to the PPG patients. Finally, the PLG patients improved disabilities, identified by the neurological assessment of the eyes, hands, and feet. In conclusion, this study demonstrated that combining a physiotherapeutic protocol with PBM treatment effectively improved functional status and reduced pain in leprosy patients.

Metabolite itaconate in host immunoregulation and defense

Metabolic states greatly influence functioning and differentiation of immune cells. Regulating the metabolism of immune cells can effectively modulate the host immune response. Itaconate, an intermediate metabolite derived from the tricarboxylic acid (TCA) cycle of immune cells, is produced through the decarboxylation of cis-aconitate by cis-aconitate decarboxylase in the mitochondria. The gene encoding cis-aconitate decarboxylase is known as immune response gene 1 (IRG1). In response to external proinflammatory stimulation, macrophages exhibit high IRG1 expression. IRG1/itaconate inhibits succinate dehydrogenase activity, thus influencing the metabolic status of macrophages. Therefore, itaconate serves as a link between macrophage metabolism, oxidative stress, and immune response, ultimately regulating macrophage function. Studies have demonstrated that itaconate acts on various signaling pathways, including Keap1-nuclear factor E2-related factor 2-ARE pathways, ATF3-IκBζ axis, and the stimulator of interferon genes (STING) pathway to exert antiinflammatory and antioxidant effects. Furthermore, several studies have reported that itaconate affects cancer occurrence and development through diverse signaling pathways. In this paper, we provide a comprehensive review of the role IRG1/itaconate and its derivatives in the regulation of macrophage metabolism and functions. By furthering our understanding of itaconate, we intend to shed light on its potential for treating inflammatory diseases and offer new insights in this field.

The role of long noncoding ribonucleic acids in the central nervous system injury

Central nervous system (CNS) injury involves complex pathophysiological molecular mechanisms. Long noncoding ribonucleic acids (lncRNAs) are an important form of RNA that do not encode proteins but take part in the regulation of gene expression and various biological processes. Multitudinous studies have evidenced lncRNAs to have a significant role in the process of progression and recovery of various CNS injuries. Herein, we review the latest findings pertaining to the role of lncRNAs in CNS, both normal and diseased state. We aim to present a comprehensive clinical application prospect of lncRNAs in CNS, and thus, discuss potential strategies of lncRNAs in treating CNS injury.

lncRNA Helf promotes hepatic inflammation and fibrosis by interacting with PTBP1 to facilitate PIK3R5 mRNA stabilization

BACKGROUND

Hepatic fibrosis is a common consequence of chronic liver diseases without approved antifibrotic therapies. Long noncoding RNAs (lncRNAs) play an important role in various pathophysiological processes. However, the functions of certain lncRNAs involved in mediating the antifibrotic role remain largely unclear.

METHODS

The RNA level of lnc-High Expressed in Liver Fibrosis (Helf) was detected in both mouse and human fibrotic livers. Furthermore, lnc-Helf-silenced mice were treated with carbon tetrachloride (CCl4) or bile duct ligation (BDL) to investigate the function of lnc-Helf in liver fibrosis.

RESULTS

We found that lnc-Helf has significantly higher expression in human and mouse fibrotic livers as well as M1 polarized hepatic macrophages (HMs) and activated hepatic stellate cells (HSCs). In vivo studies showed that silencing lnc-Helf by AAV8 vector alleviates CCl4- and BDL-induced hepatic inflammation and fibrosis. Furthermore, in vitro experiments revealed that lnc-Helf promotes HSCs activation and proliferation, as well as HMs M1 polarization and proliferation in the absence or presence of cytokine stimulation. Mechanistically, our data illustrated that lnc-Helf interacts with RNA binding protein PTBP1 to promote its interaction with PIK3R5 mRNA, resulting in increased stability and activating the AKT pathway, thus promoting HSCs and HMs activation and proliferation, which augments hepatic inflammation and fibrosis.

CONCLUSION

Our results unveil a lnc-Helf/PTBP1/PIK3R5/AKT feedforward, amplifying signaling that exacerbates the process of hepatic inflammation and fibrosis, thus providing a possible therapeutic strategy for hepatic fibrosis.

Tackling the glial scar in spinal cord regeneration: new discoveries and future directions

Axonal regeneration and functional recovery are poor after spinal cord injury (SCI), typified by the formation of an injury scar. While this scar was traditionally believed to be primarily responsible for axonal regeneration failure, current knowledge takes a more holistic approach that considers the intrinsic growth capacity of axons. Targeting the SCI scar has also not reproducibly yielded nearly the same efficacy in animal models compared to these neuron-directed approaches. These results suggest that the major reason behind central nervous system (CNS) regeneration failure is not the injury scar but a failure to stimulate axon growth adequately. These findings raise questions about whether targeting neuroinflammation and glial scarring still constitute viable translational avenues. We provide a comprehensive review of the dual role of neuroinflammation and scarring after SCI and how future research can produce therapeutic strategies targeting the hurdles to axonal regeneration posed by these processes without compromising neuroprotection.