MiR-214-3p plays a protective role in diabetic neuropathic rats by regulating Nav1.3 and TLR4

MiR-214 inhibits NF-κB pathway activation to alleviate lipopolysaccharide-induced mastitis by targeting TRAF1

Mastitis in dairy cows is defined by inflammation of mammary tissue, and represents a significant challenge in the dairy industry. The microRNA miR-214 is recognized as a key endogenous regulatory molecule with a critical role in inflammatory diseases. However, its involvement in the regulation of mastitis remains unclear. This study, investigated the role of miR-214 in dairy mastitis and explored its therapeutic potential. It was observed that miR-214 expression was reduced in an in vivo lipopolysaccharide (LPS)-induced mouse mastitis model and an in vitro LPS-induced bovine mammary epithelial cell (bMEC) inflammation model. The miR-214 mimic was found to suppress the expression of inflammatory cytokines IL-1β, TNF-α, and IL-6. Furthermore, the miR-214 mimic inhibited nuclear factor-κB (NF-κB) pathway activation in LPS-induced bMECs. Dual-luciferase reporter assay results confirmed that miR-214 targeted tumor necrosis factor receptor-associated factor 1 (TRAF1) to inhibit its expression. Silencing TRAF1 in bMECs reduced LPS-induced expression of inflammatory cytokines and NF-κB pathway activation. Conversely, TRAF1 overexpression negated the inhibitory effects of miR-214 on LPS-induced inflammatory cytokines expression and NF-κB pathway activation in bMECs. Additionally, in the in vivo LPS-induced mouse mastitis model, miR-214 alleviated pathological damage and decreased inflammatory cytokines expression in mammary tissue. These findings suggest that miR-214 inhibits NF-κB activation by downregulating TRAF1 expression thereby mitigating LPS-induced inflammatory responses. This study highlights a potential novel approach for the treatment of mastitis in dairy cows.

Clinical value of serum miR-214-3p expression in the diagnosis of type 2 diabetes mellitus and prediction of its chronic complications

BACKGROUND

The majority of diabetes cases fall into type 2 diabetes mellitus (T2DM), which is prone to chronic complications that have a long-term impact on patients. The aim of this study was to investigate the diagnostic potential of miR-214-3p in T2DM and its predictive value for chronic complications, providing a novel biomarker for the disease.

METHODS

A total of 156 patients with T2DM and 80 non-T2DM individuals were included. Serum miR-214-3p levels were measured by real-time reverse transcription quantitative PCR (RT-qPCR). The correlation of miR-214-3p with hemoglobin A1c (HbA1c) and low-density lipoprotein cholesterol (LDL-C) was analyzed by Spearman's rank correlation. The clinical value of miR-214-3p in T2DM was evaluated using the receiver operating characteristic (ROC) curve and logistic regression analysis.

RESULTS

The serum levels of miR-214-3p were decreased in T2DM patients compared to non-T2DM individuals. A negative correlation was identified between miR-214-3p expression and the levels of HbA1c and LDL-C. miR-214-3p could effectively differentiate T2DM patients from non-T2DM individuals with the area under ROC curve (AUC) of 0.884. Patients with low miR-214-3p expression had a higher incidence of chronic complications. The AUC for miR-214-3p in differentiating between T2DM patients with and without complications was 0.832. Low expression of miR-214-3p was a risk factor linked to the development of chronic complications in patients with T2DM.

CONCLUSION

Serum miR-214-3p was downregulated in T2DM and could differentiate T2DM patients from non-T2DM individuals. miR-214-3p was a promising biomarker for predicting the chronic complications of T2DM.

The Role of Inflammation in the Pathogenesis of Diabetic Peripheral Neuropathy: New Lessons from Experimental Studies and Clinical Implications

Diabetic peripheral neuropathy (DPN) is one of the most frequent complications of diabetes mellitus (DM). Its pathogenesis is still not entirely clear. Inflammation is increasingly being appreciated as a key factor in its development and progression. The aim of this review was to outline current evidence from experimental research on the role of inflammation in the pathogenesis of DPN and to suggest emerging clinical implications. Beyond commonly assessed interleukins, chemokines and tumour necrosis factor alpha (TNFα), several novel underlying mechanisms and potential therapeutic targets have been unravelled. Pathogenesis is also influenced by dietary patterns, such as iron supplementation. Furthermore, the impact of the inflammasome nucleotide-binding oligomerisation domain-like receptor pyrin domain-containing protein 3 (NLPR3) is gaining importance. The same holds true for inflammatory pathways, such as the Toll-like receptor (TLR)-associated pathways or the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway. SIRTuins are also of importance. DPN is associated with changes in macrophage polarisation. In addition, several metalloproteinases are emerging as contributors, although data is still limited. Finally, miRNAs (e.g. miR146a) are strongly linked with DPN by acting in several inflammatory pathways. However, we still need confirmation of preliminary research findings. It is hoped that new knowledge will lead to new therapeutic approaches, including stem cell-based or exosome-based therapies.

Exploring the role of miRNA in diabetic neuropathy: from diagnostics to therapeutics

Diabetic neuropathy (DN) is one of the major microvascular complications of diabetes mellitus affecting 50% of the diabetic population marred by various unmet clinical needs. There is a need to explore newer pathological mechanisms for designing futuristic regimens for the management of DN. There is a need for post-transcriptional regulation of gene expression by non-coding RNAs (ncRNAs) to finetune different cellular mechanisms with significant biological relevance. MicroRNAs (miRNAs) are a class of small ncRNAs (~ 20 to 24 nucleotide length) that are known to regulate the activity of ~ 50% protein-coding genes through repression of their target mRNAs. Differential expression of these miRNAs is associated with the pathophysiology of diabetic neuropathy via regulating various pathways such as neuronal hyperexcitability, inflammation, axonal growth, regeneration, and oxidative stress. Of note, the circulating and extracellular vesicular miRNAs serve as potential biomarkers underscoring their diagnostic potential. Recent pieces of evidence highlight the potential of miRNAs in modulating the initiation and progression of DN and the possibility of developing miRNAs as treatment options for DN. In this review, we have elaborated on the role of different miRNAs as potential biomarkers and emphasized their druggable aspects for promising future therapies for the clinical management of DN.

Elevated microRNA-214-3p level ameliorates neuroinflammation after spinal cord ischemia-reperfusion injury by inhibiting Nmb/Cav3.2 pathway

BACKGROUND

Neuromedin B (Nmb) plays a pivotal role in the transmission of neuroinflammation, particularly during spinal cord ischemia-reperfusion injury (SCII). However, the detailed molecular mechanisms underlying this process remain elusive.

METHODS

The SCII model was established by clamping the abdominal aorta of male Sprague-Dawley (SD) rats for 60 min. The protein expression levels of Nmb, Cav3.2, and IL-1β were detected by Western blotting, while miR-214-3p expression was quantified by qRT-PCR. The targeted regulation between miR-214-3p and Nmb was investigated using a dual-luciferase reporter gene assay. The cellular localization of Nmb and Cav3.2 with cell-specific markers was visualized by immunofluorescence staining. The specific roles of miR-214-3p on the Nmb/Cav3.2 interactions in SCII-injured rats were explored by intrathecal injection of Cav3.2-siRNA, PD168368 (a specific NmbR inhibitor) and synthetic miR-214-3p agomir and antagomir in separate experiments. Additionally, hind-limb motor function was evaluated using the modified Tarlov scores.

RESULTS

Compared to the Sham group, the protein expression levels of Nmb, Cav3.2, and the proinflammatory factor Interleukin(IL)-1β were significantly elevated at 24 h post-SCII. Intrathecal injection of PD168368 and Cav3.2-siRNA significantly suppressed the expression of Cav3.2 and IL-1β compared to the SCII group. The miRDB database and dual-luciferase reporter gene assay identified Nmb as a direct target of miR-214-3p. As expected, in vivo overexpression of miR-214-3p by agomir-214-3p pretreatment significantly inhibited the increases in Nmb, Cav3.2 and IL-1β expression and improved lower limb motor function in SCII-injured rats, while antagomiR-214-3p pretreatment reversed these effects.

CONCLUSIONS

Nmb protein levels positively correlated with Cav3.2 expression in SCII rats. Upregulating miR-214-3p ameliorated hind-limb motor function and protected against neuroinflammation via inhibiting the aberrant Nmb/Cav3.2 interactions and downstream IL-1β release. These findings provide novel therapeutic targets for clinical prevention and treatment of SCII.

Non-coding RNAs in diabetic peripheral neuropathy: their role and mechanisms underlying their effects

Diabetic peripheral neuropathy (DPN) is a complication of diabetes with a high rate of disability. However, current clinical treatments for DPN are suboptimal. Non-coding RNAs (ncRNAs) are a type of RNAs that are not translated into proteins. NcRNAs perform functions that regulate epigenetic modifications, transcriptional or post-transcriptional regulators of proteins, and thus participate in the physiological and pathological processes of the body. NcRNAs play a role in the progress of DPN by affecting the processes of inflammation, oxidative stress, cellular autophagy or apoptosis. Therefore, ncRNAs treatment is regarded as a promising therapeutic approach for DPN. In addition, since some ncRNAs present stably in the blood of DPN patients, they are considered as potential biomarkers that contribute to early clinical diagnosis. In this paper, we review the studies on the role of ncRNAs in DPN in the last decade, and discuss the mechanisms of ncRNAs, aiming to provide a reference for the future research on the treatment and early diagnosis of DPN.

A mechanism linking ferroptosis and ferritinophagy in melatonin-related improvement of diabetic brain injury

Ferroptosis and ferritinophagy play critical roles in various disease contexts. Herein, we observed that ferroptosis and ferritinophagy were induced both in the brains of mice with diabetes mellitus (DM) and neuronal cells after high glucose (HG) treatment, as evidenced by decreases in GPX4, SLC7A11, and ferritin levels, but increases in NCOA4 levels. Interestingly, melatonin administration ameliorated neuronal damage by inhibiting ferroptosis and ferritinophagy both in vivo and in vitro. At the molecular level, we found that not only the ferroptosis inducer p53 but also the ferritinophagy mediator NCOA4 was the potential target of miR-214-3p, which was downregulated by DM status or HG insult, but was increased after melatonin treatment. However, the inhibitory effects of melatonin on ferroptosis and ferritinophagy were blocked by miR-214-3p downregulation. These findings suggest that melatonin is a potential drug for improving diabetic brain damage by inhibiting p53-mediated ferroptosis and NCOA4-mediated ferritinophagy through regulating miR-214-3p in neurons.

Painful diabetic neuropathy: The role of ion channels

Painful diabetic neuropathy (PDN) is a common chronic complication of diabetes that causes neuropathic pain and negatively affects the quality of life. The management of PDN is far from satisfactory. At present, interventions are primarily focused on symptomatic treatment. Ion channel disorders are a major cause of PDN, and a complete understanding of their roles and mechanisms may provide better options for the clinical treatment of PDN. Therefore, this review summarizes the important role of ion channels in PDN and the current drug development targeting these ion channels.

Genetic interaction in the association between oxidative stress and diabetes in the Spanish population

Oxidative stress (OS) is a relevant intermediate mechanism involved in Type 2 Diabetes Mellitus (T2D) development. To date, the interaction between OS parameters and variations in genes related to T2D has not been analyzed.

AIMS

To study the genetic interaction of genes potentially related to OS levels (redox homeostasis, renin-angiotensin-aldosterone system, endoplasmic stress response, dyslipidemia, obesity and metal transport) and OS and T2D risk in a general population from Spain (the Hortega Study) in relation to the risk of suffering from T2D.

MATERIALS AND METHODS

One thousand five hundred and two adults from the University Hospital Rio Hortega area were studied and 900 single nucleotide polymorphisms (SNPs) from 272 candidate genes were analyzed.

RESULTS

There were no differences in OS levels between cases and controls. Some polymorphisms were associated with T2D and with OS levels. Significant interactions were observed between OS levels and two polymorphisms in relation to T2D presence: rs196904 (ERN1 gene) and rs2410718 (COX7C gene); and between OS levels and haplotypes of the genes: SP2, HFF1A, ILI8R1, EIF2AK2, TXNRD2, PPARA, NDUFS2 and ERN1.

CONCLUSIONS

Our results indicate that genetic variations of the studied genes are associated with OS levels and that their interaction with OS parameters may contribute to the risk of developing T2D in the Spanish general population. These data support the importance of analyzing the influence of OS levels and their interaction with genetic variations in order to establish their real impact in T2D risk. Further studies are required to identify the real relevance of interactions between genetic variations and OS levels and the mechanisms involved in them.

Tear Film MicroRNAs as Potential Biomarkers: A Review

MicroRNAs are non-coding RNAs that serve as regulatory molecules in a variety of pathways such as inflammation, metabolism, homeostasis, cell machinery, and development. With the progression of sequencing methods and modern bioinformatics tools, novel roles of microRNAs in regulatory mechanisms and pathophysiological states continue to expand. Advances in detection methods have further enabled larger adoption of studies utilizing minimal sample volumes, allowing the analysis of microRNAs in low-volume biofluids, such as the aqueous humor and tear fluid. The reported abundance of extracellular microRNAs in these biofluids has prompted studies to explore their biomarker potential. This review compiles the current literature reporting microRNAs in human tear fluid and their association with ocular diseases including dry eye disease, Sjögren's syndrome, keratitis, vernal keratoconjunctivitis, glaucoma, diabetic macular edema, and diabetic retinopathy, as well as non-ocular diseases, including Alzheimer's and breast cancer. We also summarize the known roles of these microRNAs and shed light on the future progression of this field.

Effects of Extracorporeal Shockwave Therapy on Functional Recovery and Circulating miR-375 and miR-382-5p after Subacute and Chronic Spinal Cord Contusion Injury in Rats

Extracorporeal shockwave therapy (ESWT) can stimulate processes to promote regeneration, including cell proliferation and modulation of inflammation. Specific miRNA expression panels have been established to define correlations with regulatory targets within these pathways. This study aims to investigate the influence of low-energy ESWT—applied within the subacute and chronic phase of SCI (spinal cord injury) on recovery in a rat spinal cord contusion model. Outcomes were evaluated by gait analysis, µCT and histological analysis of spinal cords. A panel of serum-derived miRNAs after SCI and after ESWT was investigated to identify injury-, regeneration- and treatment-associated expression patterns. Rats receiving ESWT showed significant improvement in motor function in both a subacute and a chronic experimental setting. This effect was not reflected in changes in morphology, µCT-parameters or histological markers after ESWT. Expression analysis of various miRNAs, however, revealed changes after SCI and ESWT, with increased miR-375, indicating a neuroprotective effect, and decreased miR-382-5p potentially improving neuroplasticity via its regulatory involvement with BDNF. We were able to demonstrate a functional improvement of ESWT-treated animals after SCI in a subacute and chronic setting. Furthermore, the identification of miR-375 and miR-382-5p could potentially provide new targets for therapeutic intervention in future studies.

Toll-Like Receptors (TLRs) and their potential therapeutic applications in diabetic neuropathy

One of the most common diabetic microvascular complications is diabetic neuropathy (DN). Immune cell infiltration in the peripheral nerve system (PNS), myelin loss, Schwann cell death, and axonal damage are all hallmarks of DN, which is currently believed to be a chronic inflammatory disease. Toll-like receptors (TLRs) are found in various types of nervous system cells, including Schwann cells, microglia, oligodendrocytes, astrocytes, and neurons. Proinflammatory mediators released at the end of TLR signal transduction can trigger an inflammatory response involving the nervous system. Studies on the association between TLRs and DN began as early as 2004. Since then, several studies have been conducted to assess the involvement of TLRs in the pathogenesis of DN. The focus of this review is to give a complete summary of the researches that have been done in this context, as well as an overview of the role of TLRs and their therapeutic applications in DN.