miR-223-3p and miR-24-3p as novel serum-based biomarkers for myotonic dystrophy type 1

Non-Coding RNAs in Kidney Stones

Nephrolithiasis is a major public health concern associated with high morbidity and recurrence. Despite decades of research, the pathogenesis of nephrolithiasis remains incompletely understood, and effective prevention is lacking. An increasing body of evidence suggests that non-coding RNAs, especially microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), play a role in stone formation and stone-related kidney injury. MiRNAs have been studied quite extensively in nephrolithiasis, and a plethora of specific miRNAs have been implicated in the pathogenesis of nephrolithiasis, involving remarkable changes in calcium metabolism, oxalate metabolism, oxidative stress, cell-crystal adhesion, cellular autophagy, apoptosis, and macrophage (Mp) polarization and metabolism. Emerging evidence suggests a potential for miRNAs as novel diagnostic biomarkers of nephrolithiasis. LncRNAs act as competing endogenous RNAs (ceRNAs) to bind miRNAs, thereby modulating mRNA expression to participate in the regulation of physiological mechanisms in kidney stones. Small interfering RNAs (siRNAs) may provide a novel approach to kidney stone prevention and treatment by treating related metabolic conditions that cause kidney stones. Further investigation into these non-coding RNAs will generate novel insights into the mechanisms of renal stone formation and stone-related renal injury and might lead to new strategies for diagnosing and treating this disease.

Small non-coding RNA profiling in patients with gastrointestinal cancer

BACKGROUND

Small non-coding (snc)RNAs, including microRNAs and P-element induced wimpy testis (PIWI)-interacting-RNAs (piRNAs), crucially regulate gene expression in both physiological and pathological conditions. In particular, some muscle-specific microRNAs (myomiRs) have been involved in the pathogenesis of cancer-induced muscle wasting. The aims of the present study were (i) to profile sncRNAs in both skeletal muscle and plasma of gastrointestinal cancer patients and (ii) to investigate the association among differentially expressed sncRNAs and the level of muscularity at body composition analysis.

METHODS

Surgical patients with gastrointestinal cancer or benign disease were recruited. Blood samples and muscle biopsies (rectus abdominis) were collected during surgery. Low muscularity patients were those at the lowest tertile of skeletal muscle index (SMI; CT-scan), whereas moderate/high muscularity patients were in the middle and highest SMI tertiles. SncRNAs in the muscle were assessed by RNAseq, circulating microRNAs were evaluated by qPCR.

RESULTS

Cancer patients (n = 25; 13 females, 52%) showed a mean age of 71.6 ± 11.2 years, a median body weight loss of 4.2% and a mean BMI of 27.0 ± 3.2 kg/m2 . Control group (n = 15; 9 females, 60%) showed a mean age 58.1 ± 13.9 years and a mean BMI of 28.0 ± 4.3 kg/m2 . In cancer patients, the median L3-SMI (cm2 /m2 ) was 42.52 (34.42; 49.07). Males showed a median L3-SMI of 46.08 (41.17-51.79) and females a median L3-SMI of 40.77 (33.73-42.87). Moderate-high and low muscularity groups included 17 and 8 patients, respectively. As for circulating microRNAs, miR-21-5p and miR-133a-3p were up-regulated in patients compared with controls, whereas miR-15b-5p resulted down-regulated in the same comparison (about 30% of control values). Sample clustering by muscularity and sex revealed increased miR-133a-3p and miR-206 only in moderate-high muscularity males. SncRNA profiling in the muscle identified 373 microRNAs and 190 piRNAs (72.5% and 18.7% of raw reads, respectively). As for microRNAs, 10 were up-regulated, and 56 were down-regulated in cancer patients versus controls. Among the 24 dysregulated piRNAs, the majority were down-regulated, including the top two most expressed piRNAs in the muscle (piR-12790 and piR-2106). Network analysis on validated mRNA targets of down-regulated microRNAs revealed miR-15b-5p, miR-106a-5p and miR-106b-5p as main interactors of genes related to ubiquitin ligase/transferase activities.

CONCLUSIONS

These results show dysregulation of both muscle microRNAs and piRNAs in cancer patients compared with controls, the former following a sex-specific pattern. Changes in circulating microRNAs are associated with the degree of muscularity rather than body weight loss.

A miRNome analysis at the early postmortem interval

The postmortem interval (PMI) is the time elapsing since the death of an individual until the body is examined. Different molecules have been analyzed to better estimate the PMI with variable results. The miRNAs draw attention in the forensic field to estimate the PMI as they can better support degradation. In the present work, we analyzed the miRNome at early PMI in rats' skeletal muscle using the Affymetrix GeneChip™ miRNA 4.0 microarrays. We found 156 dysregulated miRNAs in rats' skeletal muscle at 24 h of PMI, out of which 84 were downregulated, and 72 upregulated. The miRNA most significantly downregulated was miR-139-5p (FC = -160, p = 9.97 × 10^-11), while the most upregulated was rno-miR-92b-5p (FC = 241.18, p = 2.39 × 10^-6). Regarding the targets of these dysregulated miRNAs, the rno-miR-125b-5p and rno-miR-138-5p were the miRNAs with more mRNA targets. The mRNA targets that we found in the present study participate in several biological processes such as interleukin secretion regulation, translation regulation, cell growth, or low oxygen response. In addition, we found a downregulation of SIRT1 mRNA and an upregulation of TGFBR2 mRNA at 24 h of PMI. These results suggest there is an active participation of miRNAs at early PMI which could be further explored to identify potential biomarkers for PMI estimation.

Dysregulation of Serum MicroRNA after Intracerebral Hemorrhage in Aged Mice

Stroke is one of the most common diseases that leads to brain injury and mortality in patients, and intracerebral hemorrhage (ICH) is the most devastating subtype of stroke. Though the prevalence of ICH increases with aging, the effect of aging on the pathophysiology of ICH remains largely understudied. Moreover, there is no effective treatment for ICH. Recent studies have demonstrated the potential of circulating microRNAs as non-invasive diagnostic and prognostic biomarkers in various pathological conditions. While many studies have identified microRNAs that play roles in the pathophysiology of brain injury, few demonstrated their functions and roles after ICH. Given this significant knowledge gap, the present study aims to identify microRNAs that could serve as potential biomarkers of ICH in the elderly. To this end, sham or ICH was induced in aged C57BL/6 mice (18–24 months), and 24 h post-ICH, serum microRNAs were isolated, and expressions were analyzed. We identified 28 significantly dysregulated microRNAs between ICH and sham groups, suggesting their potential to serve as blood biomarkers of acute ICH. Among those microRNAs, based on the current literature, miR-124-3p, miR-137-5p, miR-138-5p, miR-219a-2-3p, miR-135a-5p, miR-541-5p, and miR-770-3p may serve as the most promising blood biomarker candidates of ICH, warranting further investigation.

Aerobic exercise elicits clinical adaptations in myotonic dystrophy type 1 patients independent of pathophysiological changes

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a complex life-limiting neuromuscular disorder characterized by severe skeletal muscle atrophy, weakness, and cardio-respiratory defects. Exercised DM1 mice exhibit numerous physiological benefits that are underpinned by reduced CUG foci and improved alternative splicing. However, the efficacy of physical activity in patients is unknown.

METHODS

Eleven genetically diagnosed DM1 patients were recruited to examine the extent to which 12-weeks of cycling can recuperate clinical, and physiological metrics. Furthermore, we studied the underlying molecular mechanisms through which exercise elicits benefits in skeletal muscle of DM1 patients.

RESULTS

DM1 was associated with impaired muscle function, fitness, and lung capacity. Cycling evoked several clinical, physical, and metabolic advantages in DM1 patients. We highlight that exercise-induced molecular and cellular alterations in patients do not conform with previously published data in murine models and propose a significant role of mitochondrial function in DM1 pathology. Lastly, we discovered a subset of small nucleolar RNAs (snoRNAs) that correlated to indicators of disease severity.

CONCLUSION

With no available cures, our data supports the efficacy of exercise as a primary intervention to partially mitigate the clinical progression of DM1. Additionally, we provide evidence for the involvement of snoRNAs and other noncoding RNAs in DM1 pathophysiology.

TRIAL REGISTRATION

This trial was approved by the HiREB committee (#7901) and registered under ClinicalTrials.gov (NCT04187482).

FUNDING

This work was primarily supported by Neil and Leanne Petroff. This study was also supported by a Canadian Institutes of Health Research Foundation Grant to MAT (#143325).

Deciphering the Complex Molecular Pathogenesis of Myotonic Dystrophy Type 1 through Omics Studies

Omics studies are crucial to improve our understanding of myotonic dystrophy type 1 (DM1), the most common muscular dystrophy in adults. Employing tissue samples and cell lines derived from patients and animal models, omics approaches have revealed the myriad alterations in gene and microRNA expression, alternative splicing, 3′ polyadenylation, CpG methylation, and proteins levels, among others, that contribute to this complex multisystem disease. In addition, omics characterization of drug candidate treatment experiments provides crucial insight into the degree of therapeutic rescue and off-target effects that can be achieved. Finally, several innovative technologies such as single-cell sequencing and artificial intelligence will have a significant impact on future DM1 research.