FTO modulates fibrogenic responses in obstructive nephropathy

FTO-mediated m6A mRNA demethylation aggravates renal fibrosis by targeting RUNX1 and further enhancing PI3K/AKT pathway

Chronic kidney disease (CKD) is a global health burden, with ineffective therapies leading to increasing morbidity and mortality. Renal interstitial fibrosis is a common pathway in advanced CKD, resulting in kidney function and structure deterioration. In this study, we investigate the role of FTO-mediated N6-methyladenosine (m6A) and its downstream targets in the pathogenesis of renal fibrosis. M6A modification, a prevalent mRNA internal modification, has been implicated in various organ fibrosis processes. We use a mouse model of unilateral ureteral obstruction (UUO) as an in vivo model and treated tubular epithelial cells (TECs) with transforming growth factor (TGF)-β1 as in vitro models. Our findings revealed increased FTO expression in UUO mouse model and TGF-β1-treated TECs. By modulating FTO expression through FTO heterozygous mutation mice (FTO+/- ) in vivo and small interfering RNA (siRNA) in vitro, we observed attenuation of UUO and TGF-β1-induced epithelial-mesenchymal transition (EMT), as evidenced by decreased fibronectin and N-cadherin accumulation and increased E-cadherin levels. Silencing FTO significantly improved UUO and TGF-β1-induced inflammation, apoptosis, and inhibition of autophagy. Further transcriptomic assays identified RUNX1 as a downstream candidate target of FTO. Inhibiting FTO was shown to counteract UUO/TGF-β1-induced RUNX1 elevation in vivo and in vitro. We demonstrated that FTO signaling contributes to the elevation of RUNX1 by demethylating RUNX1 mRNA and improving its stability. Finally, we revealed that the PI3K/AKT pathway may be activated downstream of the FTO/RUNX1 axis in the pathogenesis of renal fibrosis. In conclusion, identifying small-molecule compounds that target this axis could offer promising therapeutic strategies for treating renal fibrosis.

MicroRNA-192-5p downregulates Fat Mass and Obesity-associated Protein to aggravate renal ischemia/reperfusion injury

Acute kidney injury (AKI) is a common disorder without effective therapy yet. Renal ischemia/reperfusion (I/R) injury is a common cause of AKI. MicroRNA miR-192-5p has been previously reported to be upregulated in AKI models. However, its functional role in renal I/R injury is not fully understood. This study aimed to investigate the effects and the underlying mechanism of miR-192-5p in renal I/R progression. Hypoxia/reoxygenation (H/R)-induced cell injury model in HK-2 cells and I/R-induced renal injury model in mice were established in this study. Cell counting kit-8 assay was performed to determine cell viability. Quantitative real-time PCR and western blot analysis were performed to detect gene expressions. Hematoxylin-eosin and periodic acid-Schiff staining were performed to observe the histopathological changes. Enzyme-linked immunosorbent assay was performed to detect the kidney markers' expression. In vivo and in vitro results showed that miR-192-5p was up-regulated in the I/R-induced mice model and H/R-induced cell model, and miR-192-5p overexpression exacerbated I/R-induced renal damage. Then, the downstream target of miR-192-5p was analyzed by combining the differentially expressed mRNAs and the predicted genes and confirmed using a dual-luciferase reporter assay. It was found that miR-192-5p was found to regulate fat mass and obesity-associated (FTO) protein expression by directly targeting the 3' untranslated region of FTO mRNA. Moreover, in vivo and in vitro studies unveiled that FTO overexpression alleviated renal I/R injury and promoted HK-2 cell viability via stimulating autophagy flux. In conclusion, miR-192-5p aggravated I/R-induced renal injury by blocking autophagy flux via down-regulating FTO.

N6-methyladenosine (m6A) methylation in kidney diseases: Mechanisms and therapeutic potential

The N6-methyladenosine (m6A) modification is regulated by methylases, commonly referred to as "writers," and demethylases, known as "erasers," leading to a dynamic and reversible process. Changes in m6A levels have been implicated in a wide range of cellular processes, including nuclear RNA export, mRNA metabolism, protein translation, and RNA splicing, establishing a strong correlation with various diseases. Both physiologically and pathologically, m6A methylation plays a critical role in the initiation and progression of kidney disease. The methylation of m6A may also facilitate the early diagnosis and treatment of kidney diseases, according to accumulating research. This review aims to provide a comprehensive overview of the potential role and mechanism of m6A methylation in kidney diseases, as well as its potential application in the treatment of such diseases. There will be a thorough examination of m6A methylation mechanisms, paying particular attention to the interplay between m6A writers, m6A erasers, and m6A readers. Furthermore, this paper will elucidate the interplay between various kidney diseases and m6A methylation, summarize the expression patterns of m6A in pathological kidney tissues, and discuss the potential therapeutic benefits of targeting m6A in the context of kidney diseases.

The role of N6-methyladenosine (m6A) in kidney diseases

Chemical modifications are a specific and efficient way to regulate the function of biological macromolecules. Among them, RNA molecules exhibit a variety of modifications that play important regulatory roles in various biological processes. More than 170 modifications have been identified in RNA molecules, among which the most common internal modifications include N6-methyladenine (m6A), n1-methyladenosine (m1A), 5-methylcytosine (m5C), and 7-methylguanine nucleotide (m7G). The most widely affected RNA modification is m6A, whose writers, readers, and erasers all have regulatory effects on RNA localization, splicing, translation, and degradation. These functions, in turn, affect RNA functionality and disease development. RNA modifications, especially m6A, play a unique role in renal cell carcinoma disease. In this manuscript, we will focus on the biological roles of m6A in renal diseases such as acute kidney injury, chronic kidney disease, lupus nephritis, diabetic kidney disease, and renal cancer.

The essential role of N6-methyladenosine RNA methylation in complex eye diseases

There are many complex eye diseases which are the leading causes of blindness, however, the pathogenesis of the complex eye diseases is not fully understood, especially the underlying molecular mechanisms of N6-methyladenosine (m6A) RNA methylation in the eye diseases have not been extensive clarified. Our review summarizes the latest advances in the studies of m6A modification in the pathogenesis of the complex eye diseases, including cornea disease, cataract, diabetic retinopathy, age-related macular degeneration, proliferative vitreoretinopathy, Graves' disease, uveal melanoma, retinoblastoma, and traumatic optic neuropathy. We further discuss the possibility of developing m6A modification signatures as biomarkers for the diagnosis of the eye diseases, as well as potential therapeutic approaches.

Long noncoding RNA ENST00000436340 promotes podocyte injury in diabetic kidney disease by facilitating the association of PTBP1 with RAB3B

Dysfunction of podocytes has been regarded as an important early pathologic characteristic of diabetic kidney disease (DKD), but the regulatory role of long noncoding RNAs (lncRNAs) in this process remains largely unknown. Here, we performed RNA sequencing in kidney tissues isolated from DKD patients and nondiabetic renal cancer patients undergoing surgical resection and discovered that the novel lncRNA ENST00000436340 was upregulated in DKD patients and high glucose-induced podocytes, and we showed a significant correlation between ENST00000436340 and kidney injury. Gain- and loss-of-function experiments showed that silencing ENST00000436340 alleviated high glucose-induced podocyte injury and cytoskeleton rearrangement. Mechanistically, we showed that fat mass and obesity- associate gene (FTO)-mediated m6A induced the upregulation of ENST00000436340. ENST00000436340 interacted with polypyrimidine tract binding protein 1 (PTBP1) and augmented PTBP1 binding to RAB3B mRNA, promoted RAB3B mRNA degradation, and thereby caused cytoskeleton rearrangement and inhibition of GLUT4 translocation to the plasma membrane, leading to podocyte injury and DKD progression. Together, our results suggested that upregulation of ENST00000436340 could promote podocyte injury through PTBP1-dependent RAB3B regulation, thus suggesting a novel form of lncRNA-mediated epigenetic regulation of podocytes that contributes to the pathogenesis of DKD.

m6A eraser FTO modulates autophagy by targeting SQSTM1/P62 in the prevention of canagliflozin against renal fibrosis

The dysregulation of autophagy contributes to renal fibrosis. N6-Methyladenosine (m6A) RNA modification is a critical mediator of autophagy. Our previous studies have reported that the disorder of the PPARα/fatty acid oxidation (FAO) axis in renal tubular cells is suppressed by STAT6, which is involved in the regulation of renal fibrotic processes. Here, we found that canagliflozin significantly upregulates SQSTM1/P62, promoting PPARα-mediated FAO by inducing autophagy-dependent STAT6 degradation both in TGF-β1-treated HK2 cells and in unilateral ureteral occlusion (UUO) and ischemia-reperfusion (I/R) renal fibrosis mouse models. Knockdown of P62/SQSTM1 led to the impairment autophagic flux and the dysregulation of the STAT6/PPARα axis, which was confirmed by SQSTM1/P62^cKO mice with UUO treatment along with bioinformatics analysis. Furthermore, SQSTM1/P62 deficiency in renal tubular cells inhibited canagliflozin's effects that prevent FAO disorder in renal tubular cells and renal fibrosis. Mechanistically, the level of m6A eraser FTO, which interacted with SQSTM1 mRNA, decreased in the renal tubular cells both in vitro and in vivo after canagliflozin administration. Decrease in FTO stabilized SQSTM1 mRNA, which induced autophagosome formation. Collectively, this study uncovered a previously unrecognized function of canagliflozin in FTO in the autophagy modulation through the regulation of SQSTM1 mRNA stability in the renal tubular STAT6/PPARα/FAO axis and renal fibrosis.

RNA N6 -methyladenosine modifications and potential targeted therapeutic strategies in kidney disease

Epigenetic modifications have received increasing attention and have been shown to be extensively involved in kidney development and disease progression. Among them, the most common RNA modification, N⁶ -methyladenosine (m⁶ A), has been shown to dynamically and reversibly exert its functions in multiple ways, including splicing, export, decay and translation initiation efficiency to regulate mRNA fate. Moreover, m⁶ A has also been reported to exert biological effects by destabilizing base pairing to modulate various functions of RNAs. Most importantly, an increasing number of kidney diseases, such as renal cell carcinoma, acute kidney injury and chronic kidney disease, have been found to be associated with aberrant m⁶ A patterns. In this review, we comprehensively review the critical roles of m⁶ A in kidney diseases and discuss the possibilities and relevance of m⁶ A-targeted epigenetic therapy, with an integrated comprehensive description of the detailed alterations in specific loci that contribute to cellular processes that are associated with kidney diseases.

The m6A demethylase FTO promotes renal epithelial-mesenchymal transition by reducing the m6A modification of lncRNA GAS5

BACKGROUND

Renal interstitial fibrosis (RIF) is the main pathological change of a variety of chronic kidney diseases (CKD). Epigenetic modifications of fibrosis-prone genes regulate RIF progression. This study aimed to investigate long non-coding RNA (lncRNA) N6-methyladenosine (m⁶A) modification and its role in regulating RIF progression.

METHODS

Unilateral ureteral occlusion (UUO) was employed to construct the RIF in vivo model; and TGF-β1-treated HK-2 and HKC-8 cells were used for in vitro experiments. The mRNA and protein expressions were assessed using qRT-PCR and western blot. The proliferation and migration were evaluated by EdU assay and transwell assay, respectively. In addition, levels of inflammatory cytokines were determined by ELISA assay and qRT-PCR. Moreover, lncRNA GAS5 m⁶A level was detected using Me-RIP assay. HE and Masson staining were employed to evaluate fibrotic lesions of the kidney.

RESULTS

FTO expression was elevated in HK-2 and HKC-8 cells after TGF-β1 treatment and mouse kidney tissue following UUO, and lncRNA GAS5 was downregulated. LncRNA GAS5 overexpression or FTO silencing suppressed TGF-β1-induced the increase of EMT-related proteins (Vimentin, Snail and N-cadherin) and inflammatory cytokines (IL-6, IL-1β and TNF-α) levels in HK-2 cells. FTO suppressed lncRNA GAS5 expression by reducing the m6A modification of lncRNA GAS5. Additionally, FTO knockdown could suppress EMT process and inflammation response induced by TGF-β1 and UUO in vitro and in vivo. As expected, FTO knockdown abrogated the promotion effects of lncRNA GAS5 silencing on TGF-β1-induced EMT process and inflammation response in HK-2 and HKC-8 cells.

CONCLUSION

FTO promoted EMT process and inflammation response through reducing the m⁶A modification of lncRNA GAS5.

N6-Methyladenosine Methylomic Landscape of Ureteral Deficiency in Reflux Uropathy and Obstructive Uropathy

Background

Congenital anomalies of the kidneys and urinary tracts (CAKUT) represent the most prevalent cause for renal failure in children. The RNA epigenetic modification N⁶-methyladenosine (m⁶A) methylation modulates gene expression and function post-transcriptionally, which has recently been revealed to be critical in organ development. However, it is uncertain whether m⁶A methylation plays a role in the pathogenesis of CAKUT. Thus, we aimed to explore the pattern of m⁶A methylation in CAKUT.

Methods

Using m⁶A-mRNA epitranscriptomic microarray, we investigated the m⁶A methylomic landscape in the ureter tissue of children with obstructive megaureter (M group) and primary vesicoureteral reflux (V group).

Results

A total of 228 mRNAs engaged in multiple function-relevant signaling pathways were substantially differential methylated between the “V” and “M” groups. Additionally, 215 RNA-binding proteins that recognize differentially methylated regions were predicted based on public databases. The M group showed significantly higher mRNA levels of m⁶A readers/writers (YTHDF1, YTHDF2, YTHDC1, YTHDC2 and WTAP) and significantly lower mRNA levels of m⁶A eraser (FTO) according to real-time PCR. To further investigate the differentially methylated genes, m⁶A methylome and transcriptome data were integrated to identified 298 hypermethylated mRNAs with differential expressions (265 upregulation and 33 downregulation) and 489 hypomethylated mRNAs with differential expressions (431 upregulation and 58 downregulation) in the M/V comparison.

Conclusion

The current results highlight the pathogenesis of m⁶A methylation in obstructive and reflux uropathy.

Detailed resume of RNA m6A demethylases

N6-Methyladenosine (m⁶A) is the most abundant internal modification in eukaryotic mRNA, playing critical role in various bioprocesses. Like other epigenetic modifications, m⁶A modification can be catalyzed by the methyltransferase complex and erased dynamically to maintain cells homeostasis. Up to now, only two m⁶A demethylases have been reported, fat mass and obesity-associated protein (FTO) and alkylation protein AlkB homolog 5 (ALKBH5), involving in a wide range of mRNA biological progress, including mRNA shearing, export, metabolism and stability. Furthermore, they participate in many significantly biological signaling pathway, and contribute to the progress and development of cancer along with other diseases. In this review, we focus on the studies about structure, inhibitors development and biological function of FTO and ALKBH5.

Alteration of N6-Methyladenosine RNA Profiles in Cisplatin-Induced Acute Kidney Injury in Mice

Aim: To identify the alterations of N6-methyladenosine (m⁶A) RNA profiles in cisplatin-induced acute kidney injury (Cis-AKI) in mice.

Materials and Methods: The total level of m⁶A and the expression of methyltransferases and demethylases in the kidneys were measured. The profiles of methylated RNAs were determined by the microarray method. Bioinformatics analysis was performed to predict the functions.

Results: Global m⁶A levels were increased after cisplatin treatment, accompanied by the alterations of Mettl3, Mettl14, Wtap, Fto, and Alkbh5. A total of 618 mRNAs and 98 lncRNAs were significantly differentially methylated in response to cisplatin treatment. Bioinformatics analysis indicated that the methylated mRNAs predominantly acted on the metabolic process.

Conclusion: M⁶A epitranscriptome might be significantly altered in Cis-AKI, which is potentially implicated in the development of nephrotoxicity.

Autophagy attenuates renal fibrosis in obstructive nephropathy through inhibiting epithelialtomesenchymal transition

OBJECTIVES

To explore the relationship between autophagy and epithelial-to-mesenchymal transition (EMT), and to evaluate whether autophagy can affect the progression of renal fibrosis in obstructive nephropathy by regulating the EMT process.

METHODS

Unilateral ureteral obstruction (UUO) renal fibrosis model of rat was constructed, and the animals were divided into a sham group, an UUO group, an UUO+low-dose rapamycin group, and an UUO+high-dose rapamycin group. HE staining was used to observe the structure of the kidney, and Masson staining was used to observe renal interstitial collagen deposition. The expressions of E-cadherin, alpha-smooth muscle actin (α-SMA), Snail 1, and microtubule-associated protein-1 light chain 3II (LC3II) were detected by Western blotting, reflecting cellular EMT and autophagy. Transforming growth factor β1 (TGF-β1) induced-NRK52E cells model was constructed, and the cells were divided into a control group, a TGF-β1 group, and a TGF-β1+ Snail 1 siRNA group. To explore the effect of autophagy on EMT, the cells were also divided into a control group, a rapamycin group, and a Beclin 1 siRNA group. Western blotting was used to detect the expressions of E-cadherin, α-SMA, Snail 1, LC3II, collagen I, and fibronectin.

RESULTS

Compared with the sham group, the kidney damage in the UUO group was significantly worse; compared with the sham group, the collagen deposition in the kidney tissues in the UUO group was significantly increased, which were significantly reduced in the UUO+high-dose rapamycin group and the UUO+low-dose rapamycin group compared with the UUO group; compared with the sham group, the E-cadherin level in the kidney of the UUO group was significantly reduced, and the expression levels of α-SMA and LC3II were significantly increased (all P<0.05). Compared with the UUO group, the expression levels of E-cadherin and LC3II in the UUO+high-dose rapamycin group and the UUO+low-dose rapamycin group were significantly increased (P<0.01 and P<0.05, respectively), and the expression level of α-SMA was significantly decreased (P<0.01 and P<0.05, respectively). The expression levels of Snail 1, α-SMA, collagen I and fibronectin were significantly higher, and the E-cadherin level was significantly lower in the TGF-β1 group than those in the control group (all P<0.05). Compared with the TGF-β1 group, the expression of E-cadherin was increased significantly, and the expressions of α-SMA, collagen I and fibronectin were decreased significantly in the TGF-β1+Snail 1 siRNA group (all P<0.05). Compared with the control group, the expression levels of LC3II and E-cadherin were significantly elevated, and the expression levels of α-SMA and Snail 1 in the rapamycin group were significantly reduced (all P<0.05); the expression levels of LC3II and E-cadherin were significantly reduced, and the expression levels of α-SMA and Snail 1 were significantly increased in the Beclin 1 siRNA group (all P<0.05).

CONCLUSIONS

Autophagy plays an essential role in the regulation of EMT in obstructive nephropathy fibrosis. Autophagy can alleviate renal fibrosis by inhibiting EMT.

Alteration of N6-methyladenosine epitranscriptome profile in unilateral ureteral obstructive nephropathy

Aim: To reveal the alterations of N⁶-methyladenosine (m⁶A) epitranscriptome profile in kidney after unilateral ureteral obstruction in mice. Materials & methods: Total renal m⁶A and expressions of methyltransferases and demethylases were detected by colorimetric quantification method, real-time PCR and western blot, respectively. Methylated RNA immunoprecipitation sequencing was performed to map epitranscriptome-wide m⁶A profile. Results: Total m⁶A levels were time-dependent decreased within 1 week, with the lowest level detected at day 7. A total of 823 differentially methylated transcripts in 507 genes were identified. Specifically, demethylated mRNAs selectively acted on multiple pathways, including TGF-β and WNT. Conclusion: m⁶A modification has a functional importance in renal interstitial fibrosis during obstructive nephropathy and might be a promising therapeutic target.

Regulation of autophagy in leukocytes through RNA N6-adenosine methylation in chronic kidney disease patients

Patients with chronic kidney diseases have multiple cellular dysfunctions leading to increased atherosclerosis, impaired immunity, and disturbed metabolism. However, it is unclear what is the fundamental signaling served as a marker or as a mediator for the dysregulated function in their leukocytes or tissues. Here we hypothesized that the N⁶-Methyladenosine (m⁶A) modification of the RNA in the leukocytes is responsible for the cellular dysfunction in chronic kidney diseases. Patients with chronic kidney diseases had significantly less m⁶A abundances in leukocytes and elevated RNA demethylase FTO proteins. The uremic toxin, indoxyl sulfate, activated the autophagy flux through modulation of FTO and m⁶A modifications in RNA. Notably, knockdown of FTO or inhibit the m⁶A by 3-deazaadenosine blocks the effects of indoxyl sulfate on autophagy activation in cells. These findings provide new insights into the mechanisms underlying chronic kidney disease-associated cellular dysfunction. Targeting RNA m⁶A modification may be a novel strategy for the treatment of chronic kidney diseases and autophagy.

Meclofenamic acid promotes cisplatin-induced acute kidney injury by inhibiting fat mass and obesity-associated protein-mediated m6A abrogation in RNA

The role of RNA methylation on the sixth N atom of adenylate (m⁶A) in acute kidney injury (AKI) is unknown. FTO (fat mass and obesity-associated protein) reverses the m⁶A modification in cisplatin-induced AKI. Here, we aimed to determine FTO's role in AKI. We induced AKI in c57BL/6 mice by intraperitoneal cisplatin injection and treated the animal with vehicle or an FTO inhibitor meclofenamic acid (MA) for 3 days. Moreover, as an in vitro model, human kidney proximal tubular cells (HK2 cells) were treated with cisplatin. We found that the cisplatin treatment reduces FTO expression and increases m⁶A levels in vivo and in vitro MA aggravated renal damage and increased apoptosis in cisplatin-treated kidneys, phenotypes that were correlated with reduced FTO expression and increased m⁶A levels. Moreover, MA promoted apoptosis in cisplatin-treated HK2 cells, which was correlated with the reduced FTO expression and increased m⁶A in HK2 cells. FTO protein overexpression reduced m⁶A levels and inhibited apoptosis in cisplatin-treated HK2 cells and also blocked the MA-induced increase in m⁶A levels and apoptosis rates. In agreement, overexpression of the m⁶A-generating methyltransferase-like 3 and 14 (METTL3 and METTL14) or siRNA-mediated FTO knockdown promoted apoptosis and enhanced m⁶A levels in cisplatin-treated HK2 cells. MA increased p53 mRNA and protein levels in AKI both in vitro and in vivo, and FTO overexpression reduced p53 expression and reversed the MA-induced p53 increase in AKI. In conclusion, reduced renal FTO expression in cisplatin-induced AKI increases RNA m⁶A levels and aggravates renal damages.

MiR-122 marks the differences between subcutaneous and visceral adipose tissues and associates with the outcome of bariatric surgery

The physiological roles and clinical impacts of the differences between visceral fat (VF) and subcutaneous fat (SF) are unclear. The present study aimed to compare the miRNA signatures between visceral fat (VF) and subcutaneous fat (SF) and study their influences on outcomes of bariatric surgery. To study the microRNA signatures of the VF and SF in obesity, we performed paired microRNA arrays of the adipose tissues from 20 bariatric surgery patients. The microRNA analysis identified miR-122 as the most significant signature between VF and SF. The tissue distribution, functions, and influences on adipogensis of miR-122 were analysed by Northern blotting, microRNA mimics and inhibitors, and whole-genome microarray analysis. The outcomes of body weight changes after bariatric surgery were analysed and correlated with the miR-122 abundances. Northern blotting confirmed that miR-122 was highly expressed in VF and SF. Bioinformatics analysis of the microarray revealed that proliferator activator receptor-γ (PPAR-γ) signalling was critically affected by miR-122. The modulation of PPAR-γ by miR-122 was confirmed in murine adipocytes and human adipose tissues. Furthermore, the differentiation of preadipocytes was significantly influenced by miR-122. In obese patients receiving bariatric surgery, the ratio of VF and SF miR-122 abundance correlated with 6-month and 1-year % excess body weight loss. Our findings indicate that miR-122 is highly expressed in adipose tissue. The abundance of miR-122 affects PPAR-γ signalling and adipocytes differentiation in vitro and human adipose tissues. Higher miR-122 in VF may be associated with greater body weight loss after bariatric surgery.

Emerging roles of RNA-binding proteins in diabetes and their therapeutic potential in diabetic complications

Diabetes is a debilitating health care problem affecting 422 million people around the world. Diabetic patients suffer from multisystemic complications that can cause mortality and morbidity. Recent advancements in high-throughput next-generation RNA-sequencing and computational algorithms led to the discovery of aberrant posttranscriptional gene regulatory programs in diabetes. However, very little is known about how these regulatory programs are mis-regulated in diabetes. RNA-binding proteins (RBPs) are important regulators of posttranscriptional RNA networks, which are also dysregulated in diabetes. Human genetic studies provide new evidence that polymorphisms and mutations in RBPs are linked to diabetes. Therefore, we will discuss the emerging roles of RBPs in abnormal posttranscriptional gene expression in diabetes. Questions that will be addressed are: Which posttranscriptional mechanisms are disrupted in diabetes? Which RBPs are responsible for such changes under diabetic conditions? How are RBPs altered in diabetes? How does dysregulation of RBPs contribute to diabetes? Can we target RBPs using RNA-based methods to restore gene expression profiles in diabetic patients? Studying the evolving roles of RBPs in diabetes is critical not only for a comprehensive understanding of diabetes pathogenesis but also to design RNA-based therapeutic approaches for diabetic complications. WIREs RNA 2018, 9:e1459. doi: 10.1002/wrna.1459 This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing Translation > Translation Regulation.

A Method for Measuring RNA N 6-methyladenosine Modifications in Cells and Tissues

N⁶-Methyladenosine (m⁶A) modifications of RNA are diverse and ubiquitous amongst eukaryotes. They occur in mRNA, rRNA, tRNA, and microRNA. Recent studies have revealed that these reversible RNA modifications affect RNA splicing, translation, degradation, and localization. Multiple physiological processes, like circadian rhythms, stem cell pluripotency, fibrosis, triglyceride metabolism, and obesity are also controlled by m⁶A modifications. Immunoprecipitation/sequencing, mass spectrometry, and modified northern blotting are some of the methods commonly employed to measure m⁶A modifications. Herein, we present a northeastern blotting technique for measuring m⁶A modifications. The current protocol provides good size separation of RNA, better accommodation and standardization for various experimental designs, and clear delineation of m⁶A modifications in various sources of RNA. While m⁶A modifications are known to have a crucial impact on human physiology relating to circadian rhythms and obesity, their roles in other (patho)physiological states are unclear. Therefore, investigations on m⁶A modifications have immense possibility to provide key insights into molecular physiology.