Endothelial cell autophagy in chronic intermittent hypoxia is impaired by miRNA-30a-mediated translational control of Beclin-1

Chronic intermittent hypoxia (CIH) in obstructive sleep apnea causes damage of aortic endothelial cells, which predisposes the development of many cardiovascular diseases. Recently, both altered expression of microRNAs (miRNAs) and impaired autophagy were found to be associated with endothelial cell dysfunction in CIH. However, the exact molecular regulatory pathway has not been determined. Here, we address this question. In a mouse model of CIH, we detected significant upregulation of miR-30a, a miRNA that targets 3′-untranslated region of autophagy-associated protein 6 (Beclin-1) messenger RNA (mRNA) for suppressing the protein translation, which subsequently attenuated the endothelial cell autophagy against cell death. Indeed, unlike Beclin-1 mRNA, the Beclin-1 protein in endothelial cells did not increase after CIH. Suppression of miR-30a by expression of antisense of miR-30a significantly increased Beclin-1 levels to enhance endothelial cell autophagy in vitro and in vivo, which improved endothelial cell survival against CIH. Together, these data suggest that endothelial cell autophagy in CIH may be attenuated by miR-30a-mediated translational control of Beclin-1 as an important cause of endothelial cell dysfunction and damage.     

Affinity maturation and characterization of the ofatumumab monoclonal antibody

CD20 molecule, a phosphoprotein with 297 amino acids and four transmembrane domains, is a member of MS4A protein family. Anti-CD20 antibodies such as ofatumumab, which have been developed for cancer treatment and has demonstrated efficacy in relapsed/refractory chronic lymphocytic leukemia, are among the most successful therapies to date. Rational engineering methods can be applied with reasonable success to improve functional characteristics of antibodies. Considering the importance of this issue, we have used in silico modeling approach for the improvement of ofatumumab monoclonal antibody. Four mutated variants of ofatumumab were developed and expressed in Chinese hamster ovary (CHO) cells along with the unmodified antibody. Analysis of affinity of the purified antibodies with CD20 showed significant improvement in antigen-binding characteristics of one of the variants compared with the control antibody. This study represents the first step toward development of the second generation ofatumumab antibody with improved affinity.     

MiR-134-5p attenuates neuropathic pain progression through targeting Twist1

Neuropathic pain is a kind of chronic pain because of dysfunctions of somatosensory nerve system. Recently, many studies have demonstrated that microRNAs (miRs) play crucial roles in neuropathic pain development. This study was designed to investigate the effects of miR-134-5p on the process of neuropathic pain progression in a rat model established by chronic sciatic nerve injury (CCI). First, we observed that miR-134-5p was significantly decreased in CCI rat models. Overexpression of miR-134-5p strongly alleviated neuropathic pain behaviors including mechanical and thermal hyperalgesia. Meanwhile, inflammatory cytokine expression, such as IL-6, IL-1β and TNF-α in CCI rats were greatly repressed by upregulation of miR-134-5p. Twist1 has been widely regarded as a poor prognosis biomarker in diverse diseases. Here, by using bioinformatic analysis, 3′-untranslated region (UTR) of Twist1 was predicted to be a downstream target of miR-134-5p in our study. Here, we found that overexpression of miR-134-5p was able to suppress Twist1 dramatically. Furthermore, it was exhibited that Twist1 was increased in CCI rats time-dependently and Twist1 was inhibited in vivo. Subsequently, downregulation of Twist1 in CCI rats could depress neuropathic pain progression via inhibiting neuroinflammation. In conclusion, our current study indicated that miR-134-5p may inhibit neuropathic pain development through targeting Twist1. Our findings suggested that miR-134-5p might provide a novel therapeutic target for neuropathic pain.     

microRNA-206 overexpression inhibits epithelial-mesenchymal transition and glomerulosclerosis in rats with chronic kidney disease by inhibiting JAK/STAT signaling pathway

Chronic kidney disease (CKD) is a traumatic disease with significant psychic consequences to the patient's overall physical condition. microRNA-206 (miR-206) has been reported to play an essential role in the development of various diseases. The purpose of the present study is to investigate the effect of miR-206 through the JAK/STAT signaling pathway on epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells and glomerulosclerosis in rats with CKD. The targeting relationship between miR-206 and ANXA1 was verified. To explore the role of miR-206 in CKD, the model of CKD rats was established to detect glomerular sclerosis index (GSI), contents of interleukin-6 (IL-6) and transforming growth factor-beta1 (TGF-β1), and expression of type IV collagen. Moreover, to further determine the roles of both miR-206 and the JAK/STAT signaling pathway in CKD, the gain- and loss-of function approaches were performed with the expression of ANXA1, α-SMA, E-cadherin, vimentin, N-cadherin, and the JAK/STAT signaling pathway-related genes detected. miR-206 negatively targeted ANXA1. Overexpressed miR-206 inhibited the degeneration and interstitial fibrosis of renal tubular epithelial cells, decreased GSI of rats, and the expression of type IV collagen, TGF-β1 and IL-6. Overexpressed miR-206 inhibited the degeneration of renal tubular epithelial cells, the expression of ANXA1, α-SMA, TGF-β1, p-STAT3, STAT3, p-STAT1, STAT1, p-JAK2, and JAK2, while promoted the expression of E-cadherin. Taken together the results, miR-206 inhibits EMT of renal tubular epithelial cells and glomerulosclerosis by inactivating the JAK/STAT signaling pathway via ANXA1 in CKD.     

Roles of mesenchymal stem cells and exosomes in interstitial cystitis/bladder pain syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is characterized by several symptoms of higher sensitivity of the lower urinary tract, such as bladder pain/discomfort, urgency, urinary frequency, pelvic pain and nocturia. Although the pathophysiology of IC/BPS is not fully understood, the hypothesis suggests that mast cell activation, glycosaminoglycan (GAG) layer defects, urothelium permeability disruption, inflammation, autoimmune disorder and infection are potential mechanisms. Mesenchymal stem cells (MSCs) have been proven to protect against tissue injury in IC/BPS by migrating into bladders, differentiating into key bladder cells, inhibiting mast cell accumulation and cellular apoptosis, inhibiting inflammation and oxidative stress, alleviating collagen fibre accumulation and enhancing tissue regeneration in bladder tissues. In addition, MSCs can protect against tissue injury in IC/BPS by secreting various soluble factors, including exosomes and other soluble factors, with antiapoptotic, anti‐inflammatory, angiogenic and immunomodulatory properties in a cell‐to‐cell independent manner. In this review, we comprehensively summarized the current potential pathophysiological mechanisms and standard treatments of IC/BPS, and we discussed the potential mechanisms and therapeutic effects of MSCs and MSC‐derived exosomes in alleviating tissue injury in IC/BPS models.     

Iron-based phosphorus chelator: Risk of iron deposition and action on bone metabolism in uremic rats

Phosphate chelators are frequently used in patients with chronic kidney disease (CKD). New iron-based chelators remain understudied and offer a promising therapeutic option for the control of bone and mineral disorders of chronic kidney disease (BMD-CKD). We assessed the effect of the phosphorus chelator, chitosan-iron III (CH-FeCl), compared to calcium carbonate (CaCO₃) in BMD-CKD and the potential iron overload in uremic rats. Thirty-two animals were divided into four groups, namely the control, CKD, CKD/CH-FeCl, and CKD/CaCO₃ groups. CKD was induced by adding 0.75% (4 weeks) and 0.1% (3 weeks) adenine to the diet. The chelators were administered from week 3 through week 7. The renal function, BMD-CKD markers, and histomorphometry of the femur were assessed at week 7. The CKD group showed a significant increase in creatinine (83.9 ± 18.6 vs. 41.5 ± 22.1 µmol/L; P = 0.001), phosphate (3.5 ± 0.8 vs. 2.2 ± 0.2 mmol/L; P = 0.001), fractional excretion of phosphorus (FEP) (0.71 ± 0.2 vs. 0.2 ± 0.17; P = 0.0001), and FGF23 (81.36 ± 37.16 pg/mL vs. 7.42 ± 1.96; P = 0.011) compared to the control group. There was no accumulation of serum or bone iron after the use of CH-FeCl. The use of chelators reduced the FEP (control: 0.71 ± 0.20; CKD/CH-FeCl: 0.40 ± 0.16; CKD/CaCO₃ 0.34 ± 0.15; P = 0.001), without changes in the serum FGF23 and parathyroid hormone levels. Histomorphometry revealed the presence of bone disease with high remodeling in the uremic animals without changes with the use of chelators. The CH-FeCl chelator was efficient in reducing the FEP without iron accumulation, thereby paving the way for the use of this class of chelators in clinical settings in the future.