A Translation-Activating Function of MIWI/piRNA during Mouse Spermiogenesis.

Spermiogenesis is a highly orchestrated developmental process during which chromatin condensation decouples transcription from translation. Spermiogenic mRNAs are transcribed earlier and stored in a translationally inert state until needed for translation; however, it remains largely unclear how such repressed mRNAs become activated during spermiogenesis. We previously reported that the MIWI/piRNA machinery is responsible for mRNA elimination during late spermiogenesis in preparation for spermatozoa production. Here we unexpectedly discover that the same machinery is also responsible for activating translation of a subset of spermiogenic mRNAs to coordinate with morphological transformation into spermatozoa. Such action requires specific base-pairing interactions of piRNAs with target mRNAs in their 3' UTRs, which activates translation through coupling with cis-acting AU-rich elements to nucleate the formation of a MIWI/piRNA/eIF3f/HuR super-complex in a developmental stage-specific manner. These findings reveal a critical role of the piRNA system in translation activation, which we show is functionally required for spermatid development.

The Alazami Syndrome-Associated Protein LARP7 Guides U6 Small Nuclear RNA Modification and Contributes to Splicing Robustness.

The La-related protein 7 (LARP7) forms a complex with the nuclear 7SK RNA to regulate RNA polymerase II transcription. It has been implicated in cancer and the Alazami syndrome, a severe developmental disorder. Here, we report a so far unknown role of this protein in RNA modification. We show that LARP7 physically connects the spliceosomal U6 small nuclear RNA (snRNA) with a distinct subset of box C/D small nucleolar RNAs (snoRNAs) guiding U6 2'-O-methylation. Consistently, these modifications are severely compromised in the absence of LARP7. Although general splicing remains largely unaffected, transcriptome-wide analysis revealed perturbations in alternative splicing in LARP7-depleted cells. Importantly, we identified defects in 2'-O-methylation of the U6 snRNA in Alazami syndrome siblings carrying a LARP7 mutation. Our data identify LARP7 as a bridging factor for snoRNA-guided modification of the U6 snRNA and suggest that alterations in splicing fidelity contribute to the etiology of the Alazami syndrome.

LARP7-Mediated U6 snRNA Modification Ensures Splicing Fidelity and Spermatogenesis in Mice.

U6 snRNA, as an essential component of the catalytic core of the pre-mRNA processing spliceosome, is heavily modified post-transcriptionally, with 2'-O-methylation being most common. The role of these modifications in pre-mRNA splicing as well as their physiological function in mammals have remained largely unclear. Here we report that the La-related protein LARP7 functions as a critical cofactor for 2'-O-methylation of U6 in mouse male germ cells. Mechanistically, LARP7 promotes U6 loading onto box C/D snoRNP, facilitating U6 2'-O-methylation by box C/D snoRNP. Importantly, ablation of LARP7 in the male germline causes defective U6 2'-O-methylation, massive alterations in pre-mRNA splicing, and spermatogenic failure in mice, which can be rescued by ectopic expression of wild-type LARP7 but not an U6-loading-deficient mutant LARP7. Our data uncover a novel role of LARP7 in regulating U6 2'-O-methylation and demonstrate the functional requirement of such modification for splicing fidelity and spermatogenesis in mice.

Laparoscopic antireflux surgery or PPIs in the management of reflux-related esophageal stricture.

BACKGROUND: Gastroesophageal reflux disease (GERD) is often associated with esophageal stricture, particularly benign esophageal stricture. We aimed to evaluate the effects of balloon catheter dilation (BD) combined with laparoscopic fundoplication (LF) surgery and proton pump inhibitors (PPIs) in patients with reflux-induced esophageal strictures. METHODS: We retrospectively analyzed 116 patients with reflux-induced benign esophageal strictures who underwent balloon dilatation therapy combined with PPIs (BD-PPIs group, n = 58) and balloon dilatation combined with LF (BD-LF group, n = 58). Patients were followed up for 24 months. The outcomes of the patients were monitored, including clinical success, symptom improvement, adverse events, and the frequency of esophagitis. RESULTS: At the latest follow-up, the rate of clinical success was higher in BD-LF group than in BD-PPIs group (80.4% vs. 57.7%, P = 0.011). The patients in the BD-PPIs group required more dilation sessions to achieve successful dilation, as compared to those in the BD-LF group (2.1 ± 1.2 vs. 0.7 ± 0.8, P < 0.001). The DeMeester score, number of reflux episodes for which pH was < 4, and lower esophageal sphincter pressure were significantly better in the BD-LF group than in the BD-PPIs group (all P < 0.001). The incidence of reflux esophagitis was higher in the BD-PPIs group than in the BD-LF group, at 24 months (58.8% vs. 18.2%, P = 0.003). CONCLUSIONS: Balloon dilatation with concomitant LF is effective and safe for esophageal stricture secondary to GERD. Moreover, antireflux surgery techniques, such as Nissen or Toupet procedure, should be added for reflux-induced benign esophageal stricture.

Hyperglycemia promotes myocardial dysfunction via the ERS-MAPK10 signaling pathway in db/db mice.

Recent studies have demonstrated that hyperglycemia is a major risk factor for the development and exacerbation of cardiovascular disease (CVD). However, the molecular mechanisms involved in diabetic cardiomyopathy (DCM) have not been fully elucidated. In this study, we focused on the underlying mechanism of DCM. Leptin receptor-deficient db/db mice were used to model a type 2 diabetes mellitus (T2DM) model in our study. WT mice and db/db mice received 4-phenylbutyric acid (4-PBA) (25 mg/kg/day) and saline by intraperitoneal injection every other day for 4 weeks. WT and db/db mice were given tail vein injections of 100 µL of rAAV9-Sh-MAPK10 and rAAV9-Sh-GFP at the age of 6-8 weeks. Echocardiography was performed to measure cardiac function, histological examinations were used to evaluate ventricular hypertrophy and fibrosis. Quantitative RT-qPCR was used to assess the mRNA expression of Jun N-terminal kinase 3 (JNK3, MAPK10), atrial natriuretic factor (ANF), brain natriuretic peptide (BNP), and collagen I and III. Immunoblotting was performed to measure the levels of cardiac hypertrophy-related proteins, fibrosis-related proteins, endoplasmic reticulum stress (ERS)-related proteins and apoptosis-related proteins. TUNEL staining was performed to examine cardiomyocyte apoptosis. In contrast to 12-week-old db/db mice, 16-week-old db/db mice showed the most severe myocardial dysfunction. The DCM induced by hyperglycemia was largely alleviated by 4-PBA (25 mg/kg/day, intraperitoneal injection). Similarly, tail vein injection of rAAV9-Sh-MAPK10 reversed the phenotype of the heart in db/db mice including cardiac hypertrophy and apoptosis in db/db mice. The mechanistic findings suggested that hyperglycemia initiated the ERS response through the negative regulation of sirtuin 1 (SIRT1), leading to the occurrence of myocardial dysfunction, and specific knockdown of MAPK10 in the heart directly reversed myocardial dysfunction induced by hyperglycemia. We demonstrated that hyperglycemia promotes DCM in db/db mice through the ERS-MAPK10 signaling pathway in diabetic mice.

Endoscopic cardial constriction with band ligation in the treatment of refractory gastroesophageal reflux disease: a preliminary feasibility study.

BACKGROUND: Gastroesophageal reflux disease (GERD) is a common digestive disease, could cause extra-esophageal symptoms. Peroral endoscopic cardial constriction with band ligation (PECC-b) is a minimally invasive method for the treatment of GERD in recent years. The goals of this study were to evaluate the clinical efficacy of PECC-b to treat gastroesophageal reflux-related symptoms. METHODS: A retrospective study of patients undergoing PECC-b between January 2017 and December 2018 at a single institution was conducted. All patients confirmed GERD by endoscopy, esophageal PH-impedance monitoring, esophageal manometry and symptom questionnaires. The outcome measures included reflux-related scores, patients' satisfaction and drug independence after 12 months following surgery. RESULTS: A total of 68 patients, with follow-up of 12 months post surgery, were included in the final analysis. The symptom scores were all significantly decreased as compared with preoperation (P < 0.05). The esophageal symptom scores showed a better improvement than extra-esophageal symptoms (P < 0.001). Fifty-three (77.9%) patients achieved complete drug therapy independence and 52 (76.5%) patients were completely or partially satisfied with the symptom relief following surgery. CONCLUSIONS: The PECC-b is a safe, effective and recommended approach for the control of GERD-related symptoms. Further multicenter prospective studies are required to confirm these outcomes.

The Role of Gastroesophageal Reflux in Provoking High Blood Pressure Episodes in Patients With Hypertension.

GOALS: We assessed the relationship between gastroesophageal reflux disease (GERD) and hypertension and whether antiacid therapy could be used to control blood pressure (BP) on hypertension in patients with GERD. BACKGROUND: Gastroesophageal reflux disease (GERD) may provoke cardiovascular disease. Many factors are involved in the development of essential hypertension, but whether GERD has a role needs further study. STUDY: Patients with essential hypertension (n=86) were studied by 24-hour continuous BP monitoring and esophageal impedance and pH monitoring. Patients fulfilling the GERD criteria received 14-day therapy with omeprazole (20 mg twice a day), and the effect on BP was studied. RESULTS: Of the 86 essential hypertension patients, 38 (44.2%) had GERD. Among these 38 patients, 494 episodes of pathologic reflux (PR), and 684 episodes of high BP were recorded. PR was significantly more common at nighttime especially when supine. Of the 684 episodes of hypertension, 102 (14.9%) were synchronous with PR. GERD patients had significantly higher nocturnal BP than non-GERD patients. Antiacid therapy brought about significant reduction in all esophageal monitoring parameters as well as in BP parameters in GERD patients. CONCLUSIONS: This study demonstrated that there is significant correlation between hypertension and GERD. Antiacid therapy can restore normal esophageal pH and help maintain normal BP.

Positive association of serum FUT8 activity with renal tubulointerstitial injury in IgA nephropathy patients.

BACKGROUND: α-1,6 Fucosyltransferase (FUT8) appears to play an essential role in the pathogenesis of renal fibrosis. However, it remained unknown whether FUT8 also contributed to renal fibrosis in immunoglobulin A nephropathy (IgAN). In the present study, we explored the association of serum FUT8 activity with renal tubulointerstitial injury in IgAN patients. METHODS: Serum FUT8 activity was measured in 135 IgAN patients and 68 healthy controls from January 2016 to December 2018. The relationships of serum FUT8 activity with clinical and pathological features were analyzed. RESULTS: Relative to healthy controls, IgAN patients had significantly higher serum FUT8 activity and upregulation of renal FUT8 protein (p < .05). Among IgAN patients, there was a positive correlation of serum FUT8 activity with renal FUT8 protein expression (p < .05). Multivariable logistic regression analyses showed that serum FUT8 activity was significantly associated with serum creatinine and eGFR (p < .05). Based on a cut-off value determined from ROC curve analysis, we divided IgAN patients into a low serum FUT8 activity group (≤12.2 pmol/h/mL, n = 40) and a high serum FUT8 activity group (>12.2 pmol/h/ml, n = 95). The high serum FUT8 activity group had a higher Oxford T score, increased inflammatory cell infiltration, more severe fibrosis and poor renal function (p < .05). CONCLUSION: Serum FUT8 activity was positive association with renal tubulointerstitial injury in IgAN patients.

Knockout of glutathione peroxidase 5 down-regulates the piRNAs in the caput epididymidis of aged mice.

The mammalian epididymis not only plays a fundamental role in the maturation of spermatozoa, but also provides protection against various stressors. The foremost among these is the threat posed by oxidative stress, which arises from an imbalance in reactive oxygen species and can elicit damage to cellular lipids, proteins, and nucleic acids. In mice, the risk of oxidative damage to spermatozoa is mitigated through the expression and secretion of glutathione peroxidase 5 (GPX5) as a major luminal scavenger in the proximal caput epididymidal segment. Accordingly, the loss of GPX5-mediated protection leads to impaired DNA integrity in the spermatozoa of aged Gpx5-/- mice. To explore the underlying mechanism, we have conducted transcriptomic analysis of caput epididymidal epithelial cells from aged (13 months old) Gpx5-/- mice. This analysis revealed the dysregulation of several thousand epididymal mRNA transcripts, including the downregulation of a subgroup of piRNA pathway genes, in aged Gpx5-/- mice. In agreement with these findings, we also observed the loss of piRNAs, which potentially bind to the P-element-induced wimpy testis (PIWI)-like proteins PIWIL1 and PIWIL2. The absence of these piRNAs was correlated with the elevated mRNA levels of their putative gene targets in the caput epididymidis of Gpx5-/- mice. Importantly, the oxidative stress response genes tend to have more targeting piRNAs, and many of them were among the top increased genes upon the loss of GPX5. Taken together, our findings suggest the existence of a previously uncharacterized somatic piRNA pathway in the mammalian epididymis and its possible involvement in the aging and oxidative stress-mediated responses.

Role of fundoplication in treatment of patients with symptoms of hiatal hernia.

Gastroesophageal reflux disease (GERD) is often associated with hiatal hernia (HH). However, the need for fundoplication during hiatal hernia repair (HHR) remains controversial. The objective of this study was to evaluate the effect of HHR with concomitant laparoscopic Nissen fundoplication (HHR-LNF) in HH patients. A total of 122 patients with symptomatic HH were randomized to receive either HHR (n = 61) or HHR-LNF (n = 61). The measures of evaluating outcomes included DeMeester scores (DMS), complications, Reflux Diagnostic Questionnaire and patients' satisfaction 24 months following surgery. Despite comparable values in both groups at randomization, the DMS, total numbers of reflux episodes and percentage of time with pH < 4 were significantly higher in HHR group than in HHR-LNF group (P = 0.017, P = 0.002 and P = 0.019, respectively) at 6 months after surgery. One months postoperatively, complications were higher in the HHR-LNF group than in the HHR group (all P < 0.001), and there was no difference between the two groups at 6 months. By the end of the 2-year follow-up, HHR-LNF group showed a significantly lower reflux syndrome frequency-intensity score and greater percentage of satisfaction compared with HHR group (all P < 0.001). Laparoscopic HHR should be combined with a fundoplication in GERD patients with HH. HHR-LNF is safe and effective, not only improve reflux-related symptom, but also reduce the incidence of complications.

Contribution of hiatal hernia to asthma in patients with gastroesophageal reflux disease.

BACKGROUND: To determine the correlation between asthma and hiatal hernia (HH) in patients with gastroesophageal reflux disease (GERD)-related asthma requiring laparoscopic anti-reflux surgery. METHODS: One hundred and thirty-six GERD patients with medically refractory asthma with (80 patients) or without HH (56 patients) were enrolled. Gastroesophageal reflux disease was assessed by endoscopy, esophageal manometry, reflux monitoring and symptom questionnaires, and treated with laparoscopic Nissen fundoplication (LNF) or LNF with concomitant hiatal hernia repair (LNF-HHR). The outcome measures included patients' satisfaction and drug independence. RESULTS: The patients with HH had lower esophageal sphincters (P = .005) and higher DeMeester scores (P = .014) than those without HH. After an average follow-up of 24 months, symptom scores were significantly decreased from the preoperative values (P < .05). Compared to LNF, LNF-HHR showed a better improvement in both esophageal and asthmatic symptoms (P < .0001 and P = .016, respectively). CONCLUSIONS: The patients with GERD with asthma have a high prevalence of HH. The presence of HH maybe correlated with asthma and severe GERD. Actively treating HH not only improved reflux, but also controlled asthma symptoms.

[Effect of electroacupuncture of "Chize" (LU 5) and "Shangjuxu" (ST 37) on mesenteric microcirculation and vasoactive intestinal peptide levels in the lung, colon and hypothalamus in rats with chronic obstructive pulmonary diseases].

OBJECTIVE: To observe the influence of electroacupuncture (EA) of "Chize" (LU 5, He-sea acupoint) and "Shangjuxu" (ST 37, lower He-sea acupoint) on mesenteric microcirculation, vasoactive intestinal peptide (VIP) levels in the lung, colon and hypothalamus tissues in rats with chronic obstructive pulmonary disease (COPD), so as to investigate its mechanism underlying improvement of lung derived intestinal disorders in clinical practice. METHODS: Thirty-two male Wistar rats were randomly divided into normal control, model, EA-Chize (LU 5, EA-LU 5) and EA-Shangjuxu (ST 37, EA-ST 37) groups, with 8 rats being in each group. COPD model was established by intratracheal infusion of Lipopolysaccharide (LPS, 1 mg/mL, 0.2 mL/rat) and forced inhaling smoke, once daily for 28 days. EA was applied to bilateral LU 5 and ST 37 for 20 min, once every other day for 12 sessions. The state of mesenteric microcirculation was observed under microscope and divided into grade 0 (stagnation of blood flow), I (slow flowing and silt-like state), II (faster flowing with slight or obvious grainy feeling) and III (fast flowing without grainy feeling). The contents of VIP in the lung, colon and hypothalamus were detected using radioimmunoassay (RIA). RESULTS: Following modeling, the microvascular calibers were increased slightly in the model, EA-LU 5 and EA-ST 37 groups. Compared with the normal group, the blood flow velocity was increased significantly in model group (P < 0.05). In comparison with the model group, the blood flow velocity was reduced significantly in EA-LU 5 and EA-ST 37 groups (P < 0.01). There were no significant differences between EA-LU 5 and EA-ST 37 groups in blood flow velocity, among the four groups in VIP contents of the lung tissue (P > 0.05). The content of VIP in the colon was markedly higher in the model group than in the normal group, and that in the hypothalamus was obviously lower in the EA-LU 5 group than in the model group (all P < 0.05). CONCLUSION: EA stimulation of "Chize" (LU 5) can notably reduce hypothalamic VIP content and slow down blood flow velocity of the mesenteric microvessels in COPD rats.

Radiofrequency treatment on respiratory symptoms due to gastroesophageal reflux disease.

BACKGROUND: Diagnosis and treatment for respiratory symptoms (RSs) of gastroesophageal reflux disease (GERD) is more difficult than that for common esophageal symptoms. The goal of this study was to evaluate the efficacy and safety of radiofrequency (RF) treatment on RSs of GERD in a preliminary 12-month follow-up observation. METHODS: From April 2006 to October 2008, 505 GERD patients with mainly respiratory presentations such as wheezing, chronic cough or hoarseness, were treated by endoscopic RF. A questionnaire was completed before and after treatment, using a six-point scale ranging from 0 to 5 to assess symptom severity and frequency. The symptom score was the sum of frequency and severity. RESULTS: Symptom scores were significantly improved at the end of the follow-up period. The mean heartburn score decreased from 5.31 to 1.79. The mean regurgitation score decreased from 5.02 to 1.64; mean cough score decreased from 6.77 to 2.85; mean wheezing score decreased from 7.83 to 3.07; and mean hoarseness score decreased from 5.13 to 1.81 (P < 0.01). No major complications or deaths occurred. Minor complications included temporary post-procedural retrosternal unease or pain (n = 106; 21.0%), mild fever (n = 86; 17.0%), transient nausea/vomiting (n = 97; 19.2%), and transient dysphagia (n = 42; 9.3%). Thirty-five (6.9%) patients had recurrence of symptoms. Endoscopic RF treatment was repeated in six patients, and laparoscopic fundoplication was performed in seven. CONCLUSION: Endoscopic RF is an effective and safe means to treat RSs in patients with GERD.