ABSTRACT Lactylation, a protein post-translational modification driven by lactate, plays crucial roles in various physiological and pathological processes. However, the function and underlying mechanisms of lactylation in infection and pathogenesis of influenza A virus (IAV) remain poorly understood. Here, we demonstrated that sirtuin 1 (SIRT1) suppressed IAV replication by mediating delactylation of viral proteins. We found that IAV infection significantly downregulated the expression of SIRT1. Functional studies revealed that depletion of SIRT1 markedly enhanced replication of IAV, whereas overexpression of SIRT1 attenuated the viral replication. Mechanistically, we observed that SIRT1 interacted with IAV NP, PA, PB1, and PB2 proteins, components of the viral ribonucleoprotein (vRNP) complex, and restrained the activity of the vRNP complex, thereby repressing transcription and replication of the IAV genome. Furthermore, we identified that viral NP, PA, PB1, and PB2 proteins underwent lactylation during IAV infection, and SIRT1 facilitated the delactylation of NP, PA, and PB2. Loss of SIRT1 enhanced the lactylation of NP, PA, and PB2, while overexpression of SIRT1 impaired lactylation of these viral proteins during IAV infection. Moreover, inhibition or depletion of lactate dehydrogenase A (LDHA) robustly reduced the lactylation of NP, PA, and PB2, thereby abolishing the promotion of IAV replication caused by SIRT1 deficiency, suggesting that SIRT1 repressed IAV replication via delactylation of viral NP, PA, and PB2 proteins. Together, these results uncover a mechanism that SIRT1 suppresses IAV replication via delactylation of the vRNP components and elicit a critical role for the lactylation of viral proteins in regulating IAV infection and pathogenesis. IMPORTANCE Lactylation plays vital roles in diverse pathological processes. However, the relationship between lactylation and influenza A virus (IAV) infection remains largely unexplored. Particularly, little information is available about the lactylation of viral proteins and their roles in the IAV pathogenesis. Here, viral proteins (NP, PA, PB1, and PB2) were identified to become lactylated during IAV infection. SIRT1 interacted with and promoted the delactylation of viral NP, PA, and PB2 proteins, thereby restraining the vRNP activity and inhibiting the viral transcription and replication. Interestingly, the expression of SIRT1 decreased following IAV infection, suggesting that IAV had evolved a mechanism to downregulate the SIRT1 expression, thereby ensuring appropriate lactylation of viral proteins and facilitating the IAV replication. Together, these findings reveal a critical role for the lactylation of viral proteins in regulating the replication of IAV and provide an important insight into the complicated interplay between the host and IAV.
l
‐Cysteine Alleviates Peritoneal Fibrosis by Repressing
PKM2
in Peritoneal Mesothelial Cells
ABSTRACT Peritoneal fibrosis is one of the main causes of peritoneal dysfunction and withdrawal of patients from peritoneal dialysis (PD). Our previous study has shown that high‐glucose dialysis solution promotes glycolysis in peritoneal mesothelial cells, leading to mesothelial‐to‐mesenchymal transition (MMT) and peritoneal fibrosis. However, the molecular mechanisms remain unclear. Using single‐cell RNA sequencing (scRNA‐seq) analysis of cells from the effluent of patients undergoing PD from our previous study, we found that pyruvate kinase isozymes M2 (PKM2), a key rate‐limiting enzyme of glucose metabolism, was significantly upregulated in the mesothelial cells of patients with long‐term peritoneal dialysis (LPD). Using co‐immunoprecipitation, chromatin immunoprecipitation assay, and gene silencing techniques, we revealed that PKM2 promotes the expression of transcription factor SNAI2 by acetylating histone H3K9 (H3K9ac), thereby promoting the occurrence of MMT and hence peritoneal fibrosis. l ‐cysteine, a known PKM2 inhibitor, blocked these responses and prevented PD‐induced peritoneal fibrosis. These results could provide a novel therapeutic strategy for treating peritoneal fibrosis.
Peripheral Iridectomy With Goniosynechialysis and Goniotomy vs Trabeculectomy for Advanced PACG
ImportanceThe safety and effectiveness of combining surgical peripheral iridectomy (SPI) with goniosynechialysis (GSL) and goniotomy (GT) vs trabeculectomy for intraocular pressure (IOP) reduction remains unknown.ObjectiveTo investigate the safety and effectiveness at 1 year of SPI + GSL + GT vs trabeculectomy in advanced primary angle-closure glaucoma (PACG) without cataract.Design, Setting, and ParticipantsThis noninferiority randomized clinical trial was conducted at 8 tertiary eye centers in China. A total of 88 Chinese patients (88 eyes) with advanced PACG without cataract were enrolled from January 2022 to July 2023. Data were analyzed from August 2024 to September 2024. Mean (SD) patient age was 60.3 (7.3) years, and 52 patients (59.1%) were female. Forty-three patients were randomized to SPI + GSL + GT and 45 were randomized to trabeculectomy; 86 patients (97.7%) completed the 12-month follow-up.InterventionsParticipants were randomized 1:1 to receive SPI + GSL + GT or trabeculectomy.Main Outcomes and MeasuresThe primary outcome was IOP at 12 months (noninferior margin: 4 mm Hg). Secondary outcomes included surgical success (IOP: 5-18 mm Hg, ≥20% reduction from baseline, with or without antiglaucoma medications); postoperative complications and interventions, including bleb massage, suture lysis, or releasable sutures; and number of antiglaucomatous medications prescribed.ResultsAt 12 months, the SPI + GSL + GT group had a mean (SD) IOP of 15.6 (4.0) mm Hg vs 14.9 (4.2) mm Hg in the trabeculectomy group (difference, 0.5 mm Hg; 95% CI, −1.2 to 2.2; P = .55), which was within the 4-mm Hg noninferiority margin. Qualified success rates were 38 of 43 participants (88.4%) for SPI + GSL + GT and 42 of 45 participants (93.3%) for trabeculectomy (difference, −5.0%; 95% CI, −19.6% to 8.5%; P = .48). However, complete success rates were lower in the SPI + GSL + GT group (26 participants [60.5%]) vs the trabeculectomy group (37 participants [82.2%]; difference, −21.8%; 95% CI, −40.2% to −2.4%; P = .03). Postoperative complications were present for 8 participants (18.6%) in the SPI + GSL + GT group vs 9 participants (20.0%) in the trabeculectomy group (difference, −1.4%; 95% CI, −17.9% to 15.1%; P = .71). Postoperative interventions were lower in the SPI + GSL + GT group (3 participants [7.0%] vs 25 participants [55.6%]; difference, 48.6%; 95% CI, 32.2%-65.0%; P < .001). Median (IQR) numbers of medications used decreased from 2 (0-3) to 0 (0-1) in the SPI + GSL + GT group and from 2 (2-3) to 0 (0-0) in the trabeculectomy group (difference, −0.81; 95% CI, −1.36 to −0.26; P = .004).Conclusions and RelevanceIn this randomized clinical trial among patients with advanced PACG without cataract, SPI + GSL + GT demonstrated noninferiority (4-mm Hg margin) to trabeculectomy for IOP at 12 months, with fewer interventions (including bleb massage, suture lysis, or releasable sutures) but no difference in postoperative medication use. This suggests SPI + GSL + GT as a potential alternative to trabeculectomy for similar cases, pending validation in larger sample sizes with smaller noninferiority margins.Trial RegistrationClinicalTrials.gov Identifier: NCT05163951
Ultrasound‐targeted microbubble destruction mediates PDE5i/NO integration for cavernosum remodeling and penile rehabilitation
AbstractErectile dysfunction (ED) caused by cavernous nerve injury (CNI) is refractory to heal mainly ascribed to the adverse remodeling of the penis induced by ineffectual microvascular perfusion, fibrosis, and neurotrophins scarcity in cavernosum. Phosphodiesterase type V inhibitors (PDE5i) have been regarded as an alternative candidate drug for avoiding penile neuropathy. However, the therapeutic efficacy is severely limited due to poor accumulation under systemic medication and endogenous nitric oxide (NO) deficiency in cavernosum. Herein, an innovative liposomal microbubble (MB) loaded with both Sildenafil (one of PDE5i) and NO was designed. Ultrasound‐targeted MB destruction (UTMD)‐mediated efficient release and integration erectogenic agents into corpus cavernosum with high biosafety. On a bilateral CNI rat model, the multifunctional MB‐cooperated UTMD improved microvascular perfusion in penis, simultaneously, alleviated hypoxia and oxidative stress, indicating successful activation of NO–cyclic guanosine monophosphate pathway. Also, evaluation of the endothelial/muscular composition, intracavernosal pressure, and neural integrity in the penis proved that coordinated intervention reversed the abnormal structural remodeling and promoted the recovery of functional erection. Our work demonstrates that MB loading Sildenafil and NO combined with UTMD hold great promise to “awaken” the efficacy of PDE5i in neurogenic ED, which provided a superior option for ensuring penile rehabilitation.
Abstract T P227: The Safety of Pioglitazone for Hematoma Resolution in IntraCerebral Hemorrhage (SHRINC) Trial: Safety Results
Background and Objectives: Peroxisome proliferator activated receptor-gamma agonists, such as pioglitazone (PIO) enhanced hematoma resolution and improved functional recovery in our animal model of intracerebral hemorrhage (ICH). We conducted a translational Phase II randomized, controlled clinical trial to determine the maximum tolerated dose (MTD) of PIO in patients with spontaneous ICH and to explore the rate of hematoma resolution and clinical outcome. Methods: Patients with spontaneous ICH within 24 hours of symptom onset were randomly allocated 1:1 to placebo or PIO. Patients received escalating doses of PIO daily for three days, followed by a 30mg maintenance dose for the duration of treatment. Duration of treatment was when 75% of the ICH had resolved as determined by serial MRI or 10 weeks of treatment, whichever occurred first. The primary safety outcome was mortality at Day 14. Secondary measures of safety include any mortality, symptomatic cerebral edema, congestive heart failure, edema, hypoglycemia, anemia, and hepatotoxicity. Secondary measures of efficacy include hematoma resolution and clinical outcome. The MTD was determined using the Continual Reassessment Method. Results: From March 2009 to April 2013, 84 patients (42 PIO, 42 control) were enrolled into 11 dose tiers, with a planned range from 0.1-2.0 mg/kg/d. Table 1 demonstrates preliminary baseline and clinical characteristics of patients by treatment group. Overall, 2/84 patients died within 2 weeks after ICH; however mortality rate never exceeded prespecified criteria. The study will be complete in October 2013 and the treatment team remains blinded to treatment allocation. Secondary outcomes by treatment group and the MTD of PIO will be reported. Conclusions: We have completed the treatment phase of the SHRINC Trial. Long term follow-up is on-going. These results will provide the foundation for an efficacy trial evaluating PIO as a potential treatment for patients with spontaneous ICH.
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)
1
Comparison of BRAF inhibitor (BRAFi)-induced cutaneous squamous cell carcinoma (cuSCC) and secondary malignancies in BRAF mutation-positive metastatic melanoma (MM) patients (pts) treated with dabrafenib (D) as monotherapy or in combination with MEK1/2 inh
9016 Background: The MAP kinase (MAPK) pathway is of critical importance for keratinocyte proliferation and maturation and is essential for epidermal homeostasis. Occurrence of hyperproliferative skin lesions including keratoacanthomas (KA) and cuSCC are considered a class effect of BRAFi [Anforth 2012, Chu 2012, Mattei 2012]. These effects, as well as promotion of pre-existing RAS-driven malignancies, may be caused by paradoxical activation of the MAPK pathway downstream of BRAF in wild-type BRAF cells. As MEK inhibition blocks downstream MAPK signaling, it was hypothesized that addition of a MEKi to a BRAFi would abrogate these effects [Su, 2012]. Methods: This 4-part phase I/II study enrolled 365 BRAFV600E/Kmutated MM pts in Parts B-D. In part C, 162 pts (BRAFi and MEKi treatment-naïve, ≥ 18 yrs; ECOG PS <2; RECIST measurable disease) were randomized to D monotherapy 150mg BID (D mono) vs. the combination of D (150 mg BID) and T (1 mg or 2 mg QD). Primary endpoints included safety and efficacy. Occurrence of cuSCC (including KA) across three arms in Part C and secondary malignancies with D+T across all Parts are provided below. Results: The difference in incidence of cuSCC between D mono and the D+T (150/1) was statistically significant, whereas the difference in incidence between D mono and D+T (150/2) was not. The median time to onset of cuSCC was 30 days in D mono compared to 282 and 152 days with D+T (150/1 and 150/2, respectively). Of 365 pts who received D+T, 2 (<1%) cases of new cancers (colorectal and gliobastoma) and 2 (<1%) cases of new primary malignant melanoma were reported. Conclusions: These data support the experimental hypothesis that the occurrence of cuSCC (including KA) can be substantially reduced and delayed by the addition of a MEKi to BRAFi therapy. Clinical trial information: NCT01072175. [Table: see text]
BRAF inhibitor (BRAFi) dabrafenib in combination with the MEK1/2 inhibitor (MEKi) trametinib in BRAFi-naive and BRAFi-resistant patients (pts) with BRAF mutation-positive metastatic melanoma (MM).
9005 Background: Dual inhibition of the MAP kinase (MAPK) pathway with dabrafenib (D) and trametinib (T) in combination has demonstrated clinical benefit compared to D alone in a randomized Phase II trial in V600 BRAF-mutant MM pts, thus delaying the development of BRAFi resistance. Little is known about the efficacy of D + T after BRAFi resistance has been acquired. This analysis evaluates the ability of D + T combination to treat acquired resistance compared to the D + T combination as first-line treatment. Methods: These data from a phase I/II study include 1. BRAFi-resistant group: pts who received 150/2 D+T in Part B (n=26) and Part C (n=43) following progression on BRAFi monotherapy (mono); 2. BRAFi-naïve group: pts who received initial 150/2 D+T in Part B (n=24) and Part C (n=54). Results: Baseline characteristics (ECOG PS, M staging, LDH) were similar across all groups.In the Part B BRAFi-resistant group, 93% of pts previously received D or vemurafenib and all pts received D prior to D+T in Part C. In BRAFi-resistant group, prior best response of CR/PR (38%, 56%), SD (35%, 27%), PD (27%, 7%) was observed in Parts B and C respectively. In BRAFi-resistant group, the ORR and PFS with D+T was lower than initial D+T in BRAFi-naive group. Median duration of response (DoR) in BRAFi-resistant group cannot be calculated due to small no. of pts responding. Median DoR for BRAFi-naïve pts was 11.3 mo and 10.5 mo in Parts B and C respectively. In Part C, the 12-mo overall survival rates in BRAFi-naïve (150/2) pts was 79% vs 70% for pts initially on D mono, despite 80% pts crossing over to D+T combination. Conclusions: The clinical activity for 150/2 D+T combination is consistently superior in BRAFi-naive group vs BRAFi-resistant group in both Parts B and C. Dual MAPK blockade can delay clinical resistance to BRAF inhibition. However, once BRAFi resistance has occurred, the combination of BRAFi + MEKi is far less effective. Clinical trial information: NCT01072175. [Table: see text]