Shuhao Zhang

G-protein-coupled receptors (GPCRs) are key regulators of human physiology and are the targets of many small-molecule research compounds and therapeutic drugs. While most of these ligands bind to their target GPCR with high affinity, selectivity is often limited at the receptor, tissue and cellular levels. Antibodies have the potential to address these limitations but their properties as GPCR ligands remain poorly characterized. Here, using protein engineering, pharmacological assays and structural studies, we develop maternally selective heavy-chain-only antibody (‘nanobody’) antagonists against the angiotensin II type I receptor and uncover the unusual molecular basis of their receptor antagonism. We further show that our nanobodies can simultaneously bind to angiotensin II type I receptor with specific small-molecule antagonists and demonstrate that ligand selectivity can be readily tuned. Our work illustrates that antibody fragments can exhibit rich and evolvable pharmacology, attesting to their potential as next-generation GPCR modulators.

Patients with multiple myeloma, an incurable malignancy of plasma cells, frequently develop osteolytic bone lesions that severely impact quality of life and clinical outcomes. Eliglustat, a U.S. Food and Drug Administration-approved glucosylceramide synthase inhibitor, reduced osteoclast-driven bone loss in preclinical in vivo models of myeloma. In combination with zoledronic acid, a bisphosphonate that treats myeloma bone disease, eliglustat provided further protection from bone loss. Autophagic degradation of TRAF3, a key step for osteoclast differentiation, was inhibited by eliglustat as evidenced by TRAF3 lysosomal and cytoplasmic accumulation. Eliglustat blocked autophagy by altering glycosphingolipid composition whilst restoration of missing glycosphingolipids rescued autophagy markers and TRAF3 degradation thus restoring osteoclastogenesis in bone marrow cells from myeloma patients. This work delineates both the mechanism by which glucosylceramide synthase inhibition prevents autophagic degradation of TRAF3 to reduce osteoclastogenesis as well as highlighting the clinical translational potential of eliglustat for the treatment of myeloma bone disease.

Molecular structures are commonly depicted in 2D printed forms in scientific documents such as journal papers and patents. However, these 2D depictions are not machine readable. Due to a backlog of decades and an increasing amount of printed literatures, there is a high demand for translating printed depictions into machine-readable formats, which is known as Optical Chemical Structure Recognition (OCSR). Most OCSR systems developed over the last three decades use a rule-based approach, which vectorizes the depiction based on the interpretation of vectors and nodes as bonds and atoms. Here, we present a practical software called MolMiner, which is primarily built using deep neural networks originally developed for semantic segmentation and object detection to recognize atom and bond elements from documents. These recognized elements can be easily connected as a molecular graph with a distance-based construction algorithm. MolMiner gave state-of-the-art performance on four benchmark data sets and a self-collected external data set from scientific papers. As MolMiner performed similarly well in real-world OCSR tasks with a user-friendly interface, it is a useful and valuable tool for daily applications. The free download links of Mac and Windows versions are available at https://github.com/iipharma/pharmamind-molminer.

Background: Choledochal cyst perforation is extremely rare, and early diagnosis or prediction is important for the immediate therapeutic intervention of perforations. This study aimed to define the predictor(s) of an impending or complete spontaneous perforation of choledochal cyst and establish the optimal operative timing.Methods: All 429 consecutive choledochal cyst patients from January 2015 to December 2021, were included. A retrospective study was performed based on Kaplan-Meier analysis, and Cox univariate and multivariate analyses.Results: A total of 429 patients were included, among which, 21 had choledochal cyst perforations (group A), and 408 did not (group B). Compared to group B, the serum alanine aminotransferase, aspartate aminotransferase, direct bilirubin, gamma-glutamyl transpeptidase, indirect bilirubin, total bilirubin, and alkaline phosphatase were significantly higher in group A (p = 0.025, 0.006, < 0.0001, 0.0001, 0.001, < 0.0001, and 0.033). High serum gamma-glutamyl transpeptidase was negatively associated with perforation-free preoperative survival, and multivariate Cox regression revealed that serum gamma-glutamyl transpeptidase was an independent predictive factor for an impending or complete perforation (p = 0.042).Conclusions: A gamma-glutamyl transpeptidase level ≥ 346.5 U/L accompanied with significantly elevated liver enzymes and bilirubin levels was indicative of the possibility of an impending or complete choledochal cyst perforation, and a proactive surgical approach should be considered.

Aim: To evaluate the effect of laparoscopic-assisted resection and colorectal anastomosis with a stapling technique in the treatment of Hirschsprung disease (HSCR) in infants. Methods: From June 2018 to January 2019, 25 cases of HSCR diagnosed by clinical examination and pathology were selected at the Children's Hospital, School of Medicine, Zhejiang University, China. All children were treated with standard laparoscopic-assisted transanal endorectal pull-through surgery (the modified Swenson technique). The short segment type and the typical type with a descending colon–rectum anastomosis were both included. The long segment type had an ascending colon–rectal anastomosis after ascending colon turnover. The colorectal anastomosis was divided into traditional manual anastomosis and straight intraluminal stapler (SIS) anastomosis. According to the different methods of anastomosis, the patients were divided into a traditional group and a SIS group. Age, gender, body weight, operation time, blood loss, postoperative anal exhaust and defecation time, postoperative hospitalization time, and postoperative short-term complications were analyzed retrospectively. Results: A total of 25 children were diagnosed with HSCR. There were 17 boys and 8 girls, and their average age was 10.20 months (interquartile range, 8.60–11.30). Their average body weight was 7.90 kg (interquartile range, 7.50–8.40). There were 17 cases of the typical type, 5 cases of the short segment type, and 3 cases of the long segment type. The different colorectal anastomosis methods were divided into 10 cases in the traditional group and 15 cases in the SIS group. There were no intraoperative complications, wound infections, or anastomotic fistula. Compared with the SIS group, children in the traditional group had an increased operative time (129.5 versus 103.00 minutes; P < .0001), increased intraoperative blood loss (20.00 versus 7.00 mL; P < .0001), increased postoperative hospitalization time (12.00 versus 9.00 days; P = .0003), and increased postoperative defecation time (18.40 versus 13.20 hours; P < .0001). After 6–12 months of follow-up, there was no anastomotic stenosis or enterocolitis in the SIS group. In the traditional group, 1 child had anastomotic stenosis, which improved 6 months after anal dilatation. One case of enterocolitis occurred 4 months after the operation and was cured after enema and infusion. Conclusion: Laparoscopic-assisted resection combined with colorectal anastomosis with the stapling technique in the treatment of HSCR in infants is feasible. It had a short operation time, less bleeding, less trauma, and a rapid recovery of postoperative intestinal function. The anastomosis was smooth, wide, and reliable, and anastomotic fistula and stenosis did not occur.

Patients with multiple myeloma (MM), an incurable malignancy of plasma cells, frequently develop osteolytic bone lesions. In this study, glycosphingolipids were essential in promoting autophagic degradation of the signaling molecule TRAF3, a key step in bone-resorbing osteoclast differentiation. Specifically altering the glycosphingolipid composition with eliglustat, an FDA approved glucosylceramide synthase inhibitor, arrested osteoclast differentiation; this could be rescued by exogenous addition of the missing glycosphingolipids. Eliglustat significantly reduced bone disease in several preclinical models of MM by inhibiting osteoclastogenesis and, due to its unique mode of action, it was able to act in combination with existing bone protective drugs. Furthermore, eliglustat arrested osteoclast differentiation from the bone marrow of MM patients in a glycosphingolipid-dependent way. This work identifies both the mechanism by which glucosylceramide synthase inhibition blocks autophagic degradation of TRAF3 to reduce osteoclastogenesis as well as highlighting the translational potential of eliglustat to be combined with current treatments.

Intracellular organelles are membrane‐bound and biochemically distinct compartments constructed to serve specialized functions in eukaryotic cells. Through extensive interactions, they form networks to coordinate and integrate their specialized functions for cell physiology. A fundamental property of these organelle networks is that they constantly undergo dynamic organization via membrane fusion and fission to remodel their internal connections and to mediate direct material exchange between compartments. The dynamic organization not only enables them to serve critical physiological functions adaptively but also differentiates them from many other biological networks such as gene regulatory networks and cell signaling networks. This review examines this fundamental property of the organelle networks from a systems point of view. The focus is exclusively on homotypic networks formed by mitochondria, lysosomes, endosomes, and the endoplasmic reticulum, respectively. First, key mechanisms that drive the dynamic organization of these networks are summarized. Then, several distinct organizational properties of these networks are highlighted. Next, spatial properties of the dynamic organization of these networks are emphasized, and their functional implications are examined. Finally, some representative molecular machineries that mediate the dynamic organization of these networks are surveyed. Overall, the dynamic organization of intracellular organelle networks is emerging as a fundamental and unifying paradigm in the internal organization of eukaryotic cells.This article is categorized under: Metabolic Diseases > Molecular and Cellular Physiology

A novel thermogel system of self-assembling peptides was created by enzyme-instructed self-assembly (EISA), which was useful for 3D cell culture.

Bioactive peptides derived from proteins generally need to be folded into secondary structures to activate downstream signaling pathways. However, synthetic peptides typically form random-coils thus losing their bioactivities. Here, we show that by introducing a self-assembling peptide motif and using different preparation pathways, a peptide from insulin-like growth factor-I (IGF-1) can be folded into α-helix and β-sheet. The β-sheet one exhibits a low dissociate constant to the IGF-1 receptor (IGF-1R, 11.5 nM), which is only about three times higher than that of IGF-1 (4.3 nM). However, the α-helical one and the peptide without self-assembling motif show weak affinities to IGF-1R (KD = 179.1 and 321.6 nM, respectively). At the 10 nM, the β-sheet one efficiently activates IGF-1 downstream pathway, significantly enhances HUVEC proliferation and prevents cell apoptosis. The β-sheet peptide shows superior performance to IGF-1 in vivo, and it improves ischemic hind-limb salvage by significantly reducing muscle degradation and enhancing limb vascularization. Our study provides a useful strategy to constrain peptides into different conformations, which may lead to the development of supramolecular nanomaterials mimicking biofunctional proteins.

Background: Masseter-to-facial nerve transfer has been shown to be an effective and safe treatment option in patients with acute and subacute facial palsy. The present article aims to characterize whether there is a benefit in early nerve transfers while minimizing other confounding variables; we present a study that consist of only patients with complete facial nerve paralysis resulting from intratemporal facial nerve resections. Methods: Between 2012 and 2016, 7 masseter-to-facial nerve transfers were performed for complete facial nerve palsy after intratemporal proximal nerve resections. Pre- and postoperative photographic and video evaluations were performed using both the Sunnybrook facial grading scale and the MEEI FACE-gram software for more objective metric measurements. Statistical analysis was performed to determine which patient and surgical variables had significant effects on outcome. Results: Mean 14-month follow-up revealed that patients who underwent nerve transfer prior to 6 months’ denervation achieved postoperative oral commissural excursion of 11.1 mm versus 6.5 mm in patients who underwent nerve transfer after 6 months (P = 0.003). Performing masseter-to-facial nerve transfer to the main facial nerve trunk resulted in a significantly higher improvement in the modiolus-philtral ratio (31.6% versus 6.1%) than selective transfer in patients (P = 0.01) at the latest follow-up. Conclusions: Early masseter-to-facial nerve transfers, before 6 months of palsy duration, can potentially improve smile excursion and symmetry of open mouth smile. Additionally, truncal coaptations may provide improved tone over coapting to selective facial nerve branches. These findings necessitate larger studies regarding the importance of denervation time with fifth-to-seventh nerve transfers.