Diverse candidate antibodies are needed to successfully identify therapeutic and diagnostic applications. The variable domain of IgNAR (VNAR), a shark single-domain antibody, has attracted attention owing to its favorable physicochemical properties. The phage display method used to screen for optimal VNARs loses sequence diversity because of the bias caused by the differential ease of protein expression in Escherichia coli. Here, we investigated a VNAR selection method that combined panning with various selection pressures and next-generation sequencing (NGS) analyses to obtain additional candidates. We constructed a VNAR phage library from the spleen of the Japanese topeshark (Hemitriakis japanica). Drawing inspiration from the physiological conditions of sharks and physicochemical properties of VNARs, we examined the effects of NaCl and urea concentrations, low temperature, and preheating at the binding step of panning. NGS analysis was performed to select the specifically enriched clones under each panning condition. The identified VNARs exhibited higher reactivity than those obtained by panning without selection pressure. Additionally, they possess physicochemical properties that reflect their respective selection pressures. These results can greatly enhance our understanding of VNAR properties and offer guidance for the screening of high-quality VNAR clones that are present at low frequencies.

The blood–brain barrier (BBB) plays pivotal roles in synaptic and neuronal functioning by sealing the space between adjacent microvascular endothelial cells. BBB breakdown is present in patients with mild cognitive impairment (MCI) or Alzheimer disease (AD). Claudin-5 (CLDN-5) is a tetra-spanning protein essential for sealing the intercellular space between adjacent endothelial cells in the BBB. In this study, we developed a blood-based assay for CLDN-5 and investigated its diagnostic utility by using 100 cognitively normal (control) subjects, 100 patients with MCI, and 100 patients with AD. Plasma CLDN-5 levels were increased in patients with AD (3.08 ng/mL) compared with controls (2.77 ng/mL). Plasma levels of phosphorylated tau (pTau181), a biomarker of pathological tau, were elevated in patients with MCI or AD (2.86 and 4.20 pg/mL, respectively) compared with control subjects (1.81 pg/mL). In patients with MCI or AD, plasma levels of CLDN-5—but not pTau181—decreased with age, suggesting some age-dependent BBB changes in MCI and AD. These findings suggest that plasma CLDN-5 may a potential biochemical marker for the diagnosis of MCI and AD.

Lysosomal degradation of tyrosinase, a pivotal enzyme in melanin synthesis, negatively impacts melanogenesis in melanocytes. Nevertheless, the precise molecular mechanisms by which lysosomes target tyrosinase have remained elusive. Here, we identify RING finger protein 152 (RNF152) as a membrane-associated ubiquitin ligase specifically targeting tyrosinase for the first time, utilizing AlphaScreen technology. We observed that modulating RNF152 levels in B16 cells, either via overexpression or siRNA knockdown, resulted in decreased or increased both tyrosinase and melanin levels, respectively. Notably, RNF152 and tyrosinase colocalized at the trans-Golgi network (TGN). However, upon treatment with lysosomal inhibitors, both proteins appeared in the lysosomes, indicating that tyrosinase undergoes RNF152-mediated lysosomal degradation. Through ubiquitination assays, we found the indispensable roles of both the RING and transmembrane (TM) domains of RNF152 in facilitating tyrosinase ubiquitination. In summary, our findings underscore RNF152 as a tyrosinase-specific ubiquitin ligase essential for regulating melanogenesis in melanocytes.

Quality-of-life (QOL) is important for cancer patients with poor prognosis. However, QOL survey is difficult using patients. We created cancer scenarios and investigated QOL utility values among the general public using vignette-based methods. On the other hand, some scenarios may have been difficult for the general public to image and understand. Therefore, we conducted a QOL survey among physicians. This survey was conducted by interviewing physicians adminis-tering chemotherapy to patients for recurrent/metastatic pancreatic cancer. Responses were eval-uated using Composite Time Trade-Off (cTTO) and Visual Analog Scale (VAS) for 11 pancreatic cancer status scenarios to be evaluated (survey scenarios). Survey scenarios consisted of health state, type and Grade of adverse events. Health status was classified into two categories: Stable disease (SD) and Progressive disease (PD). Twenty responders answered in this survey, however two responses were excluded because of inconsistent responses. The stable disease had the highest QOL value for both assessment method. Whereas progression disease (PD) had the lowest QOL value. The physicians scored higher QOL values on VAS and cTTO than the general public in all survey scenarios. The QOL values obtained by physicians were consistent with the degree of sta-tus in any assessment scenarios.