Macrophage- and RIP3-dependent inflammasome activation exacerbates retinal detachment-induced photoreceptor cell death

Detachment of photoreceptors from the retinal pigment epithelium is seen in various retinal disorders, resulting in photoreceptor death and subsequent vision loss. Cell death results in the release of endogenous molecules that activate molecular platforms containing caspase-1, termed inflammasomes. Inflammasome activation in retinal diseases has been reported in some cases to be protective and in others to be detrimental, causing neuronal cell death. Moreover, the cellular source of inflammasomes in retinal disorders is not clear. Here, we demonstrate that patients with photoreceptor injury by retinal detachment (RD) have increased levels of cleaved IL-1β, an end product of inflammasome activation. In an animal model of RD, photoreceptor cell death led to activation of endogenous inflammasomes, and this activation was diminished by Rip3 deletion. The major source of Il1b expression was found to be infiltrating macrophages in the subretinal space, rather than dying photoreceptors. Inflammasome inhibition attenuated photoreceptor death after RD. Our data implicate the infiltrating macrophages as a source of damaging inflammasomes after photoreceptor detachment in a RIP3-dependent manner and suggest a novel therapeutic target for treatment of retinal diseases.

Portal or superior mesenteric vein resection in pancreatoduodenectomy for pancreatic head carcinoma

BACKGROUND

The aim of this study was to determine the added value of portal or superior mesenteric vein (PV/SMV) resection during pancreatoduodenectomy for pancreatic head carcinoma.

METHODS

A multicentre observational study was conducted in patients with pancreatic head carcinoma who underwent pancreatoduodenectomy in seven Japanese hospitals between 2001 and 2012. Clinicopathological factors were compared between patients who did and did not undergo PV/SMV resection. Those with an impact on survival were identified by univariable and multivariable analysis.

RESULTS

Of the 937 patients who underwent pancreatoduodenectomy, 435 (46·4 per cent) had PV/SMV resection, whereas the remaining 502 (53·6 per cent) did not. Some 71·5 and 63·9 per cent of patients with and without PV/SMV resection respectively had lymph node-positive disease. Patients who underwent PV/SMV resection had more advanced tumours. Perioperative mortality and morbidity rates did not differ between the two groups. Multivariable analysis revealed that PV/SMV resection was not an independent prognostic factor for overall survival (P = 0·268). Among the 435 patients in whom the PV/SMV was resected, borderline resectable tumours with arterial abutment (P = 0·021) and absence of adjuvant chemotherapy (P < 0·001) were independent predictors of poor survival in multivariable analysis. Patients with resectable or borderline resectable tumours with PV/SMV involvement had a median survival time with additional adjuvant chemotherapy of 43·7 and 29·7 months respectively. Median survival time in patients with borderline resectable tumours with arterial abutment was 18·6 months despite adjuvant chemotherapy.

CONCLUSION

Pancreatoduodenectomy with PV/SMV resection and adjuvant chemotherapy in patients with pancreatic head carcinoma may provide good survival without increased mortality and morbidity.

Usefulness of quantitative susceptibility mapping for the diagnosis of Parkinson disease

BACKGROUND AND PURPOSE

Quantitative susceptibility mapping allows overcoming several nonlocal restrictions of susceptibility-weighted and phase imaging and enables quantification of magnetic susceptibility. We compared the diagnostic accuracy of quantitative susceptibility mapping and R2* (1/T2*) mapping to discriminate between patients with Parkinson disease and controls.

MATERIALS AND METHODS

For 21 patients with Parkinson disease and 21 age- and sex-matched controls, 2 radiologists measured the quantitative susceptibility mapping values and R2* values in 6 brain structures (the thalamus, putamen, caudate nucleus, pallidum, substantia nigra, and red nucleus).

RESULTS

The quantitative susceptibility mapping values and R2* values of the substantia nigra were significantly higher in patients with Parkinson disease (P < .01); measurements in other brain regions did not differ significantly between patients and controls. For the discrimination of patients with Parkinson disease from controls, receiver operating characteristic analysis suggested that the optimal cutoff values for the substantia nigra, based on the Youden Index, were >0.210 for quantitative susceptibility mapping and >28.8 for R2*. The sensitivity, specificity, and accuracy of quantitative susceptibility mapping were 90% (19 of 21), 86% (18 of 21), and 88% (37 of 42), respectively; for R2* mapping, they were 81% (17 of 21), 52% (11 of 21), and 67% (28 of 42). Pair-wise comparisons showed that the areas under the receiver operating characteristic curves were significantly larger for quantitative susceptibility mapping than for R2* mapping (0.91 versus 0.69, P < .05).

CONCLUSIONS

Quantitative susceptibility mapping showed higher diagnostic performance than R2* mapping for the discrimination between patients with Parkinson disease and controls.

Poly(ɛ-caprolactone) (PCL)-polymeric micelle hybrid sheets for the incorporation and release of hydrophilic proteins

Sheets have several advantages over conventional gel- or particle-type drug carriers. Sheets have several notable attributes: sheets' size and shape are easily adjustable, sheets are highly accessible in surgery, and sheets have a large contact area relative to drug-targeting sites. However, it is difficult to incorporate hydrophilic proteins into hydrophobic sheets and to release the proteins over the long term in a sustained manner. In the present study, we show that "poly(ɛ-caprolactone) (PCL)-polymeric micelle hybrid sheets" can be used for the incorporation and release of hydrophilic proteins. Polymeric micelles (i.e., spaces that can incorporate hydrophilic compounds) are, in this study, uniformly dispersed in hydrophobic and biocompatible biomaterial sheet. We have clarified that the composition of block copolymer, methoxy-terminated poly(ethylene glycol)-block-poly(ɛ-caprolactone) (CH3O-PEG-b-PCL), can affect two variables: the stability of w/o emulsion and the release properties of the resulting sheets, by means of visual qualitative observations, newly developed quantitative analyses (advanced fractal analysis, advanced FD) based on deviation of the fractal dimension (FD), and release experiments. We clarified that the release behavior of BSA was affected by the composition of the block copolymers and the resulting emulsion. The results obtained in this paper show that the hydrophobic sheets in which polymeric micelles providing hydrophilic spaces were dispersed could be an effective platform for incorporating and releasing hydrophilic proteins.

[A patient with Creutzfeldt-Jakob disease supported by home medical care from the stage of disease progression to death through hospital-clinic cooperation and medical-welfare cooperation]

The patient was a 63-year-old woman who presented with slowness of speech after cerebral infarction. Diffusion-weighted MR images and investigations of cerebrospinal fluid showed abnormal values, and the patient was diagnosed as having sporadic Creutzfeldt-Jakob disease(CJD). This is an intractable disease and affects one in one million people; it progresses relatively rapidly, eventually resulting in death. For procedures such as intravenous fluid replacement and the treatment of pressure sores, we require thorough hand washing, eye protection, and disposal of gloves and dressings by incineration. It is desirable for patients to spend the limited amount of time available to them peacefully at home with their family. Visiting physicians and nurses need to take the initiative in sharing information obtained from the CJD infection control guidelines and core hospitals with welfare personnel such as caregivers, in order to provide correct information on all aspects of patient care and the management of this disease in the home environment. Excellent supportive care was provided for the patient at home, and she passed away with her family by her side.

CD300b regulates the phagocytosis of apoptotic cells via phosphatidylserine recognition

The CD300 receptor family members are a group of molecules that modulate a variety of immune cell processes. We show that mouse CD300b (CLM7/LMIR5), expressed on myeloid cells, recognizes outer membrane-exposed phosphatidylserine (PS) and does not, as previously reported, directly recognize TIM1 or TIM4. CD300b accumulates in phagocytic cups along with F-actin at apoptotic cell contacts, thereby facilitating their engulfment. The CD300b-mediated activation signal is conveyed through CD300b association with the adaptor molecule DAP12, and requires a functional DAP12 ITAM motif. Binding of apoptotic cells promotes the activation of the PI3K-Akt kinase pathway in macrophages, while silencing of CD300b expression diminishes PI3K-Akt kinase activation and impairs efferocytosis. Collectively, our data show that CD300b recognizes PS as a ligand, and regulates the phagocytosis of apoptotic cells via the DAP12 signaling pathway.

Concurrent analysis of human equilibrative nucleoside transporter 1 and ribonucleotide reductase subunit 1 expression increases predictive value for prognosis in cholangiocarcinoma patients treated with adjuvant gemcitabine-based chemotherapy

BACKGROUND

The aim of this study was to investigate the predictive and prognostic values of intratumoural human equilibrative nucleoside transporter 1 (hENT1) and ribonucleotide reductase subunit 1 (RRM1) expression in advanced cholangiocarcinoma patients treated with adjuvant gemcitabine-based chemotherapy (AGC).

METHODS

Intratumoural hENT1 and RRM1 expression levels were investigated immunohistochemically in 127 patients with advanced cholangiocarcinoma who underwent surgical resection (68 with AGC and 59 without AGC). The impacts of hENT1 and RRM1 expression on survival were evaluated.

RESULTS

High intratumoural hENT1 and RRM1 expression levels were observed in 86 (68%) and 67 (53%) patients, respectively. In a multivariate analysis of 68 patients who received AGC, high hENT1 (P=0.044) and low RRM1 expression (P=0.009) were independently associated with prolonged disease-free survival (DFS), whereas low RRM1 expression (P=0.024) was independently associated with prolonged overall survival (OS). Moreover, concurrent high hENT1 and low RRM1 expression was a powerful independent predictor of prolonged DFS (P<0.001) and OS (P=0.001) when the combined classification of hENT1 and RRM1 was introduced.

CONCLUSIONS

Concurrent analysis of hENT1 and RRM1 expression may increase the predictive value of these biomarkers for survival of advanced cholangiocarcinoma patients treated with AGC.

Magnetization amplified by structural disorder within nanometre-scale interface region

Direct magnetization measurements from narrow, complex-shaped antiphase boundaries (APBs; that is, planar defect produced in any ordered crystals) are vitally important for advances in materials science and engineering. However, in-depth examination of APBs has been hampered by the lack of experimental tools. Here, based on electron microscopy observations, we report the unusual relationship between APBs and ferromagnetic spin order in Fe₇₀Al₃₀. Thermally induced APBs show a finite width (2–3 nm), within which significant atomic disordering occurs. Electron holography studies revealed an unexpectedly large magnetic flux density at the APBs, amplified by approximately 60% (at 293 K) compared with the matrix value. At elevated temperatures, the specimens showed a peculiar spin texture wherein the ferromagnetic phase was confined within the APB region. These observations demonstrate ferromagnetism stabilized by structural disorder within APBs, which is in direct contrast to the traditional understanding. The results accordingly provide rich conceptual insights for engineering APB-induced phenomena.

Atomic disordering in antiphase boundary regions is believed to deteriorate ferromagnetic spin order in many alloys and compounds. Here, using electron microscopy, Murakami et al. report the unusual relationship between thermal antiphase boundaries and ferromagnetic spin order in Fe₇₀Al₃₀.

Mammalian STE20-like kinase 2, not kinase 1, mediates photoreceptor cell death during retinal detachment

Photoreceptor cell death is the definitive cause of vision loss in retinal detachment (RD). Mammalian STE20-like kinase (MST) is a master regulator of both cell death and proliferation and a critical factor in development and tumorigenesis. However, to date the role of MST in neurodegeneration has not been fully explored. Utilizing MST1^−/− and MST2^−/− mice we identified MST2, but not MST1, as a regulator of photoreceptor cell death in a mouse model of RD. MST2^−/− mice demonstrated significantly decreased photoreceptor cell death and outer nuclear layer (ONL) thinning after RD. Additionally, caspase-3 activation was attenuated in MST2^−/− mice compared to control mice after RD. The transcription of p53 upregulated modulator of apoptosis (PUMA) and Fas was also reduced in MST2^−/− mice post-RD. Retinas of MST2^−/− mice displayed suppressed nuclear relocalization of phosphorylated YAP after RD. Consistent with the reduction of photoreceptor cell death, MST2^−/− mice showed decreased levels of proinflammatory cytokines such as monocyte chemoattractant protein 1 and interleukin 6 as well as attenuated inflammatory CD11b cell infiltration during the early phase of RD. These results identify MST2, not MST1, as a critical regulator of caspase-mediated photoreceptor cell death in the detached retina and indicate its potential as a future neuroprotection target.

Unexpected and successful "one-step" formation of porous polymeric particles only by mixing organic solvent and water under "low-energy-input" conditions

We found that porous particles were unexpectedly obtained in a "one-step" manner only by mixing an organic solvent and water under "low-energy-input" (i.e., low-homogenization-rate) conditions. This phenomenon was attributable to the unexpected formation of the spontaneously formed water-in-oil (w/o) emulsions in the droplets of o/w emulsions. The unexpected formation resulted in the successful formation of water-in-oil-in-water (w/o/w) emulsions instead of o/w emulsions, although the mixed solution containing both an organic solvent and water were simply emulsified in the presence of block copolymers. The present study clarifies the effects of the various preparation conditions on the morphology of unexpected w/o/w emulsions and resulting particles. The porous particles are expected to be suitable drug carriers for pulmonary delivery. The results obtained in the present study show that a newly developed one-step emulsification can be a powerful and facile technique for preparing porous polymeric particles.