Therapeutic Strategies Under Development Targeting Inflammatory Mechanisms in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurological disease characterized by the progressive loss of cortical, bulbar, and spinal motor neurons (MNs). The cardinal manifestation of ALS is a progressive paralysis which leads to death within a time span of 3 to 5 years after disease onset. Despite similar final output of neuronal death, the underlying pathogenic causes are various and no common cause of neuronal damage has been identified to date. Inflammation-mediated neuronal injury is increasingly recognized as a major factor that promotes disease progression and amplifies the MN death-inducing processes. The neuroimmune activation is not only a physiological reaction to cell-autonomous death but is an active component of nonautonomous cell death. Such injury-perpetuating phenomenon is now proved to be a common mechanism in many human disorders characterized by progressive neurodegeneration. Therefore, it represents an interesting therapeutic target. To date, no single cell population has been proved to play a major role. The existing evidence points to a complex cross talk between resident immune cells and nonresident cells, like monocytes and T lymphocytes, and to a dysregulation in cytokine profile and in phenotype commitment. After a summary of the most important mechanisms involved in the inflammatory reaction in ALS, this review will focus on novel therapeutic tools that rely on tackling inflammation to improve motor function and survival. Herein, completed, ongoing, or planned clinical trials, which aim to modify the rapidly fatal course of this disease, are discussed. Anti-inflammatory compounds that are currently undergoing preclinical study and novel suitable molecular targets are also mentioned.     

Protoporphyrin‐based eggshell pigmentation predicts hatching success and offspring sex ratio in the barn swallow

Inter‐ and intraspecific variation in eggshell colouration has long fascinated evolutionary biologists. Among species, such variation may accomplish different functions, the most obvious of which is camouflage and background matching. Within species, it has been proposed that inter‐female variation in eggshell pigmentation patterns can reflect egg, maternal or paternal traits and hence may provide cues to conspecifics about egg, maternal or paternal phenotypic quality. However, the relationship between protoporphyrin‐based eggshell pigmentation and egg or maternal/paternal traits appears to be highly variable among species. We investigated patterns of intraspecific variation in Eurasian barn swallow Hirundo r. rustica protoporphyrin‐based eggshell pigmentation, and analysed its association with egg and clutch characteristics, maternal/paternal phenotypic traits and parental feeding effort. Eggshell pigmentation pattern significantly varied between breeding colonies, was significantly repeatable in first clutches laid by the same females in different years (intraclass correlation coefficient ranging between 0.56 and 0.63), but it was not significantly associated with egg traits, such as position in the laying sequence, egg mass, yolk testosterone concentration and antioxidant capacity. It was weakly or non‐significantly associated with female and male traits (sexual ornaments), but females laying darker (higher pigment intensity) first clutches had higher hatching success, suggesting that eggshell pigment intensity may predict fitness. Male nestling feeding effort was not predicted by eggshell pigmentation. In addition, females with darker breast plumage colouration (a melanin‐based trait related to fitness) laid highly protoporphyrin‐covered eggs, suggesting the presence of a previously unappreciated link between protoporphyrin biosynthesis and plumage melanisation. Moreover, the proportion of male offspring increased in clutches originating from highly protoporphyrin‐covered eggs, suggesting that parents could acquire visual cues about their future brood sex composition before egg hatching. Our results support the idea that intraspecific signalling via eggshell pigmentation is a species‐specific rather than a general feature of avian taxa.     

Subclinical Leber’s hereditary optic neuropathy with pediatric acute spinal cord onset: more than meets the eye

Background

Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by visual loss consequent to optic nerve atrophy. In some cases, LHON is associated with heterogeneous neurological extraocular manifestations and is referred to as “Leber plus disease”; rarely it is associated with a multiple sclerosis (MS)-like syndrome known as Harding disease, but no pediatric extraocular acute spinal onset is reported.

Case presentation

We describe the case of a 5-year-old girl carrying the G3460A mtDNA mutation who was referred to clinical examination for bilateral upper and lower limb weakness with no sign of optic neuropathy. Spinal cord MRI showed hyperintense signal alterations in T2-weighted and restricted diffusion in DWI sequences in the anterior portion of the cervical and dorsal spinal cord resembling a spinal cord vascular injury. No association between this mutation and pediatric spinal cord lesions has previously been reported. Alternative diagnostic hypotheses, including infective, ischemic and inflammatory disorders, were not substantiated by clinical and instrumental investigations.

Conclusions

Our case reports a novel pediatric clinical manifestation associated with the m.3460G?>?A mtDNA mutation, broadening the clinical spectrum of this disease. Early identification of new cases and monitoring of carriers beginning in childhood is important to prevent neurological deterioration and preserve long-term function.

     

Effect of bench-scale culture conditions on murine IgG heterogeneity

A stable murine hybridoma cell line, secreting IgG1 antibodies (7H3) against the soluble type I receptor for Tumor Necrosis Factor (sTNF-R1), was cultivated in two different bioreactor systems, a hollow fiber and a stirred tank fermentor, in order to evaluate the effect of culture conditions on antibody structural and functional heterogeneity. Conventional serum-supplemented and serum-free media were chosen for fermentation in stirred tank bioreactor, whereas only serum-supplemented media were used for hollow fiber cultivation. Extent of glycosylation, determined by lectin binding assays, and charge heterogeneity of murine monoclonal antibodies displayed relevant variations according to the fermentation system used. After complete sugars removal by N-glycosidase F treatment, charge heterogeneity were still observed suggesting the occurrence of additional modifications at the protein level. In vitro culture in serum-supplemented media carried out with the hollow fibre system led to higher productivity but greater antibody charge heterogeneity and differences in lectin-binding profile than cultivation in the stirred tank bioreactor.Results cumulatively indicated that hybridoma cultivation methods, but also cultivation time, influence antibody heterogeneity, both in the protein and sugar moieties. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 17-25, 1997.     

Effect of the three-dimensional organization of liver cells on the biogenesis of the γ-glutamyltransferase fraction pattern

Context Four gamma-glutamyltransferase (GGT) fractions with different molecular weights (big-, medium-, small- and free-GGT) are detectable in human plasma. Objective Verify if liver cells can release all four GGT fractions and if the spatial cell organization influences their release. Methods Hepatoma (HepG2) and melanoma (Me665/2/60) cells were cultured as monolayers or spheroids. GGT released in culture media was analysed by gel-filtration chromatography. Results HepG2 and Me665/2/60 monolayers released the b-GGT fraction, while significative levels of s-GGT and f-GGT were detectable only in media of HepG2-spheroids. Bile acids alone or in combination with papain promoted the conversion of b-GGT in s-GGT or f-GGT, respectively. Conclusions GGT is usually released as b-GGT, while s-GGT and f-GGT are likely to be produced in the liver extracellular environment by the combined action of bile acids and proteases.     

Paradoxical enhancement of S-adenosylmethionine decarboxylase in rat tissues following administration of the specific inhibitor methyl glyoxal bis(guanylhydrazone)

Treatment of rats with large but sublethal doses of methyl glyoxal bis(guanylhydrazone), a potent $\text{in vitro}$ inhibitor of animal S-adenosylmethionine decarboxylases, causes marked increases in the enzyme activity of extracts of kidney, ventral prostate, and testis which had been extensively dialyzed to remove any remaining drug. One day after administration of the inhibitor to female rats, the renal S-adenosylmethionine decarboxylase activity was 12 times the normal level and remained greatly enhanced for a further 24 hr. As indicated by decline in decarboxylase activity following depression of protein biosynthesis by injection of cycloheximide, the apparent half-life of the kidney enzyme in normal female rats is roughly 2 hr; in contrast, the apparent half-life of the enzyme is elevated to a value of more than 20 hr in animals that were previously treated with methyl glyoxal bis(guanylhydrazone). The increased renal S-adenosylmethionine decarboxylase activity following administration of the specific enzyme inhibitor $\text{in vivo}$ may thus be due, at least in part, to stabilization of the enzyme against intracellular inactivation as a result either of direct combination of the enzyme protein with the inhibitor, or with substance(s) in the tissue whose levels are influenced by treatment with methyl glyoxal bis(guanylhydrazone).